IN BRIEF
On 19 September in Girona, Leon Kaiser won the Spanish round of the UCI Gravel World Series, run over 109 kilometres, in a four-up sprint and in a time of 3h 03min 57s. The German was riding an Avona gravel bike on 32in wheels that the German brand was showing at the trade show without, road.cc notes, having revealed a single technical detail about it. According to road.cc, this is the first win for a 32in gravel bike on European soil — the outlet itself points out that the very first went to Robin Gemperle, at Unbound Gravel XL. The rider explained that these big wheels gave him, on technical descents, a level of control usually sought from a suspension fork.
| Race | UCI Gravel World Series Sea Otter Europe Girona, 19 September 2026 |
| Course | 109 km, 980 m of climbing (organiser’s figures) |
| Winner’s time | 3h 03min 57s, at an average of 35.62 km/h |
| Bike | Avona Callis in 32in, not on sale, no specs published by the brand |
| Wheels | Newmen Streem G.62: 62 mm deep, 45 mm external width, 27 mm internal width |
| Tyres | Schwalbe marked 50 (width) and 686 (the ETRTO diameter of 32in) |
| Drivetrain | Shimano GRX Di2, XTR rear derailleur, XTR 9-45 cassette, 42-tooth chainring |
| Pedals | Favero Assioma Pro MX-2 |
| For reference, the production Callis | 980 g frame in size M (clearcoat finish), 50 mm tyre clearance |
The 32in wheel spent the summer making its way into mountain bike fields; it has now won a UCI-sanctioned gravel race. On 19 September in Girona, at the Sea Otter Europe round of the UCI Gravel World Series, Leon Kaiser won on a bike about which his brand had, as of race day, published no detail — an Avona Callis built up on big wheels, spotted on the show stand before it turned up on the finish line.
A four-up sprint after 109 kilometres
The 2026 course for the Girona round covers 109 kilometres for 980 metres of climbing, according to the figures published by the organiser. Kaiser, a cross-country specialist, completed it in 3h 03min 57s at the end of a four-up sprint, at an average of 35.62 km/h. According to the results sheet relayed by granfondodailynews, Paul Voss and Fabian Rabensteiner finish one second down, Georg Egger eight seconds back.
On the results sheets, the winner appears not under a team name but under that of his bike brand, Avona. And it was the machine, more than the sprint, that caught the attention of the observers on site.
An Avona Callis in 32in that the brand says nothing about
32in wheels do not fit an ordinary gravel frame: they need a geometry drawn around them. Avona does therefore have a specific Callis, and the German brand was showing it at the trade show. But, road.cc notes, it has so far revealed no technical detail about it. On its stand, rennrad-news reports, the brand was nonetheless announcing a commercial launch on 15 October 2026. The only point of comparison available remains the spec page for the production Callis, which claims a frame of 980 grams in size M and 50 millimetres of tyre clearance. According to rennrad-news, that production model was itself on show at the event in a 32in configuration, fitted with in-house Kornkreis wheels, and would differ from Kaiser’s race bike only in a few details — without Avona having published any spec sheet for this version.
To tell 29in and 32in apart by eye, road.cc offers a simple marker: the sidewall of the Schwalbe tyres fitted to Kaiser’s bike carries the markings 50, for the width, and 686, which is the ETRTO diameter corresponding to 32in — against 622 mm for a 29in. Schwalbe has also made official G-One RS Pro and G-One RX Pro tyres in 686 mm, offered in 50 and 55 millimetres.
Deep-section Newmen wheels, in a size the brand has not listed
The bike was fitted with Newmen Streem G.62 wheels, a gravel wheel whose official spec page claims 62 millimetres of depth, 45 millimetres of external width and 27 millimetres of internal width; the CS version with carbon spokes is given at 1,530 grams a pair. As of 20 September, the gravel page on the Newmen site listed no 32in version of this wheel; the brand does, however, publish a technical page dedicated to the size, where it compares among other things the lateral stiffness of 28/29in and 32in, i.e. ETRTO diameters 622 and 686 mm.
The rest of the machine is a classic race build: Shimano GRX Di2 groupset, XTR rear derailleur paired with an XTR 9-45 cassette, a 42-tooth chainring and Favero Assioma Pro MX-2 pedals, which also supply the rider’s power data.
What Kaiser says about 32in in gravel
Asked at the finish by road.cc, the rider explained that the 32in wheels had given him, on technical descents, a level of control usually sought by fitting a suspension fork. To rennrad-news, he added that he had opted for this bike after finding in testing that its behaviour, on technical sections, brought it closer to a mountain bike, the discipline he comes from; he cites cornering hold and the ability to clear obstacles as the main benefits.
That leaves the exact significance of the result. According to road.cc, this win is the first for a 32in gravel bike on European soil. According to the same article, the format had already won in gravel with Robin Gemperle, at Unbound Gravel XL, a 350-mile event held in Kansas. The Girona success therefore brings big wheels into the UCI gravel calendar in Europe, on a bike whose spec sheet Avona had not published as of 20 September.
