Nipple/spoke angle question

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alcatraz
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by alcatraz

Thats interesting that the issue is more pronounced on the front wheel.

Maybe the front wheel hub flanges don't have enough offset to warrant an assymetric rim?

/a

by Weenie


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ergott
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by ergott

Could you post more pics of the complete wheel? What are the rims and hubs used?

pushstart
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by pushstart

Sure, I will try to get some more photos later today of complete wheels.

The hubs are Hope Pro 4. Perhaps the offset is not quite enough to justify asym for front, but the tensions were still higher on the disc-side, so I suspect that this is really just a rim deficiency.

Rims are Yishun WTD3C-DISC-ASD 28/28h (laced 2x/2x).

pushstart
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by pushstart

Sorry, a bit hard to get a detailed picture of full wheels. And I think it is similarly pronounced on the rear wheel, upon closer inspection.ImageImageImage
Image

alcatraz
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by alcatraz

If your nipples develop cracks or simply get seated over time you might notice a slight drop in tension. Could need an adjustment later.

Just go with it and see what happens. If you have to replace nipples one day it couldn't hurt to angle those problematic nipple holes by a few tenths of a millimeter using a dremel. Wheels aren't jewelry. It's a structure that has weaknesses. The nipple holes are not going to be the weakest point for a structure failure by giving them a little tilt in the right direction.

The nipples and hub flanges being alloy are going to be the weakest point is my guess.

What's your tire to chainstay clearance on this bike? These tires are huge. :D If your rear wheel stiffness drops you could one day see some chainstay rub. If you do break a rear wheel nipple it could make the bike undrivable because of the nonexistance tire clearance. When I broke a spoke once it resulted in the tire (23C) rubbing the chainstay. I solved it by clamping the wheel extremely tight at an angle in the dropout and made sure I didn't hit any bumps limping home which would have seated and damaged my chainstays. Seeing as you have throughaxles that won't be possible.

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ergott
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by ergott

I was concerned that they were laced incorrectly, but that's not the case. Looks like a matter of straight drilled nipple holes. The geometry of the hubs is not the culprit.

pushstart
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by pushstart

Good point on tire clearance! :-) these Compass Snoqualmie Pass tires are big (44mm), but I still have ~4-5mm on each side. Might not survive a spoke breaking without rubbing, though. I was a bit amazed on a ride yesterday, though, that bent a spoke (and the nipple to a 45° angle) on another set of carbon wheels (LB 36mm) when a big stick somehow launched into my wheel, but the rim/wheel stayed almost completely true. Not sure if that is a difference with these carbon rims, but made sense -- and further convinced me that carbon is pretty nice for off-road wheels (too).

Last edited by pushstart on Sun May 27, 2018 3:30 pm, edited 1 time in total.

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WinterRider
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by WinterRider

alcatraz wrote: ↑
Fri May 25, 2018 8:55 am
This might sound crazy (i'm not a wheelbuilder)
/a
The end. :roll:

alcatraz
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by alcatraz

What do you say... shall we whip them out and measure? :lol: :D

Relax... We all approach things differently. I wouldn't want a forum full of alike-thinkers. We could all use a different perspective every once and a while.

TheKaiser
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by TheKaiser

The suggestion about opening up the holes a bit with a drill bit does not sound all that outrageous to me. I've seen people do that quite a bit on the earlier CCCRims for mountain bikes that were drilled straight, and often poorly at that. You could also use a small round file, like one of the diamond grit coated ones, and if you are really worried about damage to the cut ends of the laminate you could run a q-tip through the hole with a very thin viscosity epoxy to wick into any voids in the ply.

It looks to me that (properly done) directional drilling, combined with polyax nips and the corresponding washers prevents this sort of situation, and so by re-shaping the holes you are basically just doing a DIY directional drilling to make up for the manufacturers shortcomings (albeit with more total material removed than would be optimal).

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kavitator
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by kavitator

If nipple has washer under head rim wont break- Problem could be where spoke gets in nipple - after time it can break there - and than you replace spoke.

Not big problem if you do good bed in spokes.

alcatraz
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by alcatraz

Steel can bend pretty well. Probably the alloy nipple will fail first.

/a

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