spoke torque wrench

I laced up some new rims yesterday and used a spoke torque wrench for the first time. It worked really well. I first used an ordinary spoke wrench to bring the spokes up to light tension and get the wheel somewhere close to concentric. I then went around with the torque wrench, starting at 15 inch pounds then adding 10 inch pounds per rotation, finishing at 55 inch pounds. For both rims this brought the rim quite close to true without really trying. Total runout when done torquing was only around twenty thou. Lots of pro shops consider that done, and it probably is as close as needed for most applications.
A bit more tweaking with the regular spoke wrench got them running within 5 thou both ways. And nice to know that the spokes are evenly torqued within about 5 inch pounds.
On checking some other existing wheels with the torque wrench, some done by me without torque wrench, one set done by a shop, torque values were generally very low and highly variable, anywhere from 20 inch pounds to about 50.

If the spokes are not tight enough and highly variable in tension, you can have a wheel that runs true but is not very strong.
This is why the spoke torque wrench was first made years ago, race teams used them to get wheels both true and evenly tensioned for strength at speed.
I was told by a friend in Classic racing that Buchanans use a spoke torque wrench and torque race rims to 80 inch pounds.
I haven't been able to get much other info on torque values for spokes, but 80 felt much too high for the 10 guage spokes I used, 55 felt right. Perhaps 80 is for 8 guage.

Glen

Sounds interesting, where did you find this wrench?
Fritz

What do they look like An where would i get one As it sounds good for those of us that have tried an failed at wheel building so we can check the spokes

I found that best spoke wrenches round off the nipple well before full torque reached. Only thing I found that could get the max tension in was a small adj. wrench snugged down so it would not come off w/o backing off adj each and every little tweak to each and every nipple around and around and around again and again with some the tougher spoke friction releived by a sharp RAP by hammer while straining on wrench. You can not get spokes too tight unless the threads strip off or the rim umbrellas suddenly. The ring of nipples should be severely shocked each round or so to destress before next go around. After essentially trued I go back and get each row of spokes sounding very similar in tone, all the while watching a dial guage. I found good rims are made with ~.003-.005" imperfections which is less than the rubber hysteria out of true. Its more important to get rim flat than centered d/t tire and road texture off centering no matter what.

$78 might be worth it,

http://www.ebay.com/itm/Tusk-Spoke-Torq ... 46&vxp=mtr

bwolfie said:

$78 might be worth it,

http://www.ebay.com/itm/Tusk-Spoke-Torq ... 46&vxp=mtr

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That is the one, it works great. I believe the very first spoke torque wrenches were made by Fasst Co. an preset at one setting, whatever the purchaser odered. Fasst company initiallymade them up at the request of a motorcycle race team who rightly concluded that the old ping method was pretty inaccurate.
As I see it the variable wrench has an advantage in that you can use to bring the wheel up to tension in small increments, this seems to help in getting the wheel true quite quickly. Also, I can also do my mountain bike wheels with this wrench, whereas the Fasst preset would be good for one guage of spoke only.
Hobot, there is no risk of rounding the nipple hex. There are five different precision ground heads in the kit,the 6.6 mm one fit perfectly. I would bet that at 55 inch pounds these spokes are tighter than 90 percent of the wheels running around out there.
They are definitely tighter and more even than my other bikes wheels. Also, I disagree with the idea that spokes cannot be too tight. If the tension on one spoke is so great that it is near the breaking point, then surely it will break when a big bump is enountered. The spoke flanges can also rip out if the tension is too great.
So there is a correct number, or correct range as for most things. The torque wrench gets you there.
It might not be so useful on old spokes though, what with varying thred friction and all.


Glen

I found that best spoke wrenches round off the nipple well before full torque reached.

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then you are not using a quality spoke wrench as the good ones do not round off the nipple

Someone should make spoke extensions for a regular torque wrench or they should make a 1/4" drive end for that one.

Ok got me there I'd didn't even have a spoke wrench after seeing what was supplied as merely decent ones. All's I can say is if your wrench can't torque nipples to point the spokes risk twisting up or pulling through the rim it ain't up to the torque a snugged tight cresent wrench can. I had to almost over do Peel as she got more rough wheel impact life planned than most. The ones to really study up on this are the bicycle carzies that make us motor cyclers look slip shod lazy compared.

If your spokes are tight enough to stay put and wheel true enough then you are basically done, but I don't trust torque wrenches d/t the varing binding of nipples so I go by feel and by ear. Then again I've only done 2 and each took me over a month to finally get fixed. When as tight as I could get by adj.wrench alone, I went further with teeth jarring RAP on nipple end - enough to bow the rim inward a few 1000's to gaine another ~ 1/10 turn. Would be interesting educational to have a rim tone series of video to get sense of ranges.

http://www.google.com/search?q=spoke+wr ... 67&bih=373

Hobot, if you used one as I just did, you might think differently. With new threads and antiseize on the nipple,the torque wrench gets the tension dead on. Maybe not necessary for pros, but it is interesting that Ken Buchanan insists that his professional builders use a spoke torque wrench on all of their wheels. If anyone would get a delicate feel for correct tension, it would be the guys who are doing this day in and day out. And yet Ken found enough inconsistency to warrant the use of the torque wrench. He may have also found that it actually sped things up and produced a better result, which often happens with an improved method.

I would only recommend the torque wrench for new wheel builds, or at least wheel builds using new spokes and nipples. Old spokes, frozen threads, the torque wrench is of no use.
Some people wont even use a torque wrench on headbolts, feel they can get perfect torque intuitively somehow.
Most of us need the torque wrench. The heavy duty Diesel mechanics I apprenticed with for a year all used torque wrenches and went by the factory settings. Seems hard to argue that it was a bad practice?
Glen

Can't fool me any more on half thought through mechanical fastener wisdoms that only apply to routine job processing for those that ain't really measuring end results but just close enough to get by. Bolt stretch measure and ear tone spoke tension is better if getting nic picky testy - as twist force alone does not produce same tension in each spoke, just similar twist tension. Following instructions don't always work as well as advertised but generally quite good enough. Have ya tried going around rim SMACKING spoke heads then checked torque or tone?

I hit edgy stuff that jars me to my teeth from the solid compression of tire against rim to pinch hole in tube that soon blows out. Bridge lips, big stones and crash landings on one patch. Three such events on Trixie, one event broke batter tie downs to dump acid. I figure better break it at home than away.

Maybe you can re-educate Ken Buchanan then, he must have this spoke /rim thing all wrong.

Glen

RennieK said:

Someone should make spoke extensions for a regular torque wrench or they should make a 1/4" drive end for that one.

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A bit like this?



Although I stuffed up the torque conversion and made it 3/8 instead of 1/4 so I will have to make another one up.

That said Hobot is dead right about a torque wrench being of marginal use. Slightly off topic but for mtb the spokes will wind up way to much for a torque wrench to be of use, the spoke tension is calculated by measuring spoke deflection under a set load and comparing to a known reference or by sound.

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Actually I have had pow pows with Mr. Buchanan and corrected their errors on Norton disc rims and Commando models and found out what i could get away with on Peels rear spoke sizing, so please call him and review my ridiculous protocol and get back to us. Last thing I want to do is miss lead anyone on purpose or by ignorance. I'm newbie here so not many know the scope and range Ms Peels sagas took me.

worntorn said:

I was told by a friend in Classic racing that Buchanans use a spoke torque wrench and torque race rims to 80 inch pounds.
I haven't been able to get much other info on torque values for spokes, but 80 felt much too high for the 10 guage spokes I used, 55 felt right. Perhaps 80 is for 8 guage.

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If they're using greased theads and grease between the nipple and rim,they won't be using 80 in-lbs on a british bike.They'd be likely to pull nipples through the rim and break spokes at 1/2 that.35 would be safe for most aftermarket rims.

Glen,
Thanks for posting this. When I built my wheels I had trouble finding values for what proper torque should be. I settled on about 35 inch pounds by feel.

Russ

Hi Russ. There does seem to be a dearth of info on the spoke torque values, perhaps that is because the use of these little torque wrenches by the masses is a relatively new thing.
I have asked Devon wheel in England for their recommendation on the wheels and spokes supplied. I should have done that at the start, but it is still easy enough to slacken things off or add some tension if required. It will be interesting to see how Devon's number compares to Buchanan's number.

Glen

FWIW Excel sells one w/ a torque range of 15-60 in-lbs and they have some helpful instructions posted .
I can definitely see the value of this for MC wheels, have built bicycle wheels and you can get a good feel for the spoke tension by pulling on them and plucking them then comparing the feel and tone to known good wheels but that would be hard to do w/ heavy MC spokes...anyway, thanks very much for the review and I'll acquire one for some upcoming wheel rebuilds

Cheesy said:

RennieK said:

Someone should make spoke extensions for a regular torque wrench or they should make a 1/4" drive end for that one.

Click to expand...

A bit like this?

Although I stuffed up the torque conversion and made it 3/8 instead of 1/4 so I will have to make another one up.

That said Hobot is dead right about a torque wrench being of marginal use. Slightly off topic but for mtb the spokes will wind up way to much for a torque wrench to be of use, the spoke tension is calculated by measuring spoke deflection under a set load and comparing to a known reference or by sound.

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Nice Job! I've been thinking of picking up a 1/4 torque wrench and like the idea of multi tasking tools.

Good points about bolt stretch and thread lubing's effect on torque values. Most torque setting refer to new threads with no lube so there are many considerations here. Once a fastener or component has been torqued to specs it had been stretched. Rod and head bolts etc are often stretched on manufacture in series tests so are often recommended for one use only. Other variables, does your spoke pattern touch other spokes? They often do. Are the mount holes in your hub worn which may introduce an angle to your spoke enough to pull on the left side of the threads more than the right side because there is a curve introduced to the spoke from the hub mount hole vs nipple position. Are you replacing 2 or 3 broken spokes and re-using your others?

Probably one of the best things about a torque wrench is the familiarity to the "feel" of consistent torque levels they build. You usually only get that from stripping threads. We need to learn to "feel" that stretch point. I used to break a lot of those contact breaker plate bolts. You know those little expensive ones that have the heads drilled and tapped for the points cover screws?