Addmotor Grandtan M-340 Review: 450 lb Fat-Tire Trike

Fat-tire trike · 750 W rear-mounted motor, torque sensor, throttle · 48 V 20 Ah Samsung pack, 960 Wh · differential · disc brakes on all three wheels and a parking brake · 350 lb rider plus 100 lb cargo · 20 mph · Standard and Plus · $2,399 · verified September 28, 2026

Quick Answer — Addmotor's Grandtan M-340 is a $2,399 fat-tire trike with a 750 W rear-mounted motor, a torque sensor, a differential, brakes on all three wheels and a 450 lb payload. At 12 mph on level pavement, throttle only, a charge computes to about 67 miles for a 180 lb rider and 45 with 450 lb aboard.

Ride at 20 mph instead and that level, throttle-only ride for 180 lb falls to about 39 miles; easy pedaling at 12 mph lifts it to 134. Addmotor's specification gives 40 to 85 miles, and the range tables turn your own ride into miles.

Settle two things before you order: which version fits your height, where Addmotor prints two rider windows, and how your state treats a 750 W trike, where the class section sets Addmotor's figures beside the statutes' own words.

What this review covers

The specification · What it is · Fit · The motor · The battery · Range · Carrying · Turning, brakes and lights · Suspension, tires and weather · Weight and storage · The Mercer fit test · Recalls · Class · Trails · Green and red flags · The verdict · Checklist · Buying it from us · FAQ · Limitations · The bottom line · References

How we verified this Addmotor Grandtan M-340 review

Every figure here was read on September 28, 2026, from Addmotor's Grandtan M-340 page and its specification tabs, its size drawing, Addmotor's question board for the trike, our listing and the statutes quoted in the class section. Range and fit are calculated, and each formula names the inputs it uses.

That makes the review specification-verified: a number traces to Addmotor, a statute, our store or arithmetic shown on this page, and the range model reproduces its published benchmarks before it computes anything. We sell the Grandtan, so read the red flags as closely as the green.

Written by Milad Ghobadibeygvand, BScN (Western University, 2014). Corrections: support@redtailebikes.com.

Addmotor's Grandtan M-340 specification, row by row

Addmotor sells the M-340 in two versions that differ only in wheels and size:

The rows come from the Technical, Performance and Size & Fit tabs of Addmotor's Grandtan M-340 page as served on September 28, 2026; the peak power and torque from the comparison image on that page, where the feature copy also names "90Nm of hill-climbing torque"; the rotor size from Addmotor's triple-disc image; and the box list from the page's own FAQ. The pack's 48 V times its 20 Ah is 960 Wh.

A fat-tire trike with a backrest seat and a wooden deck

Addmotor's US page calls it the "Grandtan M-340 eTrike": a step-through aluminum frame on three fat tires, a saddle with a backrest, a basket at each end and a flat wooden deck between the seat and the front wheel. The motor is rear-mounted, and a rear differential, in Addmotor's words, "lets each wheel rotate independently".

Neptune Blue, in Addmotor's studio image: the backrest saddle, the battery behind the seat tube, the wooden deck and a basket at each end.

The deck is where Addmotor pitches the trike's easy side. Its feature copy calls it a "wide wooden deck" that gives "a spacious, stylish platform to rest your feet while cruising on throttle", and the step-through frame is sold as "ultra-low", a 17.5-inch step made for "easy mounting". The page names who it has in mind:

Rediscover the pure joy of cycling without balance worries. Engineered as the ultimate fat tire electric trike for seniors, its stable wide tires turn daily rides and outdoor trail explorations into effortless, confidence-filled adventures.

Addmotor's own summary of the trike, on its Grandtan M-340 page, quoted as written.

The Standard and the Plus are the same trike on two sets of wheels. The Plus moves up from 24-inch front and 20-inch rear tires to 26 and 24, which lifts the saddle range, the standover and the handlebar an inch or so.

Addmotor's FAQ puts it plainly: "The 2" bigger tires make the Plus e-trike more suitable for taller people." Motor, pack, payload and top speed are the same on both, and our store prices both at $2,399.

One of Addmotor's own lifestyle images: a helmeted rider on a park path, the rear basket loaded for a picnic.

Does the Grandtan fit you? Saddle, step-over and reach

Addmotor's 32.5 to 39-inch seat range puts the Standard's saddle at the fit formula's height for 96 or more of every 100 riders from 5'2" to 5'6", 84 at 5'8" and 43 at 5'10"; Addmotor's recommended window runs from 5'2" to 6'4" for the Standard and from 5'5" to 6'5" for the Plus.

Addmotor publishes a drawing only for the Standard, so every table below is the Standard's, and each places the 6,068 bodies in the US Army's 2012 anthropometric survey on its geometry, saddle at 109% of inseam. The Plus adds an inch at the top of the post (40 in) and Addmotor's FAQ calls it "more suitable for taller people".

Three steps find your row:

1. Take your inseam with no shoes on. With your back to a wall, press a hardcover book up between your legs where a saddle would sit, then measure from the floor to the book's spine.
2. Look up your height below and check that your inseam sits inside that row's range; on the Standard, past a 33.6-inch inseam the post has no more height to give at 109%.
3. Settle the last half inch at home with the knee and heel checks in the setup answer.

Addmotor's Size & Fit table gives seven figures that bear on fit and on storage.

Addmotor's size drawing of the Standard. Held against its own printed lengths, three agree within 3.5 percent (the controls table below): the lowest and highest saddle and the reach line.

Will the seat post reach my saddle height?

On the Standard, yes for nearly everyone from 5'2" to 5'6", and for 84 of 100 riders at 5'8"; at 5'10" fewer than half get there at 109%, and from 6'2" none do. The formula puts the top of the saddle 109% of inseam above the pedal axle (Peveler et al., 2005), with 106% the low end of the range Ferrer-Roca and colleagues accept.

Turning that into a height off the floor needs three figures Addmotor does not list, each read from its size drawing: a crank axle 11.0 inches up, a 6.9-inch crank, and a seat post leaning back at 68.1° from horizontal.

Floor-to-saddle height for the median rider at each height, and how many of 100 have both settings inside the Standard's 32.5 to 39 inches; Army survey bodies, men and women pooled. Where a rider's formula height is above the post, the median gap is about 0.7 inches at 5'10", 1.5 at 6'0", 2.4 at 6'2" and 4.0 at 6'4".

Fully raised, the Standard's post suits a 33.6-inch inseam at 109% and a 34.6-inch one at 106%. A longer leg leaves the saddle at its stop and the knee more bent at the bottom of each stroke than the formula would set it. Addmotor's window for the Standard reaches 6'4", and the Plus, with its 40-inch post, is the version Addmotor points taller riders to.

The floor of the range matters too. Fully lowered, the 32.5-inch seat equals 109% of a 27.2-inch inseam, and at 5'0" the post reaches the formula height for 93 of 100 riders, so hold your own inseam against 27.2 inches if you stand near the bottom of Addmotor's window.

Can I stand over the frame at a stop?

Easily: at every height in the table, 95 of every 100 riders clear the Standard's 17.5-inch standover by 9.6 inches or more. The deck ahead of the crank is where your leg crosses, and Addmotor sells that 17.5-inch step as "ultra-low", for "easy mounting".

Barefoot inseam less Addmotor's 17.5-inch standover. Each cell is the clearance at least 95 of every 100 riders of that height reach; the Plus's 18.7 inches takes 1.2 inches off every row.

Do the bars feel cramped or far away?

Upright and close: the grips sit 10.9 to 14.6 inches ahead of the crank axle and 30.8 to 32.0 inches above it, so the median rider leans 10 to 15 degrees from upright. In Priego Quesada and colleagues' 2017 comparison, twenty recreational cyclists judged the most upright of three trunk positions the most comfortable.

The lean at each height is the smallest trunk angle that lets a straight arm meet the grip from the sit bones, built from the torso and arm lengths of each survey body. Addmotor fits an adjustable stem, "Easily adjust height and angle to match your ideal riding position", so raising it sits you straighter; the table takes the grips where Addmotor's drawing shows them.

Lean from vertical for the median rider seated mid-saddle, and in the last column the span from sitting forward to sitting back across the measured grip bracket.

The adjustable stem in Addmotor's close-up, with the pivot bolt that sets the bar's height and angle ringed in blue.

How much weight goes through my hands?

Between 11 and 15 percent of your body weight at most with your back relaxed; the table turns that into pounds on each hand. Ten road racers on the brake hoods in Carahalios's 2015 laboratory study put 15% of body weight on the bars; the Grandtan's relaxed-back ceiling reaches that share for the median rider from 5'8" to 6'0", and the adjustable stem is the lever that lowers it.

Slane and colleagues measured 36 riders and found pressure over the ulnar nerve, at the heel of the hand, highest in the most stretched hand position; padded gloves brought palm pressure down 10 to 28%. Raising the bar on the adjustable stem, and letting your back carry itself, keeps you away from that stretch.

Worked from each body's segment weights (Clauser et al., 1969) with the back relaxed, so each figure is an upper bound; the weights are the survey median at each height, and the bracket runs across saddle and grip positions.

What's the fastest way to set the saddle?

Aim for a knee that still bends 25 to 35 degrees when the pedal is at its lowest (Peveler et al., 2007). Addmotor's drawing shows the backrest rising with the saddle, and marks the lowest and highest settings at 32.5 and 39 inches on the Standard.

For a quick start, put your heel on the pedal at the bottom of its stroke and raise the saddle until that leg just straightens. Peveler and colleagues found the heel method landed 70% of 19 cyclists in the target range, more than either inseam formula they compared.

The fit arithmetic, step by step

Three rules drive this section: the saddle at 1.09 × inseam above the pedal axle, the lean as the smallest trunk angle at which a straight arm meets the grip, and the hand load as the upper body's weight times that lean over the reach.

For a 5'8" rider on the median 32.6-inch inseam, the formula calls for 35.6 inches from the pedal, which is 28.7 inches from the crank axle once the 6.9-inch crank comes off, and 38.0 inches from the floor, inside the post's 39.

LeMond's rule sits just above it on this frame. Its 88.3% of inseam from the crank axle comes to 28.8 inches for this rider; with the crank added back, it averages 109.5% of inseam from the pedal across the survey's bodies, inside the 109.2 ± 0.9% Peveler and colleagues report.

With no crank length, crank height, seatpost angle or grip position among Addmotor's figures, the model takes all four from Addmotor's size drawing, a studio photograph with the dimension lines drawn over it, scaled by the drawing's 43-inch handlebar height, once the drawing has been held against Addmotor's own lengths:

The lowest and highest saddle and the reach line agree with the drawing within 3.5 percent. The wheelbase, the deck and the overall length do not: the near rear wheel sits off the centerline of a three-wheeler, so those lines cannot share one scale on a side view (Limitations explains why), and the model uses Addmotor's printed standover rather than the drawing's.

A 750 W rear-mounted motor, a torque sensor and a throttle

Addmotor's Technical tab lists the motor as "48V*750W Rear-Mounted", and the page's highlights strip as "Rear-Drive Motor 750W". Asked on its question board whether 750 W is the continuous or the peak rating, Addmotor answered on March 7, 2023: "Hi, it refers to continuous motor power." The comparison image on the same page adds "1400W Peak, 90Nm Torque".

Behind the seat sits the rear differential, which Addmotor says "lets each wheel rotate independently", so the two back wheels can turn at different speeds through a bend. Addmotor's reasoning for putting the motor at the back is in its product FAQ: "Rear-mounted motor trikes offer better traction, stability, handling, and performance."

A torque sensor meters the help by how hard you push. The Performance tab lists "Torque Sensor" and seven assist levels, and the 25 A controller feeds the motor from the pack. The half-twist throttle moves the trike with no pedaling at all, which is what the wooden deck is for: Addmotor sells it as a place "to rest your feet while cruising on throttle".

The 5-inch LCD in Addmotor's image, every segment lit: battery gauge, trip and odometer, speed, the mode line, a watt readout and the assist level.

Addmotor's feature copy puts the torque figure to work on hills: "Driven by 90Nm of hill-climbing torque, experience smooth, whisper-quiet acceleration that powers through inclines without sudden jerks or lurches." What each climb costs the battery is in the hills table.

With the pack flat, you can still pedal home. "Hi, you can pedal it normally, but it would be a little more difficult to pedal than normal bikes," Addmotor answered on February 28, 2023, and the seven Shimano gears are there for that.

One 960 Wh Samsung pack

Forty-eight volts times twenty amp-hours makes 960 watt-hours, from what Addmotor's Technical tab calls a "48V*20Ah Samsung UL-certified Battery". The page sells it as "Powered by high-capacity Samsung cells, enjoy up to 85 miles of freedom on a single charge, with a quick-release design for convenient indoor charging anywhere."

That quick release means you can charge the pack indoors with the trike parked outside. "Hello, the ebike battery is removable," Addmotor answered on its question board on February 24, 2023, and the 48 V 2 A charger in the box connects through a magnetic five-pin plug.

Charging from empty takes eight to ten hours. "Hi, full charge time is 8-10 hours," Addmotor answered on March 1, 2023, and the arithmetic agrees: 20 amp-hours at the charger's 2 amps is ten hours. A 20-to-80% top-up, the band Addmotor advises for the pack's lifespan, is 12 of those 20 amp-hours, about six hours at 2 A.

Addmotor's battery advice comes in three numbers. Its battery-health post says "We recommend recharging the battery when it has a 10%-15% charge left", and its maintenance guide adds "keep your battery charge between 20% and 80% for the best lifespan" and to charge "at room temperature (between 10 and 25 degrees Celsius)", 50 to 77 °F.

For a trike that sits for a season, the same guide says to store the pack separately in a dry place at 50 to 77 °F, charged to 40 to 60%, and to recharge it every two months. Addmotor's own spare-battery listing, the "20Ah Samsung UL-Certified Battery", names the "GRANDTAN M-340 Series" among the trikes it fits.

How far the Grandtan goes, empty and loaded

Level pavement, throttle only: a full pack carries a 180 lb rider about 67 miles at 12 mph and about 39 at 20, and the full 450 lb payload about 45 miles at 12 mph. Easy pedaling at 12 mph stretches the 180 lb figure to 134 miles, and a steady 8% climb at 10 mph on the throttle brings it down to about 11.

Your own number takes three steps:

1. Look up the speed you ride and the effort you add in the first two tables, and note the miles.
2. Budget each 1,000 feet of climbing at 10 mph on 4 to 10% grades: 157 to 201 Wh on the throttle, or 142 to 182 with easy pedaling (the hills table).
3. Correct for your load and the air temperature, then plan on spending 85% of the pack.

Each table is one steady ride built from Addmotor's figures, a comparable motor's published data, drum measurements of ten fat tires and a cycling-power model checked on an open road. The formula subsection prints the equation and walks one ride through it.

The same tables serve the Standard and the Plus. Addmotor gives both the same motor, pack, weight and 20 mph top speed, and because the model fits the motor to that top speed on each version's rear wheel, the Plus's larger wheels come out at the same figures to the mile in every table below.

How many miles at each speed, and what does pedaling add?

On the throttle alone, speed sets the figure: a charge runs 84 miles at 8 mph and 39 at 20. From 12 to 20 mph the figure drops from 67 miles to 39, since the power the air takes climbs with the cube of speed, and (20 ÷ 12)³ gives 20 mph about 4.6 times the air power of 12.

Every row: a 180 lb rider on the throttle alone, over level pavement in 77 °F air. The right-hand column leaves in the pack the 15% Addmotor says to recharge at, the top of its "10%-15%" advice.

A little pedaling goes a long way: 75 W from your legs turns the 12 mph figure of 67 miles into 134. Easy pedaling here means 75 W and steady pedaling 150 W; with the motor off, those efforts alone would roll a 180 lb rider on this 110 lb trike at about 8.6 and 12.7 mph on the flat, a fair test of which column you could hold.

A 180 lb rider on flat pavement, from a full pack. "Legs alone" marks a ride your 150 W holds with no help from the motor, since that effort carries this trike and rider at about 12.7 mph. In the 134-mile and 157-mile cells your legs do more than half the work, which leans on the least-checked part of the model, the motor's losses at light load (Limitations item 5).

The assist level sets how much the motor adds to your effort and does nothing else in these sums, so choose the row for your speed and the column for your legs. Addmotor's trike-range post makes the same point about speed: "Riding a little slower can lessen the wind drag, allowing increased range."

Do the gears change the battery bill?

Change gear for your legs, and pedal to spare the battery. In the model the motor drives the rear wheels apart from your chain, so the gear you pick sets your cadence, and at a set speed and grade the pack's draw falls only as your own effort rises:

Pack watt-hours per mile for a 180 lb rider in 77 °F air; easy pedaling is 75 W from the rider and steady pedaling 150 W. At 12 mph on the flat, 150 W of your own holds the speed with the motor idle.

Use the seven gears for a comfortable cadence, and the lowest ones for starts and climbs, most of all with a loaded rear basket. Addmotor's range post says the same about starts: "When you accelerate after coming to a stop, it uses a lot of energy."

What does each hill cost the battery?

A great deal: at 10 mph on the throttle, each 1,000 feet of climbing on 4 to 10% grades takes 157 to 201 Wh beyond the same distance on the flat, or 142 to 182 with easy pedaling. Raising you and the trike accounts for 54 to 69% of the throttle figure and the motor and pack lose the rest, and Addmotor's range post agrees that "hills take a lot of energy".

A 180 lb rider on the 110 lb Grandtan makes 290 lb to raise, and lifting that 1,000 feet takes 109 Wh at the wheels. Up 8% at 10 mph on the throttle the pack pays 184 Wh per 1,000 feet, so all 960 Wh would carry you up about 5,200 feet with none left for the flat; the model earns nothing back on descents, which keeps a hill budget cautious.

At 10 mph with 180 lb aboard; throttle only in every column but the last, where you add 75 W of easy pedaling. Past 10%, a steady 10 mph on the throttle alone needs more than the motor's rated 750 W in the model: on a 12% grade your easy pedaling brings it back inside, at about 7 miles to the charge, and on 15% neither does, so slow down or shift down.

Planning a day with climbs? Price the hills on top of the flat miles. Twenty level miles at 12 mph on the throttle, about 287 Wh, plus 1,000 feet of climbing at 8%, about 184 Wh, comes to about 471 Wh of the 816 Wh in 85% of the pack. Wind and stops come on top, because the model rides every mile at one steady pace.

How far does a full 450 lb load go?

On the flat, weight costs a little; on a climb it costs a great deal. Extra pounds add to the tires' and the grade's share of the work but nothing to the air's, so light and heavy loads drift further apart as the road tilts up.

The rider plus everything carried; the model adds the trike's own 110 lb to every row. Throttle only. The bottom row is the full 450 lb Addmotor rates the Grandtan to carry, 350 lb of rider and 100 lb in the rear basket; up 8% at 10 mph that load needs more than the motor's rated 750 W in the model, so pedal or slow down.

Filling the payload costs about a third of the level range. Going from 180 lb to 450 lb aboard takes the 12 mph ride from 67 miles to 45 and the 15 mph ride from 55 to 39. On a grade each added pound must be lifted too (the hills section), and Addmotor's range post names "the rider's weight or the weight of their luggage" among the factors that make range "a difficult question to answer".

How much range does winter take?

More with every degree below room temperature. Worth 67 miles at 77 °F, the 12 mph throttle ride comes to about 53 miles at 32 °F and about 48 at 14 °F.

Level ground, 180 lb aboard. The central figure in each row rests on McMaster University's measured LG HG2 cell, recomputed at a 0.5C discharge from the lab's 77, 50, 32 and 14 °F runs, with the rows between interpolated and the cells assumed to sit at air temperature; Addmotor names Samsung cells without a model number.

The bracket spans the published cell data. Its low end is the least capacity a Samsung data sheet gives at that temperature for a discharge of one to four times capacity per hour (25R and 30Q at 32 °F, 35E at 14 °F), and its high end the most energy Casado and colleagues recorded in 2025 at a gentler rate.

At freezing, three losses stack. The cells give back about 89% of their 77 °F energy, 80 to 93% across sources, and 32 °F air is about 9% denser under the gas law in the U.S. Standard Atmosphere.

The tires stiffen as well: the model raises rolling resistance 0.5% for each °F under 77 °F (0.9% per °C), a rate between Rothhämel's fit for a 42 mm tire and Bicycle Rolling Resistance's average for road tires, and holds the 41 °F value below that.

Charge indoors in winter. Addmotor's cold-weather post says to "Always charge your battery indoors at room temperature because cold weather can harm the battery cell if you charge it at lower temperatures", and it wants gloves on "at all times", since "the accelerator and brakes are both operated by hand".

Does tire choice or riding posture change the range?

On level ground, the tire matters more to range than your posture does. Ten 26 × 4.00 fat tires ran on Bicycle Rolling Resistance's drum at 12 psi, 18 mph and a 94 lb load, and drew between 23.2 and 42.1 W.

With no drum figure for the Grandtan's own tires, the model uses the median of the ten, a coefficient of 0.0105, and brackets it with the lowest and the highest.

Miles from a full charge, 180 lb aboard, level ground. The highest of the ten is Kenda's Juggernaut Pro, which reads 0.01262 on its own test page.

For pressure, Addmotor's range post notes that touring riders check it "before each ride" and advises "the same before any lengthy tour", since "The system weight (rider plus e-trike), the tire model, and the surface you are riding on are some variables that affect the proper tire pressure." The drum figures above were taken at 12 psi.

No drum measures sand, gravel or grass, so the tables cover pavement only; send us your route and we will price its paved miles and climbs. Posture weighs more as speed climbs: Tengattini and Bigazzi measured a drag area of 0.640 m² across 37 upright cruiser riders, the figure used here, and 0.603 m² across 90 everyday mountain-bike riders, which would lift the 15 mph throttle ride from 55 miles to 57.

Addmotor's 85 and 40 miles, as steady rides

Both ends of Addmotor's range line up with a steady ride the model can name. Addmotor's page lists "40-85 miles" in its Technical tab and "85 Miles (PAS1)" in its highlights, and on its question board it gave two rides with speeds attached: "Addmotor etrike 2023 can go 8mph at PAS1 up to 90+ miles, 20 mph at pas 7 up to 40 miles."

The model at the two speeds in Addmotor's February 14, 2023 answer, 180 lb aboard on level ground. The last column is the rider effort that brings the model to Addmotor's distance: about 5 W, a light touch on the pedals, in both rides.

Read the other way, all 960 Wh over the stat strip's 85 miles leaves 11.3 Wh a mile, which the model spends at about 7.7 mph on the throttle alone, 14.8 mph with easy pedaling or 17.9 with steady pedaling; over the table's 40 miles, 24.0 Wh a mile is the throttle alone at about 19.9 mph.

Plan on 85% of the row that matches your ride. Addmotor recommends recharging "when it has a 10%-15% charge left", and planning on the rest leaves the upper 15% of that advice in the pack: at 12 mph on the throttle, 57 of the full 67 miles.

If you ride for the pack's lifespan, plan on the 20–80% band instead. Addmotor's maintenance guide asks you to "keep your battery charge between 20% and 80% for the best lifespan", which is 60% of the pack, 576 Wh:

The miles inside the band, 180 lb aboard on level ground. At 8 mph your 75 W alone holds the speed, about 8.6 mph on the flat, so the motor draws nothing.

The formula behind every range figure

Holding a steady speed takes a steady flow of power at the rear wheels, and the model Martin and colleagues validated on an open road in 1998 gives it in one line for constant speed in still air:

P = v × [ m × g × (Crr × cos θ + sin θ) + ½ × ρ × CdA × v² ]

In it, P is the power at the wheels, v the road speed, m the mass of rider, load and trike together, g gravity, θ the slope's angle, Crr the tires' rolling resistance (0.0105 is a drag of 1.05% of the weight on the tires), ρ the air's density and CdA the rider's drag area, a measure of the air pushed aside.

The first bracketed term is the tires and the slope; the second is the air, and once multiplied by v, the air's share grows with the cube of speed. Three stages lie between those wheels and the pack:

1. Your pedaling reaches the rear wheels through the chain at 97.7% efficiency, the chain figure Martin and colleagues measured, and the motor makes up the difference.
2. The motor is modeled on a comparable motor with published figures: Bafang's 2021 OEM workbook gives its RM G0H0 a no-load speed of 510 rpm (n0) and a rated speed of 426 rpm (nT) at 48 V, and "≥ 80" percent efficiency. Addmotor publishes a 20 mph top speed and no motor speeds, so the model keeps Bafang's shape at Addmotor's 48 V and 750 W and sets its unloaded speed, 21.8 mph, where a 180 lb rider on the throttle just reaches 20 mph on level ground.
3. The pack gives up a small share of its energy as internal loss, at the efficiency Arango, Lopez and Ceren measured on a 48 V pack.

From those, watt-hours per mile = battery watts ÷ mph, and miles = 960 Wh × the share of pack energy available at that temperature ÷ watt-hours per mile.

One ride, worked end to end: a 180 lb rider holding 12 mph on the throttle, on level pavement. At the wheels that ride needs 131.4 W: 72.9 W against rolling resistance and 58.5 W against the air.

At 12 mph the 24-inch rear wheels turn 168 times a minute. The motor model gives the motor 1.50 N·m of torque per amp, a 0.405 Ω winding and a 0.83 A no-load current, all derived from Bafang's published figures at the fitted speed.

Holding this ride, it turns out 7.5 N·m on 5.8 A at 79% efficiency, below its rated 80% at so light a load, and draws 166.8 W.

Adding the pack's own losses, the battery supplies 172.0 W, which at 12 mph is 14.34 Wh a mile: 960 ÷ 14.34 is about 67.0 miles, or 56.9 with 15% held in reserve.

Two published benchmarks, reproduced. Each piece of the model returns the figure its own source prints:

The model's self-test reproduces Appendix I of Martin and colleagues (8.36 m/s, a 90 kg system, a 0.3% grade) and the RM G0H0's rated point in Bafang's workbook, and zero torque at the fitted no-load speed. At 82% efficiency instead of Bafang's 80% floor, the 12 mph throttle ride rises from 67 miles to 73 (Limitations item 4).

The trike's weight is the other open input. Addmotor's table prints 110 lb and its March 17, 2026 answer "about 123 lbs"; at 123 lb the 12 mph throttle ride comes to 65 miles instead of 67, the 15 mph ride to 54 instead of 55, and the 8% climb at 10 mph to 10 instead of 11.

180 lb aboard; the only change between the columns is the trike's own weight.

No measured ride on the Grandtan with the rider's weight and speed stated was found to set beside the model. the 103 questions on Addmotor's board, the captions of 14 owner and reviewer videos read in full and 242 Reddit posts were read on September 28, 2026; the one owner mileage on Addmotor's board states no speed, and the videos give estimates and odometer totals.

Carrying: two baskets, a deck and 450 lb

Addmotor rates the Grandtan at "350+100 LBS": a 350 lb rider plus 100 lb of cargo, 450 lb in all, the figure its question board repeats ("the max weight capacity of addmotor m340 is 450lbs", March 15, 2023). Count it as you plus everything aboard, and keep the cargo share in the rear basket at or under its 100 lb.

Two older Addmotor posts print a lower figure under the Grandtan M-340's name: "280+100 lbs" in a September 23, 2024 comparison and "Payload Capacity: 280 + 100 lbs." in a February 24, 2025 list. If you will carry more than 380 lb in all, email us before you order and we will confirm the rating in writing.

The rear basket measures 20.5 × 16 × 9.5 inches and the front one 13.5 × 10 × 5, both in the box. Addmotor's feature copy sells the pair for "weekly grocery runs to camping trips with pets", and says the trike "seamlessly hitches to an optional 220 lbs trailer" that is not part of our listing.

Addmotor's own image: a rider and two dogs beside the parked trike, the rear basket behind the seat.

A medium dog rides in the rear basket. Asked about a 40 lb dog, Addmotor answered on July 17, 2025 "Sure, the rear basket came with a max payload of 100 lbs, you could ride with your little fur baby." The waterproof basket bag is extra: "This product does not include storage bag, which must be purchased separately," Addmotor wrote on December 31, 2025.

The Grandtan carries one person. It has one seat, and Addmotor's March 12, 2024 answer on a front child seat was "Sorry, it doesn't look like the Grandtan's handlebar stem will fit this." For two riders on three wheels we sell Addmotor's M-380 tandem, where each rider pedals independently.

Turning, brakes, a parking brake and the lights

Three wheels ask for a new habit in corners. Asked whether the trike is stable, Addmotor answered on March 9, 2023: "Hi, it's a 3 wheel electric trike, so it will more stable than 2 wheels, but it takes practice to get used to turning. Get a helmet for your falls." The rear differential lets each back wheel turn at its own speed through the bend.

Addmotor's post for new trike riders sets out the practice: learn the power and speed settings first, practice in a safe place, and choose a first route with "no obstacles or tight turns". Its beach post adds that a new rider "might also need a little time to get used to how it turns and balances on uneven ground", at "a speed that lets you react".

Addmotor's image of the three disc brakes, one on each wheel, on 180 mm rotors.

Every wheel has a brake. The Performance tab lists "Mechanical Disc Brakes On Each Wheel", and Addmotor's triple-disc image names the rotors at 180 mm. If a brake feels soft or rubs, email us the symptom and we will point you to the adjustment.

The parking brake holds it on a slope. The Performance tab lists "Parking Brake: Yes", and Addmotor settled an older answer on February 3, 2025: "It has parking brake right now." Set it before you load the baskets or climb onto a trike parked on a grade.

The brake lever with its parking-lock button, in Addmotor's close-up.

The lights run off the main battery. The Performance tab lists a headlight and a taillight "Controlled By Display with Brake Light Function", and Addmotor names the set its "EB 2.0 Lights System".

The EB 2.0 lights in Addmotor's image: the headlight over its reflector, and the taillight, which Addmotor's table says doubles as a brake light.

Suspension, tires, gears and weather

The front fork carries the suspension: an "Oil Spring Fork with 80mm of Travel" in the Performance tab, and the rear is rigid. For a trike with suspension at both ends and the same 750 W rating, Addmotor's Grandtan X adds a rear shock; our store listed it at $2,899 on September 28, 2026. Our Grandtan X review sets the two side by side.

The tires are 4-inch fat tires on "Aluminum Double Wall" rims, with inner tubes ("Hello, there are tubes in the tires," Addmotor, February 23, 2023). For soft sand, Addmotor's February 20, 2023 answer was "You may have to let some of the air out of the tires for a smoother ride in the sand."

The Shimano 7-speed drivetrain in Addmotor's image, with the chain's path traced in light.

Rain is fine; standing water is not. Addmotor's March 1, 2023 answer: "The electric bike is waterproof, but we still suggest not taking the bike into the water which exceeds the lowest line where the controller is." It asks you to dry the electrical parts after a wet ride, and its maintenance guide says "Never submerge the battery in water or use high-pressure sprays."

Near the sea, Addmotor's answer of November 7, 2025 is a routine: "All metal can eventually rust near saltwater. For long-term protection: • Rinse with fresh water after use. • Wipe it down or allow it to air dry completely. • Store indoors, in a garage, or a sealed shed."

110 or 123 pounds: parking, doors and transport

At 110 lb in Addmotor's Technical tab, and "about 123 lbs" in its March 17, 2026 answer, the Grandtan is a trike you wheel into place. It runs 77.6 inches long and 32.3 inches wide as the Standard, 78 and 33.5 as the Plus, and it does not fold: "Sorry, this electric fat trike are not available to fold up to transport," Addmotor answered on March 15, 2023.

Measure your doors before it arrives. At 32.3 inches the Standard needs a doorway at least that wide, and the Plus 33.5 inches; a narrower door means a garage, a shed or a ground-floor room with a wider opening.

For a car or an RV, Addmotor's March 17, 2026 answer points to a hitch rack: "You may search the key word "Hitch Carrier" to seek for a rack to carry the trike. FYI, the trike weighs about 123 lbs." Rate the rack for at least 123 lb and for a three-wheeler's width.

The Mercer fit test

The Mercers, the same seven people, stand beside every bike we review, so each machine answers the same fit questions (meet the Mercers). Each verdict reads a figure Addmotor publishes (the rider windows, seat range, standover and payload) or the fit tables built from them.

Every adult in this household is inside Addmotor's windows; the choice is between the Standard and the Plus. The standover table clears Addmotor's 17.5 inches by a wide margin at every height, the Standard suits Ruth, Dana and Maya at the formula saddle, and Frank and Jack are the riders for whom Addmotor's Plus exists.

Has it been recalled?

No. On September 28, 2026 we searched the Consumer Product Safety Commission's recall data in its title, product-name and manufacturer fields for Addmotor, ADDMOTOR, Add Motor, Addmotor Tech, Motan and Addrider, and for 19 of Addmotor's model families, Grandtan among them, and read every field of a 623-record corpus of bicycle, e-bike, battery and scooter recalls.

None names Addmotor, its company names or a model family, and no record in the corpus carries an Addmotor model code such as M-340.

The search proved it could see recalls first: the same queries returned 1 for Ancheer, 54 for Specialized and 24 for Trek.

Class and road rules: 750 W at the line

Settle this before you order. Addmotor's US page publishes a 750 W motor, a throttle and a 20 mph top speed, the very figures the federal definition draws its lines at, so the words each law uses decide where the Grandtan lands.

Under 15 U.S.C. § 2085(b), a federal low-speed electric bicycle is "a two- or three-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts (1 h.p.)", with a motor-only top speed "less than 20 mph" on a paved level surface with a 170-pound rider aboard.

§ 2085(b) and Addmotor's Grandtan page, both read September 28, 2026.

Addmotor's 750 W and 20 mph are the definition's own numbers, and the definition asks for less than each. A published top speed is the maker's figure, not the statute's motor-only test with a 170-pound rider, and whether the trike measured that way comes in under 20 mph is not something a specification table settles.

California draws the power line inclusively. Read on September 28, 2026, California Vehicle Code § 312.5(a) builds its definition on "an electric motor that does not exceed 750 watts of power", its class 2 motor stops helping "when the bicycle reaches the speed of 20 miles per hour", and § 231 gives a bicycle "one or more wheels" and says "An electric bicycle is a bicycle."

Across the 50 states and DC, the state's own words decide. Read against each definition's watt wording, throttle rule, top speed and wheel count, Addmotor's published figures sit inside 26 jurisdictions' e-bike definitions and outside 23 of them through September 30, 2026; two, Alaska and Kentucky, publish no e-bike definition.

Each state's definition as read into our state law atlas and screened September 28, 2026. Twenty of the 23 set their motor limit in the words "less than" 750 watts, which a 750 W motor does not meet; New Jersey's turns on its throttle rule, and Montana and Rhode Island define an e-bike on two wheels, as Alabama and New Jersey also do.

Connecticut is the one row that moves on a known date. Public Act 26-24 § 26 rewrites its definition from October 1, 2026 to take in a motor of "not more than seven hundred fifty watts". Connecticut's definitions section, § 14-1, defines no "bicycle" of its own, so the wheel count stays open there: from that date 22 jurisdictions remain outside, and for Connecticut, email us and we will confirm how it treats a three-wheeler.

A state that leaves the Grandtan outside its e-bike definition still decides for itself how the trike is treated on its roads, as a moped, a motor vehicle or something else, and what riding it there asks of you. Each state's full answer is in our 50-state e-bike law atlas; for California, our California e-bike law page goes further.

Trails and public land: who decides

Off the road, whoever owns or manages the land decides whether the Grandtan may go there. The Bureau of Land Management defines an e-bike by a 750 W line of its own, and on national forests the decision is made district by district.

On Bureau of Land Management ground, 43 CFR 8340.0-5 defines an e-bike as "a two- or three-wheeled cycle with fully operable pedals and an electric motor of not more than 750 watts (1 h.p.)", so a 750 W trike fits its words.

It is spared the off-road vehicle rules only where the field office has decided e-bikes ride like bicycles, and only while "the motor is not exclusively propelling the e-bike for an extended period of time".

That last condition matters on a trike with a footrest. Cruising with your feet on the deck is the motor propelling the trike alone, and where the exception does not apply, 43 CFR 8341.1 keeps an off-road vehicle to land designated "open to off-road vehicle use".

In National Forests, the Forest Service directives of March 31, 2022 handle e-bikes as motor vehicles, "managing all classes of e-bikes as motor vehicles" as the notice at 87 FR 41278 puts it, and where a Ranger District has published a motor vehicle use map, 36 CFR 261.13 bars riding "other than in accordance with those designations".

The land manager's own document settles each row; nothing in Addmotor's specification settles any of them.

The penalty rule for BLM land, 43 CFR 8340.0-7, sets "a fine of not more than $1,000" or imprisonment "for not longer than 12 months", or both, for a violation. Agency-by-agency detail is in our public-land e-bike guide.

Green flags / Red flags

Green flags

• A 450 lb payload, written as 350 lb of rider plus 100 lb of cargo, with a basket at each end in the box.
• A differential and brakes on all three wheels, plus a parking brake for loading on a slope.
• A 960 Wh Samsung pack: about 67 miles at 12 mph on the throttle for a 180 lb rider on the level, and 45 with the full 450 lb aboard.
• A torque sensor, seven assist levels and a throttle, with a wooden deck to rest your feet on when the throttle does the work.
• A 17.5-inch standover that 95 of 100 riders at every height from 5'0" to 6'4" clear by 9.6 inches or more.
• Two versions for two height ranges: the Standard for 5'2" to 6'4" and the Plus, on bigger wheels, for 5'5" to 6'5", at the same price on our store.
• A backrest saddle and an upright cockpit: the median rider leans 10 to 15 degrees, with an adjustable stem to sit straighter.
• Seven colorways, all orderable in the Standard on our store on September 28, 2026.

Red flags

Each one is about fit: who the Grandtan is wrong for, and what to do instead.

• Wrong if your inseam is above 33.6 inches and you want full leg extension on the Standard. Look at the Plus, Addmotor's version for taller riders, and find your row in the saddle table.
• Wrong if your state's e-bike definition is the rule you must ride under and it says "less than" 750 watts. Find your state in the class table; email us and we will match you to a trike that fits your state's words.
• Wrong if it has to go up stairs or through a door under 32.3 inches. It weighs 110 to 123 lb and does not fold; the Citytri E-310 folds, at $1,699 on our store.
• Wrong if you want rear suspension. The Grandtan has its travel at the front; the Grandtan X adds a rear shock at the same 750 W rating.
• Wrong if two adults want to ride together. It has one seat; the M-380 tandem seats two, each on their own pedals.
• Wrong for long climbs past 10% on the throttle alone. At 10 mph the model needs your legs there; pedal and shift down, or send us your hills and we will run them. Our Grandtan Turbo review computes Addmotor's 1,000 W mid-drive holding 10 mph up a 15% grade on the throttle.
• Wrong for a trail open to non-motorized bicycles only. Where a land manager does let e-bikes ride as bicycles, BLM's rule still asks that the motor not propel you alone for an extended period; our public-land guide lists who manages what, and we will check your trail.
• Not a trike for two riders or a child passenger. It has one seat; your state's age rules for riders are in our 50-state law atlas.

Buy it if / Buy something else if

Buy it if you want three stable-footed fat tires, a backrest seat and a basket at each end, with a torque sensor for easy pedaling and a throttle for days you'd rather rest your feet on the deck, computed at 67 miles at 12 mph on the throttle for a 180 lb rider and 45 with the full 450 lb aboard.

It also asks for a rider inside Addmotor's windows, 5'2" to 6'4" on the Standard and 5'5" to 6'5" on the Plus, a ground-level spot and a door at least 32.3 inches wide, and somewhere indoors to charge.

For $2,399 you get a 750 W rear-mounted motor, 90 N·m in Addmotor's figures and a 960 Wh Samsung pack, a differential, disc brakes on all three wheels, a parking brake, an 80 mm fork, seven Shimano gears and both baskets. Through Shop Pay on our listing, the 12-month plan is $216.53 a month at 15% APR, $2,598.36 in all.

Buy something else if it must fold, where the Citytri E-310 at $1,699 and Eunorau's NEW-TRIKE 2.0 at $2,499 both do; if you want a differential trike for less, where Eunorau's ONE-TRIKE 2.0 is $1,799; or if two of you ride together, where the M-380 tandem starts at $4,099.

Our Addmotor brand profile sets the Grandtan beside every other Addmotor on our shelf, and our e-bike reviews hub is where our reviews of other makers' trikes and bikes are gathered.

Before you buy: the checklist

Ten checks before you spend $2,399; the first three decide where the Grandtan can go and who can ride it.

1. Find your state in the class table and read its own page in our law atlas.
2. Look up the rule for each trail or park you will ride, since the land manager decides where the trike may go.
3. Choose the version by height: the Standard for 5'2" to 6'4", the Plus for 5'5" to 6'5".
4. Measure your inseam against the fit tables, knowing the Standard's post tops out for an inseam of 33.6 inches at 109%.
5. Measure the door and the parking spot for 32.3 inches of width (33.5 on the Plus) and 77.6 to 78 inches of length.
6. Add up yourself and the load and keep it at or under 350 lb of rider plus 100 lb of cargo.
7. Plan the transport: a hitch rack rated for 123 lb and a three-wheeler's width.
8. Match your ride to a row in the range tables, add the climbing, and keep 15% of the pack back.
9. Choose where it will charge: indoors, at 50 to 77 °F, with 8 to 10 hours free from empty.
10. Practice turning in a quiet lot before the first ride out, as Addmotor advises new trike riders.

Buying it from us

Why buy the Grandtan from Redtail

Our listing priced the Grandtan M-340 at $2,399 in all seven colorways, Standard or Plus, on September 28, 2026, with $2,899 shown as the regular price. Our part starts when you order.

Red, one of the seven colorways at $2,399.

Every colorway has its own button. Addmotor listed the Plus with stock in three colors on September 28, 2026, so those are the Plus buttons here; for the Plus in another color, email us and we will confirm it before you order.

Each button adds that colorway and version to your cart at $2,399, as our store listed it on September 28, 2026.

Pearl White, on white-wall tires.

Changing your mind works differently under our refund policy. A trike still unopened in its sealed factory packaging can come back when you ask within 72 hours of delivery, minus a 15% restocking fee and return shipping, and canceling an order costs a 3% transaction fee; we would much rather settle your fit, load and route questions first.

Frequently asked questions

How far can the Addmotor Grandtan M-340 go on one charge?

Addmotor's own figures are 40 to 85 miles, with 85 on the lowest assist level. Computed for level pavement on the throttle, your full pack covers about 67 miles at 12 mph for a 180 lb rider, 39 at 20 mph, and about 45 at 12 mph with the full 450 lb aboard; climbing at 10 mph costs 157 to 201 Wh per 1,000 feet (the range tables).

How fast does the Grandtan M-340 go?

Addmotor publishes a top speed of 20 mph for the Grandtan, in its Technical tab and in the page's highlights. How your state treats a machine at that speed is in the class section.

Is the Grandtan M-340 street legal, and what class is it?

That depends on your state's words. Addmotor's 750 W and 20 mph sit inside the e-bike definitions of 26 jurisdictions, California's inclusive "does not exceed 750 watts" among them, and outside 23 through September 30, 2026, 20 of them definitions that say "less than" 750 watts; from October 1, when Connecticut's new wording takes effect, 22 remain outside (the class table). Tell us your state and we will send you its rule.

What's the difference between the Grandtan Standard and Plus?

Wheels and size. The Standard rides on 24-inch front and 20-inch rear tires for riders from 5'2" to 6'4"; the Plus on 26 and 24 for 5'5" to 6'5", with a saddle range an inch higher. Addmotor says "The 2" bigger tires make the Plus e-trike more suitable for taller people", and our store prices both at $2,399.

What height rider does the Grandtan fit?

Addmotor gives 5'2" to 6'4" for the Standard and 5'5" to 6'5" for the Plus. On the Standard's 32.5 to 39-inch seat, 96 or more of every 100 riders from 5'2" to 5'6" reach the formula's saddle height, 84 at 5'8" and 43 at 5'10"; if your inseam is over 33.6 inches, your saddle will sit at the top of the Standard's post (the fit section).

How much weight can the Grandtan carry?

450 lb in all, written by Addmotor as "350+100 LBS": up to 350 lb of rider and 100 lb of cargo. With the full 450 lb aboard, the model still gives you about 45 miles at 12 mph on the throttle over level pavement (the weight table) Two older Addmotor posts print "280+100 lbs" under the Grandtan's name, so above 380 lb confirm with us before you order.

How much does the Grandtan weigh?

110 lb in Addmotor's Technical tab, and "about 123 lbs" in its March 17, 2026 answer. Choose a hitch rack rated for the higher figure (parking and transport).

Is the Grandtan stable, and does it tip over?

Three wheels keep it standing when you stop, and cornering is the skill to learn. Addmotor's own answer: "it takes practice to get used to turning." Practice slow turns in a quiet lot first, as Addmotor's new-rider post advises, and wear a helmet (turning and brakes).

Does the Grandtan have a parking brake and a differential?

Yes to both: Addmotor's Performance tab lists "Parking Brake: Yes" and "Differential: Yes", and its February 3, 2025 answer confirms "It has parking brake right now." Set the parking brake before you load the baskets on a slope.

Can I pedal the Grandtan if the battery dies?

Yes. Addmotor's answer: "you can pedal it normally, but it would be a little more difficult to pedal than normal bikes." The seven Shimano gears let you choose a low one for the ride home.

How long does the Grandtan's battery take to charge, and is it removable?

Eight to ten hours from empty on the 2 A charger, in Addmotor's March 1, 2023 answer, and yes, the pack comes off: "Hello, the ebike battery is removable," Addmotor answered on February 24, 2023. Charge it indoors at room temperature, as Addmotor advises (the battery section).

Can the Grandtan carry my dog?

Yes, in the rear basket: asked about a 40 lb dog, Addmotor answered that "the rear basket came with a max payload of 100 lbs". Count the dog in the 100 lb cargo share, and buy the basket bag separately if you want one (carrying).

Does the Grandtan fold, and will it fit through my door?

It does not fold, in Addmotor's words, "not available to fold up to transport". Your doorway needs at least 32.3 inches for the Standard and 33.5 for the Plus; for a trike that folds, the Citytri E-310 is $1,699 on our store.

How do I transport the Grandtan?

On a hitch rack: Addmotor's March 17, 2026 answer suggests searching "Hitch Carrier" and notes the trike weighs about 123 lb. Choose a rack rated for that weight and a three-wheeler's width, and take the battery off for the drive.

Can the Grandtan handle sand, gravel or grass?

Addmotor sells its 4-inch tires for "loose gravel, sandy shores, and cracked pavement", and for sand it suggests letting "some of the air out of the tires for a smoother ride". The tables cover pavement only; send us your usual route and we will price its paved miles and climbs.

How much assembly does the Grandtan need?

Addmotor ships it 85% assembled: "All you need to assemble is the front wheel, front fender, pedals, and handlebar," in its June 12, 2023 answer. Its product page links a video for the final steps.

What if my Grandtan won't turn on?

Email us your order number, photos and any code on the display. Our refund policy covers a bike that "won't power on, won't charge, shows an error code, or has a faulty component": "we coordinate repair or replacement remotely."

What warranty does the Grandtan M-340 have?

Buy it from us and a fault becomes our job: send photos and your order number, we open the claim with Addmotor and see it to the end, and our listing commits Redtail to coordinating the repair or replacement "at no cost to the customer". Want Addmotor's own terms for your order? Ask us before buying and we will have them confirmed in writing.

Can I finance the Grandtan?

Yes. Shop Pay on our listing came to $216.53 a month for 12 months at 15% APR on September 28, 2026, $2,598.36 in all, or $819.74 a month over 3 months; rates run 0 to 36% APR by eligibility.

Limitations of this review

Twenty-six points this review cannot settle, listed so you can weigh them.

1. We sell this trike. Read the red flags with the same care as the green.
2. This review is specification-verified. Its figures come from Addmotor's published documents, statutes, our own store record, the published research the range and fit sections cite, or arithmetic on this page.
3. Each range figure is one steady ride: one speed, one grade, no wind and no stops. Stops, starts, headwinds and soft ground cost more.
4. Bafang's figures stand in for Addmotor's motor. Addmotor gives its rating, peak and torque but not its motor speeds or how the motor is geared to the differential. At 82% efficiency instead of Bafang's 80% floor, the 12 mph throttle ride rises from 67 miles to 73.
5. At light motor load the model has no measured check. Where your legs do most of the work, as in the steady-pedaling column at 15 mph, the answer rests on motor losses we could not check against a published motor map.
6. The motor's unloaded speed is fitted to Addmotor's top speed. The model sets it where a 180 lb rider on the throttle just reaches Addmotor's 20 mph; a motor with a higher unloaded speed and a speed limiter would draw a little differently near 20 mph.
7. Addmotor prints more than one weight: 110 lb in its table, "about 123 lbs" in a March 17, 2026 answer and "around 108 lbs" in a December 21, 2024 post; the tables use 110 lb, and the check at 123 lb in the formula section moves each ride by one or two miles.
8. The model treats the rear wheels as the 20 × 4.0 tire's nominal 24-inch diameter on the Standard and 28 inches on the Plus; Addmotor prints no outer diameter, and because the unloaded speed is fitted to the top speed on each, the range figures come out the same on either.
9. Addmotor's two ride figures come from its February 14, 2023 answer, written for "Addmotor etrike 2023"; they are set beside the model as Addmotor's own figures.
10. No measured range day on the Grandtan was found. The routes read are listed at the end of the formula section; the one owner mileage on Addmotor's board states no speed.
11. Every figure assumes all 960 Wh are usable. The documents read here do not say how much of the pack the battery management releases; on one measured pedelec, researchers at KIT found 75% in use during a standard range test.
12. The tire coefficient is the median of ten 26 × 4.00 fat tires at 12 psi, a different tire from the Grandtan's, and the tire table brackets it.
13. The cold figures rest on one cell's laboratory data. Addmotor names Samsung cells without a model number, so the central line uses McMaster University's measured LG HG2 cell, bracketed by Samsung and other published cell data.
14. The charge time is Addmotor's, 8 to 10 hours from empty in its March 1, 2023 answer; the 20-to-80% figure is 12 amp-hours at the charger's 2 amps, before charging losses.
15. Addmotor publishes a drawing only for the Standard, so the fit tables are the Standard's; the Plus is covered by Addmotor's own window and saddle range, and we will run a Plus rider's figures by email.
16. The fit figures use the US Army's ANSUR II bodies: 6,068 soldiers aged 17 to 58, measured in 2010 to 2012, who are not the US public, so your own inseam decides your row.
17. The cockpit is measured on Addmotor's size drawing. The crank, crank height, seatpost angle and grips are read at the 43-inch handlebar scale, with three published lengths agreeing within 3.5%; the wheelbase, deck and overall length do not, because the near rear wheel of a trike sits off the centerline of a side view.
18. The hand figure is a ceiling with a relaxed back. On a real ride your back and arms carry part of the load, and we found no study that measures hand load on a trike set up like this one.
19. The 109% formula is a starting point. In 19 trained cyclists it put 55 to 65% inside the 25-to-35-degree knee range and the heel check 70%, so the knee range and the heel check should settle the saddle.
20. The certification is as Addmotor lists it, "UL 2271 & 2849"; no certificate number was read. Where a building or an insurer asks for one, email us and we will request Addmotor's documents in writing.
21. Several of Addmotor's answers quoted here date from 2023, when its question board described an earlier Grandtan; each is quoted with its date, and the specification rows are the current page's.
22. The class table reads each state's definition as our law atlas records it, screened September 28, 2026; a state can change its words, as Connecticut does on October 1, 2026, and three-wheeler wording outside the definition section was not read for every state.
23. Trail access is set locally. The land manager's rule decides, it can change, and neighboring systems differ.
24. Colorways, prices and stock were read on September 28, 2026, and each can change, as can the Shop Pay terms and Addmotor's New York City shipping pause.
25. What ships with the trike is from Addmotor's product FAQ: the battery, both baskets and a charger. Addmotor's box list names further accessories that our listing does not list, so email us before you order and we will confirm in writing what ships with an order placed here.
26. Two older Addmotor posts print "280+100 lbs" under the Grandtan M-340's name, against the "350+100 LBS" of its product page and its question board; the tables use the product page's figure, and above 380 lb we confirm the rating in writing before you order.

The bottom line

At $2,399, the Grandtan M-340 puts a 750 W rear-mounted motor, a torque sensor and a 960 Wh Samsung pack under a step-through fat-tire trike with a backrest seat, a wooden deck, two baskets, a differential, disc brakes on all three wheels, a parking brake and a 450 lb payload.

For a 180 lb rider on level pavement, the model gives about 67 miles at 12 mph on the throttle, or 134 with easy pedaling, and with the full 450 lb aboard still about 45; each 1,000 feet of climbing at 10 mph costs 157 to 201 Wh on the throttle.

The right owner is a rider who wants three wheels under them and baskets at both ends, fits the Standard at 5'2" to 6'4" or the Plus at 5'5" to 6'5", keeps the trike at ground level behind a door of 32.3 inches or more, and rides where their state's words take in a 750 W machine.

On Shop Pay, the Grandtan costs $216.53 a month for 12 months at 15% APR.

Before you order, settle two things with us: which version your height and inseam call for, and your state's rule for a 750 W trike. Tell us your height, your roads and your trails, and our reply will name the version and the rule for each.

Mint Green, on orange-wall tires.

Source register

What each document behind this review supports.

T1 is the record itself, read from whoever issued it: a statute, a federal regulation or notice, the maker's own product page, drawing, question board and posts, and our own store record.

T2 is a party's own publication about its product or its measurements: the motor maker's workbook and research groups' and laboratories' published measurements.

Expiry conditions

Re-read this page if Addmotor changes the Grandtan M-340's price, specification, motor, battery, range figures, top speed, weight, payload, size drawing, FAQ or question-board answers; if Addmotor lifts or changes its New York City shipping pause; or if the colorways, the prices, the stock or the Shop Pay terms change on our store.

Re-read it too if a state changes its e-bike definition, after Connecticut's October 1, 2026 change is read into our atlas, or if a recall is published naming Addmotor or a Grandtan. Verified September 28, 2026.

References

The full bibliographic record for each document cited above, with the date it was retrieved.

1. Addmotor Tech, Grandtan M-340 eTrike — product page (Size & Fit, Technical, Performance and Delivery tabs, highlights strip, feature sections, product FAQ, comparison image, colorway options and prices, as served for the United States). Retrieved September 28, 2026. https://www.addmotor.com/products/grandtan
2. Addmotor Tech, Grandtan M-340 size drawing (m-340-size), on the product page. Retrieved September 28, 2026. https://www.addmotor.com/u_file/2603/photo/m-340-size_1773719992.png
3. Addmotor Tech, Grandtan M-340 triple disc brake image (180 mm), on the product page. Retrieved September 28, 2026. https://www.addmotor.com/u_file/2607/photo/180mm-triple-disc-brakes_1785323012.jpg
4. Addmotor Tech, Grandtan M-340 eTrike question board, Addmotor's dated answers cited here: q2626 (March 17, 2026), q2615 (December 31, 2025), q2589 (November 7, 2025), q2380 (July 17, 2025), q2279 (February 3, 2025), q1915 (March 12, 2024), q1546 (June 12, 2023), q1268 and q1262 (March 15, 2023), q1117 (March 9, 2023), q1047 (March 7, 2023), q0861 and q0857 (March 1, 2023), q0804 (February 28, 2023), q0685 (February 24, 2023), q0653 (February 23, 2023), q0506 (February 20, 2023), q0299 (February 14, 2023). Retrieved September 28, 2026. https://www.addmotor.com/question_p248/
5. Addmotor Tech, 7 Tips for Electric Bike Battery Health (blog). Retrieved September 28, 2026. https://www.addmotor.com/blog/7-tips-for-electric-bike-battery-health
6. Addmotor Tech, A Complete Guide to eBike Battery Maintenance (blog). Retrieved September 28, 2026. https://www.addmotor.com/blog/a-complete-guide-to-ebike-battery-maintenance
7. Addmotor Tech, 9 Tips to Improve the Range of Your Electric Trike (blog). Retrieved September 28, 2026. https://www.addmotor.com/blog/9-tips-to-improve-the-range-of-your-electric-trike
8. Addmotor Tech, 4 Tips For Riding Electric Tricycle in Cold Weather (blog). Retrieved September 28, 2026. https://www.addmotor.com/blog/4-tips-for-riding-electric-tricycle-in-cold-weather
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