PromptCritical 

What's the latest on good e-bike conversion kits?

I'm looking for something for my better half as she can't keep up with me on a single and there are some rides we'd like to do on singles rather than our tandem.

I think I'd prefer a front hub conversion as it seems like it would be easy to remove and re-install, but I'm open to ideas. I saw an article about Cytronex on Cycling Weekly, and it seems impressive, and the Bafang units seem OK.

Any experience anyone could share would be appreciated!

Polaris OBark

Mid-drive is the best. Front hub is the worst and arguably the most hazardous.

I used a cyc photon conversion kit. The most popular are the Bafang BBSO2 and similar variants.

Arrowana

I've got a Bafang BBS02, it has done it's job quite well. Only real complaints are the very small amount of threads that are left for the lockring to grab if you install it in a 73mm bottom bracket shell, and that it only has a cadence sensor instead of a torque sensor. Feels like you are spinning your feet to activate the motor, rather feeling like the motor is adding power to your pedal stroke like on a bike with a torque sensor. The kit can put out more power than I feel safe using on the bike it is installed on, but you can just use it at lower power levels.

Another option would be to get yourself a bike that is more upright, makes it much easier to go at a pace that is slow enough for someone else to keep up.

Polaris OBark

If it were me (and it was, a couple of years ago), just get her a decent e-road bike. She uses it for commuting, and rehab after a hip replacement. Now she can kick my arse when she is on a standard bike.

PromptCritical 

Why is it dangerous? Traction? Torque steer? Change in handling? Axle coming out of the fork dropouts?

PromptCritical 

A decent e-bike is 3-6x the cost of a conversion and we’d probably only use it 4-5 times a year.

I tried talking her into that and it was a hard “no”.

2old

My first "e" was a 36V, 350w Dillenger kit on a rigid MTB, and it was great fun on and off road. The power built gradually and the front end never spun the tire. The same can't be said about my latest conversion with a 48V, 500w Bafang kit on the same bike (my daughter wanted an e-bike and I transferred the kit to a cruiser for her). There's good advice above about just building a mid, but other options may be viable too.

PromptCritical 

Did the front wheel drive cause any other handling problems? We only want the motor to put out a maximum of 150w and wouldn’t be using a hand throttle so wheel spin shouldn’t be a problem.

RB1-luvr

This contraption seems kind of neat.

2old

[QUOTE=PromptCritical;23367289]Did the front wheel drive cause any other handling problems? We only want the motor to put out a maximum of 150w and wouldn’t be using a hand throttle so wheel spin shouldn’t be a problem.[​ ​ ​ ​
No, that system functions perfectly even after 10 years. The Shenghi motor, in concert with its controller seems designed well for a front application. The only reason I don't recommend Dilleneger these days is they seem to have pretty much abandoned the US market and their batteries may have been sitting around a while, although the one on that bike is seven or eight years old.

crackerdog

Promptcritical: Front fork can break if the motor is too strong.

PromptCritical 

What do you mean by a "novice install"? I've never installed an eBike conversion, but there isn't anything I won't do myself on a bicycle and I have a lot of experience (I'm a recovering (poorly) engineer) with other machinery. What is the issue? I'm only looking for a low power unit (200watts).

2old

Many (most) individuals think a torque arm is necessary with rear hubs to keep the steel axle from rotating in the softer aluminum dropouts. I ran a 1000w rear system in aluminum dropouts for several years without a torque arm, but put one on my daughter's much less powerful front hub. There's nothing esoteric about kit installations IMO, but front end failures can be catastrophic, so if you end up with one, I wouldn't install on a carbon fork and aluminum only with a torque arm.

randomgear

Grin Technologies ( eBikes.ca) out of Vancouver, B.C. Canada offers a wide variety of hub-based e-motors. Very informative website, but likely best if you have some knowledge of lower voltage electrical.

PromptCritical 

Thanks, that’s a great site! I know quite a bit about electricity as long as it is greater than 5v

Nvreloader

Guys, If I can ask a question,
I have this bike I want to add a Bafang 02 motor to, it has 21 sp 3x7,
that I would prefer to keep, I like pedaling this lite weight bike.

There plenty of room to mount the motor, and keep the folding aspects,
can I still keep the 21 speeds?

The 48v 17.5 a battery will fit on the down tube just upstream from the motor.
See more info on this bike here:
https://www.montaguebikes.com/cx-com...ing-bike-2009/

Thoughts or suggestions,
Tia

2old

If you mean a BBS02 motor, you'll have only one chainring up front, ergo a 1 X 7 system. You may be able to fit a Microshift cassette, derailleur and shifter and have 11 X 46 gearing (AIR); about $75 for these components at Universal Cycle. This will increase your gearing range with one of the various 30 - 52 or so front chainrings available for the BBS02.