you could check out carbonsports for further details.

tobias.

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nothing.

Thanks. Only in German at present?

Ignore me, I found the English bit.

why are those wheels uphill only? There are lighter wheels that have no descending restrictions. Carbonsports can you shed some light on this?

Braking surface less resistant.

Carbonsports says:
"The “L’Alpe d’Huez” wheelset has been developed specifically for the demands of uphill time trials. To achieve the least possible rotary mass, the rim’s brake surfaces have been lightened. Thus, the brakes must be used sparingly and not with brute force. Only use these wheels in flat or uphill sections. They are not designed for the braking forces encountered when riding downhill. We offer other wheels for these purposes."

See http://www.carbonsports.de/English/index.html click on the wheel and then click on all the sections of l'Alpe...

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"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

well, i dont know about that (not being able to hard brake)

what would happen if you did brake hard? i guess it would be a good back wheel (use the normal version for the front); front wheel is what really stops you on the downhill. but i guess its progress from carbonsports, keep it up.

Well, if the guys who make them say so...I'd believe them.
The rims are probably light (fragile) re: buckling due to side impact and/or concentrated loading or squeeze pressure on the rim wall.

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"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

They would be great track rims as well!

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Success is how far you you bounce back up after being knocked down