1/17/14 2:02 PM

I have been using pitch throughout my wheel building life. This way longer and/less can be adjusted for. Pretty safe window sticking with 3x and 28 as the Lowest spoke count. Except for the 16 spoke Reynolds rim replacement where I borrowed a TM-1 and used the chart after measuring the blade per the Park PDF etc.

I have 12 year old wheels still going strong with minimal tweek, road zero, off road a little more.
Even started re-rimming to A23s on the old road wheels. Open Pros removed still decent overall with
some brake wear, worse on the CX from wet dirt etc.

But, I am sure I have some under and over tensioned slightly, or at least recognize the likelihood.

So enter strain gauges, Park TM-1 at the low end.

Does the readout on this thing show newtons ? Does the conversion chart show NM/KG ? Well I know to KG, but from what? Googling note netted an answer to that.

EDIT:
I should add that when I had the TM-1 I had borrowed I cheacked about every wheel I had out of curiosity. They where all to the high side. But I am reading the TM-1 in fact reads a good margin to the high side today googling fest.

I in fact loosed up one wheel set after that to the Park Spec, and wound up re-tensioning it later. Flexed too much and rear creaked a bit. This means soft spoked wheel to me. Not ever had any stress cracks @ the nipple hole in any of my builds FWIW.

1/19/14 10:29 AM

...before I ever owned a tensiometer. However, that was back in the day when 36 spoke wheels were the norm, using 28 spokes was considered "radical" and rims were much lighter and weaker.

I've been out of the business for over 30 years, so I only build wheels for my own bikes and Linda's these days. The last dozen or so sets have been built using a tensiometer, at first a Wheelsmith and more recently, a Park. It's been interesting and educational, though a bit frustrating, as I have yet to discover the secret (if there is one) to getting perfectly even spoke tension AND a wheel that's round and true. It appears that although rims are much better than they used to be, variations at the seam and in overall roundness and flatness of the rims still result in uneven spoke tension.

Today's lower spoke count wheels require much higher tension and are less forgiving than "old school" 36 and 32 spoke wheels, so achieving optimum tension is more critical (hence the tensiometer). I've also found that although modern rims are stronger, over-tensioning them results in a seriously unstable wheel. I recently had one case of this in the truing stand, where the rim became completely unresponsive and unpredictable. Fortunately, I was able to reduce the tension and "bring it back from the brink" and the finished wheel has been fine for the thousand or so miles I've put on it.

I've also played around with using pitch, but it seems to me that it's really only useful for checking the tension of spokes relative to each other in the same wheel, as there's no way to know what the proper pitch should be for a variety of hub/spoke/rim combinations. I suppose if you have a wheel with known tension and you are duplicating it exactly, you could use pitch to achieve the same tension. I just use it to locate spokes that are too tight or loose relative to the rest. It's also very useful for balancing the drive side spoke pairs in 16/8 spoke pattern rear wheels.

1/19/14 11:58 AM

I DLed this a long while back. I do find the wheels a little flexy and go tighter by a 1/2 step to almost a full step once i use my own sense of tension. I think it is superposed to be 32x wheels. I use a guitar tuner that has a mike. If I get tighter spokes or slightly higher tension, my technique is same as with hops. I to go 180^ and work there first. I have found this makes for more equally tensioned wheel that are rounder. Tension judged by pitch.

This has been working for me in 10 builds, as infant compared to your 1000s certainly. But hopefully my mechanical aptitude and general broadness/experience working with my hands keeps my product reasonable consistent. And having 12 year old wheels in service with 1-2 tunes help me feel confident I am on the right track.

Also, my fav build config is 14/15 drive and revos for the rest of the wheelset. I actually find the revo on the rear assists for building with the asymmetrical tension on the rear.

My mast build was the ENO, no dish and was like building a front really... Picked up anouther ENO wheel with a 1/2 shot Open pro I am going to ebuild too. Thinking about making the Roubaix a stupid light long wheelbase SS treker. ;)

1/19/14 12:07 PM

do all final tensioning/truing with the tyre mounted and aired-up to full pressure.

you can see the spoke tension drop appreciably and the dish will often change noticeably when going from zero to 7-bar.

1/19/14 12:12 PM

Not sure I buy that Walter. But I am going to see when I do the second ENO up, you got my curiosity up, ;)

1/19/14 12:17 PM

...then it must be so! ;-)

http://velonews.competitor.com/2011/11/bikes-and-tech/technical-faq/technical-faq-with-lennard-zinn-spoke-tension_198452

1/19/14 1:32 PM

OK, but .0625" is significant? I say not really, just IMO. Most folks [not us;)] ride on wheels at least that out of true.

I was thinking my fat ass loading the wheel would have more effect that that. ;) Maybe this is why I like wheels tensioned to the tight side. Being over 200 lb and all. [less than a little over about now. ;(]


OK, later. ride time while I record some foooseball...

1/19/14 2:23 PM

...and it's consistently offset to one side, that just irks me to no end.

i like my wheels to go in clean and not have to re-center the brakes. went to all the trouble of building up a neat and evenly tensioned and straight wheel after all.

riding around with an out-of-true or out-of-dish wheel is sloppy, same as having a loose headset or mal-adjusted shifting -- something a triathlete would do, but no self-respecting cyclist! ;-)

1/19/14 9:15 PM

.0625" out-of-dish wheel same as having a loose headset?

OK, if you say so... ;)

1/21/14 6:30 AM

...I've never done that, nor do I know any other wheel builder who does it. Moreover, I seriously doubt that the recommended tensions from rim manufacturers are devised with an inflated tire on the rim. While building wheels is all about attention to detail, that seems to be going a bit too far.

1/21/14 7:30 AM

I recommend the Park Tension meter tool. It's another quality Park tool. It comes with a tension chart, with newtons (IIRC) and spoke gauge measuring piece. FWIW, I'm tone deaf and a perfectionist.

1/21/14 8:52 AM

more of an issue with clinchers.

"(2) Inward pressure by the inflated tube.
A clincher tire puts inner tube pressure in direct contact with the rim. An average road clincher rim is 0.5″ wide and presents a 77″ length. Surface area equals 38.5 sq in. If air pressure is 100psi, then total force felt by the rim is 38.5 X 100 = 3,850lbs. This 2 ton force is trying to make the rim smaller and is great enough to elastically deform many metal rims more than 0.1″ in circumference. <u>This may not sound like much but it has a large and measureable effect on spoke tension. 0.1″ circumference = 0.032″ diameter, or 0.016″ radius. This is nearly one full nipple turn. Imagine the loosening effect.</u>"

http://www.wheelfanatyk.com/blog/wheelbuilding-tip-16-clinchers-tubulars/



"Spoke tension in beginning was around 85 kg - after release air it rise to around 100kg. From 0,37mm to 0,32mm."

https://www.youtube.com/watch?v=ZL-XznfqQRI



<img src="http://fcdn.mtbr.com/attachments/wheels-tires/684879d1359601749t-tire-pressure-spoke-tension-crest-29er-pressurization.jpg">
<img src="http://fcdn.mtbr.com/attachments/wheels-tires/684983d1359601749t-tire-pressure-spoke-tension-pressurizing-crest-after-readjustment.jpg">

1/21/14 9:21 AM

But then you will also need to account for temperature's influence on tire pressure readings. Does anybody built wheels in freezing temps, too?

1/21/14 9:28 AM

and maintain abolute-zero temps...need to remove all variables! ;-)

1/21/14 9:50 AM

lol!