Bike Size Finder
Geometry

Stack, reach, and standover

Compare Bike Stack and Reach

Size labels such as 54 or Medium do not mean the same cockpit on every brand. Stack, reach, and standover let you compare published geometry in millimeters.

How to read the numbers

  • Stack is the height of the front of the frame.
  • Reach is how far the handlebars sit ahead of the bottom bracket.
  • Standover is top-tube height when you stand over the bike.
  • A higher stack-to-reach ratio is typically a taller, more upright cockpit. A lower ratio is typically longer and racier.

Pick two or three bikes

Choose two bikes, or add a third. The comparison URL can be shared.

Choose two different bikes to see stack, reach, and standover side by side. A third bike is optional.

Looking for size labels by height? Open bike size comparisons.

Example

Trek Domane SL 5 vs Specialized Roubaix

A medium-size endurance road comparison using the published stack, reach, and standover numbers. Use the pickers above to compare other bikes.

Bike type

Trek Domane SL 5

road

Specialized Roubaix

road

Stack

Trek Domane SL 5

571 mm

Specialized Roubaix

580 mm+9 mm

Reach

Trek Domane SL 5

380 mm

Specialized Roubaix

378 mm-2 mm

Standover

Trek Domane SL 5

754 mm

Specialized Roubaix

766 mm+12 mm

Stack-to-reach ratio

Trek Domane SL 5

1.50

Specialized Roubaix

1.53

A higher stack-to-reach ratio is typically a taller, more upright cockpit. A lower ratio is typically longer and racier.

Trek Domane SL 5 geometry on the brand siteSpecialized Roubaix geometry on the brand site

Numbers last checked 2026-08-29.

Full size comparison

Trek Domane vs Specialized Roubaix Size

FAQ

Short answers for comparing published bike geometry.

What are stack and reach?

Stack is the height of the front of the frame. Reach is how far the handlebars sit ahead of the bottom bracket. Together they describe cockpit height and length better than a size label such as 54 or Medium.

What is standover?

Standover is the height of the top tube when you stand over the bike. If a brand table does not list standover for the compared size, that measurement is shown as not listed.

What does stack-to-reach ratio tell me?

Divide stack by reach. A higher ratio is typically a taller, more upright cockpit. A lower ratio is typically longer and racier. Use it with the millimeter numbers, not instead of them.

Can I compare a road bike with a mountain bike?

Yes. The numbers still compare cockpit height and length. Riding position, handling, and size labels will not map one-to-one across bike types.

Where do these numbers come from?

Each bike links to the brand geometry page we last checked. Confirm the exact model year on that page before buying.