If you?re a pro equipment spotter (read ?anorak?) you will probably have noticed the Xentis four-spoke wheel on the front of Jan Ullrich?s time trial bike. And you will have read about how a mechanic fitted it the wrong way round for last year?s Tour of Germany time trial, costing him an estimated 20 watts. Ullrich still won the time trial, but lost the overall win to Levi Leipheimer by 31 seconds.

Independent tests have shown the Mark 1 to be extremely aerodynamic ? when it?s the right way round. We have even seen a test showing that the wheelset (including the rear) is faster than a rear disc/composite front.

A carbon-fibre monocoque construction using the Austrian company?s in-house One Shot technology ensures that the Mark 1 has no wind-catching joins and no weak spots. And helpful white stickers identify the leading edge.

They are not only super-aerodynamic but the weight is impressive too for a composite wheelset which incorporates a 42mm deep-section rim ? 1,448g for the tubular version, Shimano or Campagnolo. Hubs are DT Swiss Hugi.

They cost £1,249 in 700c tubular and £1,175 clincher per set.

Contact Onimpex 01925 570916, www.onimpex.co.uk.