Front wheel motor on a light singlespeed bike?

[20ston]

will it work?

got a light singlespeed mtb, gearing is 32/16.
had thoughts of fitting a light front hub motor, like the one on the cytronix bikes.
couple of questions,
will it work,
and if it does, which kit is best for it.

thanks

 

[KirstinS]

Yep no reason it can't work. Cytronex do a single speed (or they did anyway)

Kits are more troublesome as there really is only the tongxin motor that does the superlightweight, stealth assist thing. This is the motor used by Cytonex

Generally your other motor choices are be heavier (but also more powerful)

Cytronex does not have a kit yet (I've been waiting 1.5 years for it to appear!) but would convert for you (going rate around £1000)

The Electric Bicycle Company are the only other UK company who sell the Tongxin motor. They do sell kits but have very different battery/control setup to Cytronex

You can order a tongxin kit yourself directly from China. Search this site for Jerry Simon as he has made long and detailed posts about tongxin biulds as how/who to order them from.

If your are not THAT bothered about a tongxin after all then your options are many and varied! You may well decide this as tongxins are really suited to road bikes - they are not especially robust nor powerful (but they are the lightest, stealhiest looking and have no drag - so dont affect handling when not under power)
.
To name a few of your UK based options

Ezee
Juicy
Kudos
8Fun
Oxygen


Or if you you decide you want an offroad 72v powerhouse then talk to Xipi bikes (Frank)

And finally you might want to test drive a few off the peg bikes first to see what suits you most

cheers
K

 

[eddieo]

but aren't other motors really to big for skinny wheeled/tyres road bikes?

 

[flecc]

but aren't other motors really to big for skinny wheeled/tyres road bikes?

The eZee motor is ok, no fatter than the SB they used on the Torq 1 with skinny 700c rims, and SB now make some slim and small diameter models which some members report as having no real drag. Won't be as silent as the Tongxin roller drive, but otherwise ok.

 

[KirstinS]

but aren't other motors really to big for skinny wheeled/tyres road bikes?

well the OP talks about a single speed mountain bike.....hence I was a little confused as to what he/she actually is seeking to achieve. If its a MTB that is simply being used on the road (i.e has MTB forks) then any of the bigger motors should be fine


EDIT crossed with FLecc

 

[laroche]

20ston

There is an issue with the gearing on the bike whichever motor you choose. With a 2:1 ratio and assuming a 26" wheel (ie a gear of 52") you would have to pedal at 97RPM to reach the 15mph limit for electric bikes - impossible for a casual cyclist. Swapping the rear sprocket for a 12 increases the gearing to 69" and drops the required cadence to 73RPM - manageable, but still going some.

 

[20ston]

thanks for the input.

trying to sort a decent offroad bike with assist is proving to be a pain.
i have 2 very good mtb's, but to convert them is either gonna be very expensive or just plain wont work.

 

[eddieo]

An MTB with no gears make no sense..and why I thought you were discussing a drop handle bar road bike

 

[20ston]

a mtb with no gears makes for a very easy to maintain very quiet very light very enjoyable bike.
been using one for 10yrs without any problems.

 

[catsnapper]

I converted a single speed On-One Inbred to assist, using a front wheel 250W Bafang motor with a 2 spd SRAM Automatix rear hub. This gives 55" and 76", with an automatic change up or down at around 10.5 mph. No additional cables as it has a coaster brake, in fact one less as I don't need a rear brake cable

I've also used it with an 8spd Alfine hub, which covers almost all eventualities, but more cables to thread around and a bit more weight.

A small LiPo battery pack and a Lyen Mini-Monster controller gives the motor excellent performance when needed, but doesn't have a significant effect on the non-assisted performance.

Alan

 

[flecc]

Using a low geared bike like yours offroad 20ston, the speeds will be on the low side so you need the motor to drive the wheel on the slow side to keep it on the power band. Using a motor meant for a 700c rim in a 26" will drop the speed a little to more nearly match the speed with pedalling on a 32/16. An expensive but even better alternative would be a Heinzmann motor, since they also come in lower speed very high torque versions, ideal for climbing and rough stuff. They are on the large diameter side but aren't heavy.