New wheels! (Fulcrum Racing 5)

[EasyPeez]

Andy, straight-pull spokes have a disadvantage in that the tension is held by the weakest part of the spoke - that being the mushroomed head. An elbow is stronger and more durable. Straight-pull spokes are almost always necessitated by a design quirk without a reason, usually aesthetics or marketing differentiation. Elbow spokes wheels are better but don't look exotic.

Ah, ok. So straight pull are indeed all fur coat and no knickers, then. I thought there must be some performance advantage that I was unaware of. Thanks for clarifying.

Having said that, they are excellent spokes. If you are considering having wheels built with CX-Rays, rather spec Sapim Laser spokes.

I don't mind the expense as I am saving up and looking at this as a one-off. I am going for the best parts I can reasonably afford so thought, as the spokes take the majority of the strain and are the cheapest element in a wheel build, to go for the best of the best spokes and work backwards from there. I'll take a look at the Lasers; it seems they are more or less the same weight for approx 2.5x less money. Assuming durability is similar they seem a good alternative.

none of the disadvantages of bladed spokes. These are their tendency to twist in use and lie flat against the wind.

Wouldn't this only happen if they weren't properly tightened up though? Or are you saying the wind can gradually cause them to twist loose?

Never fit spokes, especially expensive spokes, with aluminium nipples

Yep, thanks to your previous advice I am ignoring the temptation to match orange nipples to my orange hubs and am speccing black brass.

Thanks again for all the advice

 

[Yellow Saddle]

Ah, ok. So straight pull are indeed all fur coat and no knickers, then. I thought there must be some performance advantage that I was unaware of. Thanks for clarifying.


I don't mind the expense as I am saving up and looking at this as a one-off. I am going for the best parts I can reasonably afford so thought, as the spokes take the majority of the strain and are the cheapest element in a wheel build, to go for the best of the best spokes and work backwards from there. I'll take a look at the Lasers; it seems they are more or less the same weight for approx 2.5x less money. Assuming durability is similar they seem a good alternative.


Wouldn't this only happen if they weren't properly tightened up though? Or are you saying the wind can gradually cause them to twist loose?


Yep, thanks to your previous advice I am ignoring the temptation to match orange nipples to my orange hubs and am speccing black brass.

Thanks again for all the advice

Lasers/Revolutions are excellent but require special building skills. Find a good builder. They are hellishly difficult to bring up to good tension because they twist when you turn the nipple and you cannot hold them. The flat spokes on the other hand are easy to hold, you simply use a little slotted instrument. Round ones cannot be held, not even with pliers or mole grips. But it can be done.

Why do CX-Rays twist in use? The primary reason spokes twist in use is residual torque in the spoke left over from the build. This is usually heard when you first ride new wheels and you can, within the first few hundred meters, hear the spokes make a zirrrts noise and you know (and can verify later on in the jig) that they've untwisted. However, with flat spokes you can prevent residual twist and I have no explanation for why they do it against all logic. Sometimes the little bit of movement (you can even see it in some of the photos I googled to find a photo of the wheels in question in this thread) is against tension. One day I shall have an aha moment but to date not, not even in reading everything on the subject and using all I've learnt of engineering. They just do it. Have a look at anyone's Zipp wheels next time you have an opportunity. One or two of the spokes will have twisted to paddle against the wind.