New Bontrager Aeolus RSL climbing wheels have been spotted fitted to Trek-Segafredo team bikes ahead of stage one of the Tour Auvergne-Rhne-Alpes. Currently Bontrager lists 37, 51, 62 and 75mm deep versions of its Aeolus RSL wheelsets, and two other Pro spec wheelsets with wider 25mm internal rim diameters. The new wheels feature carbon spokes. Ashley Quinlan / Our Media The new wheels feature updated branding, but they are materially different in that they feature carbon spokes a first for Bontragers wheelset lineup. Carbon spokes are gaining popularity in the pro peloton currently, with purported benefits for weight and stiffness, while various team mechanics have claimed to BikeRadar that theres an increasing belief that concerns around reliability have been addressed. The rims are 'just' 21mm wide internally, and remain hooked. Ashley Quinlan / Our Media The supplier of the spokes is unknown, but they look similar to Vonoa spokes used by many other brands. These rims appear to be evolutions of the Bontrager Aeolus RSL 37 wheelset, continuing to use a 21mm internal rim diameter. Bontrager has also stuck with a hooked rim design, indicated by the 'TC' (tubeless crotchet) demarcation all other things being equal, hookless rims are said to be marginally lighter due to the absence of a hook, but Bontrager has stayed firm here. The team is using lightweight Tripeak hub shells. Ashley Quinlan / Our Media 21mm is narrow by modern standards, but the lower width should result in a low rim weight regardless of the presence of a hook. The hubs on these wheels arent Bontrager-spec, though. Instead, Trek-Segafredo is using Tripeak hub shells a supplier of lightweight accessories to many teams in an attempt to cut further weight. The team was tight-lipped when asked for details before the race start, so well report on their availability and any further design tweaks in due course.