Spokes Aint Spokes - or are they?

[Monkeypants]

hmmm, from that perhaps I should increase to 80 inch pounds. I asked the torque setting question of Devon and the response was that spoke torque wrenches did not exist in the 40s, 50s and 60s.It occurs that while that is true, there are a whole host of things we use today which make jobs easier, computers and email correspondence for example.
I'm all for anything that can produce a better job, more consistent results or just make the job easier!

Glen

 

[deejay499]

When I had my wheels done for the outfit, I enquired about using SS spokes on an outfit and the wheelbuilder said they use them on their grass track outfits without a problem. Time will tell if he was correct.

 

[Oldhaven]

I am lacing a 21 inch Central Wheel Classic Elite rim for my Rapide, (really nice looking rim), and have followed the conversations here and elsewhere about spoke torque. I have a torque wrench and was going to go into the 60 to 80 inch pounds area, as Davidd does with Buchanan components but as I get to the range of 45 to 50 I find that my sense of feel is telling me to stop. I can further see that as I rotate the rim the flat area below the raised lined area reflects the light differently, indicating slight distortion from the tension at each spoke hole. I have got the rim to +/- .010 both ways, and the spokes ring true though not exactly all the same. These are 9 gauge spokes and the nipples are 1/4" plated brass. The nipples are smaller than the ones I had on the 20" rim. It has a 9 gauge spokes and 9/32 stainless nipples combination from Buchanan's. I am a bit concerned about going any higher, and will stop at just between 45 and 50. I checked with Central Wheel and their wheel builders only lace and tune by sound and feel, and don't use torque wrenches. Are the 80 to 100 figures Buchanan uses for just their heavier gauge spokes and larger stainless steel nipples? I suspect that the smaller size and brass material of the plated nipples would not stand up to a higher torque, just from my instincts of over 50 years tightening things (and stripping a few early in my learning process).
I measured the thickness of the rim and it is about 1/16" I happened to have a black painted 19" rim around, probably dating from the 50's, and it is about .020 thicker, another reason telling me to stop where I am. The Elites are given special polishing treatment and may be thinner, as David mentions in his quote. Interestingly the black rim has blue striping where the red would be on a black lined Vincent rim.

Ron

Martyn,

I have always used Buchanan SS spokes (one size or style) on the racer and street bikes. Buchanan ships directions with their SS spokes that tell the builder to torque the spoke to 80-100 inch pounds or the spokes will break. I have never had a broken spoke. If you are not going to use a torque wrench, I would use steel spokes. They will survive all sorts of abuse with fewer failures. I would probably recommend steel spokes for sidecar work, but I have had such good luck with the SS on my bikes that I would definitely give SS a try on my own sidecar machine. You should not try these high tensions with re-plated rims as the spoke nipple area is polished too thin and the nipple will pull through.

David

 

[Monkeypants]

In searching for information on spoke torques, I found a few factory recommendations. They were all in the 45 to 55 inch pound range. KTM calls for 50 inch pounds on their dirt bike wheels. Those wheels would take a greater pounding than most road bikes will ever see.
I also found an interview of the Senior Mr. Buchanan where he discusses the spoke torque they use. As David posted, it is never less than 80 inch pounds and sometimes even higher for very heavy motorcycles with very heavy gauge spokes. He also mentioned that they only use these very high tensions on their own brand of rim, the Sun brand, as it is designed to withstand that high tension. When they are lacing other brands they use somewhat lower tensions. I have a pair of Sun alloy rims on one Rapide and they are almost as heavy as Dunlop chrome over steel rims!
With the Morad flanged alloy rims and 9 gauge spokes, I stopped tightening at 55 inch pounds, it felt about right.
Glen

 

[Monkeypants]

He also mentioned that Buchanans use torque wrenches on all wheel builds.
Glen

 

[davidd]

I think torque wrenches have become popular because the motocross boys use them quite a bit. If a spoke is damaged they replace it and run it up to the correct torque, and they are off to next race. I loaned my torque wrench to another Vincent owner who proceeded to pull a nipple through a brand new steel rim. This provoked a discussion where I was told that Buchanan's had revised their figures lower. I called Kenny Buchanan and talked to him for about 20 minutes and he said that they had not amended their torque numbers. He told me they vary quite a bit from make to make. He said a Harley Sportster front hub will break at anything over 25 lbs. My understanding from our conversation is that you can run the spokes looser, it just increases the likelihood of breakage.

I don't know if they still include instructions with their spokes, but attached is a copy of the instructions I received when I ordered spokes and rims from them for the racer. I think I have a good sense of feel, but I thought that the instructions were included specifically to overcome that. Still, I think you should follow your sense of feel, after all you are riding it. My sense of feel now is that everybody is riding around with loose spokes!

David

 

[Monkeypants]

I was very happy to be using the spoke torque wrench recently when lacing up some Central wheel supplied Morad/Akront flanged alloy Commando rims. These were for my MK3 Commando which has a big offset and conical type hubs. I found them to be quite difficult to true as there is a big difference in spoke angle and length side to side. After much fiddling, the offset was correct and the rim was running close to true at about 40 inch pounds, so getting close to completion. I was going to stop at around 50, however one nipple stripped out with a bang at 45 inch pounds. I replaced it and carried o when another let go. I realized something was wrong and started checking things to find that I had been supplied with 10 gauge spokes and 9 gauge nipples. The diameter difference of about twelve thousandths meant that the nipples threaded a bit loosely onto the spokes, bjt held firm until around 45 inch pounds at which point they let go. I'm not sure I would have found this without the torque wrench. Without the wrench I likely would have made the incorrect assumption that my tensioning was too great or never have gone high enough to even spot the problem.

 

[Oldhaven]

Thanks guys. I finished up with all in the 45-55 inch pound range. The torque wrench helped me too because it allowed me to get them all nearly uniform before I got into the final truing stage, and I didn't have to guess or resort to weights and scales to know where I was, regardless of the final figure. It will also be useful after I get on the road as I can determine if things are going slack, and David has me being careful. Central sent a couple of extra spokes and a spare nipple, so aside from the PITA factor, I can afford to break a spoke or nipple, but I did not want to pull one through the (pricey) rim. I can understand what Buchanan is saying, as it must be like head bolts. You don't want that initial stretch to happen after you start riding. It would be interesting to measure a spoke, including the bend dimensions, before and after tensioning, but I am not messing with it now.

I got the Tusk adjustable torque wrench kit, but it did not have a head to fit the .218 nipple flats. The smallest it had was 6.1mm. I had to make a 5.6mm head to fit it, and of course it has to have the right offset and dimensions. Their manual wrenches come in smaller sizes, but not the torque wrench. Something to watch out for if you want to buy a wrench.

Ron