After breaking a couple of spokes on my ride home from work last week, I was faced with another opportunity to “true” a bicycle wheel.Anyone who has seen The Triplets of Belleville will probably recall a scene where one of the characters spins a racing bike’s wheel on a model of the Eiffel Tower, stopping the spinning from time to time to adjust the tension of a spoke.My own “truing stand” is simply my upturned bicycle. I have invested in a few tools – and spare spokes – after going through this a couple of times before. I do like to fix things, and if it makes economic sense, I will buy special tools as needed.For whatever reason, all the spokes I have replaced have been on the rear wheel of my Schwinn hard-tail mountain bike, so I often need to remove the cassette. The whole process usually goes something like this:

1. remove headlight from handlebars, so that I can turn the bike over and have it balance on the saddle and the bars
2. turn the bike over and balance it in a convenient location
3. remove the quick release spindle from the wheel
4. remove the wheel, pulling the chain out of the way and persuading it to stay to one side if possible
5. with the wheel removed, fit the special tool – rather like a socket wrench – to the locking ring that holds on the cassette
6. replace the spindle, since that will help the socket-wrench-like tool stay in place in the next step
7. fit the chain whip tool onto the cassette
8. use an adjustable wrench to turn the socket wrench-like tool, loosening the ring tht holds on the cassette
9. remove the spindle, and then the socket wrench tool
10. remove the locking ring, and the cassette
11. remove the tire, tube, and rim liner from the wheel
12. find the broken spoke, remove the pieces after having made note of exactly how that spoke fit into the whole pattern – which of its neighbors did it go over or under, etc.
13. fit the replacement spoke into position, insert the nipple through the hole in the rim
14. use a screwdriver on the flat end of the nipple to tighten up the spoke a bit
15. put the wheel back into place on the bike

This is where it gets pretty interesting, and crazy making.Think about the word “wheel” for a minute. What comes to mind? How would you articulate the concept of a wheel? It is unlikely that you will go very far without using the word round.If you are going to be a wheel you need to have a circular shape, sure, but it is just as important to be in one plane – to be flat.Making your bike wheel both round and flat is a very mechanical lesson in geometry. We have the very obvious circle, and then the plane, but there are triangles involved as well.Without a pencil and paper to sketch with, It may be a bit tough for me to convey where triangles fit in this. If you imagine having sliced a bicycle wheel in half, through the center of the axle, you can see the spokes drawing a triangle between where the spokes join the rim and each end of the hub.For the front wheel, this triangle is symmetrical, but on the back wheel , the two flanges of the hub are not the same diameter. So spoke lengths will vary.Back to the truing process.So our objective is clear enough – make the wheel flat enough that it doesn’t rub against the brakes as it rotates, without making the rim more egg shaped than round. Reaching this goal is a matter of “cut and try” – make a small adjustment, spin the wheel. Taking sight along the edge of the wheel as it spins helps. Repeat until it is all usable again.I have now run out of replacement spokes, so I think I will be buying a new wheel soon. This old wheel will become a backup.