BH keeps its gravel range under a single name. Everything is a GravelX, and the suffix tells you which frame you are looking at: R for Racing, AT for All Terrain, no suffix for the aluminium model. Sizes are letters, XS to XL, not centimetres. The important detail for smaller riders is that the three frames do not share a size run. Only the R and the alloy GravelX are made in XS. Browse all BH bikes at Bikeroom.
Please note. These sizes are indicative and a starting point, not a guarantee of fit. BH does not publish a static height chart. It publishes a size calculator on each product page, which takes your height and returns one size or a pair. The bands below are that calculator's own answers, read for every height from 150 cm to 210 cm.
Quick size finder
BH's calculator works at category level, so it returns the same answer for every GravelX. Where it returns two sizes, it is telling you that you sit on a boundary.
| Rider height | Leg length (inseam) | GravelX R | GravelX AT | GravelX alloy |
|---|---|---|---|---|
| 150 to 157 cm | 68 to 72 cm | XS | not made | XS |
| 158 to 168 cm | 72 to 77 cm | XS or SM | SM | XS or SM |
| 169 to 172 cm | 77 to 80 cm | SM | SM | SM |
| 173 to 176 cm | 80 to 82 cm | SM or MD | SM or MD | SM or MD |
| 177 to 181 cm | 82 to 85 cm | MD | MD | MD |
| 182 to 183 cm | 85 to 86 cm | MD or LA | MD or LA | MD or LA |
| 184 to 186 cm | 86 to 88 cm | LA | LA | LA |
| 187 to 188 cm | 88 to 89 cm | LA or XL | LA or XL | LA or XL |
| 189 to 210 cm | 89 cm and up | XL | XL | XL |
The height bands are BH's own calculator output. The inseam column is our cross check and not BH data, so use it for standover and saddle height only. Riders under about 169 cm should note that the AT has no XS, which is the single biggest sizing consequence of choosing between the two carbon frames.
How to measure yourself
Height. Stand barefoot against a wall, heels together, looking straight ahead. Rest something flat on your head, level against the wall, mark the wall and measure from the floor.
Leg length (inseam). Barefoot, feet about 15 cm apart, press a hardback book up into your crotch as a saddle would sit. Keep it level against the wall, mark the top edge and measure down to the floor. Inseam matters more than height for standover and saddle height.
New to the category? Start with our introductory guide to gravel bikes.
GravelX R (gravel race)
The R is the race frame: no storage hatch, no flexing rear triangle, a 426 mm chainstay and the only carbon GravelX offered in XS. It runs five sizes. The numbers below are 2027 model year data from bhbikes.com.
| Size | Stack (mm) | Reach (mm) | Rider height |
|---|---|---|---|
| XS | 510 | 366 | 150 to 168 cm |
| SM | 540 | 370 | 158 to 176 cm |
| MD | 556 | 377 | 173 to 183 cm |
| LA | 577 | 387 | 182 to 188 cm |
| XL | 598 | 398 | 187 to 210 cm |
Note the step from XS to SM: 30 mm of stack for 4 mm of reach. If you are around 160 cm the two sizes are almost the same length and quite different heights, so the choice is about bar height, not about reach.
Fit character: low and stretched, closer to a road race bike than most gravel frames.
GravelX AT (all terrain)
The AT is the version with the downtube storage hatch and the flexing rear end that BH calls its Smooth Riding System. It uses a 428 mm chainstay against the R's 426 mm, and it starts at SM, so it is four sizes rather than five.
| Size | Stack (mm) | Reach (mm) | Rider height |
|---|---|---|---|
| SM | 540 | 370 | 158 to 176 cm |
| MD | 556 | 377 | 173 to 183 cm |
| LA | 577 | 387 | 182 to 188 cm |
| XL | 598 | 398 | 187 to 210 cm |
Stack and reach are identical to the R at every shared size. Reviewers have described the two frames as geometrically the same, and on stack and reach they are. The differences that BH publishes are the 2 mm of chainstay and the missing XS.
Fit character: the same position as the R, with a rear end tuned to take the edge off.
GravelX alloy
The aluminium GravelX is the entry frame, built from hydroformed 7005 tubing with a carbon fork. It is a genuinely different shape, not a reskin: 435 mm chainstays, a 405 mm fork and a 27.2 mm round seatpost. Five sizes, XS to XL.
| Size | Stack (mm) | Reach (mm) | Rider height |
|---|---|---|---|
| XS | 529 | 361 | 150 to 168 cm |
| SM | 538 | 373 | 158 to 176 cm |
| MD | 561 | 377 | 173 to 183 cm |
| LA | 582 | 387 | 182 to 188 cm |
| XL | 601 | 398 | 187 to 210 cm |
At MD the alloy frame is 5 mm taller in stack than the carbon ones and identical in reach. From LA upwards it stays a few millimetres taller. The bigger practical difference is the 435 mm chainstay, which adds stability and room for luggage.
Fit character: the most relaxed GravelX, with a long back end built for loaded riding.
GravelX Evo (the previous carbon generation)
Most BH gravel bikes on the second hand market are still badged GravelX Evo, in R and AT versions. BH's own remaining Evo pages list four sizes, SM to XL, with stack of 540, 558.8, 579.7 and 598.6 mm and reach of 370, 377, 387 and 398 mm. In other words the Evo fits you the same as the current carbon GravelX, to within a millimetre or two. If you are shopping pre-owned, the size that fits you now will still fit you on an Evo.
What riders say about BH gravel sizing
Two dated tests are worth reading before you commit to a size.
- The position is road bike low. In its December 2024 test of the GravelX R 6.5, velomotion made the point that the same frame shape is used for BH's cyclocross bike, and described a short head tube, a long top tube and a rider stretched out with a significant drop. That matches the numbers: 556 mm of stack at MD is low for a modern gravel bike.
- The R gives up the flexing rear end, not the comfort. Reviewing the GravelX R 5.5 in 2025, bikeboard.cc noted that the R drops the pivot and the open chainstays of the AT, saving over 100 grams, and still found the ride comfortable. It also recorded a 940 g frame in size Medium and 45 mm of maximum tyre clearance.
One caution on older write ups. The 2025 reviews describe the R as a four size frame. BH's current chart lists five, with the XS added, so check the size run on the model year you are actually buying.
Between two sizes?
BH's calculator hands you two sizes on purpose at 158 to 168 cm, 173 to 176 cm, 182 to 183 cm and 187 to 188 cm. In those bands the frame will not decide for you.
- Take the smaller size for a lower front end, quicker steering and a shorter wheelbase. It suits racing and riders with a shorter torso.
- Take the larger size for a longer reach and more stability when the bike is loaded. It suits bikepacking and riders with long arms.
- Between an R and an AT at the same size, the fit is the same. Choose on the rear end and the storage hatch, not on the numbers.
The carbon GravelX uses the FSA SMR semi integrated cockpit with a separate stem and handlebar. Changing stem length later is possible, which gives you a little more room to correct a borderline size than a one piece bar would.
Shop BH at Bikeroom
- All BH bikes for the full range, gravel included
- Gravel bikes to compare the GravelX against other brands
- BH e-bikes for the iGravelX and the rest of the assisted range
For the other BH categories, see the BH road bike size guide and the BH mountain bike size guide. If assistance interests you, our piece on the BH iRS1 e-road bike covers how BH builds its light assist platform.
If you are on one of BH's boundary heights and cannot decide between two letters, talk to our concierge with your inseam and the stack and reach of your current bike.
Disclaimer: the sizes in this guide are indicative and offered as general guidance, not as a fitting guarantee. Geometry figures are official BH manufacturer data for the model years named, taken from bhbikes.com, and BH can change them between model years. Height bands are BH's own size calculator output, which BH itself describes as indicative. Always confirm against the exact bike you are buying and, where possible, with a professional fit.
Sources: BH Bikes GravelX range and geometry; velomotion, December 2024; bikeboard.cc, 2025.
