I’m about to build up a new wheelset with an extra wide UDC Chromoly hub and Stealth Pro rim. Others have used the 3-cross lacing pattern for wheels built with these components, but I have a question about spoke length. The spoke length calculator on UDC UK predicts a 3-cross pattern needs 371.5mm spokes, but the 14g SS spokes from UDC are 376mm long. Does this extra length present a problem? Will the spoke ends poke thru the rim (potentially puncturing the inner tube)?
My RTL teammate Will Sklenars built a wheelset with the same components and had trouble getting optimal spoke tension as the nipples got to the end of the their threads before the wheel was optimally tensioned. Would extra short nipples help to prevent this occurring? Is there even such a thing as an extra short nipple?
Can anyone shed any light on this? I don’t really want to get 1/2way thru a wheelbuild and find I’ve got the wrong nipple length or something.
My spokes are definitely 376mm. I measured 4 and they were all 376mm, or very close to it.
I was thinking that 4-cross lacing pattern could work, provided I could find some longer nipples. Predicted spoke length needed for 4-cross is 380.75mm, so I’d need some nipples 5mm longer than the standard ones. I wonder whether these Halo XL extra long nipples might do the trick.
I recently built my wheel with non-ultra-wide UDC square-taper hub, SS spokes and stealth pro rim, using what I think were the Halo XL nipples. I did it in a four-cross pattern, and it was just about right.
But I don’t know that the nipples are any longer in the thread than normal ones - they do have a longer ‘shoulder’, meaning the square shape grabbed by the spoke tool comes out further. There are a couple of mm unthreaded under part of this square section, so your spoke has to go in a little way before it starts to meet the thread.
I guess they are meant to work with slightly thicker rim structures, as you can get the spoke wrench onto the nipple further up, but the length of the spoke will work out the same as with normal nipples. I think.
Sorry not to be more help with the ultra-wide hub though.
My new wheel is Stealth Pro, 14g spokes and normal width Nimbus ISIS hub, built 4-cross. Roger built it for me, so I expect it’s “right”. I don’t know what the nipples are, but one of them broke off after 20 miles… hopefully it’s only an odd weak one - Roger’s sending me some spares. They look to be brass, but painted black rather than plated.
You can’t make up for too-short spokes with longer nipples; if the spoke doesn’t penetrate up into the head/thick-part of the nipple, the thin/weak part of the nipple bears all of the load and the nipple will eventually fail at the junction between the thin part and the head.
If you have a wheel which has been experiencing nipple failures, I’d remove the tire and rim strip and inspect the spokes lengths. Ideally, the spokes should come flush with the bottom of the screwdriver slot in the heads. Sticking out a little is ok in double-wall rims (provided you don’t run out of threads when you’re tensioning the wheel). A millimeter or so short is probably ok as well, but you want to be sure that the spoke is getting good purchase on the head of the nipple. If they are “short”, I’d also verify that the spoke tension is correct, especially on a 36" wheel, as the spokes will stretch 1-2mm when tensioned.
My understanding is that Unicycle.COM has spoke blanks and can custom cut any length you want.
I’ve emailed Roger at UDC UK and he said:
"I do 4 cross and it seems to be ok. I have built over a dozen wheels like that and done a lot of miles on mine without a problem.
You need to do it 4 cross, unless you want to cut down the 376mm spokes and then you can use any nipples.
I have used both 14 and 16mm nipples but the 16 are definately better."
Looks like a trip to my local nipple dealer is order to get me some 16mm nipples! I think I’ll get black ones to contrast with the white of the Stealth rim.
For the record 4 cross lacing pattern is pretty much impossible. You’ve got to use 3-cross with this combination of components. I used these Wheelsmith extra long nipples instead of the standard 14G SS nipples.
Why do you say that? Roger built my wheel 4-cross and it seems fine (I replaced that broken nipple I mentioned in my earlier post and have had no problems since - I think it must have been a dodgy one).
Mine’s a normal-width hub though, so perhaps the difference in hub widths makes the difference between “just long enough” and “just too short”. I don’t know. Roger’s got vastly more wheel-building experience than I have, so I trust his judgement of how best to do it.