bikerbobbbb

For lateral and radial wobble, how much is acceptable?

I see this Park Tools gauge supposedly measures to the hundredth of a millimeter.
https://www.parktool.com/product/dia...-stands-ts-2di

I think I was around a mm while truing a wheel today. When I stopped looking so closely I couldn't tell there was a wobble from farther back. Kind of a, "What the hell am I doing?" moment there. Good enough for now considering I've spent more time on that than I anticipated. More true = Less wear and tear? On previous times, I'm pretty sure I found the spot where the rim was welded together because there seemed to be a little bump there, across from the rim hole, that couldn't be adjusted with the spoke nipples.

DOS

keithdunlop

According to Park, "acceptable" true is less than 1.00 mm laterally and .5mm radially.

Andrew R Stewart 

As mentioned in another ongoing thread here. 1mm for both is pretty close and if spoke tension evenness is worsened by closer run out then 1mm is good enough. Remember what's the neck of the proverbial hour glass. It's not a rim trued to 1mm... Andy

CliffordK

I'm sure it depends on the wheel and bike. For a 20" kid's bike with coaster brakes, maybe 1/8" or so.

@DOS is probably correct that 0.5mm is a good target, more or less for a road wheel. 0.25mm? I have had issues with a hop at the seam before, as @bikerbobbbb suggests. Sometimes touching the seam with a file will help.

My last truing, I got down to where I was seeing hop based on the right/left tension discrepancy of a dished wheel, so time to stop.

I'm still not great at getting perfectly even spoke tension, but as I get tighter tolerances, and ping the spokes, I think I can start getting more even tension.

mrrabbit 

As a standard for myself, I aim for + / - .002 inch.

Most wheels, whether it's basic and entry rims used, or high end rims, I can achieve this quite easily.

But often times, I'm compromising and sacrificing that and settling for + / - .003, .004 .005 up to .006

Reason is simple....relative tension between spokes each side is WAAAY more important than trueness.

Very rare is a rim that can be trued to + / - .001 or even .000 with all else well and equal. For most rims, trying to true a perfect wheel is to fight surface extrusion in the rim itself.

In other words, you're no longer truing the wheel...you're fighting surface defects.

"Hey molecule, get in line with the rest so I can have my perfectly trued wheel."

However, I will say that DT Swiss bare rims that are sold specifically for custom builds (not rims included in factory built wheels) are where I now most often see rims that can be trued in the + / - .000 to .001 ballpark.

DT Swiss bare rims for custom builds are simply top notch rims. DT Swiss quality is among the best, if not THE best.

=8-)

prathmann

I figure that one mm is good enough since I've rarely seen a tire that doesn't have a wobble of about that much. At one time I was running some 38mm wide tires that just barely cleared the chain stays and I had to deliberately untrue the rim so that the tire edge ran true enough not to rub.

mtbikerinpa

Most of the new rims that we get in my shop can be trued pretty darn close other than the seam. Sometimes I sand/file the seam smooth out of ocd. High performance wheels can get into the .001 or so range but even close to that is splitting hairs. If I get within .020 or .010" its usually good for most users. On my personal trail bike that uses discs, I really don't mind 1mm if the spokes are tensioned solid. Stability is far more important structurally than an imperceivable hop in a rock garden.

79pmooney

I focus a lot more on even tensions and round than the wobble. If the tensions are significantly uneven, it will be an ongoing challenge to keep tat wheel true. Get the tensions good and that is a happy wheel even if it bugs me to look at it. A lot of rims are out of round at the joint, so I will compromise there on being as round as I would like.

Ben

Gresp15C

Peripherally related to the thread, these days when someone tells me about wheel problems, my first step is to check their spoke tensions by plucking the spokes. It's good to have a realistic tolerance goal for wheel truth so that people don't panic over a perfectly good wheel, even if we hold ourselves to a tighter tolerance when possible.

For me, it's partly pride, and partly wanting to improve my skills. Also, when someone spins one of my wheels (I work in a building full of engineers), it needs to look as good as a good commercial wheel.

Retro Grouch 

The rim will determine what is possible.

Lower cost rims are made by coiling an extrusion and cutting through the coil with a saw. If they don't account for the saw kerf, the rim will always have a bit of a flat spot at the seam. No amount of fiddling with spoke tensions will replace the metal cut away by the saw.

JonathanGennick 

I think you did well. (I've only built eight wheels so far, so take what I say w/that level of inexperience in mind). Forum posts used to have me convinced I needed to chase crazy tolerances, but real life experience has me thinking that less than a millimeter and even tensions are a better goal. If I can hold the wheel in my hands and spin it and not notice anything, then I'm probably going to be happy. I like to think I'm at about the 1/2 mm level on my most recent build. I'm just eyeballing the indicator gap though, so can't be precisely certain of the gap size.

Hoopdriver

If I achieve <1mm with good tensions, I quit. In most cases, tires will wobble more than that.

Kovkov

ThermionicScott 

My truing stand isn't set up to measure radial or lateral wobble, so I don't true to any particular numbers.

What I'll do is true until slight movement to the calipers in and out result in either silence or a cacophony of clicks and scrapes that are too frequent and small to fix. I'm sure that's well below 1mm, but again, I don't have exact measurements.

As with others above, some rims (even premium-priced ones) have forced me to compromise a little on even tension or true, to keep one or the other from being horrible. The good news is that those wheels have been perfectly fine on the road, and only bug me when I have them on the stand with the tensiometer out.

fietsbob

On the road when I broke a rear spoke (1 out of 48, it was not significant),
I re-trued it to not touch the brake pads, and rode on
to where I could take off the gear cluster and replace the spoke,
with a spare I had with me..
then re trued it again.. to be like it was originally..

sweeks

Rim truing tolerance is more critical with rim brakes, obviously. With discs (or coaster or roller brakes) it's probably more a matter of esthetics.

fietsbob

Or obsessiveness.. lots of that expressed here..

Mrrabit sells the wheels he builds , so he meets and exceeds what customers require..

sweeks

[QUOTE=fietsbob;20664636]Or obsessiveness.. lots of that expressed here..
Hahahaha! And what's expressed is probably just the tip of the proverbial iceberg.

davidad

I shoot for .5 mm in both directions.

WizardOfBoz

Mr. Rabbit, I was going to say that's nuts, but...

Ok, when you've done something that many times, and you apply yourself, I guess you get good at it. I doubt anyone riding today would notice the difference between 0.002 and 0,004 inches (that's 0.05 and 0.1mm, btw). So this variation is way below the noise level of other stuff in biking. But if you can do it, great!

The other info in your post (specifically, that consistent spoke tension is as important if not more so than 0.001 or 0.002) was useful. Thanks!

nfmisso

exactly - and drum brakes.

I like my brake pads close to the rims, I just like the feel - so I go for even tension and tight tolerance. I can achieve ±.003" reliably on Velocity rims, not quite as good on Sun CR18 rims.

sweeks

My preference as well. It's more than just "feel" though... it's less frequent adjustment. :-)
(Roller brakes are drum brakes)

HerrKaLeun

Radial and lateral truing and equal tension all have to compromise. I usually get both truings to way under 1mm while keeping tension very even. If I get true to much under 1mm I lose some tension equality.
This is based on guesses since it is hard to measure 1 mm gap, I basically go by having "almost no gap". I notice that lateral trueness is limited by the decal sticker. I end up having it so true that the feelers just hit the sticker.

I noticed for new wheel with quality components it is easier to accomplish. i once trued Walmart steel rim wheels... let's not even go here.

For structural integrity I assume equal tension and radial trueness are more important than lateral trueness. Especially with disc brakes I'd be comfortable with 1mm out of lateral true if radial and tension are perfect.

In the end the tire is not perfect either.

It is an iteration. I start by getting it about lateral true and dished, then radial, then check tensions, adjust lateral and radial trueness and dish, then tension again..... and so on.

JonathanGennick 

Hah! I'm glad I'm not the only one who has encountered that issue.