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Argon 18 Sum Pro vs Cervélo Caledonia-5: 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
Argon 18 Sum Pro
6 sizes: XXS, XS, S, M, L, XL
Full size guide
2026endurance geometry
Cervélo Caledonia-5
6 sizes: 48, 51, 54, 56, 58, 61
Full size guide
In one look

The Argon 18 Sum Pro is built as a race geometry frame, the Cervélo Caledonia-5 as a endurance geometry frame. The Cervélo Caledonia-5 cockpit runs about 19 mm shorter, a noticeably more compact position. Across matched sizes, the Cervélo Caledonia-5 stack sits about 14 mm taller than the Argon 18 Sum Pro, which generally means a more upright position before spacers.

For the Argon 18 Sum Pro in XXS there is no Cervélo Caledonia-5 size with a comparable position: the range simply does not reach there.

Switching from a Argon 18 Sum Pro?

Your closest Cervélo Caledonia-5 size, and what will still feel different about the position.

You ride the Argon 18 Sum Pro inTake the Cervélo Caledonia-5 inThe position will feel
XS4812 mm taller · 22 mm shorterDifferent position
S5114 mm taller · 20 mm shorterDifferent position
M5415 mm taller · 19 mm shorterDifferent position
L5615 mm taller · 18 mm shorterDifferent position
XL5813 mm taller · 18 mm shorterDifferent position

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 Argon 18 Sum Pro 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 Cervélo Caledonia-5 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: Argon 18 Sum Pro or Cervélo Caledonia-5?

Across matched sizes, the Cervélo Caledonia-5 stack sits about 14 mm taller than the Argon 18 Sum Pro, which generally means a more upright position before spacers.

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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