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#21
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Spoke threads exposed on new wheel - Safe?
"B.C. Cletta" wrote in message om... "Josh Gatts" wrote in message ... You could also measure the length of a nipple to the base of the slot (N), the length of the threading (T) on a spoke, and the length of exposed thread (E). If your existing spoke is length L, you buy spokes of length L + N - T + E. Heh heh. it's 56-TPI so 6 exposed will be 6/56 inches too long. The OP has 6 threads exposed on the hub side of the nipple. So 6 exposed will be 6/56 inch too *short*, right? --Josh |
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#22
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Spoke threads exposed on new wheel - Safe?
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#23
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Spoke threads exposed on new wheel - Safe?
Pete Biggs writes:
I just noticed that Peter Chisholm has recommended just replacing the nips with 16mm. That's probably the best & cheapest solution, although it may look a little goofy. That won't help much, the threads in most longer nipples not being any longer than the short ones. It will only be a cover-up, not an improvement in thread engagement. Does that include DT: one of the most popular makes? DT 2.0 x 16mm have 22.5 turns worth of thread, 12mm have 18. That's not the way it was supposed to work. That would require a different spoke length for the same ERD but different nipple lengths. I hope someone who doesn't build wheels didn't mess this up. As you see from this thread, ones first impression is that the threads should be longer, when in reality they should not, all rim ERD's requiring the same length spoke regardless of nipple type. I have one inch nipples for wood rims that have the same length of threads at the head end as medium and short nipples, the ones commonly used on metal rims today... except for he aero crew. I'm screwing nipple onto spoke (with an extra long threaded section) and counting turns from the point where it engages enough to just hold, to point where end of spoke is flush with top of head. That's too bad. Where have all the experts gone??? Jobst Brandt |
#24
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Spoke threads exposed on new wheel - Safe?
"Mark Vieselmeyer" wrote: I also had less than ideal results with an OCR rim. I just built a wheel with a Ritchey Aero Road OCR rim that spocalc lists as 606mm, and I ended up with about 1mm protruding out the back end of the nipples. Looking at spocalc again, it has in parentheses "ERD is nipple contact dia + 3mm for nipples". Does that comment mean I needed to make some adjustment to the numbers before plugging them into the calculator? I know I had the right hub dimensions, because I verified them calipers. Anyone have a good technique for measuring ERD? My copy of Spocalc shows all Ritchey 700c rims as 606mm ERD, with a note that says "Spoke Seat 602mm." No mention of +3mm, but 602 + 3 would be 605mm which sounds like it would have been perfect for you. Art Harris |
#25
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Spoke threads exposed on new wheel - Safe?
"B.C. Cletta" wrote:
or (B): simply measure the depth of the hole from the bead diameter, 622-mm for a 700c. don't forget to 2x it. Ooh, I never heard that one. Clever! Art Harris |
#26
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Spoke threads exposed on new wheel - Safe?
"S. Anderson" wrote in message . .. "Dave S" wrote in message om... Last night, I built a new rear wheel for cross riding using a Record 36 hole hubs, a Ritchey OCR Comp rim (called Trekking on web site) and DT 14/15 spokes. On inspection, I noticed that the left side as 2-3 threads exposed all around whereas the right side has 5-6 threads exposed. I'm comcerned that the spokes are too short and I don't have enough threads embedded in the brass nipples. Is this wheel safe or should I rebuild it with longer spokes? Rebuild it. 1 or 2 is ok in a pinch. 5 or 6 is NFG. Especially on the drive side. Cheers, Scott.. Sorry guys, a question. Any spoke/nipple area failures I've ever had (usually from objects being caught in the wheel) have either popped the head off the nipple or torn the rim (once.) Unless others have seen stripped threads, why would a shorter engagement make a difference Cheers Hugh Fenton Serbia and Montenegro - but that's another story |
#27
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Spoke threads exposed on new wheel - Safe?
"Hugh Fenton" wrote:
Sorry guys, a question. Any spoke/nipple area failures I've ever had (usually from objects being caught in the wheel) have either popped the head off the nipple or torn the rim (once.) Unless others have seen stripped threads, why would a shorter engagement make a difference Less thread engagement means more load (and more friction) on the threads that are engaged. In addition to a greater chance of failure, it could make it harder to turn the nipples when truing. Art Harris |
#28
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Spoke threads exposed on new wheel - Safe?
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#29
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Spoke threads exposed on new wheel - Safe?
Less thread engagement means more load (and more friction) on the threads
that are engaged. In addition to a greater chance of failure, it could make it harder to turn the nipples when truing. hey art the only "engineering" argument for more threads is friction. all stress anyalsis shows it's only the first 3 threads that take the load. the rest are just along for the ride. jb |
#30
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Spoke threads exposed on new wheel - Safe?
Jobst- That won't help much, the threads in most longer nipples not being any
longer than the short ones. It will only be a cover-up, not an improvement in thread engagement. BRBR 16mm DT nipples has 4mm more threads, starting the same relative place on the nipp as 12mm ones...Sincle the spoke looks about 4mm too short, I would try this $3.20 solution first, or have the LBS give you a few to try. Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302 (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene" |
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