Frame geometry, decoded

Know how a bike rides before you buy it

Compare the geometry of the bike you own against the one you're eyeing. No charts to decode, just a plain-words verdict about position, handling and climbing.

We compare frame geometry, the part of the bike you can't change after you buy. Weight, stiffness and components are a different story, and we'll tell you when they matter more.

Backroad M/L → G85 L

"The G85 is a calmer, more stable bike that seats you more upright. Pedaling stays identical."

How it works

Three steps from doubt to decision.

1

Pick your bikes

Search the database or paste any geometry table. Your current bike is the reference, so you already know how it feels.

2

We match the sizes

Labels lie: an M/L in one brand is an L in another. We match by reach so the comparison is fair, and show you why.

3

Read the verdict

A rules engine turns geometry deltas into ride feel: position, handling, climbing, and what a stem swap can fix.

Not another geometry table

Every number gets interpreted, weighted and honestly flagged.

Plain words, not columns

"Calmer steering, more weight on your hands" instead of nine rows of millimetres you have to interpret yourself.

Size-matched comparisons

We compare by reach, not by sticker. If the fair match is a different label, we say so, and show the alternative.

Honest about uncertainty

Missing fork data? Below the feel threshold? We flag it instead of guessing. Trail beats head angle when we have it.

Geometry only, on purpose

Reviews tell you how a bike rides as a whole. We answer a narrower question honestly: what the frame numbers themselves mean. When two frames are twins, we say so, and point you to where the real differences live.

Popular comparisons

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New to geometry? Start with the guide

Reach, stack, trail, seat angle: what each number means, how they interact, and why single numbers lie.

Read the guide →

Frequently asked questions

Is this a bike review?

No. We compare frame geometry only: the numbers that define position, handling and pedaling. Weight, stiffness, wheels and components shape the ride too, and reviews cover those well. We cover the part reviews usually skim: what the geometry chart actually means.

How accurate is the ride-feel verdict?

It is a rules engine, not a road test. It reads the geometry deltas, weighs them, and describes the direction and size of the difference in plain words. It is honest about thresholds: below a certain delta it simply says the two are the same.

Can I still compare a bike that isn't in the database?

Yes. Choose "Enter geometry manually" in the search box and type in reach and stack (the two required numbers), plus any others you have. The more you enter, the fuller the verdict.

Does a suspension fork change the numbers?

Yes. Under sag a suspension fork slackens the head angle and lowers the front, so we flag it: the stability we report is the floor, not the ceiling.