Replicating indoor bike geometry on my mountain bike

Hello All

Got a question for you folks. I use TR software in two places: 1) indoor bike at home on a dumb trainer and 2) Stages bikes at the gym. Both use the same left crank gen 3 Stages power meter. But I can produce a lot more power at the gym. My guess this has to do with geometry and glute engagement due to being more forward leaning in the gym. I’d like to replicate my position in the gym Stages bike on my mountain bike, which will likely require moving some spacers and changing stem angle, but I need to know what to shoot for. Part of the answer is measuring distances which are the sides of a triangle formed by the bottom bracket, bars and the saddle. But in addition to distances I need to establish angles of said triangle. Does anyone know of a simple and accurate method of measuring the angles? I was thinking of getting a laser protractor, but there may be a simpler way that escapes me.


All you need is a tape measure and 4 foot level.

And an exist topic here.

Just use a spirit level and a tape measure to do stack and reach.

Hold spirit level vertical in line with the centre of the BB and measure horizontal to the handlebars. Also measure horizontal to the tip (or sit bone position depending whether the saddles are similar enough).

Then hold the spirit level horizontally on the base bars and measure down to the centre of the BB.

Apologies if that’s not what you’re looking for. That’s how I set up all my bikes.

Saddle height is measured the normal way with a tape measure from BB to sit bone spot/a consistent position you can find repeatedly. It won’t necessarily be exactly the same depending pedal differences etc.

1 Like

Damnit too slow :sweat_smile:

1 Like

Thank you!

1 Like