Does Mavic's previous flagship Ksyrium model still hold up?
A small French company called Roval invented the first specialist wheels but Mavic popularised them with the Helium 10 years ago. The Ksyrium followed in 1999 and little has been changed of the original design today, save for a tougher painted finish to the aluminium spokes and the machining of material from the midi section rims to save weight.
The hubs have a good reliability record and the distributors R J Chicken have an effective spares backup service to retailers. You have to be riding very hard and fast to tell them apart from the climb-light ES version but they are expensive compared to the handbuilt wheels of comparable weight.
Price includes skewers, wheel magnet, wheel bags and tools for truing.