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Is it true that the they twist small amounts as you hit bumps while you ride, and that's why they loosen? Would gluing spoke nipples simply solve this problem?

  • 2
    Maybe, but it would create a bigger problem if (when) you need to true the wheel. – mattnz Jul 1 '16 at 3:13
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    Isn't spoke prep just thread lock? – alex Jul 1 '16 at 3:17
  • @alex yes I have always thought it does the same thing. Blue thread locker simply degreases creep but doens't require heat to unlock. Red threadlock would require a blowtorch to head the nipple to true the wheel. – Criggie Jul 1 '16 at 3:25
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    I have never seen any evidence that "nipple creep" is a real problem in real-world conditions. Spokes loosen mainly because they stretch, and much of the "stretch" is due to the elbow straightening out. – Daniel R Hicks Jul 1 '16 at 12:24
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    During the dawn of downhill racing in Scotland we would build the wheels up, use red loctite, take them out and put some stress (jumps) on them and come back to the shop for a final true. It takes a while for loctite to activate in a hypoxic environment so we had a bit of time. Worked like a charm. – user26705 Jul 10 '16 at 7:27
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I have to say I think this is a myth, for a properly built wheel.

Spokes have threaded ends which the nipples screw onto. Like almost all screw threads, they are self-locking. Since the spokes of a properly built wheel are under a high level of tension, there is no "play" in the threads. In addition, any torque would have to overcome the high clamping force the nipple head is exerting on the wheel rim.

For the spokes to loosen, the load would have to deform the rim enough to relieve the spoke of all tension so that the nipple can turn. If the spokes are this loose they would readily flex sideways if you pressed on them.

There is some potential for spokes to loosen a little with a newly built wheel, if the builder has not relieved the spoke torsion. In this situation the torsion in the spoke shaft can overcome the clamping force, and wheel will go out of true in the first few km of use.

See

  • So to test whether this (spokes micro-unscrewing) could happen, you would have to put your weight on the bike + whatever gear you have (say if you're touring), and then have someone feel the tension on the bottom spokes? – Ryder Bergerud Jul 3 '16 at 1:49
  • To test whether the nipples are unscrewing, simply use a magic marker to mark one side of the nipple (after the wheel is trued a final time after break-in). If the marks twist around during use then the nipples are unscrewing. – Daniel R Hicks Jun 25 at 11:27
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As you ride, your wheel deforms slightly. This allows the spokes to vary in tension over the course of a revolution. If the nipple threads have play in them, then this cyclic weighting and unweighting allows the nipples to move.

You may be suffering from low spoke tension over the whole wheel.

Spokes twist when the nipple is tightened, which may result in a spoke that looses tension very quickly while riding, putting the wheel back out of true. Spoke prep helps get the nipple up to tension with reduced twisting of the spoke.

  • Yep. The spokes will twist, especially on the straight pull varieties. The standard remedy for an already built wheel is simple. Tighten the spoke a 1/4 more than needed, and immediately back it out a 1/4 turn. Aero spokes are held in place by a gizmo that slips over the flattened body. I just use an adjustable wrench to hold them in place. – user26705 Jul 10 '16 at 7:24

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