Trek Speed Concept geometryTime trial / Triathlon · 2022 · 4 sizes, from S to XL
The Trek Speed Concept is a time trial / triathlon bike available in 4 sizes, from S to XL. Stack ranges from 492 to 565 mm and reach from 390 to 445 mm. Its geometry is tall and short, built for comfort. All sizes share 410 mm chainstays.
What size Speed Concept 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 Trek. The ones that matter most for choosing a size are in bold.
| Size | S | M | L | XL |
|---|---|---|---|---|
| Stack | 492 | 517 | 541 | 565 |
| Reach | 390 | 416 | 426 | 445 |
| Effective top tube | 495 | 518 | 541 | 565 |
| Head tube length | 65 | 90 | 115 | 140 |
| Head angle | 72.2° | 72.5° | 72.5° | 72.5° |
| Chainstay length | 410 | 410 | 410 | 410 |
| Wheelbase | 967 | 995 | 1,020 | 1,047 |
| BB drop | 80 | 80 | 80 | 80 |
| Fork offset | 45 | 45 | 45 | 45 |
| Trail | 61 | 60 | 60 | 60 |
| Standover | 760 | 785 | 808 | 831 |
| Seat tube (method not stated) | 499 | 525 | 549 | 574 |
| Seat angle (method not stated) | 78.0° | 78.0° | 78.0° | 78.0° |
Source: Trek 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 Speed Concept 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 492/390 mm in size S to 565/445 mm in size XL). 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 Speed Concept in size M?
Stack of 517 mm and reach of 416 mm, with an effective top tube of 518 mm and a head angle of 72.5°.
Is the Speed Concept a racing or an endurance bike?
Endurance. In size M its stack-to-reach ratio is at percentile 68 of time trial / triathlon bikes: a tall, short position.