BMC Roadmachine geometryRoad · 2027 · 6 sizes, from 47 to 61
The BMC Roadmachine is a road bike available in 6 sizes, from 47 to 61. Stack ranges from 525 to 645 mm and reach from 370 to 398 mm. Its geometry is tall and short, built for comfort. All sizes share 415 mm chainstays.
What size Roadmachine 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 BMC. The ones that matter most for choosing a size are in bold.
| Size | 47 | 51 | 54 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|
| Stack | 525 | 550 | 570 | 595 | 620 | 645 |
| Reach | 370 | 379 | 383 | 388 | 393 | 398 |
| Head tube length | 112 | 138 | 154 | 181 | 207 | 233 |
| Head angle | 71.4° | 71.4° | 72.2° | 72.2° | 72.2° | 72.2° |
| Chainstay length | 415 | 415 | 415 | 415 | 415 | 415 |
| Front centre | 579 | 596 | 594 | 607 | 620 | 633 |
| BB drop | 75 | 75 | 75 | 75 | 75 | 75 |
| Fork length | 379 | 379 | 379 | 379 | 379 | 379 |
| Fork offset | 50 | 50 | 45 | 45 | 45 | 45 |
| Trail | 63 | 63 | 63 | 63 | 63 | 63 |
| Standover | 726 | 762 | 786 | 807 | 828 | 849 |
| Top tube (method not stated) | 520 | 537 | 546 | 559 | 571 | 581 |
| Seat tube (method not stated) | 414 | 461 | 488 | 508 | 529 | 550 |
| Seat angle (method not stated) | 74.2° | 74.2° | 74.2° | 74.2° | 74.2° | 74.2° |
Source: BMC 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 road bikes. Further right means more of that quality.
Bikes with similar geometry (size 54)
The closest size of other road models, by stack and reach.
Frequently asked questions
What size Roadmachine 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 525/370 mm in size 47 to 645/398 mm in size 61). 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 Roadmachine in size 54?
Stack of 570 mm and reach of 383 mm.
Is the Roadmachine a racing or an endurance bike?
Endurance. In size 54 its stack-to-reach ratio is at percentile 71 of road bikes: a tall, short position.