Ridley Triton Fast geometryTime trial / Triathlon · 2027 · 4 sizes, from XS to L
The Ridley Triton Fast is a time trial / triathlon bike available in 4 sizes, from XS to L. Stack ranges from 476 to 568 mm and reach from 406 to 480 mm. Its position sits between racing and endurance. All sizes share 410 mm chainstays. Data from 2027; geometry from 2025 is also available.
What size Triton Fast do I need?
Enter the stack and reach of a bike that fits you well and we will tell you which size is closest and how to set it up.
Enter your stack and reach to see which size fits you best.
Geometry chart by size
Measurements in mm and degrees, as published by Ridley. The ones that matter most for choosing a size are in bold.
| Size | XS | S | M | L |
|---|---|---|---|---|
| Stack | 476 | 508 | 538 | 568 |
| Reach | 406 | 420 | 450 | 480 |
| Effective top tube | 490 | 510 | 535 | 560 |
| Head tube length | 70 | 100 | 130 | 160 |
| Head angle | 71.0° | 71.5° | 72.0° | 72.0° |
| Chainstay length | 410 | 410 | 410 | 410 |
| Wheelbase | 1,004 | 1,020 | 1,054 | 1,089 |
| BB drop | 78 | 78 | 78 | 78 |
| Seat tube (method not stated) | 490 | 510 | 540 | 570 |
| Seat angle (method not stated) | 80.0° | 80.0° | 81.0° | 82.0° |
Source: Ridley official website · data from 11 Nov 2026. Spot a mistake?
Stack and reach of every size
Higher means a taller front end; further right means a longer reach. The blue dot is your search.
Character of each size
Compared with other time trial / triathlon bikes. Further right means more of that quality.
Bikes with similar geometry (size S)
The closest size of other time trial / triathlon models, by stack and reach.
Frequently asked questions
What size Triton Fast do I need?
It depends on your position, not just your height. The most reliable way is to compare the stack and reach of a bike that fits you with those of each size (from 476/406 mm in size XS to 568/480 mm in size L). The size finder on this page shows the closest size and the stem and spacers you would need.
What are the stack and reach of the Triton Fast in size S?
Stack of 508 mm and reach of 420 mm, with an effective top tube of 510 mm and a head angle of 71.5°.
Is the Triton Fast a racing or an endurance bike?
In between. In size S its stack-to-reach ratio is at percentile 43 of time trial / triathlon bikes: neither very low nor very tall.