Bicycle Mechanics - Wheel truing and winter temps

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View Full Version : Wheel truing and winter temps


naisme
01-21-04, 12:08 PM
Any guess on how the real cold affects spoke tentions? I've trued the front wheel, for a bike I ride most everyday (commute) and I had to true it again last night. I also broke like the 5th spoke on the damn thing. It is getting to be annoying.

I've taken it all the way back to a couple turns showing at the nipple and then went through every spoke tightening them a little at a time, until the wheel was round then went to true, checked the dish, the round and got it spot on. I even added a 1/4 twist to the spokes to make sure they were tight. (this is the third time I've trued this wheel)

This should do it, right? I'll know tonight as it will be in the sub-zero temps when I ride for home.

Any idea what I might be doing wrong?


sch
01-21-04, 06:57 PM
Are you sure you are releasing all the torqued tension
on the spokes? As the linear or radial tension on the spokes builds up they tend to twist when the spoke
nut is turned and this is slowly released when riding such that the wheel drifts out of true. In the old days of pure aluminum rims it was easy to bounce on a rim and let the spokes ping and pop to get rid of twist. Spoke prep helps by making the threads slippery. By
bouncing I mean put the rim on the floor vertically like it is on the bike and lean on the rim with both hands and
bounce your full weight on the rim, rotate the rim a few spokes and repeat. You should hear some pings as the
spoke torque relaxes. Repeat until you have gone around the wheel 2x. On heavy cross section aero rims the assist of a 200# + person may be needed. Temperature should have very little to do with trueness of the wheel. Steve

Jay_2004
01-21-04, 07:48 PM
have you actually tried lossening them 1/4 of a turn.....this can take most the twist out i think....


Rev.Chuck
01-21-04, 09:36 PM
If you have broken five spokes, that is a sure sign the spokes are fatiguing out(Or the wheel was poorly built) I don't reccomend detensioning and retensioning a wheel unless you have an issue like several broken spokes at once from stuffing the der into them.
Stress relieving while tensioning/trueing is a good idea. Squeezing the spokes together works OK but I prefer to brace the wheel against my forearms(Like holding a steering wheel) and stomach. Then flexing the area at my hands(furthest from my stomach) up. You have to be caeful as this is also a good way to taco a wheel.

naisme
01-23-04, 09:58 AM
Are you sure you are releasing all the torqued tension
on the spokes? As the linear or radial tension on the spokes builds up they tend to twist when the spoke
nut is turned and this is slowly released when riding such that the wheel drifts out of true. In the old days of pure aluminum rims it was easy to bounce on a rim and let the spokes ping and pop to get rid of twist. Spoke prep helps by making the threads slippery. By
bouncing I mean put the rim on the floor vertically like it is on the bike and lean on the rim with both hands and
bounce your full weight on the rim, rotate the rim a few spokes and repeat. You should hear some pings as the
spoke torque relaxes. Repeat until you have gone around the wheel 2x. On heavy cross section aero rims the assist of a 200# + person may be needed. Temperature should have very little to do with trueness of the wheel. Steve
What I usually do is lay the wheel on the floor and hold one side with my knees and the other i lean into with my arms, I've had a couple pop when doing this, and I turn the wheel. This is exactly what I didn't do to this wheel when I finished truing the last time. But, I don't think that one spoke would have loosened so many spokes, unless the integrity of the rim or wheel was compromised in some way. There were a lot more than a few loose. That is why I de tentioned everything and rounded it then trued it, and "popped" it. It was just unusual to see, and a bit unnerving to find out after having ridden on the wheel 150 miles.

Would a fork being out of align mess with the physics of a wheel enough to throw it out of alignment?