bike geometry

BMC RoadMachine 2026

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 BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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	Recorded geometry
RoadMachine geometry	56	559 mm	Recorded geometry
RoadMachine geometry	61	581 mm	Recorded geometry
RoadMachine geometry	58	571 mm	Recorded geometry
RoadMachine geometry	54	546 mm	Recorded geometry
RoadMachine geometry	47	520 mm	Recorded geometry

What is the head tube angle of the BMC RoadMachine 2026?

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 °	Recorded geometry
RoadMachine geometry	56	72.2 °	Recorded geometry
RoadMachine geometry	61	72.2 °	Recorded geometry
RoadMachine geometry	58	72.2 °	Recorded geometry
RoadMachine geometry	54	72.2 °	Recorded geometry
RoadMachine geometry	47	71.4 °	Recorded geometry

What is the seat tube angle of the BMC RoadMachine 2026?

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 °	Recorded geometry
RoadMachine geometry	56	74.2 °	Recorded geometry
RoadMachine geometry	61	74.2 °	Recorded geometry
RoadMachine geometry	58	74.2 °	Recorded geometry
RoadMachine geometry	54	74.2 °	Recorded geometry
RoadMachine geometry	47	74.2 °	Recorded geometry

What is the trail of the BMC RoadMachine 2026?

Trail is the ground distance between the steering-axis intercept and the front tire contact point. Also searched as fork trail, mechanical trail.

Configuration	Size	Trail	Source
RoadMachine geometry	51	62.7 mm	RideDNA-derived
RoadMachine geometry	56	62.9 mm	RideDNA-derived
RoadMachine geometry	61	62.9 mm	RideDNA-derived
RoadMachine geometry	58	62.9 mm	RideDNA-derived
RoadMachine geometry	54	62.9 mm	RideDNA-derived
RoadMachine geometry	47	62.7 mm	RideDNA-derived

What is the wheelbase of the BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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	415 mm	Recorded geometry
RoadMachine geometry	56	415 mm	Recorded geometry
RoadMachine geometry	61	415 mm	Recorded geometry
RoadMachine geometry	58	415 mm	Recorded geometry
RoadMachine geometry	54	415 mm	Recorded geometry
RoadMachine geometry	47	415 mm	Recorded geometry

What is the bottom bracket drop of the BMC RoadMachine 2026?

Bottom bracket drop is the vertical distance from the wheel-axle line down to the bottom bracket. Also searched as BB drop.

Configuration	Size	Bottom bracket drop	Source
RoadMachine geometry	51	75 mm	Recorded geometry
RoadMachine geometry	56	75 mm	Recorded geometry
RoadMachine geometry	61	75 mm	Recorded geometry
RoadMachine geometry	58	75 mm	Recorded geometry
RoadMachine geometry	54	75 mm	Recorded geometry
RoadMachine geometry	47	75 mm	Recorded geometry

What is the bottom bracket height of the BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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	Manufacturer-published
RoadMachine geometry	56	45 mm	Manufacturer-published
RoadMachine geometry	61	45 mm	Manufacturer-published
RoadMachine geometry	58	45 mm	Manufacturer-published
RoadMachine geometry	54	45 mm	Manufacturer-published
RoadMachine geometry	47	50 mm	Manufacturer-published

What is the head tube length of the BMC RoadMachine 2026?

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	Recorded geometry
RoadMachine geometry	56	181 mm	Recorded geometry
RoadMachine geometry	61	233 mm	Recorded geometry
RoadMachine geometry	58	207 mm	Recorded geometry
RoadMachine geometry	54	154 mm	Recorded geometry
RoadMachine geometry	47	112 mm	Recorded geometry

What is the seat tube length of the BMC RoadMachine 2026?

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	Recorded geometry
RoadMachine geometry	56	508 mm	Recorded geometry
RoadMachine geometry	61	550 mm	Recorded geometry
RoadMachine geometry	58	529 mm	Recorded geometry
RoadMachine geometry	54	488 mm	Recorded geometry
RoadMachine geometry	47	414 mm	Recorded geometry

What is the standover height of the BMC RoadMachine 2026?

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 BMC RoadMachine 2026?

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	Manufacturer-published
RoadMachine geometry	56	379 mm	Manufacturer-published
RoadMachine geometry	61	379 mm	Manufacturer-published
RoadMachine geometry	58	379 mm	Manufacturer-published
RoadMachine geometry	54	379 mm	Manufacturer-published
RoadMachine geometry	47	379 mm	Manufacturer-published

What is the wheel flop of the BMC RoadMachine 2026?

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 °^‡	62.7 mm^*	983.8 mm^*	415 mm^‡	75 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 °^‡	62.7 mm^*	1002.1 mm^*	415 mm^‡	75 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 °^‡	62.9 mm^*	999 mm^*	415 mm^‡	75 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 °^‡	62.9 mm^*	1013 mm^*	415 mm^‡	75 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 °^‡	62.9 mm^*	1025.9 mm^*	415 mm^‡	75 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 °^‡	62.9 mm^*	1036.9 mm^*	415 mm^‡	75 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. Values prioritize RideDNA calculations. * RideDNA calculated (including corrections where published values differ). Unmarked values are manufacturer-published; matching independently calculated values are identified in their source notes. † Manufacturer did not publish this dimension; † alone means no reliable value is available. ‡ Staff reference or source not confirmed; see the source note. Open Geometry Audit for the original published values, calculated geometry, and deltas.

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 °, Trail +0 mm, Wheelbase +18.3 mm, Chainstay +0 mm, BB drop +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 °, Trail +0.2 mm, Wheelbase -3.1 mm, Chainstay +0 mm, BB drop +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 °, Trail +0 mm, Wheelbase +14 mm, Chainstay +0 mm, BB drop +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 °, Trail +0 mm, Wheelbase +12.9 mm, Chainstay +0 mm, BB drop +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 °, Trail +0 mm, Wheelbase +11 mm, Chainstay +0 mm, BB drop +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 inputs above. They are separate from recorded 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