Getting your Ridley size right
If you take one thing from this guide, make it this: Ridley runs long. Owners say it constantly, a Ridley medium often fits like another brand's large, and riders moving over from an endurance bike are routinely told to drop a full size. The Belgian brand pairs relatively short top tubes with steep seat angles, which on the newest bikes inflates the reach figure, so Ridley itself advises sizing by actual top tube length rather than the reach number. Keep that in mind as you read the tables below.
Browse the range any time over on the Ridley collection at Bikeroom.
Worth flagging. The sizes here are a guide, not a guarantee. Ridley publishes one height chart across its road bikes rather than per model numbers, and fit always comes down to your proportions and flexibility. Confirm with a bike fit before you commit.
Fast size lookup
Ridley uses letter sizes and a single road height chart. Find your height, check your inseam, and read across to your model. Remember the Noah Fast tops out at L and the Fenix starts at XS.
| Rider height | Leg length (inseam) | Noah Fast (aero) | Falcn RS (all round) | Helium (climbing) | Fenix (endurance) |
|---|---|---|---|---|---|
| 152 to 162 cm | 69 to 74 cm | XXS | XXS | XXS | XS |
| 160 to 170 cm | 73 to 78 cm | XS | XS | XS | XS |
| 168 to 176 cm | 77 to 82 cm | S | S | S | S |
| 174 to 183 cm | 80 to 86 cm | M | M | M | M |
| 181 to 190 cm | 84 to 90 cm | L | L | L | L |
| 188 to 198 cm | 88 to 94 cm | L (max) | XL | XL | XL |
The Fenix geometry runs XS to XL, though current builds are often stocked in S, M and L only. If you are near a boundary, favour the smaller size given how long Ridley fits.
How to take your measurements
For height, stand barefoot against a wall and measure to the top of your head. For your inseam, hold a book against the wall between your legs like a saddle and measure floor to spine. With Ridley especially, take the extra step of comparing the top tube length of a bike that already fits you, since the reach numbers can read longer than they ride.
The road models in detail
Noah Fast (aero)
The third generation Noah Fast is the pure aero weapon, with progressive geometry, a steep seat tube and long looking reach. Because that steep angle stretches the reach figure, this is the model where sizing by top tube matters most. Sizes: XXS, XS, S, M and L.
| Frame size | XXS | XS | S | M | L |
|---|---|---|---|---|---|
| Stack (mm) | 497 | 504 | 521 | 541 | 565 |
| Reach (mm) | 386 | 399 | 410 | 420 | 428 |
| Rider height | 152 to 162 | 160 to 170 | 168 to 176 | 174 to 183 | 181 to 190 |
Those reach numbers look big because of the seat angle, not because the bike is enormous. Do not panic and size down twice; compare top tube length instead.
Falcn RS (all round race)
The Falcn RS is Ridley's do it all race bike, blending aero and low weight, and it comes up roomy for its label. A slightly taller stack and more relaxed reach than the Noah mean most riders take their normal size or drop one coming from an endurance brand. Sizes: XXS, XS, S, M, L and XL.
| Frame size | XXS | XS | S | M | L | XL |
|---|---|---|---|---|---|---|
| Stack (mm) | 492 | 513 | 530 | 551 | 573 | 599 |
| Reach (mm) | 374 | 378 | 388 | 397 | 404 | 411 |
| Rider height | 152 to 162 | 160 to 170 | 168 to 176 | 174 to 183 | 181 to 190 | 188 to 198 |
Tall riders after an aggressive fit often go one size smaller than their height suggests here; comfort seekers should hold their chart size.
Helium (climbing)
The Helium is the lightweight climber, with a taller stack and shorter reach than the Falcn at the same label, plus the classic tall Ridley head tube. It is being gradually succeeded by the Falcn RS but remains a lovely pure climbing bike. Sizes: XXS, XS, S, M, L and XL.
| Frame size | XXS | XS | S | M | L | XL |
|---|---|---|---|---|---|---|
| Stack (mm) | 507 | 527 | 542 | 573 | 599 | 624 |
| Reach (mm) | 379 | 374 | 384 | 390 | 396 | 403 |
| Rider height | 152 to 162 | 160 to 170 | 168 to 176 | 174 to 183 | 181 to 190 | 188 to 198 |
The two smallest sizes have an unusual reach step, so treat XXS and XS figures as approximate and verify against a current spec sheet.
Fenix (endurance)
The Fenix is the endurance model, with the tallest stack and shortest reach in the road line for a comfortable, upright day out. There is no need to size down here; pick your height bracket. Sizes: XS, S, M, L and XL.
| Frame size | XS | S | M | L | XL |
|---|---|---|---|---|---|
| Stack (mm) | 517 | 541 | 565 | 591 | 615 |
| Reach (mm) | 377 | 385 | 392 | 401 | 409 |
| Rider height | 160 to 170 | 168 to 176 | 174 to 183 | 181 to 190 | 188 to 198 |
The friendliest fit Ridley makes. Some owners note larger gaps between sizes, so the top tube comparison is again your friend.
What Ridley owners report
Almost every conversation lands on the same point: Ridley fits long, so a rider whose other bikes are large frequently ends up on a Ridley medium. People coming from Trek Domane or Specialized Roubaix are widely advised to size down one to match the reach. The head tubes run tall, giving a higher front than the racy branding suggests, and the short top tube with steep seat angle means a setback seatpost is a common addition. On the aero bikes the integrated cockpit leaves little room to change stack later, so it pays to get the size right at purchase.
Torn between two sizes?
Given how long Ridley rides, the smaller frame is usually the safer race choice, tuned up with spacers if needed, while endurance riders should stay in their height bracket. Long legs and a short torso are the classic reason to size up. If you would rather not gamble, send us the top tube length of a bike you love and we will match it.
Shop Ridley
- Ridley Noah Fast for flat out aero
- Ridley Helium for lightweight climbing
- All Ridley bikes including the Falcn RS and Fenix
Not sure? Our concierge speaks fluent geometry
Ridley's long fit trips up a lot of first time buyers. Send our concierge team your height, inseam and ideally the top tube of your current bike, and we will steer you to the right size. Talk to our concierge.
Everything here is guidance given in good faith rather than a fitting guarantee. Ridley publishes a single road height chart, so per model ranges are our alignment to it, and geometry can change between model years. The Helium XXS and XS reach figures are approximate. Always confirm against the specific bike you are buying.
