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I posted this over in the Fixed forum but have gotten no replys so I thought I would try here:

Built my first set of wheels - Fixed
<HR style="COLOR: #b7b7b7" SIZE=1><!-- / icon and title --><!-- message -->Black 28 hole Formula hubs

Black IRD Candence Niobium rims

14-15-14 Wheelsmith stainless spokes

Green alloy nipples

Rear - 2X
Front - Radial


I used Sheldon Brown's wheel building page as a guide- but probably not as much as I should have. Once I had the rear wheel laced and I was starting to bring things up to tension, I noticed that the spokes went to each side of the hub in pairs rather than every-other. I pulled out all the spokes on the freewheel side (flip-flop hub), and moved one spoke from each pair on the fixed side over one hole. I laced up the freewheel side. Done! Nope. Turns out I didn't pay enough attention when I moved the spokes on the fixed side- the right flange spokes were going to the left drilled holes. I cooled off for 2 or 3 hours trying to convince myself it really didn't matter (how much can 1 millimeter really change things?) I decided to make the switch but had a genius idea first: I wrapped a piece of tape around each of the crosses, then removed all of the nipples. All I had to do was flip the whole mess over and reinstall the nipples, right? Wrong! It didn't change a thing! (Idiot!) Well, I could have made it work, but the valve stem wouldn't have been in the right place any more. I removed all of the tape, put every thing back in neat little piles, and started over. Having already made every possible mistake, I got the whole wheel built and trued in about two hours. The radially laced front wheel went together even faster.

Question: How round do I need to get them? Getting them true and centered was easy, but they are still not exactly round. The difference between the high and low areas is about 1 millimeter or less.

jpeg's are not loading so crappy gif's will have to do.
 

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With the right rims, you can get to 0.05mm. The rims has to be stiff and well made. My frst vote is the Velocity Deep V, but there are lots of others. My Aerohead set is +/- 0.05mm both ways as well.

-Eric
 

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Are you sure it's 0.05mm or 0.00197" ? I'm asking because 0.4-0.5mm is already quite good when you take the welding area into account (if present), and if the parts permit it, 0.2mm is excellent no matter how you look at it.
 

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Yeah that's what I was thinking

divve said:
Are you sure it's 0.05mm or 0.00197" ? I'm asking because 0.4-0.5mm is already quite good when you take the welding area into account (if present), and if the parts permit it, 0.2mm is excellent no matter how you look at it.
Just tried to measure that on my vernier calipers, that's pretty small! I can't visually decern much between tenths of a millimeter much less hundreths. I agree, around half a millimeter is pretty good with most high-quality rims; a select few I can maybe get to .2mm. Less than that and it's either a futile effort or a waste of time, since the displacement of the tire will negate any deviations in the rim that small.
 

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Argentius said:
I'm sure he meant .5 mm...
No. I meant 0.05mm. I have modified my Park TS-3 with rollers on the dial indicators so they are much more accurate than most stands. The only thing better is a Villum. You cannot see any movement with the eye.

-Eric
 

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Completely pointless

ergott said:
No. I meant 0.05mm. I have modified my Park TS-3 with rollers on the dial indicators so they are much more accurate than most stands.
Well, that's neat, but it's completely pointless. IMO there is no need for this kind of tolerance and it's just a waste of time to strive for it.
 

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Kerry Irons said:
Well, that's neat, but it's completely pointless. IMO there is no need for this kind of tolerance and it's just a waste of time to strive for it.
If the components are capable of being true to a higher standard and it takes a little more effort, then why not? Phil Wood hubs are the standard for fit and finish. Are other hubs good? Sure.

It's really not difficult. 0.2mm is a reasonable standard and still a sign of guality. I just think that I it can be done, I'd rather try to get the rims as true as possible.

-Eric
 

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No offense, but I have to agree with Kerry and like to add that I'm skeptical that it's even possible to maintain such a tolerance. To elaborate, when you mount a clincher tire and pump it up to 100psi, it will have already effected the trueness to considerably larger extent than 0.05mm. When it's a rear wheel the dishing will slightly have changed in addition as well.
 

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divve said:
No offense, but I have to agree with Kerry and like to add that I'm skeptical that it's even possible to maintain such a tolerance. To elaborate, when you mount a clincher tire and pump it up to 100psi, it will have already effected the trueness to considerably larger extent than 0.05mm. When it's a rear wheel the dishing will slightly have changed in addition as well.
Just to satisfy the skeptics.

http://websites4ever.com/ergott//wheeltrue.mov

A high resolution is available. I just don't know where to host it. I have 9mb and 27mb files.

Is it necessary to have the wheels within these tolerances? No. Do I do it anyway? Yes. I just enjoy the attention to detail. I'm sorry if that bothers anybody.

-Eric
 

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divve said:
No offense, but I have to agree with Kerry and like to add that I'm skeptical that it's even possible to maintain such a tolerance. To elaborate, when you mount a clincher tire and pump it up to 100psi, it will have already effected the trueness to considerably larger extent than 0.05mm. When it's a rear wheel the dishing will slightly have changed in addition as well.
Here is a wheel with a tire inflated to 120psi.

http://websites4ever.com/ergott//wheeltruewithtire.mov

-Eric
 

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It's hard to see what these dials are displaying on the low res movies. Am correct in assuming that a single line represents .01mm and the area between two numbers .1mm?

Providing the above is correct I sort of see -.05 to +.07 without tire and -.05 to +.05 with? Maybe we have different definitions of runout. To me that's .12mm and .1mm as I count both sides.

I've done test like this myself with and without tires in the past and I've found that results with such small tolerances are highly dependent how good of a tire you get with clincher rims.

Nevertheless, those tolerance are extremely good. I only have modern builds laying around with welded rims joints. None of them would allow to be that true without messing up the spoke tension uniformity too far. I do have a few +/- .2 and +/- .15, which according to your definition (by me assumed), would be half the value of runout...so depending on how you define the runout I can agree that it's possible.
 

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divve said:
It's hard to see what these dials are displaying on the low res movies. Am correct in assuming that a single line represents .01mm and the area between two numbers .1mm?

Providing the above is correct I sort of see -.05 to +.07 without tire and -.05 to +.05 with? Maybe we have different definitions of runout. To me that's .12mm and .1mm as I count both sides.

I've done test like this myself with and without tires in the past and I've found that results with such small tolerances are highly dependent how good of a tire you get with clincher rims.

Nevertheless, those tolerance are extremely good. I only have modern builds laying around with welded rims joints. None of them would allow to be that true without messing up the spoke tension uniformity too far. I do have a few +/- .2 and +/- .15, which according to your definition (by me assumed), would be half the value of runout...so depending on how you define the runout I can agree that it's possible.


I stated above "Aerohead set is +/- 0.05mm both ways as well" The first test was a front wheel. The second was a rear wheel from a different set. I always thought the measurement was from center. If it is total then I apologize if I was misleading. Is total (your measurement) what people call runout? I'll have to show you guys what some other rims do.

I've seen one rim that would wave between spokes as much as 0.15mm. Tension was at about 100kgf. The compromise was an acceptable tenion and what I would can the average center of the rim. Total runout by your definetion was 0.2mm - 0.3mm, but you could plainly see how the tension of the spokes effected the roundness of the rim in comparison to the Aeroheads above. Did you ever notice the way OPs wear with a wavy pattern between spokes (sort of a scallop effect)? That's about a 0.03-0.05mm difference in between. The tension of the spokes is pullling the sidewalls of the rims in.

-Eric
 

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Kerry's right. .

Kerry Irons said:
Well, that's neat, but it's completely pointless. IMO there is no need for this kind of tolerance and it's just a waste of time to strive for it.
At that point the wheel begins to "fight back," and it becomes a thing of diminishing returns. And concentrically it's, stupid as the tires you buy aren't that true in that orientation so why bother.
 

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KATZRKOL said:
At that point the wheel begins to "fight back," and it becomes a thing of diminishing returns. And concentrically it's, stupid as the tires you buy aren't that true in that orientation so why bother.

Stupid is it not. A wheel that lasts until the the brake tracks wear out or the rim is damaged beyond repair starts out with even tension, correct spoke lengths and as true as possible. As stated above, the tolerances weren't that different from what other people use as a standard. If you only true wheels to just under the point where the tire doesn't mask the imperfections your wheel will be a piece of crap.

Please elaborate on "At that point the wheel begins to "fight back,"". What point and what tension are you talking about?


-Eric
 

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ergott said:
I stated above "Aerohead set is +/- 0.05mm both ways as well" The first test was a front wheel. The second was a rear wheel from a different set. I always thought the measurement was from center. If it is total then I apologize if I was misleading.
First, why do it "good enought" when one can do it really "good" ?!
I liked that Eric did go for 0.05mm (or 0.1mm in total), it's a aim for a perfectness.

How can somebody believe that the wheeltrueness decreases when one add a tire?
Eric killed a myth with his video?
If a tire have a influence at trueness of a wheel, my first concludion would be:
Low/uneven spoketension -> bad wheel.
(I need to look up in "The Bicycle Wheel" (if there is such thing mentioned),
to see that this really possible.

Mavic does really specify a maxium pressure ratings for the tires, but I suspect that the
rim does not stands against the high pressures, e.g. weak rim (strength of the rim) is the limiting factor). But Eric is well beyond the margin of safety.
Althougth my theoretical question would be if the trueness would be affected by a pressure at 140psi, but that is far beyond useful value for most of tire and affects the safety. (less traction)
Most 23mm tires does really have a max. value of around 100-120. Why go higher?

***
My aim is height difference is between 0.5mm to 1.0mm.
I am aiming for 0.1mm, but in practice I usually got between 0.1-0.3 mm.
(I use my thumbfinger to get a space of measure/feel, a cheap and a effective tool)

Mostly because of crappy wheel (low motivate), bad time and I need to learn more.
I have planned to build new wheel, and then I'll try to do it really good - not good enought!

Second: Radial spokes at fronts are cool for most peoples, but add little value of use.
if you can or want, rebuild it with 2 cross front? ;)
A fixed demands a nonradial wheels... :D

Second: Even spoketension and stressrelieving are important.
Correct/enought stressrelieving is difficult to find,
I found Jobst Brandts own words in a FAQ, and absorbed it here in a summary:

grasp quickly a least four spokes with your hands (use a lot of force and gloves),
throught the whole wheels. Then true it up again with a higher tension as a goal.
(Do it several times?)
That gives more load to the wheel than Sheldon Browns mentions in his home pages with his crankarm-procedure.

I need to read more (I have ordered "The Bicycle Wheel"), and verify it myself, so I haven't testet it throughtfully myself.

Recently I asked for help here about my crappy 24 spokes wheel. Got ~7% difference in tension, which seemed okay. But it did recently go out of trueness recently so my suspection is that this wasn't stress relieved good enought by me. dammit! ;)
That's why I searched more about stress relieving.
When I have got more time, I'll try to do it more carefully.
Or I'll build a new wheel, I does not know yet.
 

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Mavic maximum tire pressure

tidelag said:
Mavic does really specify a maxium pressure ratings for the tires, but I suspect that the
rim does not stands against the high pressures, e.g. weak rim (strength of the rim) is the limiting factor). .
Actually, they do. I don't know if it is in the wheel owner's manuals, but the only place it appears on the web site is in the dealers only section (password protected). For road wheels, the maximum tire pressure for a various width tires is:

19mm 10.0 bar/146 psi
23mm 9.5 bar/138 psi
25mm 9.0 bar/131 psi
28mm 8.0 bar/117 psi
32mm 7.0 bar/103 psi
 
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