Curved washers, tension for a carbon rim

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crewdoglm
Posts: 10
Joined: Wed Sep 26, 2012 3:52 am

by crewdoglm

I am about to build up a set of 50MM 28H generic carbons (Ebay "Jerry's store). Taking the view here that "Jerry" et al are the OEM's to huge $$ known brands. (My $2800 Reynolds 46's still have the sticker from "Jiu Jeng.") Jerry himself - maybe Jiu Jeng, indicates 150 kg as the max and further states that he builds these to 130 all the time without curved washers. I am dismissing that for obvious reasons and going with washers. So, who knows the best washers? The Sapims? I am thinking 120 on the tension. Opinions cleared hot: go

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eric
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by eric

If you post a link to the rims then maybe someone will recognize them and know something about them.

Chances are you can't get the curved Sapim washers into the rim as the nipple holes will be too small. The PolyAxe washers are 7mm which fits through most nipple holes (well, all that I have tried them on).

With any washer you want the washer to fit the contour of the rim. If the washer is say 10mm across and your aero rims are 7mm wide at the spoke bed, the force will be borne on the sides of the washer. It the washer is thin and flexible it will conform to the rim shape, but thicker washers like the PolyAxe and Pillar's small washer will not. They'll be concentrating the force on smaller thinner parts of the rim. Not what you want.

Before I tried PolyAxe washer on XR270 rims I cut a broken one at a spoke hole so I could see how the washer matched the inner profile of the rim. On that rim it's pretty good.

When I built wheels with FarSports carbon clincher rims I did not use washers becuse I did not know how they'd fit. Even though the FarSports are very light for 50mm deep rims the spoke bed is much thicker than the typical aluminium rim spoke bed. So much that I should have used 14mm nipples rather than 12mm. If your rims have a thick spoke bed then you probably do not need washers.

wrcompositi
Posts: 135
Joined: Tue Dec 04, 2012 3:57 am

by wrcompositi

[quote="eric"]If you post a link to the rims then maybe someone will recognize them and know something about them.

Chances are you can't get the curved Sapim washers into the rim as the nipple holes will be too small. The PolyAxe washers are 7mm which fits through most nipple holes (well, all that I have tried them on).


Thanks for the insight Eric! :thumbup: I'm about to buy rims from Farsports and not sure if it's necessary to use washers, it's good to know Farsports' rims have robust beds.
Last edited by Frankie - B on Tue Jan 01, 2013 8:50 pm, edited 1 time in total.
Reason: deleted the quote

ultraman6970
Posts: 5
Joined: Mon Dec 31, 2012 9:12 am

by ultraman6970

+1 on this one. Even with some aluminum rims you have the same problem but you arent off resources tho. I believe is pillar, they have smaller nipple washers, the problem is get them in the US.

Good luck.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
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by eric

Pillar nipple washers are slightly smaller in outer diameter than the Sapim PolyAxe washers. You can get them from bdopcycling.com. If you need measurements I can take them.

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