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I am planning to buy an e-bike and I have been wondering what’s the right thing to choose between:

  • 1 X 8 traction, 29”, 36V • 16Ah → 576Wh battery, or
  • 3 X 9 traction, 27.5”, 36V • 10.4 Ah → 374Wh battery

The second bike looks more like a bike I have been used to (having many speeds), but it has smaller wheels and battery than the first one which has only 8 speeds though…

I know this shouldn’t be the only parameters when choosing an e-bike, but however, coming from the classical MTB world, I am very tempted to like having more speeds.

How important is to have many gears on a e-bike?

Both are pedal assisted bikes, but assuming that I am using the no pedal assisting, or maybe I just ran out of battery — which one would help more?

I am interested in both: being able to go uphill easily, and reach fast speeds on flat terrain and I am just guessing that the 3x9 would be actually better but I am really unsure...

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  • Amount of Wh is battery capacity, basically the number of battery cells in the pack, nothing to do with drivetrain or motor power btw
    – SamA
    Commented Sep 26, 2022 at 12:32
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    The difference between a total battery capacity of 499Wh vs 501Wh is obviously negligible. You might want to clarify the actual difference rather than stating an inequality.
    – user2705196
    Commented Sep 26, 2022 at 13:09
  • Is this a pedal assist e-bike?
    – user2705196
    Commented Sep 26, 2022 at 13:11
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    Is the motor in the bottom bracket or a hub motor on one of the wheels? Makes a huge difference: if the motor is in the bottom bracket the power is going through the gearing; if it's on the wheel, then they're independent systems.
    – Charles Duffy
    Commented Sep 27, 2022 at 19:25
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    what is the goal of this ebike? commuting? mtbing? touring?
    – EarlGrey
    Commented Sep 28, 2022 at 6:37

5 Answers 5

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It sounds like you are trying to choose between two specific ebikes. If you come from a bike riding background and intend to use the ebike in a similar context as you did a traditional bicycle, I would choose which ever one you judge fundamentally to be the better bike for your use. Part of "better bike" is familiarity with controls, access to preferred gear ratios, and so on. Part is quality of ebike and traditional bike components. If you like all the in-between ratios you get with the 3x9, and you're going to use it correctly, go for it. If you always just hung out in the middle ring and shifted on the cassette anyway, definitely you will like the 1x8 for its simplicity.

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  • That's exactly my doubt: I am unsure about the actual ratios of the gears and wheels — not sure if the one which has 8 speeds can go as fast as the one having 27 speeds, and if I can go uphill easily in the same way (8 vs 27 speeds)... Mostly I am wondering for the speedy part — I want it to be as fast as possible, by peddling slowly.
    – Ionică Bizău
    Commented Sep 26, 2022 at 8:40
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    You can simply read up on the cassette and chain rings of the bikes and plug them into any online gear ratio computer to see the overall spread.
    – arne
    Commented Sep 26, 2022 at 11:50
  • Can you post specs of the bikes?
    – SamA
    Commented Sep 26, 2022 at 11:56
  • I think the OP's question (and mine) is exactly why on earth you'd need 27 gears if you are likely using 3 or 4 anyway at all because you have the motor assist! Because how do you know somebody is on an E-bike? Because they are fast but in an unreasonably high gear (and old and in an upright position so that they will all end up with bad backs, but that's irrelevant here). The important thing is that even at high speeds you don't need to adjust your gear to the speed as precisely as you must without motor.
    – Peter - Reinstate Monica
    Commented Sep 28, 2022 at 8:18
  • Peter - I ride e-cargo bikes, and I can assure you, the top and bottom range of the gearing are still useful to me. Though, most would probably agree 3x9 is overkill for almost any application, unless it's the only option. I have fun playing around with front derailleurs when they're there. And even on an assisted bike, you can dial in the gearing according to the terrain and your desires.
    – SamA
    Commented Sep 28, 2022 at 12:49
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The amount of gears will mostly only matter in case you intend to run it without the motor support (or in an "eco" mode corresponding to little-to-no motor support). Then it's pretty much like a regular bike. Similarly, in case your e-bike stops helping past 25km/h which is common, it's like a regular bike from there on as well.

But when using the motor, I ride my ebike quite differently from how I'd ride an ordinary bike. For example going down to the lowest gears at a stop light would be ridiculous. I have 10 gears and shift down to maybe gear 7. Otherwise I'll just get a needlessly slow start. Whereas on a regular bike that's not a good option, you would have a hard time just getting the pedal down when using too high gears from a stand still.

I barely use the lowest gears at all, save for when climbing some seriously steep hill. For normal climbs somewhere around 5 out of 10 works just fine, though the motor performs better at lower gears. At speeds past 25km/h my motor shuts off, and since I only have 10 gears I can't really go much faster than that. If I pedal like crazy then maybe I can get it up 28km/h... I would imagine that having more gears would let me go faster in "manual mode".

As for which bike to pick, larger battery capacity is much more important than gears. You'll not like having to charge it all the time. I wouldn't go with smaller wheels either, personally, but I guess that depends on personal preference and what terrain you'll use it in.

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    That's funny. I find I pick up faster still on my ebike if I anticipate and shift down when I have to come to a stop. Sure, I could just lay into the crank every time, and with a powerful hub motor it probably would feel just fine, but at least with the mid drive type I'm used to, natural shifting still works wonders. Spin up faster, hit top speed faster!
    – SamA
    Commented Sep 26, 2022 at 12:30
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    It is very difficult to ride E-bike over 25 km/h with no assist. Not impossible but this is not often done, unless downhill. And starting on the smallest sprocket eats that sprocket in 1000 km so while convenient, likely cannot be recommended.
    – nightrider
    Commented Sep 26, 2022 at 16:03
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    For example going down to the lowest gears at a stop light would be ridiculous -- this is true no matter what kind of bike you're on (provided you have something resembling "normal" gearing)
    – Paul H
    Commented Sep 26, 2022 at 18:16
  • This is what I see a lot in the streets (people using generally higher gears on E-bikes). I suppose that using adequate gears when accelerating takes some load off the motor because your legs are doing more of the work, so it's good for both battery and heart. But in general I'd doubt that 27 gears are necessary for E-bikes. The use of gears probably also depends on whether you have a hub or middle motor: The middle motor goes through your transmission and therefore struggles with bad gears as much as you do, and benefits from an adequate gear equally, while the hub motor couldn't care less.
    – Peter - Reinstate Monica
    Commented Sep 28, 2022 at 8:48
  • Similarly, in case your e-bike stops helping past 25km/h which is common, it's like a regular bike from there on as well. I'd beg to differ. E-Bikes are insanely heavy and are more or less unrideable above assistance speeds.
    – SirHawrk
    Commented Sep 28, 2022 at 13:29
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From some indirect knowledge (researching e-bikes and helping my brother purchase and set up his e-bike), number of gears (past 3 or so) shouldn't be a big factor. Hopefully someone else chimes in with more experience.

One of the big drawbacks of most hub motors (motor in the hub of your wheels) is that they don't make use of the gearing you already have on the bike. I see there are some e-bike hub motors with gears but AFAIK that generally isn't the case.

The important gears to look at for any mid-drive e-bike (which I assume is what you are looking at) should be the lowest and highest gears - does the lowest gear give you enough torque in all situations (standing start at a green light, up a steep hill), and does the highest gear allow you to drive as fast as you'd like to go? Any gears in between would obviously help you get from lowest to highest but I think for e-bikes anywhere above 3 or 5 gears ought to be plenty (unless some other ratio is way off).

I think this in some way answers your question as stated but doesn't satisfy you - you now likely want to find out how the lowest and highest gears compare between the 2 bikes you're looking at. And I can't help with that unfortunately.

Best of luck!

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    If you want to ride with little (or no, for example if you run out of battery) assistance in a hilly area, 3 gears won't go low enough for the climbs, and you'll spin out on the downs. With 7 or 8 and a wide ratio cassette things get more useful, but you'll still be relying on the motor to get up anything steep
    – Chris H
    Commented Sep 26, 2022 at 12:17
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    I always find the point about hub motors not using the gearing a bit silly. Electric motors work perfectly great with fixed transmission, as evidenced by the fact that most electric cars are fixed-gear. A Tesla model X can both climb steeper than a cyclist, and drive much faster, all in a single gear. The real problem with hub motors is that they need to be small and light, therefore can't have as many poles or reduction gears as electric cars or middle motors.
    – leftaroundabout
    Commented Sep 26, 2022 at 15:15
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    @leftaroundabout One reason for that may be that the Tesla Roadster has 10,000 Nm of torque. Of course it performs nicely. Put that in my hub and I won't need gears either.
    – Peter - Reinstate Monica
    Commented Sep 28, 2022 at 8:55
  • @Peter-ReinstateMonica yeah but you don't need 10 000 Nm, you just need the kind of torque that mid-drive e-bike motors offer, and that would also be almost as good for a hub with fixed gearing. Even in the lowest gears of a MTB you don't have much reduction, and the high gears are outright counterproductive for an electric motor, which could easily offer as high RPM as you could possibly wish for.
    – leftaroundabout
    Commented Sep 28, 2022 at 13:11
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    @SamA I quite agree. But there's an argument to be made that “relatively little power” is besides the point – it is really all about torque. Most E-bikers probably consider the electric most important on steep climbs, but an under-torqued hub motor will offer the least power in that situation. Even a small gearless hub motor can offer good power at high speed on the flat, but that's when they need it the least – except perhaps for regenerative breaking (which for me would actually a be major consideration with an e-bike).
    – leftaroundabout
    Commented Oct 1, 2022 at 6:48
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From experience, the three fastest gears are mostly enough on commuting over moderate terrain. The fastest gear is convenient for cruising at 25 km/h on tarmac, next one is for gravel and the like, and one more is great in crossings and other places where you do not actually require any speed but need good acceleration and easy start instead.

However if you attempt some mountain biking or otherwise have a steep descent in your commuting, you may need the slow "climbing" gears. The power from the engine falls rapidly with the cadence and is not enough to sustain the climbing on a fast gear on any slope. Middle gears are also good for emergency riding if the battery gets flat that may happen on a long weekend ride.

One of my E-bikes has 9 gears, another has 12 and I always wonder why does it need that much. Only adds price to the cassette.

This for a mid-drive E-bike where you and engine share the same gear. I have no riding experience with other designs.

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I would answer your question at face value:

It is less important to have many gears on an electric bike, because you have an extra 250W (at least!) to help to push you uphill or against the wind. Unless you are riding very severe terrain, you won't find the low gears of so much use on your electric bike.

I have also seen arrangements on electric bikes where a 3 ring setup has been fitted at the factory but doesn't work correctly due to the design of the frame (and cannot be made to work correctly). If the bike is from a not-so-well known maker, you would perhaps be wiser to choose the more simple system, which has a certain amount more guaranteed reliability.

The battery capacity should be a big decider -- more capacity generally gives more mileage but with a little extra weight.

In an ideal world, you would try riding both before you make your decision, to see which feels better.

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  • Re triples, I wasn't thinking that frame design would be an issue in reliability. However, the front shifting may tend to be less reliable than a double or 1x. They might be more complex for a newer cyclist to learn to use to their full potential.
    – Weiwen Ng
    Commented Sep 26, 2022 at 12:22
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    You need the sufficient speed of rotation to get these 250 W out. Otherwise the help from the engine is limited by the rotation momentum rather than power and with fast gear at slow speed may not be a lot.
    – nightrider
    Commented Sep 26, 2022 at 15:59
  • @nightrider great point! Of course, it's still alot of extra help over no motor, and much easier to maintain that power-band speed up an incline.
    – Noise
    Commented Sep 26, 2022 at 18:12
  • For a hub motor, where there's only one gearing, then it may or may not be much use under high load -- that built-in gearing can be optimized for fast starts, or for top speed, but the same motor won't generally do that well for both. (This is of course completely different for a motorized bottom bracket).
    – Charles Duffy
    Commented Sep 27, 2022 at 19:27

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