Converting an old bike to an ebike

For discussions about bikes and equipment.
GayUnicorn
Posts: 50
Joined: 11 Jun 2021, 10:44pm

Re: Converting an old bike to an ebike

Post by GayUnicorn »

Still looking at this and the idea of a kit that could be moved to a new bike is appealing.

Has anyone managed serious miles on the Chinese motors and batteries as the few spoken to seem to be the 10miles a week types.

Also are they sealed until worn out for repair or can you grease them?

The ones with pedals interesting over the hub drive ones.
Oldjohnw
Posts: 7764
Joined: 16 Oct 2018, 4:23am
Location: South Warwickshire

Re: Converting an old bike to an ebike

Post by Oldjohnw »

GayUnicorn wrote: 13 Jun 2021, 10:40am Still looking at this and the idea of a kit that could be moved to a new bike is appealing.

Has anyone managed serious miles on the Chinese motors and batteries as the few spoken to seem to be the 10miles a week types.

Also are they sealed until worn out for repair or can you grease them?

The ones with pedals interesting over the hub drive ones.

I do about 70-100 miles a week (several local utility trips plus one or two rides of about 30-40 miles) and in normal circumstances 3 or 4 camping trips averaging about 400 miles each. Mine is front hub drive and torque sensor. I live in hilly country.
John
Trikesnbikes
Posts: 39
Joined: 1 Apr 2020, 3:37pm

Re: Converting an old bike to an ebike

Post by Trikesnbikes »

Both the Bafang and Tongsheng bottom bracket motors are user serviceable. Look for YouTube instruction videos. Indeed, taking the drive side cover off and injecting plenty of grease round the drive gears from new makes the motors smoother and quieter but probably voids the warranty. The Bafang tends to be quieter than the Tongsheng. Spares such as bearings and clutch units are readily obtainable for the Bafangs and a little more difficult for the Tongsheng. I have covered several thousand miles on Bafangs on tandem trikes and hundreds of miles on Tongsheng on solo bikes and recumbent trikes.
Bonzo Banana
Posts: 413
Joined: 5 Feb 2017, 11:58am

Re: Converting an old bike to an ebike

Post by Bonzo Banana »

GayUnicorn wrote: 13 Jun 2021, 10:40am Still looking at this and the idea of a kit that could be moved to a new bike is appealing.

Has anyone managed serious miles on the Chinese motors and batteries as the few spoken to seem to be the 10miles a week types.

Also are they sealed until worn out for repair or can you grease them?

The ones with pedals interesting over the hub drive ones.
The majority of ebikes sold are hub based because of their lower pricing. The direct drive hub motors have no moving parts at all except for the bearings in the axle like any wheel. It's a brushless motor. Those hubs can last 10s of thousands of miles however replacing the sealed bearings can be time consuming.

The geared hub motors have a 3 planetary gears typically made of nylon that perhaps you would get 3 years of more of normal use as a minimum and then would need replacing.

I'd expect to get maybe 20k miles out of a direct drive hub before it needs much in the way of attention and perhaps 8k out of a geared hub but also whether the hub motor is fitted to the rear or front is a factor. The bearings in a front hub motor may last longer as there is less weight on that wheel compared to the rear.

If I was guessing at reliability for types of ebike motor I would have the following order of reliability;

1. Direct drive hub front
2. Direct drive hub rear
3. Geared hub front
4. Geared hub rear
5. Mid-drive motor

Huge benefits to hub motors as well regarding reduced wear on the drivetrain, chain, cogset, chainrings etc I've seen it stated they can last up to 3x as long typically with a hub motor. Also with regard front hub motors less strain the spokes etc as you don't have the riders own power and the motor power turning the same wheel and applying force to the same spokes. You are sharing the driving power between front and rear wheels which has benefits to road safety too although makes steering much heavier especially with a direct drive motor. Your arms may get more of a workout that most cyclists won't be used to unless they have a front basket that turns with the handlebars.

However in performance terms I think the best motor for normal weight cyclists on the road would be a geared hub motor and for off-road use it has to be a mid-drive motor if you are doing serious trails. Direct drive is definitely best for heavy cyclists just because its stronger and more abuse-able in my opinion.
GayUnicorn
Posts: 50
Joined: 11 Jun 2021, 10:44pm

Re: Converting an old bike to an ebike

Post by GayUnicorn »

Very interesting, talked to one of the local repair shop guys and I think they were generally interested.
One of them I believe was a helicopter or plane mechanic retired and seemed genuinely interested.

Kind of thing that appeals is a 40mile range with lights.

Interesting stuff and great to have a wealth of experience on the forum.
Post Reply