Sebastian Roth is back with his amazing tunings. He had the lightest wheelset during some weeks but Gunter Mai beat him with his 704,4g Lew Pro VT-1 wheelset. The Lightweight Challenge 700 Sebastian had, weighted 721,3g... it's about a few gramms difference so he went ahead to lighten further his hoops to beat the american product.
Well, the structure of the Challenge 700 is already pretty light and so he couldn't save weight here. His front wheel was already lightened as much as possible too, it included the full ceramic bearings, the carbon axle. Its weight was 298,8g. But the rear wheel still had some weight save potential: it was 422,5g but deserved some more attention.
"I wanted to save a lot of grams here without influencing the stability of the wheel" said Sebastian.
First he looked at the bearing: the Lightweight Obermayer rear wheels use a Tune mechanism, and obviously their bearings. Unfortunately the central XOT bearing designed by Tune is only available in hybrid ceramic, not in full ceramic. There was thus some weight save over here: he replaced the XOT hybrid ceramic bearing by a combination of a 6902 and 6802 full ceramic bearing. Although the stiffness probably is down to a lower standard since there are two separated inner races instead of a single wide one, it saves weight.
Second, the Campagnolo rotor was the only part that was not lightened at all: the biggest weight reduction came from here. The pawls were drilled, the body received an extra machinning where the thickness was high enough. The weight of the body, including the 6802 central bearing was only 31,9g while it is normally about 40g.
Third, the carbon axle received some lighter alloy end caps and ended the weight reduction at 24,2g.
His Challenge wheels now weight 697,1g and they were renamed Challenge 600.