spoke torque wrench

rvich · May 26, 2013

I have worked along side respected mechanics who tighten bolts on everything absolutely as tight as they can get it. Frankly it frightens me. My life experience is that equipment tends to last longer when you use the least amount of torque required for the job. And I couldn't agree more that using a torque wrench helps define the feel for the fasteners. I also really like knowing that a "set" is all near the same, whether it be my timing cover, or head or anything else. For the past twenty years I have been wrenching on large diameter pipe flanges. You learn to respect a tightening sequence and equal torque when you are trying to keep a 12 inch pipe from leaking under pressure.

Russ

worntorn · May 26, 2013

Agreed, and although there is the occasional old mechanic who will claim he can sense torque accurately down to a couple of foot pounds, when it gets to inch pounds I doubt any of us are very accurate.
I told my friend about the Torque spoke wrench and his response was quite negative. He has always laced his wheels using the ping method and believed it to be very accurate. So using the torque wrench we checked a set of Morad flangeless alloy rims from Central Wheel that he laced last month and has not ridden on yet.
Spoke tension varied from 20 to 40 inch pounds, so 100 % variation low to high, using the ping method. Perhaps spokes are not as musically perfect as a piano string.
He has borrowed the wrench and is redoing the wheels to a uniform 55 inch pounds then true from there, will likely end up like mine did, +- 5 inch pounds from target and running very true.

Glen

Hobot · May 26, 2013

Unread postby worntorn » Sun May 26, 2013 7:38 am
Agreed, and although there is the occasional old mechanic who will claim he can sense torque accurately down to a couple of foot pounds, when it gets to inch pounds I doubt any of us are very accurate.
I told my friend about the Torque spoke wrench and his response was quite negative. He has always laced his wheels using the ping method and believed it to be very accurate. So using the torque wrench we checked a set of Morad flangeless alloy rims from Central Wheel that he laced last month and has not ridden on yet.
Spoke tension varied from 20 to 40 inch pounds, so 100 % variation low to high, using the ping method. Perhaps spokes are not as musically perfect as a piano string.
He has borrowed the wrench and is redoing the wheels to a uniform 55 inch pounds then true from there, will likely end up like mine did, +- 5 inch pounds from target and running very true.

Glen

What a bunch of Hog Wash to post to this list Glen, this puts you near blacksheep hobot camp. Peel's got wheel on again so may give a little Tinkle Tinkle Litter Star spoke tune for ya. Btw id you care really get fancy with spoking refinement go search up the spoke tuning devices that use sonics to assess tension.

worntorn · May 26, 2013

This from a guy who uses a crescent wrench to tighten spokes and recommends tightening almost to the breaking point? :shock:
I can live with your disapproval.

Glen

Hobot · May 26, 2013

tag up this back ground... Some of Peel's spokes sound like a glass tapped pitch
[video]http://www.youtube.com/watch?v=BHP5xjBP-9I[/video]

Tee-hehe Glen, I assume you are just slapping back at me in jest as I did you in total agreement. Do note [pun] that a normally trued wheel will not have each row of same length and angle spokes at same tension, that takes extra tedium time with a hammer, dial guage for the delicate metal distorting wrench forces if you and items can stand the tension. One does not pluck spokes like a string to play but tap-rap like a xylophone plates to ring.

Peekaboo here for mechanical ways to avoid Teaser-wrench
http://www.google.com/search?q=spoke+te ... 67&bih=373

Like the strings of a guitar or harp, bicycle spokes ring when plucked. The resulting musical pitch is higher if a spoke is tighter, and the optimum pitch does not depend on the thickness of the spoke. To know what the musical pitch should be, all you need to know is the approximate spoke length and whether you will be using plain-gauge spokes or butted spokes, which are effectively shorter since their ends are thicker. At the end of this article is a table of optimum musical pitches. You may go there now in case you only need to look up a pitch and spoke length. Please read the rest of the article first if you haven't done that already. You may also read a scientific explanation of how spoke tension relates to musical pitch.

If the tension of two laced spokes is very different, you will hear a dull thud. Pull the spokes across each other with your fingers to see which one is looser. Lift the looser spoke away to pluck the tighter one alone and check its pitch. Check for rim damage or a crooked rim joint near the unequally-tensioned spokes. Rebend the rim if necessary so the wheel will true up with the spokes at a more nearly equal tension. (Rebending rims is a subject for another article. . .) If you can't achieve a true wheel with even spoke tension, it's time for a new rim.

mo here
http://www.bikexprt.com/bicycle/tension.htm

T-wrench method may not get ya into rim rebending level but should begin to sound more like steel drums with a rim around than isolated plates.
[video]http://www.youtube.com/watch?v=reQB1Eslr5M[/video]

Cheesy · May 26, 2013

worntorn said:
Agreed, and although there is the occasional old mechanic who will claim he can sense torque accurately down to a couple of foot pounds, when it gets to inch pounds I doubt any of us are very accurate.
I told my friend about the Torque spoke wrench and his response was quite negative. He has always laced his wheels using the ping method and believed it to be very accurate. So using the torque wrench we checked a set of Morad flangeless alloy rims from Central Wheel that he laced last month and has not ridden on yet.
Spoke tension varied from 20 to 40 inch pounds, so 100 % variation low to high, using the ping method. Perhaps spokes are not as musically perfect as a piano string.
He has borrowed the wrench and is redoing the wheels to a uniform 55 inch pounds then true from there, will likely end up like mine did, +- 5 inch pounds from target and running very true.

Glen

Thats interesting, now I would question your results for the torque wrench but since there were some low numbers its a bit hard to question as the breakaway torque wont be as significant. Maybe his pitch is off!
What might be interesting is if you have an Android or Apple device, there are various musical instument tuning apps that will give a frequency, you could see what your spokes come out as with that method.

I have been building a set of mtb wheels with carbon rims and thin butted spokes using the information that is liked from the page Hobot gave so when they are done I will get them checked with a tension meter like the one Hobot posted as well to verify the method.

Out of curiosity do you know what the actual spoke tension you are aiming for is?

worntorn · May 26, 2013

One rim manufacturer recommended 60 inch pounds, two others recommended 48 so I went in the middle at 54. Buchanans definitely recommends 80 or even 85, however that is with their own Sun rims and is likely with the heavier #8 spokes, seems much too high for #10 spokes.

Glen

rvich · May 27, 2013

At the risk of hitting the hornets nest with a stick...

I found it beneficial when working on my old Dunlops (new spokes and nipples) to work on getting the wheel true first, by feel. Then I went around and worked on getting the torque values closer to even without letting the wheel misbehave. It took some time and some thinking about what to slack and what to take up to get it all there. But eventually I ended up with a very true wheel and torque values near even. My tendency without the wrench (and no I am NOT a master builder) was to keep tightening. By studying torque values I was able to judge more easily where things were getting overly tight. Just sayin'...so that if there are other rookies out there trying this at home, it might be of help.

New, quality made wheels probably won't have as many flat spots and wobbles at the 40 year old Dunlops.

Russ

worntorn · May 27, 2013

Sounds like a good approach. There is a thread going on the Vincent site about wheelbuilding problems, mainly spoke breakage of some new Stainless steel spokes in some pofessionally built new wheels. The consensus is that stainless steel spokes are a poor choice. When a part breaks people automatically assume the part is at fault even if the problem is elsewhere.
If the wheel was laced like some I have checked here, then just a few of the spokes were doing most of the load bearing. When a big load comes on, pow one of those spokes lets go and we assume it was too weak for the job. If the tension had been roughly even the breakage would not occur, but uneven tension is a hard thing to see whereas a broken stainless steel spoke is quite easy to see!

Glen

rvich · May 27, 2013

I learned recently that some stainless spokes have cut threads and some have rolled threads. Were I going to tighten them to 80 lbs I would prefer the rolled thread. They are a larger diameter for a given gauge of spoke and thus stronger.

Russ

PS-Buckanans' spokes are rolled

T95 · May 27, 2013

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.

Nice job Cheesy,
Is the sockets attachment point on the spoke wrench somewhat critical in determining the torque applied to the nipple? How would one calculate the new torque value?
Gary

rvich · May 28, 2013

Torque extension calculator:

http://www.belknaptools.com/support-lib ... alculator/

But its fairly straight forward in that if you increase the length of the wrench by 10% then you increase the applied torque by 10%.

Mark F · May 28, 2013

Here's a torque wrench extension calculator from Norbar.
They also do an app for your smart phone. Makes life easy out in the shed. :wink:

http://www.norbar.com.au/Calculators/To ... lator.aspx

worntorn · May 28, 2013

rvich said:
I learned recently that some stainless spokes have cut threads and some have rolled threads. Were I going to tighten them to 80 lbs I would prefer the rolled thread. They are a larger diameter for a given gauge of spoke and thus stronger.

Russ

PS-Buckanans' spokes are rolled

Hi Russ

Devon also uses spokes with rolled threads. I have some spare Devon spokes on the way. Just for interests sake, it would be good to do a test to see at what torque the spokes break or threads let go.
I've also got a set of rims and spokes coming from Central Wheel in the UK, it will be interesting to compare those items to the Devon rims and Buchanans Sun rims I have here.

Glen

T95 · May 28, 2013

Mark F said:
Here's a torque wrench extension calculator from Norbar.
They also do an app for your smart phone. Makes life easy out in the shed. :wink:

http://www.norbar.com.au/Calculators/To ... lator.aspx

Thanks for the response about torque values. I'll look over both calculators and keep them for reference.
By chance I happened to be at our corpe yard today and one of the mechanics had a torque wrench in his hand. He mentioned that if you place the torque wrench at 90 degrees to the extension, rather than in-line, the torque values do not need to be recalculated. Handy for some applications but for spoke nipples its likley easier to stay inline. Sorry for the hijack!

spoke torque wrench

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