Frame sizing tool

Find your perfect fit.

Answer three quick questions and we'll match you to the right Montu frame size — using your actual body geometry.

Not sure which bike is right for you? Take the Bike Finder quiz first →

This tool gives a starting-point frame size based on your measurements. It is not a replacement for a professional bike fit, which considers flexibility, posture, injury history, and biomechanics.
1
Choose your bike
Kopis
Gravel / Adventure
XS · S · M · L · XL · XXL
Osiris
Endurance Road
XS · S · M · L · XL
Nui V2
Aero Allroad
XXS · XS · S · M · L · XL

2
Your measurements
1
Height Stand against a wall in socks, heels together. Measure floor to top of head.
2
Inseam Place a book between your legs, spine up. Measure floor to the spine.
3
Torso From C7 vertebra (base of neck bump) to the top of your hip bone.
4
Arm length From shoulder tip to wrist crease, arm relaxed at your side.
Height
175
cm
Inseam
82
cm
Torso length
54
cm
Arm length
63
cm

3
Riding position preference

This doesn't change your frame size — it adjusts the target reach and stack to reflect how the bike should be set up for you (stem length, spacers, bar height).

Relaxed
Upright and comfortable. Less strain on back and neck.
Sport
Balanced reach. Efficient and versatile for most rides.
Aggressive
Forward and stretched. Race-ready and aerodynamic.
Your recommended size
M
Montu Kopis
Sport position
Fit match
Reach — adjusted for position
mm
Stack — adjusted for position
mm
Seat tube length
mm
Saddle height (from BB)
mm

Important — this tool is not a substitute for a professional bike fit. Frame size recommendations are based solely on the measurements you entered and published geometry data. They do not account for your flexibility, injury history, riding posture, cleat position, or biomechanics — all of which a qualified fitter will assess in person. Use this tool as a starting point only. For a final setup, we strongly recommend a professional bike fit. Book a consultation with us or seek a certified fitter in your area.