Bike Build Project

[Biggles]

Hi All

Seems what I have now is a useless bike for the want of a gearbox. This is my current bike.

http://www.proriderleisure.com/leisure/electric-bikes/e-wayfarer-electric-folding-bike-silver.html

In case you haven't seen my problem, my gearbox has gone and it seems my batteries are also on the way out.

What I do have is a frame I like and works well for what I need.

Using the frame as a new base what would you recommend I do. I am of course using this off road so not at all bothered about exceeding 250w. I am a bit chunky too :-(

I am an engineer by trade and need a winter project so this is right up my street, I just don't have the product and equipment knowledge.

Kevin

 

[Deleted member 4366]

Let's look at your motor problem first. You have the wheel off, so it's an easy job to check the gears. Just undo the six screws around the outside and you can tap it apart by banging on the end of the axle. It might be that you've had water in it, which makes everything rusty, in which case bearings have to be replaced. They don't cost much. If it is the gears, which is not that likely, you can get a new set for about £25.

These small folders often have very wide frames, which means that replacements are tricky. The width depends on which brake you have. The photo in the link seems to show both a disc brake and a servo hub brake, which is not possible. Can you tell me what you have or show me an actual photo?

All our normal component suppliers only stock the 135mm width motors and I don't know ant more powerful 150mm ones, though you can find your exact motor on Aliexpress for about £90.

The noise might be an electrical problem. When the controller doesn't get the right timing signal from the hall sensors (assuming a sensored motor and controller), you get exactly the problem you describe, which can be caused by something as simple as a bad connection or water where it shouldn't oughta.

Without upgrading the motor, you can still get a bit more power out of it, but you will have to change the controller under the battery. Andrew, the guy from Oxydrive has some rather nice 17aH batteries that will fit your bike. They're surplus Oxygen ones. You can find his number on the Oxydrive website. I think they're about £200 and should fit directly.

 

[Biggles]

Hello Dave

Thanks very much for getting back to me. Will I need to remove the gear wheel and brake asssy to dismantle the motor?

You say its unlikely to be the gears, but the motor is running turning the wheel backwards but with no real resistance. I can't see how it could be anything else but gears. Once apart would you be able to decide what the gears were and where to get them?

I have put some photos of my wheel here https://picasaweb.google.com/118423750983308708465/InstantUpload. The brake is a hub type brake. Pia Conde I think.

The width between my rear forks is 170mm. The crank tube seems to be about 78mm. The Bafang kits I've seen for a mid drive conversions seen to need a 73mm tube, but I recall seeing somewhere in my research a kit or adaptor that can got to 100mm. But that might not have been Bafang.

My current thoughts are to use a 500w middrive Bafang at 36v, I could then use my current battery, or now you have told me of the 17Ah one I could change it for that.

Is there any advantage of going to 48v? I have also seen a number of 48v hub motor conversions up to 1000w.These all seem to be brushless / gearless. Would the lack of gearing make it sluggish.

Lots of Q's I know, but it's the only way I'm going to learn.

Regards

Kevin