spoke torque

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DucMonzter
Posts: 40
Joined: Sun Feb 02, 2014 4:05 am

spoke torque

Postby DucMonzter » Mon Jun 29, 2020 11:29 pm

Hello all,

Does anyone have a recommended torque spec for the spoke nipples on a Monza Junior wheel? I recently rebuilt my front wheel using original-style components (steel rim, 3mm steel spokes, brass nipples) and am trying to equalize the spoke tension prior to final truing. The manufacturer of my spoke torque wrench recommended 36 in-lbs (4.1 N m) for these thin spokes (vs. 48 in-lbs (5.4 N m) for modern ones). However, I’m concerned that this setting may be too high due to a previous experience with a brass nipple pulling through a hole on a similar rim before reaching that value. Any thoughts?

Thanks,
Jeff

blethermaskite
Posts: 477
Joined: Thu Mar 01, 2018 1:06 am
Location: northern ireland

Re: spoke torque

Postby blethermaskite » Tue Jun 30, 2020 10:44 am

Jeff, I have built dozens and dozens of wire wheels and have never used a torque nipple wrench, you build your wheel tightening the spokes up evenly by feel, then true your rim, then go over all the spokes again feeling for any not that tight (with your spoke wrench) and carefully pull these up while checking you are not knocking your rim out of truth again, then spin your wheel slowly whilst holding a screwdriver against the spokes.....listen to the tone and any not tight that you may have missed will ring at a lower tone, tighten these up a little more, then go round them all and give a little more tension, then a last check on truth. A good guide on spoke tension is to try to squeeze two spokes together with your fingers at a point were they cross each other if you can't move them a little say by 1mm relative to one another you are too tight. If you built it too tight it will break spokes in service, a wire wheel needs a little spring in it to work properly. For interests sake I adjusted the offset on a wheel for a client recently, the wheel had been professionally built with new spokes and rim by a well known British wheel building firm......I have never worked on a wheel that had its spokes so tight, my spoke wrench was rounding the nipples trying to get them loose (I think I ruined about 8 of them) frankly I personally would not have used a wire wheel in that excessive state of tension.
Remember after you have run your newly built wheel for about 500 miles go round the spokes again checking their tension.
Hope that helps.
Cheers,
George

DucMonzter
Posts: 40
Joined: Sun Feb 02, 2014 4:05 am

Re: spoke torque

Postby DucMonzter » Thu Jul 02, 2020 2:04 am

George - thank you for your wheel building advice. I've been following your procedure and have found it to be quite effective. One observation I had is that the outer spokes ring at a higher tone than the inner ones. I believe this is due to the outer spokes touching the hub flange - effectively shortening the spoke like a fret on a guitar string. Is this correct and do you have a method to equalize the tension between the inner and outer spokes?

The last time I built up a set of wheels, I brought them to a professional wheel-builder to check my work. He basically tensioned all the spokes with a torque wrench.... so I thought I needed that tool. Obviously, it wasn't necessary.

Thanks again for your help!
Jeff

blethermaskite
Posts: 477
Joined: Thu Mar 01, 2018 1:06 am
Location: northern ireland

Re: spoke torque

Postby blethermaskite » Thu Jul 02, 2020 9:16 am

Jeff, don't get me wrong I'm not saying a spoke torque wrench is not necessary for many people who build wire wheels....but I don't use one, and have never felt the need for this tool, in fact when I started building wheels I don't believe such a tool even existed,the task of wire wheel building is unfortunately for someone new to it very much a "learned through experience thing", In answer to your question, you are right in the different tone ring between inner and outer spokes and I neglected to advise on that.... if you spin your wheel slowly while ringing the spokes you should be just able to hear for want of a better guide the "ding dong ding dong ding dong" of the alternate spokes as it rotates and insure that as much as possible you can get this alternate tonal ringing evenly around the wheel.....this is not possible in every case especially when trying to true a wheel using a second hand rim that may have had previous damage and been subsequently straightened, under these circumstances you need to use differential spoke tension to pull the rim perfectly true in first instance and then aim to equalise spoke tension once you have achieved concentricity, but in practice the wheel may need to be put back in service for a few hundred miles of road use before you can relax the odd "tight" spoke that was necessary to pull the rim true, obviously under this circumstance ringing the spokes is not a great way to assess spoke tension until the rim has settled, hope that helps, sorry this is a tricky process to explain :) .
Cheers,
George

Ventodue
Posts: 952
Joined: Mon Mar 08, 2010 3:23 pm
Location: Montpellier, France

Re: spoke torque

Postby Ventodue » Thu Jul 02, 2020 4:57 pm

Good stuff, George. Interesting. Thanks.


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