Bicycle Mechanics - Spoke tension / eyelets pulling out
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11-20-07, 02:57 AM
I've recently built a wheel.
The rim is double walled and single eyeleted.
It is a Kinlin cross country rim.
I put a lot of torque on the rear wheel everytime I ride.
I built the wheel with ultra high tension.
I am beginning to notice the eyelets are starting to pull out of the rim.
However, there is no cracking.
Is this normal, the eyelets pulling out a couple millimeteres from the rim?
Is there anyway to prevent the eyelets from pulling all the way through?
Should i relieve the tension?
Or am I bound to be buying a new rim?
11-20-07, 04:12 AM
When you say "I built the wheel with ultra high tension", what does that mean? Rims have tension specifications and if you are well beyond the specified maximum tension, you are asking for trouble. I would buy another rim and consider this a not so costly lesson. If you decide to ride this rim, make sure your health insurance premiums are all paid up.
11-20-07, 07:06 AM
When I say I built the wheel with ultra high tension, I mean that I made the spokes really tight.
I've done this before on a road wheel (ultra tight spokes) and the eyelets are still okay,
However this wheel, since I ride hard on it, I think is adding to the issue.
I am guessing eyelets should not come out even a little bit.
11-20-07, 07:21 AM
Ok - to clarify my concern and question. When I ask what do you mean by ultra high, I mean what Kgf measurement if you used a tension meter. Most wheels(but certainly not all) behave well with a Kgf of 100 - 120 on the drive side rear with the non drive a bit lower. I do my open pros at 115 and consider that to be my limit. I build off road wheels in the same range for the most part depending on the published specs for the rim.
My guess is that:
A. Your "ultra high tension " is to high for the rim and you have a dangerous risk of sudden failure. Probably not as big a deal on the rear as in front but I wouldn't ride it.
B. Your "ultra high tension " is within range of the spec but however you "put a lot of torque" into the wheel when riding, you are beyond the limits of that rim/assembly and need a tougher wheel like a Rhino Lite.
For the record, I weigh in at 225 and put a ton stress on my hardware. I have broken frames, cassettes and chain-rings but never wheels on my MTB. My road wheels are perfect since learning how to build my own. If you are pulling the eyelets out, there is something wrong with the build or you are simply trying to use components that are not up to the job for your particular riding style.
11-20-07, 07:31 AM
lymbzero, there is no way to quantify "ultra high tension" or "really tight".
rims are rated in kilograms of force (kgF). some rims are rated that you tension the spokes to 100kgF and other to 120 kgF.
the question is, what tension were the spokes on the kinlin rim and what does the manufacturer state that the rim _requires_ for tension.
on SOME rims, a few eyelets might not have been crimped fully and can lift off the roof of the rim a bit. this should be too big and issue _UNLESS_ you've set the tension of the spokes too high. if this is the area around the eyelets will soon fail.
borrow a tensiometer from a local shop and find out what exactly ultra high tension is......we need a number.
11-20-07, 09:14 AM
Ah, each rim has its own tension specification!
I guess in my ignorance I just thought any mountain bike rim could handle equal or more tension than a road wheel.
There is no good way for me to find out what the specific tension rating of this rim is since Kinlin doesn't have a website, or contacts for that matter.
As for the tensiometer, I may be able to find one, somewhere.
The rims are made of Niobium alloy, which (I think) is softer than most aluminum rims.
I guess the trade off is weight versus strength.
I will however own up to "simply trying to use components that are not up to the job for your particular riding style."
I guess next time I'll spend the extra cash on style specific parts. IE, trials / downhill rims.
I'll ride the wheel until it explodes.
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