Sapim CX-Ray spokes not stiff?
agg25
Posts: 619
Looking at a new AM wheelset (Bor hubs/ZTR Arch EX/brass nipples), and the wheelbuilder has advised against the Sapim CX-ray spokes saying they're light and all but a bit flexy/not as stiff as his recommendation (which I can't remember). Any truth to this?
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Comments
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Yes, they are not as stiff as a standard 2.0/1.8/2.0 DB spoke.0
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it shouldnt make a difference as spokes work under tension. Thinner spokes require higher tensions to make up for the extra bit of stretch they have. DT Revs and CX rays have the same diameter (the CXrays are forged flat afterwards), so will perform the same but crucially you can use a spoke holder on a bladed spoke and get a high tension without any spoke twist.
Strength wish, there is no difference. Sapim say that CX-rays actually have a longer fatigue life.
If you want stiff wheels i would get a heavier and stiffer rim combined with CXrays to drop the weight back to the same. ie Crest with Butted spokes isnt going to be as stiff as 719 mavic with cxrays, but the weight will be the same.
Neil (superstar)0 -
They work under tension, but the stiffness of the wheel is determined by the elasticity of the spoke, and not tension (to a point). Spoke cross section determines spoke elasticity. Adequately tensioned wheels are no more flexible than highly tensioned ones, but highly tensioned wheels are less likely to come loose - wheel stiffness does not vary significantly with spoke tension unless a spoke becomes totally slack.
32 spokes, 3x, with CXrays does build into a more flexible wheel than a standard 14/15g spoke. But they do have good fatigue qualities as you say, and critical tensile strength.0
