Choosing an e-bike for hills

Why watts do not predict climbing

Every budget e-bike in this market claims 1000W or more, and almost none climb the same way. The watt figure is not why they differ.

Power is the rate of doing work. Torque is turning force. On a gradient at low road speed, what gets you up is turning force at the wheel — and two motors rated at the same wattage can produce very different torque depending on winding, magnet count, gearing inside the hub and how the controller is programmed. This is why a mid-drive rated at 250W can out-climb a hub motor rated at four times that.

The number that would tell you is torque in newton-metres. Mid-drive manufacturers publish it routinely; budget hub-motor brands rarely do.

That is not a reason to avoid the bikes. It is a reason to stop reading wattage as though it answers the question, and to look instead at what a listing does tell you: whether there are two driven wheels, what the brakes are, what the gearing is. Our motor wattage guide takes the power figures apart in more detail.

Rated versus peak, on a climb that lasts

Two power figures appear on most listings and only one of them describes hill riding.

Rated power is what the motor can hold more or less continuously without exceeding its thermal limits. Peak power is the short burst the controller will allow before something gets too hot — useful for pulling away from a junction or cresting a short rise, and gone within seconds.

A climb is not a burst. If your route has a half-mile at 8%, you are asking the motor for sustained output for two or three minutes at a road speed low enough that airflow over the hub is minimal. The rated figure governs that period; the peak figure has nothing to say about it.

When comparing bikes for hilly ground, line up rated against rated and ignore the headline. AMYET's S8 outranks the single-motor bikes on paper because its rated figure is doubled, not because its peak figure is.

Heat, thermal cutback and what bogging down feels like

A hub motor is an electric motor sealed inside a wheel. It sheds heat through the casing into the passing air, which means its cooling depends on road speed — exactly the thing that is lowest when you most need power.

On a long climb the sequence is predictable. The motor draws high current at low rpm, where it is least efficient, so a large share of the energy becomes heat rather than motion. The windings warm, then the magnets. As temperature rises the motor becomes less efficient still, which produces more heat. Most controllers respond by reducing current to protect the hardware.

From the saddle this feels like the bike quietly giving up. Speed bleeds away, the assist becomes vague, and pedalling harder does not bring it back. It usually recovers after a few minutes of easy riding, which is why the problem is often misdiagnosed as a battery issue.

What reduces it

• Keeping road speed up, for airflow and for a motor turning nearer its efficient range.
• Contributing power yourself. Every watt you add is a watt the motor does not have to make.
• Splitting the load. Two motors sharing a climb each run cooler than one doing all of it.
• Not stopping halfway up. Restarting on a steep gradient means the highest current at the lowest speed, which is the worst combination for heat.

Hub versus mid-drive, and why gearing changes everything

A mid-drive motor sits at the cranks and delivers its torque through the chain and the cassette. When you drop into a low gear, the drivetrain multiplies the motor's torque exactly as it multiplies yours. A mid-drive in its lowest gear is a different machine from the same mid-drive in its highest.

A hub motor sits in the wheel, downstream of the gears. Whatever torque it makes arrives at the wheel unmultiplied, and changing gear does nothing to it. A 7-speed hub-motor bike has one motor gear, and that gear is chosen by the manufacturer for a sensible cruising speed rather than for a 12% gradient.

All three AMYET bikes use hub motors — the G60 and EB26 with a single rear hub, and the S8 with a driven hub at each end. That is the norm at this price, because hub motors are cheaper to build and simpler to maintain, and it is the main reason budget e-bikes are generally better on rolling terrain than on steep terrain.

Why a 7-speed drivetrain still matters

It is tempting to dismiss the gears on a hub-motor bike since they do not multiply motor torque. That is a mistake, for two reasons.

First, the gears govern your contribution. Spinning a low gear at a comfortable cadence for the length of a climb can add a sustained couple of hundred watts from a moderately fit rider — power that goes straight into reducing motor load, and therefore motor heat, and therefore how much cutback you experience near the top. Second, a geared bike remains a bicycle when the battery is empty, which on a hilly route is not an academic point.

AMYET lists a 7-speed drivetrain on all three bikes, described as Shimano on the G60.

Two motors: a traction answer as much as a power answer

Dual-motor bikes are sold on power, but on a hill their more important contribution is often grip.

As a bike climbs, weight transfers rearward. That helps a rear hub find traction, up to the point where the front wheel goes light and begins to wander. On loose ground — gravel, wet leaves, sand, snow — a single rear hub applying high torque simply spins, and no amount of extra wattage fixes a wheel that has already broken traction.

A second driven wheel changes that. The same total torque is split across two contact patches, so each is asked for less, and the front wheel pulls rather than merely steering. It also halves the thermal load per motor on a sustained climb — a quieter benefit than the acceleration figures, and a more useful one.

AMYET lists the S8 with dual 1000W motors and all-wheel drive against single 1000W rear hubs on the G60 and EB26. The cost is money — $1,049 against $689 and $669 — plus weight and consumption, since two motors drain a pack faster than one. On flat ground that buys very little. On the terrain this guide is about, it buys more than any other single specification. Our single vs dual motor guide and the G60 vs S8 comparison both work through the trade.

Reading a maximum slope claim

Gradient is quoted two ways and the difference is large enough to mislead. A percentage is rise over run: a 10% grade climbs one metre in every ten travelled horizontally. Degrees measure the angle itself. The two are related by a tangent, and they diverge sharply as the slope steepens.

• 10% grade is about 5.7 degrees.
• 20% grade is about 11.3 degrees.
• 30% grade is about 16.7 degrees.
• 35 degrees is a grade of about 70%.

For context, the steepest paved public roads tend to fall in the 20 to 30% region, and a climb most riders would call brutal is usually between 12 and 18%.

Treat any maximum-slope number as a rough ranking signal between models in the same range rather than as something you can plan a route around. It tells you that AMYET positions the S8 above the single-motor bikes for gradient. It does not tell you how the bike behaves three minutes into a real climb with a rider and a rucksack on it.

What goes up: braking is half the problem

Buyers shopping for hills think about climbing. The descent is the part that actually demands hardware.

A heavy e-bike descending a long gradient turns a great deal of potential energy into heat in the brakes, continuously, for as long as the hill lasts. Once the pad compound overheats, braking force falls away — fade. And on cable-operated brakes your hands are doing the work, so hand fatigue on a ten-minute descent is a real limit rather than a theoretical one.

Mechanical versus hydraulic

Mechanical discs pull the pad through a cable. Lever feel is softer, force depends on hand strength, and cables stretch and need adjustment as pads bed in. Hydraulic discs move fluid instead: they need far less hand force, self-adjust for pad wear, and modulate more finely, which matters most when you are tired and the surface is loose.

AMYET lists hydraulic disc brakes on the S8, mechanical discs on the EB26, and describes the G60 only as dual disc without claiming hydraulic — which normally means mechanical, since brands that fit hydraulics say so. AMYET does not publish a rotor diameter for any of the three, and rotor size is a major determinant of both outright stopping power and heat capacity. On a bike carrying this much mass, that omission matters.

If your riding involves repeated long descents, treat braking as the first specification rather than the last — see the EB26 vs S8 comparison.

Weight, and planning range for a hilly route

Mass works against you in both directions: it is what the motor must lift on the way up and what the brakes must control on the way down.

AMYET does not publish a bare bike weight for any of the three models. The EB26 listing shows 30 kg, roughly 66 lb, but that is a shipping figure including packaging rather than the weight of the bike. For context, fat-tire e-bikes with 1000W-class motors and packs of this size generally sit in the 70 to 80 lb region, and a full-suspension dual-motor bike sits above that. On flat ground the difference is barely noticeable. On a 12% climb it is the whole story.

Budgeting energy for elevation

Where a heavy fat-tire e-bike might use roughly 25 watt-hours per mile on mixed flat riding, sustained climbing can push that beyond 40 — and a dual-motor bike with both wheels driving higher again.

Notice how far those sit below the headline claims — AMYET lists 30–65 miles for the G60, up to 60 for the EB26 and 70–75 for the S8. Nothing is wrong with the published numbers; they describe gentle riding on flat ground, which is not what a hill route is. Plan against the lower figure and read our battery and range guide for the full arithmetic. If you are also close to a payload ceiling, the guide for heavier riders covers how mass interacts with wheels and brakes, and the full buying framework puts terrain in order against everything else.