Colnago TT1 geometryTime trial / Triathlon · 2026 · 3 sizes, from S to L
The Colnago TT1 is a time trial / triathlon bike available in 3 sizes, from S to L. Stack ranges from 471.7 to 490.7 mm and reach from 396.5 to 426.5 mm. Its position sits between racing and endurance. All sizes share 400 mm chainstays.
What size TT1 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 Colnago. The ones that matter most for choosing a size are in bold.
| Size | S | M | L |
|---|---|---|---|
| Stack | 472 | 491 | 491 |
| Reach | 397 | 407 | 427 |
| Head angle | 72.0° | 72.0° | 72.0° |
| Chainstay length | 400 | 400 | 400 |
| BB drop | 72 | 70 | 70 |
| Seat tube (method not stated) | 508 | 528 | 528 |
| Seat angle (method not stated) | 77.0° | 77.0° | 77.0° |
Source: Colnago 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 M)
The closest size of other time trial / triathlon models, by stack and reach.
Frequently asked questions
What size TT1 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 471.7/396.5 mm in size S to 490.7/426.5 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 TT1 in size M?
Stack of 490.7 mm and reach of 406.5 mm.
Is the TT1 a racing or an endurance bike?
In between. In size M its stack-to-reach ratio is at percentile 39 of time trial / triathlon bikes: neither very low nor very tall.