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Cervélo R5 vs Trek Madone Gen 8: geometry and fit comparison

Matched sizes, stack and reach deltas, and a fit check against your own body instead of guessing from two separate size charts.

2026race geometry
Cervélo R5
6 sizes: 48, 51, 54, 56, 58, 61
Full size guide
2025race geometry
Trek Madone Gen 8
6 sizes: XS, S, M, ML, L, XL
Full size guide
In one look

The Cervélo R5 is built as a race geometry frame, the Trek Madone Gen 8 as a race geometry frame. Reach is nearly identical across matched sizes. Across matched sizes the Cervélo R5 and Trek Madone Gen 8 front ends are within a few millimetres of each other, so posture will depend more on cockpit setup than on the frame.

Switching from a Cervélo R5?

Your closest Trek Madone Gen 8 size, and what will still feel different about the position.

You ride the Cervélo R5 inTake the Trek Madone Gen 8 inThe position will feel
48XS10.899999999999977 mm taller · 1.3000000000000114 mm longer
51S9.799999999999955 mm taller · 1.5 mm longer
54M1.3999999999999773 mm taller · 0.6999999999999886 mm longer
56ML5.5 mm lower · 2.1000000000000227 mm shorter
58L8.700000000000045 mm lower · 6.300000000000011 mm shorter
61XL0.7000000000000455 mm lower · 6.300000000000011 mm shorter

Which one fits you better?

Run the same measurements through both frames. The likely size and the full fit report can differ more than the spec sheets suggest.

Quick size check

What Cervélo R5 size fits you?

Get an instant frame estimate, then continue into the full fit report to check cockpit reach, bar drop, and setup risks before you buy.

No account needed for this check. The full report keeps this bike preselected.

Quick size check

What Trek Madone Gen 8 size fits you?

Get an instant frame estimate, then continue into the full fit report to check cockpit reach, bar drop, and setup risks before you buy.

No account needed for this check. The full report keeps this bike preselected.

FAQ

Which has the taller front end: Cervélo R5 or Trek Madone Gen 8?

Across matched sizes the Cervélo R5 and Trek Madone Gen 8 front ends are within a few millimetres of each other, so posture will depend more on cockpit setup than on the frame.

Can the same rider take different sizes on these two bikes?

Yes, and it happens often: frame labels are not standardized. Use the matched-size table for geometry, then run the fit check below with your own measurements for each bike.

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