Summary
- Schwalbe announced on 18 September that the G-One RS Pro and G-One RX Pro will come in 32 inch, in 50 and 55 mm, from April 2027. The ETRTO diameter is 686 mm, per off-road.cc.
- Schwalbe's head of product management, Felix Schäfermeier, says the size gives more stable handling, better traction and more comfort. BikeRadar quotes him opening with scepticism about the idea.
- Robin Gemperle won the 2026 Unbound XL on prototype 32 inch G-One RX Pro tyres fitted to a prototype Scott, which Scott says will not reach production.
- The bikes are the bottleneck. Cycling Weekly lists Mosaic, Salsa, Stinner and a handful of framebuilders, with mainstream production still thin.
- Every gravel bike in the pre-owned market is 700c. That ecosystem is not going anywhere for years.
What Schwalbe actually announced
Two models, two widths, one date. The G-One RS Pro is the fast, low-tread racing tyre. The G-One RX Pro is the one with more bite for loose ground. Both arrive in 32 inch, 50 and 55 mm, in April 2027, per off-road.cc and BikeRadar. Schwalbe will also sell 32 inch inner tubes and 32 inch mountain bike tyres in the same window.
A 32 inch tyre is not a new rim diameter conjured from nothing. It is the 686 mm ETRTO bead seat, taller than the 622 mm of 700c and 29er. Mount a 55 mm tyre on it and the outside diameter passes 80 cm, which Cycling Weekly's Simon Smythe identifies as the source of most of the problems below.
| 700c gravel, 45 mm | 32 inch, 55 mm | |
|---|---|---|
| Bead seat diameter | 622 mm | 686 mm |
| Tyres on sale today | Every gravel brand | Prototypes and small batches |
| Schwalbe availability | Now | April 2027 |
| Production bikes | Hundreds of models | A short list |
| Pre-owned market | The whole category | None |
The case for the bigger wheel
The argument is geometric. A larger wheel meets an obstacle at a shallower angle, so it climbs over instead of stopping against it. On the washboard and chunk of long American gravel that matters more than it does on tarmac.
Schwalbe's own claim, in Schäfermeier's words to off-road.cc, is stability, traction and comfort. Note what is not in that list. Schwalbe has not published rolling resistance numbers for the 32 inch tyres against the 700c versions. The lower impedance argument is sound in theory and is not yet a figure anyone can quote.
The strongest evidence so far is a race result. Gemperle rode prototype 32 inch G-One RX Pro tyres to victory at Unbound XL, a 350 mile event, in just over 21 hours. That is a real test on the kind of course the size was designed for.
The case for waiting is also the case against the wheel
Tyres are the easy part. The rest of the system is where 32 inch is thin.
- Frames. Clearance for a 686 mm rim with a 55 mm tyre is not something a 700c gravel frame can be persuaded into. It needs a new front triangle and a new fork.
- Forks and rims. Neither is widely available to buy separately yet, which limits custom builds as much as it limits brands.
- Small riders. Smythe's point is the sharpest one. Once the wheel passes 80 cm, toe overlap and front-end geometry get difficult below roughly 1.73 m of rider height. No brand has shown a convincing answer.
- Weight and acceleration. More circumference means more rim, more tyre and more rotating mass. That is paid back on rough ground at steady speed, and paid out at every surge.
- Resale. A 32 inch bike bought in 2027 will sit in a market with almost no wheel, tyre or spare supply for several years.
Cycling Weekly counts Mosaic's titanium GT-1 i55 32 as a production model, Salsa Fargo framesets, plus Stinner and a short list of builders and component makers. Vittoria and Kenda are expected to follow Schwalbe with their own gravel rubber. Canyon has built exactly one, for LeBron James. That is a scene, not a category.
What the new race bikes tell you
The three gravel race bikes launched this month are all 700c. The Ridley Kanzo Fast 2.0 clears 58 mm, the Factor Elara clears 57 mm, and the new Canyon Grail clears 57 mm. A colleague sets out the whole pattern in our gravel race bikes 2027 explainer, also in this batch.
That is the industry's actual bet for the next two seasons: keep 700c, go wider. Brands committed tooling to 57 mm clearance in 2026 knowing the 32 inch conversation was already running. They are not expecting to replace those frames in a year.
Who should wait, who should not
Wait if you race long, rough American style gravel and you are over about 1.80 m. Wait also if you were going to order a custom frame anyway, and can live without spare tyres on a shop shelf. Under those conditions a 2027 purchase makes sense.
Do not wait if your riding is European gravel, forest tracks, white roads and mixed surface days. A 40 to 47 mm tyre on a 700c bike is still the quick choice there, and nothing announced in September changes that.
Do not wait if you are under about 1.73 m. The geometry problem is unsolved, and the first bikes will not be built for you.
Do not wait if value matters. The cheapest good gravel bike today is a pre-owned one, and it will be 700c.
Will 700c gravel bikes lose value when 32 inch arrives?
We have no data and will not guess. What we can say is that supply of parts, tyres and wheels for 700c is enormous and will not thin out because a second size exists alongside it.
Can I fit 32 inch wheels to my gravel bike?
No. The frame and fork clearance needed is beyond any 700c gravel frame on sale.
The gravel category at Bikeroom lists new and pre-owned bikes together, and the pre-owned gravel collection is where the value sits. If the plan is to change tyre size rather than bikes, the wheels collection is the place to start, since internal rim width decides how wide you can usefully go.
If you are holding off on a gravel bike because of a wheel size that has no bikes behind it yet, talk to our concierge.
Sources: off-road.cc, 18 September 2026; BikeRadar, 18 September 2026; Cycling Weekly, Simon Smythe, 18 September 2026; Cycling Weekly, Gemperle at Unbound XL, 30 May 2026.
