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Soft AND Tender
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Discussion Starter · #1 ·
Will a wheel that is out of true affect the alignment of a disc brake rotor within the calipers? In other words, might the rotor rub the pad in the area that the wheel is out of true since it is pulling one side or the other? Or does the "trueness" not transfer itself all the way from the rim to the hub?
 

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carpe mañana
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cbratt said:
Will a wheel that is out of true affect the alignment of a disc brake rotor within the calipers? In other words, might the rotor rub the pad in the area that the wheel is out of true since it is pulling one side or the other? Or does the "trueness" not transfer itself all the way from the rim to the hub?
The rotor is attached to the hub, so it is not affected by the spokes/rim, anotherwords, the trueness of the wheel has no effect on the rotor itself. That being said, the rotor does come out of true itself.

_MK
 

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Premium Member
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48,238 Posts
cbratt said:
Will a wheel that is out of true affect the alignment of a disc brake rotor within the calipers? In other words, might the rotor rub the pad in the area that the wheel is out of true since it is pulling one side or the other? Or does the "trueness" not transfer itself all the way from the rim to the hub?
No, that is one of the advantages of disc brakes. If the rim is out of true, the brakes still work.
 

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carpe mañana
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7,308 Posts
dingleberry said:
If the rotor is out of true is there hope to beat or bend it back true? If so how? Is it time to shell out $30 and buy a new one?
Definatelly. If you really want to get serious, you should get the drumstix: http://www.utahmountainbiking.com/fix/diskrotortrue.htm.

A crescent wrench will do the job fine, however, most of the time. Just spin the wheel when it is on the bike, and the bike is upside down, and when you hear a rub, stop it, turn the wheel 180 degrees, or half of the revolution, so the bent area is as far away from the caliper as possible, put the disc inside of the crescent wrench and bend it the opposite direction of the bend in the rotor. It will take a little while to get a hang of it, but it is pretty easy to do once you had some practice.

_MK
 

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Carpe Noctem
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311 Posts
I have straightened many a rotor from minor warps to sharp, severe bends where the rotor wouldn't slide through the caliper without pads. The drumstix are a very good system that takes some practice to master and is best used with a dial guage and a Park TS-2 truing stand. The cresent wrench is a decent alternative to the drumstix and if you've got three of 'em they can work very nearly as well on sharp bends.

Most of the warped rotors I see are gradual and when viewing the rotor between the pads with the wheel spining slowly the rotor seems to meander from one side to the other. In these cases I find the trouble spot, pinch a spoke next to it(it is important to work the point of greatest deviation as exactly as possible), rotate the wheel about 180 degrees to be sure you're not fighting the caliper or bending the rotor anywhere else, drop a clean rag over the rotor and bend it by hand. Why by hand? because the steel tools mentioned before isolate the forces at the edges of the jaws and create small sharp bends and/or divots in the rotor face. If the warp is gradual fix it by hand, if it's severe or sharp use tools. Either way, it's better to make 5 small corrections than 1 large overcorrection. Be careful and patient.
 
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