A Wheel Re-build Problem

Pupa in Italy has tried to re-build a rear wheel, which is very brave and a great thing to learn to do. There is a problem though and help is needed, the spokes seem to be too long and too short on one side. Here is the answer

Question:
Hi Samuel. I think I need your help. I bought a 32 paired spoke rim wheel recently and changed its hub to one equipped with Campagnolo cassette. I rebuild the wheel and managed to have it fairly true round and dished. The problem is this: the right side spokes were all protruding quite evenly from their nipples but the left side ones seemed to be one too short one too long in an alternate fashion. I’ m pretty sure there’s not any lacing error, so I’m thinking to build the left side with two different length spokes, which is not so “natural” but I really can’t figure what’s wrong with this wheel. The new hub was the same dimensions as the old Shimano one so the spokes were the right length too. Any suggestion? Thank you.

Hi Pupa,

Well done trying to rebuild a wheel, the first time can be difficult and scary, so good for you. It sounds like you have rebuilt the left side wrongly by one hole. This would cause each alternate spoke to be too short and too long. Leave the right side as it is as it sounds all correct. Take some of the spokes out of the left side and try the spokes again by replacing the spokes one hole further towards one of the shorter spokes, one way or the other. If you go the wrong way then it will be very short and probably won’t reach the nipple and if you have gone the other way the spoke will be far too long and you will be able to tell right away.

Also take a look at the spokes; do they cross over below the valve hole? If so, then they are wrong. No wheel should be built with the spokes crossing at the valve hole, if they are like this then you need to move the spoke pattern round by one hole in the hub, this should sort it all out.

If this doesn’t cure your problem then it might be a good idea to start again from scratch, if the rim is the same and they are the old spokes, then everything should go back the same way as it was before. Well done and good luck.