Hub motor based e-bikes and Gear cassettes

[KamyFC]

Hi guys,

I had a question regarding e-bikes and Gears.
And this is related to Hub motor based e-bikes and not Mid Drive systems.

Usually in a normal cycle - we have a 7 speed or a 9 speed cassette at the back and a 3 speed cassette at the front.
So that makes it a 7 * 3 = 21 speed gear system or a 9 * 3 = 27 speed gear system.

I wanted to know if most hub motor based e-bikes only have 1 speed cassette at the front?
I have observed most or majority of e-bikes only have a 1 speed cassette and thus only comes with a rear derailleur.

Is that a valid observation regarding hub motor based e-bikes?
And many e-bikes like the Sonders - dont even have space for a cassette apart from the single speed one!

so ebike companies making most hub motor based e-bikes seem to do this to save cost or make things simple?

Also having front and rear derailleur, will mean front and rear trigger shifters add to that a LCD accessory, a Twist and go throttle and your handle bar gets pretty crowded!

 

[George S.]

I have converted bikes with two front hubs and a rear hub. With a front hub you never touch the existing drive train so on one conversion I have a 27 speed setup. On the rear drive I have a 21 speed, 3x7.

Yes, there is a lot on the handlebar and sometimes shifters get moved to awkward places. I have replaced stock shifters that didn't work with cheap and very basic shifters.

You don't have to shift much with a hub motor. You can use the throttle to get going, for example. With a mid-drive, it might be normal to downshift to a starting gear every time you stop. Sadistic European manufacturers compound this by removing throttles completely on mid-drives.

 

[Douglas Ruby]

Higher end hub motor e-bikes such as Stromer ST2 and Specialized Turbo family now use 10 or 11 speed rear cassettes so have either 11-36 or 11-40 rear clusters. They then use 48 to 52 tooth front chain rings. With the extra help of the motor and the very wide ratio rear cassette, the need for a second or third front chain ring is lessened.

 

[harryS]

The design of a derailleur and hub motor system does not prevent use of a multi cog gear in front. It reduces cost to get rid of the front shifter, and many riders wouldn't use that many gears anyway. I do though.

When I built my first e-bike with a rear geared hub, I kept the front shifter. After a while, I found I still liked to pedal. and in that case I still use the middle and high gears. I always liked the feel of a smooth shifting front shifter. I still downshift when I come to a stop too. Easier on the system (which includes your legs) to start in lowest gear.

I agree that it can get pretty crowded between the handlebar grips when you keep the front shifter controls. In addition to the PAS control and LCD, I also need a bell and a headlight.

I think they dropped the derailleur on the Sondors fatbike just to save some money. That is a sixty pound bike. I doubt many owners want to pedal it very far when the motor is not running. I also converted a cheap fatbike to an e-bike, using a similar geared motor, but my bike has a six speed freewheel. I like to pedal that one too, with the motor helping, and I really need the gears.

 

[KamyFC]

Thanks guys - answered my question very well.

I'm a cyclist and love my front and rear shifting. But i love e-bikes too.
I guess i will have to live without the front shifter with my hub based e-bike!

 

[MLB]

Mid drive motors usually use single ring fronts not because they didn't think you need them (not necessary, but nice) but because there was no way to mount them without being way off center.
But there are 2 ring hub motors and more coming all the time. Haibikes Yamaha powered bikes use dual front rings giving you a much wider speed range.
Hub motors, being in the wheels, don't affect the gearing choices at all and can use triple front rings if desired.

 

[harryS]

KamyFC, there's few things better on a bike than the feel of a smooth front shifter. Manufacturers are dropping them to lower costs, and many e-bikers don't care. Indeed, many don't want to shift gears at all. If you take one of your favorite old bikes and install your own rear hub motor, you can have whatever you like.

An e-bike motor does have a sweet spot where it's most efficient. Having more gears and the ability to put the bike in that gear would in theory make for longer battery life. Cars now have six speeds or more in their automatic transmissions to get better mileage.

I am a recreational rider, so I still want to pedal and provide at least half the power. I still use two of the front rings on my hub motor bike. Just as an experiment, I rode my mid drive bike for a few miles in the higher gears (no front shifter) and no pedalling. I burned up 3X-4X more power per my wattmater, and the motor got pretty hot. I don't like that.

 

[Douglas Wever]

My Pedego Ridge Rider is 10 in the rear and two at the crank for twenty gears.

My Trek traditional Domane SL 6 is 50/34 at the crank and an 11 speed cassette.