Different tension on one spoke

Question

I was plucking at the spokes of my rear wheel today which has an asymmetric lacing pattern. It's 2 spokes (both tangential to the rim) on the drive side along with a single spoke on the non-drive side. There are 7 of these triplets spread across the rim.

So in one pair of DS spokes, one spoke had a dramatically different pitch than the other spoke in the pair. This spoke also felt a tiny bit looser when pushed on.

Spinning the wheel and using the brake blocks as a reference, the rear wheel is slightly out of true. There is some lateral bias - but the runoff looks pretty tiny. Definitely not an issue even when running brake pads very close to the rim. This to me suggests that this should not be an issue. Blame me for being paranoid regarding an expensive wheelset that's almost brand new.

In any case, what are the chances of having this loose spoke pop in the future? Should I bring the wheel into a shop and ask for a truing? Do all shops check for even spoke tension at the end of a truing? I've heard of people who got their wheels trued only to end up with a cracked rim shortly afterward or popped spokes - presumably because the mechanic didn't bother to check spoke tension.

Answer 1

The spoke most likely to "pop" would be one of the other two in the triplet as they have to take more of the strain (making up for the loose one). If your wheel is still true, just tighten the nipple of the loose spoke until it sounds the same as the others. Do it gradually while checking this is not affecting the wheel trueness.

Answer 2

You have a brand new wheelset which is within 0.05mm of true yet has wide variation in spoke tension.

Because the wheel is true it probably means that when the wheel was built attention was not paid to balancing the spoke tensions. That is a sign of low quality wheel building.

Tension among all spokes should be +/- 5%. Or course on the rear wheel the DS and NDS may use different tensions, as much as 40% difference.

You should at least take it back to your point of purchase and see what they have to say.

Finally this year I tired of constantly truing my 16/24 bladed spoke lightweight wheels, and purchased 32/32 round spoke medium weight wheels with Velocity A23 rims from a local wheel builder who offered a lifetime guarantee of wheel tuning. Nice - the spokes all came with balanced tension, and the wheels are solid meaning I never have to true them - except when I ran into a crevice, scraping the rims and flatting a tire. Still, barely out of alignment, but the wheel builder tuned it up anyway - nice guy. Much better than dealing with a faceless company. And oh yeah - these reliable wheels were one half what I paid for the unreliable ones.