Thursday, 14 August 2014

Rebuilding bike.2

Bike.2 has a motor I got from Ebay from a company called "Germanladen". The motor and bike work fine, but I wanted to use the new two-speed wheel, and of all the bikes I could work on, I decided that this was my least favourite.

The spokes arrived today. So I read the expert view on building a wheel. You can see how complicated it is. But my view is, if someone else can do a task, then I can too.

I installed the key spoke, using a spoke washer. Then the next, and the next, until I'd installed all 9 of the first run. Then I took them out again, because I decided that the spoke washer was causing a problem. And installed them again.

Then I did the second run of nine, then the third and the fourth.

To install a spoke, you have to thread it through the hub hole, then bring it to the correct rim hole, and screw in a nipple; that attaches the spoke to the hub, and you can tighten the nipple to get the necessary tension. I managed to get one of the nipples inside the rim. The first time I did this, I took all the spokes out to get the nipple out. The second time I did it, I had nearly all the spokes installed. So I left it there. As a result, I'll have a slight rattle in the wheel. It adds character.

Then I put the wheel on the bike, and discovered that, although the forks are wide enough to take the hub, the forks get narrower after a couple of inches, and that fouls the hub, which means the wheel won't turn, which is a bit of a disadvantage in a bike. Ladysolly called dinner at that point, so I had a think while I ate.

After dinner, I went out to the Volvo, and got the jack out. It's a screw jack, used for lifting the car when you want to change a wheel. So, as you can imagine, it can exert a lot of force when you turn the handle. I put the jack between the forks (which I measured at 10 cm separation), and turned the handle, spreading the forks. You can do this with steel forks, which I have, but *NOT* with aluminium. I spread the forks about an inch, which reduced to half an inch when I took the jack out. I tried the wheel, that wasn't enough. So I repeated the process, spreading the forks even more. When I'd finished, I had forks that were 1 cm wider than before, and they weren't fouling the hub.

Next, I had to true the wheel; that means, making sure it doesn't have a wobble. To my great surprise, it was already true! So I went round the wheel tightening up each spoke by one turn, which left them nice and tight, and the wheel was still true.

So now bike.2 has a new motor and wheel. It weighs 12 pounds, which is  6 1/2 pounds less than the Germanladen wheel, and that's worth having, because I'm lifting this bike several times each day.

Tomorrow, I'll install the controller, throttle and other electronics. And then see how well it works.

1 comment:

  1. This is the single most useful blog post I have ever read. Am ordering the Xiong Da motor right now. Brilliant.