Just an experiment, I was trying to understand, why the saddle top measured (with tape measure) around 2cm (from BB, both on 165mm cranks) higher on the Bumblebee than the Donobru, but felt very similar (in terms of leg extension, pedalling motion...).... It's an ongoing investigation but will be putting that saddle back on I expect.
You have different pedals on both bike and different contact point with the strap.
You have different pedals on both bike and different contact point with the strap.
See what happen if you swap them round.