Saturday, January 26, 2013

It's Bucking Fuckled!

Wheel Balancing on the Cheap!
With new tyres fitted, I'm left somewhat skeptical as to whether the bike shop actually balanced them! I purposely removed the old weights and cleaned the rims before taking the bike down there because they often balance them with the old weights still attached. But now I have a bike with no weights on either wheel. Sometimes you can be lucky enough to get a wheel balance perfectly without weights, but two on the same bike? Hmm.

Enough is enough, it was time to make a static wheel balancer out of the scrap steel and wood hanging around the garage. The only cost to me was the bearings (608Z) which were $9.00 delivered for ten of them! Sorted. 
Now I'll be able to fit my own tyres and balance them for a lot less cost.

Make your own wheel balancer.

Here's a couple of bits of angle iron that a local firm let me have for nothing, four of the 608Z skateboard bearings, and the front wheel spindle from the GSX.

With a line marking the middle of the length of steel, I positioned the bearings so that they'd sit slightly proud of the edge and as close together, without touching, as possible. The razor blade was ideal to hold them apart. A quick dot applied with a permanent marker through the middle of the bearings and I was ready to centre punch the steel.

Couple of whacks with a hammer and we're ready to drill. Usual engineering practice, use a small pilot drill first and build up to the necessary 8mm required for these bearings.

Bear in mind that you want to be as close as possible to the top of the steel, without cutting through when you go up the drill sizes.

Perfect. Plenty of metal left for an 8mm bolt.

Now take your 608Z bearings and remove the metal shields. I'm using a pick. Although the photo shows me on the outside edge, it's actually easier from the inside lip. Don't push in too far or you will wreck the inner race - this I know from the first attempt! After the practice session with the first bearing I found it easy to sort the rest.

See the grease? For this purpose, it's better to wash it off. I used petrol and an airline to clean all of the grease out. We'll use WD40 as a lube because there's just too much friction with grease in there. 
The 8x1.25mm bolt with washers is how we'll attach each bearing. The washers serve as spacers to prevent the outer race binding with anything. Once bolted to the steel, it can be mounted to a length of wood and placed across some old boxes.

Cheap and easy!

Apply WD40 to the bearings and spindle once it's spinning, stand back and wait.

But how do I balance the wheel?

  1. Spin the wheel and let it come to a rest. Move it slightly and see if it tries to come back to the same point.
  2. Take a weight, stick-on or clamp type, and fix it to the highest point of the wheel. 
  3. Spin the wheel again and see where it comes to rest. If it comes to rest at the same point, it needs more weight where the first one was placed. If the weight you fitted stops at the bottom, it's too heavy. If the wheel stops in multiple positions, you have perfect balance.

Spinning the GSX wheel up on this apparatus soon shows up a slight buckle... f#$k! That's the secondhand wheel I bought to replace my original. Oh well, we'll see what it's like on the road.