breanach8

Noticed that my back Mavic is running true but about 1.5mm out of roundness. So is this an acceptable amount? Is it best get it seen too or wait for next service?

The road around here are very rough so it's understandable they may need attention once in a while!

Bill Kapaun

How OCD are you?
Is the "spot" opposite of the valve stem at the rim joint?

cny-bikeman

It's not the amount that's important but the cause. A long progression to a high or low spot is not as important as a small area that's affected. The latter could be a few spokes that are significantly lower/higher tension than the rest, or if a low spot an indication of rim damage (and looser spokes).

breanach8

My OCD is bad, very bad!

Is a nice smoot difference. Nothing like a bad high or low spot overs few inches.

dbg

Is this 1.5mm observed on a rim (no tire mounted) in a truing stand? 1.5mm seems pretty small and probably within a margin of error for tire/tube/rim seat variation.

cny-bikeman

If it bothers you get it fixed. Roundness is more difficult to correct so better to get to it sooner, and you may need to have the spokes properly tensioned anyway.

UnsafeAlpine

If you're noticing the difference with the tire mounted, make sure the tire is seated all the way around the wheel.

dsbrantjr

"If you're noticing the difference with the tire mounted, make sure the tire is seated all the way around the wheel."

And that the tire itself is not the source of the out-of-roundness. I have seen many tires with that magnitude of variation.

breanach8

Not in the tyre, def on wheel.

bobotech

Good lord, 1.5mm and its not a flat spot then forget about it, you won't feel it. And if you think you feel it, then you are just being anally OCD and need to just put it out of your mind.

However if the high/low spot is a flat spot caused by damage to the wheel, then you might notice it and that might be needed to be looked at but I doubt it. I ride on a mavic wheel that was in an accident and has a flat spot. Used a pair of saw horses and a 2x4 and banged the dent out as much as possiible. When riding on it now, you still can't notice it but the flat spot is definitely still there.

fietsbob

open the wallet , brand new wheel hand built starting with a perfectly round rim, and don't complain about the cost.

Andrew R Stewart 

My answer is "it depends". First is the condition of the high/low points as others have mentioned. Second is the tire, not whether it's seated well (which is a factor of course) but what is the profile of the tire. If you're running a skinny 20mm wide thing pumped up to 140psi then a 1.5mm out of round might be felt. But if you're running a 38mm pumped to 70psi I'd be surprised if you could tell when riding. The puffier the tire gets the greater it's being not perfectly even as well, given good seating.

For those of us who build wheels a 1.5mm out of round is pretty large an amount, but not unheard of, for a new build up. Whether it's too much depends on a bunch of factors that are controled by the parts used, the dimensions of the rim, the number of spokes (one reason i like building 48* tandem wheels, with that many contact points you can make the wheel pretty true compared to a 28* one) and the need for close tolerances given the tires and terrain.

If you can't feel the out of round when riding and the spokes are well/evenly tensioned I say you've found the tolerance that you can live with, or not. Andy.

FBinNY 

Not counting the OCD factor, what matters is the effect. There are two considerations:

1- can you feel it riding? Generally a small radial difference spread over a large area (egg shaped) won't have any functional effect.

2- is it bad enough to cause a large local difference in tension? If there's small a radial error but the tension is still fairly even, then it's moot. OTOH, if there's a large tension difference in the affected area, and balancing the tension makes it worse yet, then it should be dealt with, but that can be an involved process.

In most cases a small radial error in a wheel (not caused by a crash) is something best left alone. When dealing with stuff like this consider that this is a bicycle, not a spaceship.

marqueemoon

That's more than I would ideally want, but if you can't feel it while riding and the pads are still fully contacting the rim at the high/low points I wouldn't sweat it.

gmt13

It's more than I would accept if building up a new wheel; however I doubt that you could feel it when riding. If you feel the wheel was well built to begin with I would say forget about it and ride on.

-G

breanach8

Thanks Guys. I really have to get my OCD under control!

And dont get me started on scratches!

I can in NO way feel it riding. I am swapping them out onto my brand new Madone on Friday, so my OCD can rest easy, for a while!

Bill Kapaun

It's the kind of thing I might try to "clean up" a bit IF I had the wheel off the bike for other service and wasn't in a hurry to get things back together.
I certainly wouldn't go out of my way to mess with it.

bobotech

Thank you for the signature quote.

Weird, I added your quote to my signature and saved it but it isn't showing up.

GamblerGORD53

I sure would not leave it that bad on an otherwise good rim. I have a 1 inch wide flat spot on a wheel with the same 1.5 or 2mm dip. I can feel it plenty on a smooth road. It is livable, but not that hard to rectify either. I wouldn't worry about spoke tension. If it's a hump then tighten the center spoke a half turn and the neighbors a quarter and maybe the next ones a bit.

I finally figured out the best method is a piece of electrical tap accross the frame, touching the rim. Rock the wheel back and forth watching the tape flutter. Tighten where it moves the most. I built two Dyad wheels last spring. I'm sure I got it to a few thousandths on the round and used nylock nipples to keep it that way. And yes I have seen tires spoil the efforts. My other wheels have always gone wobbly over time, spending hours on them every tire change.

FBinNY 

That's because I have trademark and copyright protection on it.

FBinNY 

Bicycles are like impressionist paintings, most beautiful if you don't look too closely.

bobotech

can I have your old stuff? LOL

I actually love the extreme ocd guys. We at our bike co-op get lots of good stuff that ocd people just give up because it quite isn't perfect. Wheels with a slight ding in them, shifters that are scuffed, outdated stuff, etc. If it wasn't for you guys, we would not get so much nice stuff!

osco53

I like my Sram X7 twist shifters more now that I got to Ride a bike upgraded with X.0's,,,The owner and his OCD swear they are so much better..

They shifted just like mine,,lol

zacster

Roundness is better than square. Square wheels are a real pain to get going.

Wil Davis

Yup, tell me about it!





- Wil