Tricky wheelbuilding Puzzle



Sam E-b

New Member
Jul 21, 2013
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Help!

I have a 40 spoke rear wheel of a tandem bicycle. I'm replacing the rim, which is bent after hitting a big pothole at high speed. It's a velocity fusion 40-spoke rim. This is the first wheel that I've built, though I've wanted to try this for a long time. (I'm using Sheldon Brown's website as my reference guide). It is a triple cross spoke pattern.

The problem I'm experiencing is that half of the spokes seem like they are too long! the problem spokes are the leading spokes from the outside of the flange on the drive side (shown in dark blue in Sheldon's diagram) and the trailing spokes from the inside of the flange on the non-drive side (shown in Yellow). When you go along the outside of the rim the pattern is: 2-spokes of the right length, 2 that seem to short, 2, 2, 2, all the way around.

I've checked 1000 times and the sequence of spokes on my wheel is the same as his diagram (trailing drive side, trailing non-drive, leading drive side, leading non-drive, in that order repeating itself the whole way around) and the pattern just LOOKS right.

BUT... Something's wrong.

The spokes are the proper length (again, I'm using the same spokes as before) the rim is the right size (700c). and I am TOTALLY BAFFLED.

Help?
 
Without seeing your wheel, the problem is that you have probably not "twisted" the wheel the proper amount before adding the first CROSSING spoke ...

  • LOOK at two adjacent spokes next to one another on the flange of either side ...
  • put a piece of tape on the rim at the nipple end of one of them ...
  • put a piece of tape on rim at the end of the other spoke ...
  • by MY count, there should be 13 spoke(-holes) between them.

If that is the case then you may need to unlace the hub & ensure that the correct spokes are being used for each side of the hub.

Posting some pics may be beneficial in analyzing what is wrong if THAT doesn't help you resolve your problem.