New Sapim Super spoke

[Gregorio]

...

and increases in strength by 120N in the middle section.

Do spokes ever fail in the middle section?

[Epic-o]

Thanks jmartpr. I'm just searching around the net...

Maybe a good start for a new set...just as a mag90 hub that i would like to have in hands.

It will retail for 1500€ aprox. Start saving...

[Geoff]

http://www.light-bikes.de/website/new/2 ... felge-nabe

[rruff]

These are 1.8/1.4/1.8 mm spokes compared to Lasers and Revs and XL14s which are 2.0/1.5/2.0. They will be less stiff in direct proportion to their weight, as Eric mentioned. This is also the case with Ti spokes, since the elastic modulus/weight ratio is essentially the same for metals. Increasing the tension does not make the wheel stiffer... unless the spokes are going slack and the higher tension prevents this.

I'd be more excited if they were oval like CX-Rays...

[Danton]

Indeed, as has been said on here many times, you need a certain degree of tension but once you hit this point, any additional tension is of little benefit and soon becomes detrimental to the wheel, in terms of spokes breaking and rims failing. More isn't better.

These should be useful spokes, especially for the front wheel.

[mythical]

Yes but as Andy2 says, they don't build into good wheels because of their elasticity.

People, please think a bit more thoroughly before loudly exclaiming such faulty hypotheses.

[Danton]

Maybe elasticity was the wrong word? (Sorry, English is not my first or second language)

[andy2]

My error.
Please forgive me.
The Pillar Ti standard round spokes, the one's I feel are comparable to the Tune/Sapim superspoke, are pretty elastic.
The flat spokes like the Pillar Ti Aero are equal to or better than the Sapim Cx-Ray / Dt Aerolite in the stretch department.

[fdegrove]

Hi,

I'd be more excited if they were oval like CX-Rays...

End of story.

Ciao,

[ScienceIsCool]

The stiffness of the wheel is achieved through the tension of the spokes
where wheel geometry and the actual force achieved through wheel architecture is the most important factor determening wheel stiffnes.

http://www.sheldonbrown.com/rinard/wheel/index.htm

Spoke tension does not change stiffness. What affects wheels stiffness is angle between spoke and rim, number of spokes, spoke material, and cross-sectional area.

Imagine a small block of aluminum, on opposing sides (left and right) a spoke-like wire is attached. These wires are tensioned a bit so that the block is sitting there with a spoke pulling in opposite directions.

The block has zero-sum force acting on it, so it stays stationary. If you push it to the left with Z Newtons of force, the tension on the left spoke changes by -Z Newtons, and the tension on the right changes by +Z Newtons. The amount the block moves will depend on the change in tension (Z Newtons) in each wire and the amount the material stretches in mm/N. The amount it stretches in mm/N will depend on the material type and the cross-sectional area.

Note that it does *not* depend on the starting tensions on the left and right spokes.

John Swanson

[andy2]

You do need tension, enough tension to pre-tension the wheel, right?! The wheel needs enough tension so that the riders weight + the forces acting on it are less than the prestress. This way the wheel maintains it's structural integrity under real life dynamic loads.
Kinda like prestressed concrete.
Other than that you're just repeating what I said in my post.

[ScienceIsCool]

Correct, the pretension needs to be greater than any applied load to help preserve structural integrity. Also, it prevents premature failure due to fatigue. Cyclical stresses that unload the spoke cause more fatigue damage than if the spoke remains under tension.

John Swanson

[Bobbie]

Here is an article about the Sapim Superstrong spoke; www.wielernet.be/blog/58/sapim-superspoke.html (dutch)

[strobbekoen]

Spoke tension does not change stiffness. What affects wheels stiffness is angle between spoke and rim, number of spokes, spoke material, and cross-sectional area

That's only true if you measure one deflection in a static environment up to the point where spokes go slack.
A bit simplistic.
In a dynamic environment where load changes due to a varation in rider weight, terrain and power applied to the wheel under different conditions, and any combination of those, the stiffness of a wheel is what you said, plus the stiffness of the rim, plus the spoke tension required to keep the wheel from losing it's structural integrity - this can show itself as flexing, spokes going too slack, or eventually failure due to repeated stress.

[xnavalav8r]

Are these spokes available anywhere?