bike geometry

RoadMachine 2026

Name: RoadMachine 2026
Brand: BMC

Compare size-specific bike geometry, including reach, stack, angles, wheelbase and the measurements that influence fit and handling.

BMC › RoadMachine › Standard › RoadMachine

RoadMachine geometry measurements

Choose the recorded size and configuration. Geometry figures can change by size; RideDNA does not collapse those values into one misleading answer.

What is the reach of the RoadMachine?

Reach is the horizontal distance from the bottom bracket to the top of the head tube. Also searched as frame reach.

Configuration	Size	Reach	Source
RoadMachine geometry	51	381.6 mm	RideDNA-derived
RoadMachine geometry	56	390.8 mm	RideDNA-derived
RoadMachine geometry	61	398.8 mm	RideDNA-derived
RoadMachine geometry	58	395.8 mm	RideDNA-derived
RoadMachine geometry	54	385.1 mm	RideDNA-derived
RoadMachine geometry	47	371.6 mm	RideDNA-derived

What is the stack of the RoadMachine?

Stack is the vertical distance from the bottom bracket to the top of the head tube. Also searched as frame stack.

Configuration	Size	Stack	Source
RoadMachine geometry	51	549 mm	RideDNA-derived
RoadMachine geometry	56	594.4 mm	RideDNA-derived
RoadMachine geometry	61	643.9 mm	RideDNA-derived
RoadMachine geometry	58	619.2 mm	RideDNA-derived
RoadMachine geometry	54	568.7 mm	RideDNA-derived
RoadMachine geometry	47	524.4 mm	RideDNA-derived

What is the effective top tube of the RoadMachine?

Effective top tube is the horizontal distance between the head-tube and seat-tube centerlines. Also searched as ETT, virtual top tube, horizontal top tube.

Configuration	Size	Effective top tube	Source
RoadMachine geometry	51	537 mm	RideDNA-derived
RoadMachine geometry	56	559 mm	RideDNA-derived
RoadMachine geometry	61	581 mm	RideDNA-derived
RoadMachine geometry	58	571 mm	RideDNA-derived
RoadMachine geometry	54	546 mm	RideDNA-derived
RoadMachine geometry	47	520 mm	RideDNA-derived

What is the head tube angle of the RoadMachine?

Head tube angle describes the steering-axis angle relative to the ground. Also searched as HTA, head angle, steering angle.

Configuration	Size	Head tube angle	Source
RoadMachine geometry	51	71.4 °	RideDNA-derived
RoadMachine geometry	56	72.2 °	RideDNA-derived
RoadMachine geometry	61	72.2 °	RideDNA-derived
RoadMachine geometry	58	72.2 °	RideDNA-derived
RoadMachine geometry	54	72.2 °	RideDNA-derived
RoadMachine geometry	47	71.4 °	RideDNA-derived

What is the seat tube angle of the RoadMachine?

Seat tube angle describes the seat-tube angle relative to the ground. Also searched as STA, seat angle, effective seat angle.

Configuration	Size	Seat tube angle	Source
RoadMachine geometry	51	74.2 °	RideDNA-derived
RoadMachine geometry	56	74.2 °	RideDNA-derived
RoadMachine geometry	61	74.2 °	RideDNA-derived
RoadMachine geometry	58	74.2 °	RideDNA-derived
RoadMachine geometry	54	74.2 °	RideDNA-derived
RoadMachine geometry	47	74.2 °	RideDNA-derived

What is the wheelbase of the RoadMachine?

Wheelbase is the distance between the front and rear wheel axles. Also searched as axle-to-axle length.

Configuration	Size	Wheelbase	Source
RoadMachine geometry	51	1002.1 mm	RideDNA-derived
RoadMachine geometry	56	1013 mm	RideDNA-derived
RoadMachine geometry	61	1036.9 mm	RideDNA-derived
RoadMachine geometry	58	1025.9 mm	RideDNA-derived
RoadMachine geometry	54	999 mm	RideDNA-derived
RoadMachine geometry	47	983.8 mm	RideDNA-derived

What is the chainstay length of the RoadMachine?

Chainstay length, also called rear center, is the distance from the bottom bracket to the rear axle. Also searched as Chainstay, rear center, rear centre.

Configuration	Size	Chainstay length	Source
RoadMachine geometry	51	408.2 mm	RideDNA-derived
RoadMachine geometry	56	408.2 mm	RideDNA-derived
RoadMachine geometry	61	408.2 mm	RideDNA-derived
RoadMachine geometry	58	408.2 mm	RideDNA-derived
RoadMachine geometry	54	408.2 mm	RideDNA-derived
RoadMachine geometry	47	408.2 mm	RideDNA-derived

What is the bottom bracket height of the RoadMachine?

Bottom bracket height is the vertical distance from the ground to the bottom bracket. Also searched as BB height.

Configuration	Size	Bottom bracket height	Source
RoadMachine geometry	51	268 mm	RideDNA-derived
RoadMachine geometry	56	268 mm	RideDNA-derived
RoadMachine geometry	61	268 mm	RideDNA-derived
RoadMachine geometry	58	268 mm	RideDNA-derived
RoadMachine geometry	54	268 mm	RideDNA-derived
RoadMachine geometry	47	268 mm	RideDNA-derived

What is the front center of the RoadMachine?

Front center is the distance from the bottom bracket to the front wheel axle. Also searched as front centre.

Configuration	Size	Front center	Source
RoadMachine geometry	51	598.6 mm	RideDNA-derived
RoadMachine geometry	56	609.5 mm	RideDNA-derived
RoadMachine geometry	61	633.2 mm	RideDNA-derived
RoadMachine geometry	58	622.3 mm	RideDNA-derived
RoadMachine geometry	54	595.6 mm	RideDNA-derived
RoadMachine geometry	47	580.5 mm	RideDNA-derived

What is the fork offset of the RoadMachine?

Fork offset is the perpendicular distance between the steering axis and the front axle. Also searched as fork rake, rake.

Configuration	Size	Fork offset	Source
RoadMachine geometry	51	50 mm	RideDNA-derived
RoadMachine geometry	56	45 mm	RideDNA-derived
RoadMachine geometry	61	45 mm	RideDNA-derived
RoadMachine geometry	58	45 mm	RideDNA-derived
RoadMachine geometry	54	45 mm	RideDNA-derived
RoadMachine geometry	47	50 mm	RideDNA-derived

What is the head tube length of the RoadMachine?

Head tube length is the measured length of the frame's head tube. Also searched as Head tube, head tube.

Configuration	Size	Head tube length	Source
RoadMachine geometry	51	138 mm	RideDNA-derived
RoadMachine geometry	56	181 mm	RideDNA-derived
RoadMachine geometry	61	233 mm	RideDNA-derived
RoadMachine geometry	58	207 mm	RideDNA-derived
RoadMachine geometry	54	154 mm	RideDNA-derived
RoadMachine geometry	47	112 mm	RideDNA-derived

What is the seat tube length of the RoadMachine?

Seat tube length is the recorded length of the frame's seat tube; measurement conventions can differ by manufacturer. Also searched as Seat tube, seat tube, frame size.

Configuration	Size	Seat tube length	Source
RoadMachine geometry	51	461 mm	RideDNA-derived
RoadMachine geometry	56	508 mm	RideDNA-derived
RoadMachine geometry	61	550 mm	RideDNA-derived
RoadMachine geometry	58	529 mm	RideDNA-derived
RoadMachine geometry	54	488 mm	RideDNA-derived
RoadMachine geometry	47	414 mm	RideDNA-derived

What is the standover height of the RoadMachine?

Standover height is the ground-to-top-tube height at the manufacturer's stated measurement point. Also searched as Standover, stand over height, standover clearance.

Configuration	Size	Standover height	Source
RoadMachine geometry	51	737.9 mm	RideDNA-derived
RoadMachine geometry	56	783.2 mm	RideDNA-derived
RoadMachine geometry	61	828.1 mm	RideDNA-derived
RoadMachine geometry	58	805.6 mm	RideDNA-derived
RoadMachine geometry	54	760.7 mm	RideDNA-derived
RoadMachine geometry	47	702.9 mm	RideDNA-derived

What is the fork length of the RoadMachine?

Fork length is the axle-to-crown distance recorded for the fork. Also searched as axle to crown, A2C.

Configuration	Size	Fork length	Source
RoadMachine geometry	51	379 mm	RideDNA-derived
RoadMachine geometry	56	379 mm	RideDNA-derived
RoadMachine geometry	61	379 mm	RideDNA-derived
RoadMachine geometry	58	379 mm	RideDNA-derived
RoadMachine geometry	54	379 mm	RideDNA-derived
RoadMachine geometry	47	379 mm	RideDNA-derived

What is the wheel flop of the RoadMachine?

Wheel flop is a calculated steering-geometry value based on trail and head tube angle. Also searched as flop.

Configuration	Size	Wheel flop	Source
RoadMachine geometry	51	18.9 mm	RideDNA-derived
RoadMachine geometry	56	18.3 mm	RideDNA-derived
RoadMachine geometry	61	18.3 mm	RideDNA-derived
RoadMachine geometry	58	18.3 mm	RideDNA-derived
RoadMachine geometry	54	18.3 mm	RideDNA-derived
RoadMachine geometry	47	18.9 mm	RideDNA-derived

Geometry

Available sizes: 51, 56, 61, 58, 54, 47.

RoadMachine geometry

Jump to size: 47 · 51 · 54 · 56 · 58 · 61

RoadMachine geometry geometry by size
Size	Reach	Stack	ETT	HTA	STA	Trail	Wheelbase	Chainstay	BB drop	BB height	Front center	Fork offset	Head tube	Seat tube	Standover	Fork length	Wheel flop	Max tire
47	371.6 mm	524.4 mm	520 mm	71.4 °	74.2 °	—	983.8 mm	408.2 mm	—	268 mm	580.5 mm	50 mm	112 mm	414 mm	702.9 mm	379 mm	18.9 mm	—
51	381.6 mm	549 mm	537 mm	71.4 °	74.2 °	—	1002.1 mm	408.2 mm	—	268 mm	598.6 mm	50 mm	138 mm	461 mm	737.9 mm	379 mm	18.9 mm	—
54	385.1 mm	568.7 mm	546 mm	72.2 °	74.2 °	—	999 mm	408.2 mm	—	268 mm	595.6 mm	45 mm	154 mm	488 mm	760.7 mm	379 mm	18.3 mm	—
56	390.8 mm	594.4 mm	559 mm	72.2 °	74.2 °	—	1013 mm	408.2 mm	—	268 mm	609.5 mm	45 mm	181 mm	508 mm	783.2 mm	379 mm	18.3 mm	—
58	395.8 mm	619.2 mm	571 mm	72.2 °	74.2 °	—	1025.9 mm	408.2 mm	—	268 mm	622.3 mm	45 mm	207 mm	529 mm	805.6 mm	379 mm	18.3 mm	—
61	398.8 mm	643.9 mm	581 mm	72.2 °	74.2 °	—	1036.9 mm	408.2 mm	—	268 mm	633.2 mm	45 mm	233 mm	550 mm	828.1 mm	379 mm	18.3 mm	—

Length measurements are in millimeters; HTA and STA are in degrees. ETT means effective top tube.

Size-to-size changes

Differences are calculated from the recorded values; they are not fit recommendations.

RoadMachine geometry: 47 → 51 — Reach +10 mm, Stack +24.6 mm, ETT +17 mm, HTA +0 °, STA +0 °, Wheelbase +18.3 mm, Chainstay +0 mm, BB height +0 mm, Front center +18.1 mm, Fork offset +0 mm, Head tube +26 mm, Seat tube +47 mm, Standover +35 mm, Fork length +0 mm, Wheel flop +0 mm
RoadMachine geometry: 51 → 54 — Reach +3.5 mm, Stack +19.7 mm, ETT +9 mm, HTA +0.8 °, STA +0 °, Wheelbase -3.1 mm, Chainstay +0 mm, BB height +0 mm, Front center -3 mm, Fork offset -5 mm, Head tube +16 mm, Seat tube +27 mm, Standover +22.8 mm, Fork length +0 mm, Wheel flop -0.6 mm
RoadMachine geometry: 54 → 56 — Reach +5.7 mm, Stack +25.7 mm, ETT +13 mm, HTA +0 °, STA +0 °, Wheelbase +14 mm, Chainstay +0 mm, BB height +0 mm, Front center +13.9 mm, Fork offset +0 mm, Head tube +27 mm, Seat tube +20 mm, Standover +22.5 mm, Fork length +0 mm, Wheel flop +0 mm
RoadMachine geometry: 56 → 58 — Reach +5 mm, Stack +24.8 mm, ETT +12 mm, HTA +0 °, STA +0 °, Wheelbase +12.9 mm, Chainstay +0 mm, BB height +0 mm, Front center +12.8 mm, Fork offset +0 mm, Head tube +26 mm, Seat tube +21 mm, Standover +22.4 mm, Fork length +0 mm, Wheel flop +0 mm
RoadMachine geometry: 58 → 61 — Reach +3 mm, Stack +24.7 mm, ETT +10 mm, HTA +0 °, STA +0 °, Wheelbase +11 mm, Chainstay +0 mm, BB height +0 mm, Front center +10.9 mm, Fork offset +0 mm, Head tube +26 mm, Seat tube +21 mm, Standover +22.5 mm, Fork length +0 mm, Wheel flop +0 mm

RideDNA-derived values

These deterministic calculations use the recorded manufacturer inputs above. They are separate from manufacturer facts and are not fit recommendations.

RoadMachine geometry size 51 stack Reach Ratio: 1.44
RoadMachine geometry size 56 stack Reach Ratio: 1.52
RoadMachine geometry size 61 stack Reach Ratio: 1.61
RoadMachine geometry size 58 stack Reach Ratio: 1.56
RoadMachine geometry size 54 stack Reach Ratio: 1.48
RoadMachine geometry size 47 stack Reach Ratio: 1.41