Originally Posted by
bobonker
I'm having a problem with set of custom wheels that I bought. I'll have to dig up all of the specs, but the rims are 25 mm deep with Sapim bladed spokes 20 front and 24 rear.
The front goes out of true frequently (I've had to true it 4 times now) and every time I check it, its one (always the same one) spoke that has lost some tension. I tighten it back down, the wheel goes back to true, but it keeps happening. Should I overtighten the problem spoke and then pull it back to true by adding more tension to the opposing spokes?
Ideally you'd only do that if that spot is farther from the hub than the rest.
The rim may have a slight bend or thickness/other stiffness variation (often at the joint) in it which requires that spoke to be looser than the rest. This can come from damage or imperfect manufacturing.
If the rest aren't as tight as they should be, that spoke may not be tight enough to keep the nipple from turning. You might check spoke tension (with a tension meter, of which the Park TM-1 is the only model with a consumer friendly price tag around $50) and aim for a reasonable 110kgf average.
You may need to compromise on radial run-out to get enough tension on that spoke (tighten both it and its opposing members even if they aren't low). It takes a lot of error to be noticeable so that's probably OK.
You may have put too big a bend in the rim running over a road obstacle to keep it true without loosing spoke tension. If that's happened be glad you have custom wheels with off-the-shelf rims that are readily replaced (use the same spokes).