Bicycle Mechanics - Hope Disc front hub.. spoke tension seems off...

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robo
10-01-05, 10:47 AM
Having just built my first wheel, i succumbed to the temptation to begin fiddling with my existing wheels. I guess, to a man with spoke wrench and truing stand, everything looks like a wheel that needs adjustment.. Or something :)

Anyway.. I have a front wheel that i got custom built by JensonUSA this summer. It's a Hope Disc front hub, with Wheelsmith DB spokes (14/15/14 i believe), alloy nipples, and a Mavic 717 Disc rim.

I haven't actually had any problems with the wheel, but decided to stick it on the truing stand and see how it looked. It turns out it was perfectly true, but when i plucked the spokes, the pitches seemed really low (around a G below Middle C on the disc side, and a dull thud on the non-disc side). The disc side has a slightly taller flange than the non-disc side, so some variation in pitch is to be expected, but as i understand it, a dull thud is not a good sign.

So, i started tightening up all the spokes, while trying to keep the wheel true. In the end, i had gotten the disc side to around middle-C, while the non-disc side is somewhere between an F# below middle-C and the same dull thud. There is a lot of variation in the pitches of the spokes - a lot more than in the new wheel i just built up.


Anyway, is this OK? Should i be concerned? Should i have left the tension the way it was when i got it from JensonUSA?


Thanks,

Robin


Retro Grouch
10-01-05, 12:11 PM
If it was my bike, I'd definitely redo it.

I assume that you really don't know how Jensen built the wheel. You do know, however, know how you build wheels. The worst thing that can happen is that, after you retension and retrue the wheel, it will fail. If that happens, you'll know that you did something wrong and, hopefully, learn from the experience.

robo
10-01-05, 06:52 PM
If it was my bike, I'd definitely redo it.

I assume that you really don't know how Jensen built the wheel. You do know, however, know how you build wheels. The worst thing that can happen is that, after you retension and retrue the wheel, it will fail. If that happens, you'll know that you did something wrong and, hopefully, learn from the experience.

So that basically means taking out all the tension and then re-tensioning and truing?


Retro Grouch
10-02-05, 07:05 AM
So that basically means taking out all the tension and then re-tensioning and truing?

Yeah. I'd back off all of the nipples until I could see just one spoke thread. Then I'd retension the wheel by tightening every spoke, no more than 1/2 turn at a time, until I brought it up to proper, even tension. That spoke head seating process that guys call "stress relieving", that's important too. Make your final adjustments for roundness and side-to-side wobble and you're good to go.