# Wheels: How true is true enough?



## dinga (Oct 23, 2015)

I bought a used wheelset for my road bike and they do not seem to be true. When I apply the break a little bit, I can see the rim is touching the break pad unevenly. I don't have a way to measure, but my guess is the rim is off at least as much as 2 mm. 
Is it something I need to worry about? My average speed on flat road is 20 mph.

If indeed the rims of both the front and rear wheels are 2mm off, what might go wrong? 
Would it damage the wheels further?
Would it be unsafe to ride in high speed (20+ mph)?
Would it go not as fast?
How true is true enough? 2mm off? 1mm off, or less than 1mm off?

How much would it cost to make them true from a local bike shop?

Many thanks.


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## cxwrench (Nov 9, 2004)

dinga said:


> I bought a used wheelset for my road bike and they do not seem to be true. When I apply the *break* a little bit, I can see the rim is touching the *break* pad unevenly. I don't have a way to measure, but my guess is the rim is off at least as much as 2 mm.
> Is it something I need to worry about? My average speed on flat road is 20 mph.
> 
> If indeed the rims of both the front and rear wheels are 2mm off, what might go wrong?
> ...


Why is this such a challenge for so many people? They're *brake* pads. 

Most wheel builders shoot for a fraction of a mm in both lateral and radial runout. If it's a mm or 2 you won't crash, but it will most likely get worse over time.

Speed shouldn't be a problem. 

How much will it cost? Dunno, maybe you should ask your local bike shop instead of people here that have never been to that shop. When I true a wheel the labor charge starts at $20.00 and goes up depending on how long it takes.


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## dcgriz (Feb 13, 2011)

@dinga



> If indeed the rims of both the front and rear wheels are 2mm off, what might go wrong?


If your wheels are that much off, most probably you have drastically uneven spoke tensions. This will eventually lead to broken spokes.



> Would it damage the wheels further?


Yes, see above



> Would it be unsafe to ride in high speed (20+ mph)?


Could be. Specially if you have one of these low spoke wheels and one breaks off. 



> Would it go not as fast?


Obviously not.



> How true is true enough? 2mm off? 1mm off, or less than 1mm off?


True enough is at 0.1mm with a true rim. Some rims are not as true as others so some wobbling may be inevitable.


As cx said the cost of truing depends on the shop. However, you do not want JUST truing. You need truing and stress relieving and equalizing tensions. At a wobbling of 2mm more than just truing is going on.


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## nsfbr (May 23, 2014)

I wouldn't ride wheels that were that untrue. Then again, I'd just true them up. If the are just out of tru but the spokes are not completely out of whack tension wise, this should be a 5-10 minute task per wheel. If you needed to loosen everything up and start over, it is more like 30 minutes to an hour _depending on the person doing it_. I would take about an hour, and that is because I'm slow. I can't imagine it taking anywhere near that long if someone who did this for a living was doing it.

When I'm done the imperfections around the weld on the rim is usually what touches the finger in the stand, so it is well within a half a mm laterally and radially. When I was learning I used a 0.003" shim to test myself. I think that was overkill.


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## dgaddis1 (Sep 27, 2008)

dcgriz said:


> True enough is at 0.1mm with a true rim. Some rims are not as true as others so some wobbling may be inevitable.


If we're talking about total runout (farthest point to the left, all the way over to the farthest point to the right), and you're using a dial indicator to measure, then 0.1mm is a little crazy IMO. And with lots of rims (especially disc brake rims) it's not even achievable. And even if you think you have it that close, flip the wheel over and measure the other side of the rim. The rim width likely isn't within 0.1mm. Then there's the whole issue of the seam...

Plus, the wheel is going on a bicycle where the frame and fork are flexing, the tire casing is flexing, and you're riding on a road that's nowhere near 0.1mm from perfectly smooth. It doesn't need to be that true, and chasing that number isn't worth the time needed.

I build to 1/4mm for lateral runout. Sometimes it's less though, this DT Swiss TK540 rim (which is a beefy welded touring rim with a machined sidewall) came out at 0.11mm - https://www.instagram.com/p/BBKmb_cypuq/?taken-by=dgaddis12


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## dcgriz (Feb 13, 2011)

@dgaddis

Lateral trueness target at 0.1mm is doable with the right rim and the right number of spokes and the right amount of time. My absolute max limit on lateral trueness is at 0.2mm. Either will be more evident to the builder than to the rider. I had some rims that could not be tamed while maintaining relatively equal spoke tensions; I dont use these makes any longer and I dont do 24 spokes or less.


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## Mike T. (Feb 3, 2004)

dcgriz said:


> @dgaddis
> 
> Lateral trueness target at 0.1mm is doable with the right rim and the right number of spokes and the right amount of time. My absolute max limit on lateral trueness is at 0.2mm. Either will be more evident to the builder than to the rider. I had some rims that could not be tamed while maintaining relatively equal spoke tensions; I dont use these makes any longer and I dont do 24 spokes or less.


When I build wheels for others (which is rare) I get them more true than when I build for myself because I know that there are other things more important than ultra-true - and that is, equal spoke tensions (or as equal as possible while providing acceptable trueness). That plus sufficient over all tension.

For most people, wheel wobble (or lack of) is their only way of qualifying a "good" wheelbuild and no matter how much you tell them that tension equality trumps trueness, they still have a skeptical eye. That's why I spend more time on them going back & forth between equal tension and true.

I don't measure runout on my own wheels anymore (I do have a dial indicator truing setup). Close is close enough.


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## dcgriz (Feb 13, 2011)

Mike T. said:


> When I build wheels for others (which is rare) I get them more true than when I build for myself because I know that there are other things more important than ultra-true - and that is, equal spoke tensions (or as equal as possible while providing acceptable trueness). That plus sufficient over all tension.
> 
> For most people, wheel wobble (or lack of) is their only way of qualifying a "good" wheelbuild and no matter how much you tell them that tension equality trumps trueness, they still have a skeptical eye. That's why I spend more time on them going back & forth between equal tension and true.
> 
> I don't measure runout on my own wheels anymore (I do have a dial indicator truing setup). Close is close enough.


I agree that equalizing tensions, even at the expense of truing, is paramount in keeping the wheel together. As I mentioned earlier, some rims are not true to begin with so a compromise between truing and equalizing is inevitable and necessary to enhance the wheel built quality and longevity. 
When I build my wheels I strive to be as precise as possible. It's not because I have to but more because I want to. I believe I mentioned earlier that after a certain point of precision the effects are more about the builder's satisfaction than about the rider. Time spent building them is not a concern because building wheels is a hobby to me. So, I'm aiming for the 0.1mm mark. If I was to build wheels for others, I guess lateral trueness to 0.2 mm most probably would have been the sweet spot between quality of the wheel and labor cost to build it.


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## Lombard (May 8, 2014)

nsfbr said:


> When I'm done the imperfections around the weld on the rim is usually what touches the finger in the stand, so it is well within a half a mm laterally and radially.


Hmmm. If this is a guide to "true enough", does this indicate that I've been too fussy? Sometimes I'll hear that "dink, dink, dink" against the weld, but if I close the fingers just a tad more, I'll find another slight imperfection to adjust. The truing stand definitely amplifies imperfections and I can get quite obsessive.


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## changingleaf (Aug 20, 2009)

Are you saying that one brake pad touches the rim before the other? If so, then your calipers most likely need to be rotated so that they are centered around the wheel. If the wheel looks like it is closer to one side of the frame or fork then the dish of the wheel is off - meaning the rim is not centered with respect to the hub.


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## Lombard (May 8, 2014)

dcgriz said:


> @dgaddis
> 
> Lateral trueness target at 0.1mm is doable with the right rim and the right number of spokes and the right amount of time. My absolute max limit on lateral trueness is at 0.2mm. Either will be more evident to the builder than to the rider. I had some rims that could not be tamed while maintaining relatively equal spoke tensions; I dont use these makes any longer and I dont do 24 spokes or less.



This brings up an issue I had trying to "tame" an older Velocity Dyad wheel off a used bike. No matter how hard I tried, I could not get what I considered an acceptable compromise between true and equal spoke tensions. I even loosened all the spokes all the way and "rebuilt" the wheel. If spoke tensions were acceptably equal, wheel had a bunch of tiny hops. If the wheel was acceptably true, there were spoke tensions that were off by at least 5 graduations on the tensiometer. To make things more difficult, the disparities were rarely in between adjacent spokes.

Is this a junk rim at this point? The rim looked round to the naked eye when the spokes were slack.


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## dgaddis1 (Sep 27, 2008)

Lombard said:


> This brings up an issue I had trying to "tame" an older Velocity Dyad wheel off a used bike. No matter how hard I tried, I could not get what I considered an acceptable compromise between true and equal spoke tensions. I even loosened all the spokes all the way and "rebuilt" the wheel. If spoke tensions were acceptably equal, wheel had a bunch of tiny hops. If the wheel was acceptably true, there were spoke tensions that were off by at least 5 graduations on the tensiometer. To make things more difficult, the disparities were rarely in between adjacent spokes.
> 
> Is this a junk rim at this point? The rim looked round to the naked eye when the spokes were slack.


What's the magnitude of the tiny hops, aka how tiny are they?


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## Lombard (May 8, 2014)

dgaddis1 said:


> What's the magnitude of the tiny hops, aka how tiny are they?


"Tiny" in the sense that they are not "waves". I can't say in mm, but large enough to look bothersome.


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## dgaddis1 (Sep 27, 2008)

Is it just the top edge of the brake track, or the outer edge of the rim itself?

Is the tire bed reasonably round?

Without seeing it it's hard to say what to do. When in doubt, cut the spokes and lace up a new rim.


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## Lombard (May 8, 2014)

dgaddis1 said:


> Is it just the top edge of the brake track, or the outer edge of the rim itself?
> 
> Is the tire bed reasonably round?
> 
> Without seeing it it's hard to say what to do. When in doubt, cut the spokes and lace up a new rim.



Hmmm. Sounds like the rim may be toast. Hubs are good Tiagras. No wonder the bike was so cheap. That may be a good project for next fall/winter.

Or I could just true the wheel, uneven tensions and all and ride them into the ground i.e. until a NDS spoke breaks for lack of tension. These are 36 holers, so if I break one, 35 will certainly get me home.


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## dcgriz (Feb 13, 2011)

Lombard said:


> This brings up an issue I had trying to "tame" an older Velocity Dyad wheel off a used bike. No matter how hard I tried, I could not get what I considered an acceptable compromise between true and equal spoke tensions. I even loosened all the spokes all the way and "rebuilt" the wheel. If spoke tensions were acceptably equal, wheel had a bunch of tiny hops. If the wheel was acceptably true, there were spoke tensions that were off by at least 5 graduations on the tensiometer. To make things more difficult, the disparities were rarely in between adjacent spokes.
> 
> Is this a junk rim at this point? The rim looked round to the naked eye when the spokes were slack.


Some rims are like that and nothing anyone could do about it! I had a Deep V that was like that. No matter what I did it wasn't getting trued to where I wanted it to be if I was to keep tensions relatively equal. On top, I had a hop at the joint because it was not evenly jointed. 
On the bright side, as awful as it looked, it worked fine on a 32 Ultegra. I still have the set and has not given me any trouble other than annoyance of not being where I want my wheels to be.

On your Dyads, 5 graduations is a football field. Throw the darn thing away and build yourself another wheel for heaven's sake.


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## Lombard (May 8, 2014)

dcgriz said:


> On your Dyads, 5 graduations is a football field. Throw the darn thing away and build yourself another wheel for heaven's sake.


Thanks DC. It sounds like another new wheel build is in my future. What rim would you recommend for a rim brake hybrid/touring bike - a 36 holer I could lace to my existing Shimano hubs? I was looking for a box type rim around 19mm internal width in the 500-600g range. Something robust, but not ridiculously heavy like a Ryde. DT Swiss TK540 looks like a possibility, but it's only 18.2mm. And although I am a bit shy about going with Mavic, the A719 is probably one of their better offerings.


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## dcgriz (Feb 13, 2011)

Lombard said:


> Thanks DC. It sounds like another new wheel build is in my future. What rim would you recommend for a rim brake hybrid/touring bike - a 36 holer I could lace to my existing Shimano hubs? I was looking for a box type rim around 19mm internal width in the 500-600g range. Something robust, but not ridiculously heavy like a Ryde. DT Swiss TK540 looks like a possibility, but it's only 18.2mm. And although I am a bit shy about going with Mavic, the A719 is probably one of their better offerings.


Well, I can tell you what I'm about to built for my self for a commuter/light touring bike I'm waiting delivery on.
H+Son TB-14, 36h all around, White Industries 135 OLD MI5 for the rear, Schmidt Son 28 for the front.
I plan on 33-38mm tires, depending whether on paved or unpaved roads, load, etc. The fork and the stays would fit tires 45++mm w/o fenders just in case we play in the snow.

IMO, either of the TK540 or the A719 you mentioned would be good choices. The DT maybe more appropriate for touring. The DT may also be of better quality than the Mavic, but I think its the luck of the draw for the particular rim you get; has not been consistently good or bad.


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## Lombard (May 8, 2014)

dcgriz said:


> Well, I can tell you what I'm about to built for my self for a commuter/light touring bike I'm waiting delivery on.
> H+Son TB-14, 36h all around, White Industries 135 OLD MI5 for the rear, Schmidt Son 28 for the front.
> I plan on 33-38mm tires, depending whether on paved or unpaved roads, load, etc. The fork and the stays would fit tires 45++mm w/o fenders just in case we play in the snow.
> 
> IMO, either of the TK540 or the A719 you mentioned would be good choices. The DT maybe more appropriate for touring. The DT may also be of better quality than the Mavic, but I think its the luck of the draw for the particular rim you get; has not been consistently good or bad.



Ahhh, I hadn't thought of the H+ Son TB14. A real retro rim! At only 14mm deep and 505g, it's robust for sure. It's only 17.5mm wide though. I'll be running 38mm tires, so that's a bit narrow for that.

Interesting the inconsistency you point out on the Mavic A719s. I believe some are still made in France while others are made in China. Do you think that might have something to do with the inconsistencies?


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## dcgriz (Feb 13, 2011)

Lombard said:


> Ahhh, I hadn't thought of the H+ Son TB14. A real retro rim! At only 14mm deep and 505g, it's robust for sure. It's only 17.5mm wide though. I'll be running 38mm tires, so that's a bit narrow for that.
> 
> Interesting the inconsistency you point out on the Mavic A719s. I believe some are still made in France while others are made in China. Do you think that might have something to do with the inconsistencies?


Fitting 38 mm tires and 17.5mm inside rim width its not a problem. Heck, you could put up to 50mm tires on this rim and still be within ETRTO stds.

I would not even want to begin speculation on what is causing the intermittent QC issues with Mavic. Maybe country of origin has something to do with it, maybe not.


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## Lombard (May 8, 2014)

dcgriz said:


> Fitting 38 mm tires and 17.5mm inside rim width its not a problem. Heck, you could put up to 50mm tires on this rim and still be within ETRTO stds.


OK, point taken that they are well within ETRTO standards. Though the trend is toward wider rims for the given tire size (17.5mm for road tires), I thought I'd try and find something wider for better handling. Heck, there's enough fork and stay clearance to fit 29er rims, but it's nearly impossible to find them nowadays for rim brakes. Oh well.


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## dcgriz (Feb 13, 2011)

Lombard said:


> OK, point taken that they are well within ETRTO standards. Though the trend is toward wider rims for the given tire size (17.5mm for road tires), I thought I'd try and find something wider for better handling. Heck, there's enough fork and stay clearance to fit 29er rims, but it's nearly impossible to find them nowadays for rim brakes. Oh well.


The bulbing non-aero rim-tire shape is not a concern of mine when I run these tires on this bike. The squirming of the tire I have yet to experience myself with either 32's or 35's and rims of this width. I have not used 38's yet because none of my road bikes would fit them although this is soon to change


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## Lombard (May 8, 2014)

dcgriz said:


> .....with either 32's or 35's and rims of this width. I have not used 38's yet because none of my road bikes would fit them although this is soon to change


Do tell!  

And you have road bikes that fit 35s? The largest size I can fit on either of my road bikes are 28s. My hybrid and touring bikes are a different story. I run 38s on those, but could run even larger.


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## dcgriz (Feb 13, 2011)

we've derailed this long enough. Check your PM.


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