Design and visualise custom bike geometry online. Enter frame dimensions, tube angles and stack and reach values to generate a scaled frame drawing. Export your geometry as a .json file for use with custom lug and dropout design. Free to use, no sign-up required.
How to use the frame designer
Start by selecting a bike type — road, gravel or mountain bike — then input your key geometry numbers. The tool draws the frame to scale in real time so you can see how changes to reach, stack, head angle and seat angle interact. Use it to validate geometry before committing to a build, or to compare different size variants side by side.
When you’re happy with your geometry, export it as a .json file.
Why geometry matters
Reach and stack set where your body sits relative to the bottom bracket. Head angle and trail determine how the steering responds. Chainstay length and bottom bracket height define how the bike accelerates and balances on technical terrain. These numbers don’t exist in isolation — getting them right for a rider’s body and riding style is the difference between a bike that works and one that transforms how they ride.
This tool is used during the design process at Creature Cycles and is shared freely as part of our commitment to open, transparent framebuilding.
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