How close do you true your wheels?

[bing!]

I was truing my USED wheels today. Ive been using a thin piece of paper as a feeler gauge to set the truing indicator close to the rim. If it doesnt rub on both sides then its set. Despite this, I still see a little wobble on the rim. Visually, it doesnt hit or rub on the indicator on the gauge.

Do I true it some more? The wobble is probably less than half an millimeter? Maybe even less than that. When is a used wheel "trued enough"?

Thanks.

 

[2wheel_lee]

When is a used wheel "trued enough"?

This is hotly debated in some forums.

The reality is that with disc brakes, true enough is when the tires don't rub the chain or seat stays, and with rim brakes, true enough is so that the brakes can be adjusted so they engage when you want and the rims don't hit the pads. That's as true as it needs to be.

You can make it as true as 0.125", 0.020", or 0.003" if you really have the skill and patience. You'll never feel the difference on the trail, as most tires can deviate more than any of the above specs.

 

[RustyIron]

A brand new wheel should be perfect. But before long, it's being subjected to intense sideways forces and getting bashed against rocks. After it starts getting dings, it's unlikely that it will ever be perfect again.

I keep close track of my spoke tensions as I try to pull the wheel back to true. If one side gets too tight, or the other too loose, I call it "good enough." You have to decide for yourself what amount of spoke tension inequality and runout is acceptable. If half a millimeter is the best you can get, I wouldn't worry about it.

 

[bing!]

I'm not particular about too much accuracy. I'm new to this, I just want to get to the point where it won't affect the bikes performance. 0.125 inch is too big I think. If I get it to .020" can I assume I'm good?

@RustyIron - youre right, its pretty easy to true the wheel, but getting the spoke tension approximately equal, and maintain a good dish, lateral and radial true is what takes me a while. Im currently setting spoke tension by feel. Will probably try a tone generator soon.

 

[HatTrick]

I shoot for 0.010" radially and laterally when I true but I am happy if ends up less than 0.020". I bought a new bike a couple months ago and the rear wheel had radial runout of 0.080" so I took it back for replacement.

 

[bing!]

I think I'll go buy these to see what I'm really doing. Thanks!

http://www.harborfreight.com/1-inch-travel-machinists-dial-indicator-623.html
http://www.harborfreight.com/multipositional-magnetic-base-with-fine-adjustment-5645.html

 

[2wheel_lee]

A brand new wheel should be perfect.

I know that you're technical enough to know that a wheel will not be perfect. Ever.
There will always be some deviation - even if it is ever so slight.

I try to get my road wheels pretty close. I don't have the dial indicator gauge setup, so I just get them about "that" close.
For my own DH mountain wheels, I'm not that critical, since the first ride will probably cause a ding or a flat spot, anyway.

 

[RustyIron]

You're right. I was playing fast and loose with the term "perfect." Is it too late to change it to, "pretty damn good?"
"RCH?"
Or perhaps, "DH," as my wife would say?

 

[chupacabra]

In any wheel, there are compromises. You may be able to get it very near perfectly true and very near perfect hop, but you may be sacrificing evenness in tension. On a MTB wheel, I find it most important it to get tensions as close as possible. For trueness I aim for less than .25mm and for hop less than .2mm. If I can get those numbers and keep the relative tensions close to 5% deviation from average, I am satisfied.

 

[2wheel_lee]

As chupacabra will likely agree, it also depends on the quality of the actual rim itself.

 

[chupacabra]

^^^^yep

 

[bing!]

In any wheel, there are compromises. You may be able to get it very near perfectly true and very near perfect hop, but you may be sacrificing evenness in tension. On a MTB wheel, I find it most important it to get tensions as close as possible. For trueness I aim for less than .25mm and for hop less than .2mm. If I can get those numbers and keep the relative tensions close to 5% deviation from average, I am satisfied.

Your response motivated me. I checked the tension on the wheel and found the drive side to have more tension than the disk side. One spoke also was also too loose compared to the others, however i compensated.

I backed all the spokes out and started anew. Its ok now. Will finish it up tomorrow.

Thanks.

 

[chupacabra]

Your response motivated me. I checked the tension on the wheel and found the drive side to have more tension than the disk side. One spoke also was also too loose compared to the others, however i compensated.

I backed all the spokes out and started anew. Its ok now. Will finish it up tomorrow.

Thanks.

Sorry for any confusion. The drive side on the rear will have more tension than the non-drive. The tensions should be compared on the same side of any dished wheel.

 

[bing!]

Sorry for any confusion. The drive side on the rear will have more tension than the non-drive. The tensions should be compared on the same side of any dished wheel.

Hey thanks for the pm and the tips. Its starting to all click in my cabeza now. I fixed the drive drive side tension.

While at it, it was able to work around the lack of a tensiometer. I started hitting the spokes with the back of a screwdriver and listening to the tones it makes. It helps that i can tune a guitar Getting the tones even on each side gets the wheel pretty close to true. I true from there and repeat steps as necessary.

 

[DirtymikeTDB]

I didnt read all the responces but here is my take on my wheels

Road bike...... Absolutly dead nutts perfect... No hop, no wobble...... Too much to go wrong.

Hardtail.....wobble is ok to a point... but no hops

BMX wheel.... Who cares, its just going out again anyways

XC bike disc brakes.... no hops, little bit of wobble acceptable, but as little as you can manage

xc rim based brakes..... Same as road.... perfection

dh/freeride....... not so picky other than I pick on my self on the job I do..... I still try to get as good as possible when I have the time to do so, but hops are more acceptable for FR and DH... you generally have six inches plus suspension, so a little hop wont bother the rider......