Cervélo S5 vs Trek Madone Gen 8: which bike is right for you?

Compare ride character, intended rider, geometry, and fit. Add your measurements to see which bike suits you better and which size to choose on each.

Fit verdict: these frames put you in effectively the same position, so geometry will not decide this pair. What can: the sourced differences below and, once you enter your measurements, your size and setup on each frame.

Compare them for meCompare geometry and sizes

In one look

Cervélo S5: race geometry. Trek Madone Gen 8: race geometry.

  • Across matched sizes, the frame fronts of Cervélo S5 and Trek Madone Gen 8 differ by only a few millimetres. Stem and spacer choices will have more effect on handlebar position.
  • The forward length of the frame is nearly the same across matched sizes.

The frame standards line up and we hold no sourced weight or performance claim that separates them. What is left to decide is your size and setup on each frame.

  • Price

    Cervélo S5 is the dearer of the two, going by the cheapest build you can buy of each; Trek Madone Gen 8 starts lower.

Subjective findings from independent tests on stock or near-stock builds. Tyres, pressure and size change how a frame feels.

We compare differences at frame and model level. Components, current price, and availability depend on the exact build and seller.

2026 • race geometry
Cervélo S5
Full size guide
2025 • race geometry
Trek Madone Gen 8
Full size guide

Fit and size differences

Geometry does not separate these bikes: matched sizes put the rider in effectively the same position.

Typical difference across matched sizes: frame front height 2 mm, forward length 3 mm.

For a personal answer, the fit-and-size path uses your measurements to show only the relevant frame sizes. The full chart remains available as a reference.

View geometry for every size

How do Cervélo S5 and Trek Madone Gen 8 sizes compare?

See the closest size matches and the differences in stack, reach, and riding position.

Cervélo S5
51
Stack 519, Reach 376
Trek Madone Gen 8
S
Stack 530, Reach 378

Stack: 11 mm taller

Reach: practically identical

Cervélo S5
54
Stack 542, Reach 384
Trek Madone Gen 8
M
Stack 546, Reach 384

Stack: 4 mm taller

Reach: practically identical

Cervélo S5
56
Stack 565, Reach 392
Trek Madone Gen 8
ML
Stack 562, Reach 389

Stack: 3 mm lower

Reach: 3 mm shorter

Cervélo S5
58
Stack 588, Reach 401
Trek Madone Gen 8
L
Stack 582, Reach 394

Stack: 6 mm lower

Reach: 7 mm shorter

Cervélo S5
61
Stack 608, Reach 409
Trek Madone Gen 8
XL
Stack 610, Reach 402

Stack: practically identical

Reach: 7 mm shorter

The same size label can create a different position on each frame. Stack and reach are one part of the decision; the personalized comparison connects them to your body and each bike’s ride character.

FAQ

Can the same rider take different sizes on these two bikes?
Yes. Frame labels are not standardized, so the same rider may need different sizes. This comparison deliberately avoids a generic matched-size answer and hands your measurements to Bike Fit instead.
Which frame has the higher front: Cervélo S5 or Trek Madone Gen 8?
Across matched sizes, the frame fronts of Cervélo S5 and Trek Madone Gen 8 differ by only a few millimetres. Stem and spacer choices will have more effect on handlebar position.

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