Here are both the exercise bikes I was given to use for this project.
(I get on well with the gymnasium staff)

[Linked Image from i175.photobucket.com]
We stripped the black one it was in poor condition. I intend to experiment with that one and keep the red one until we know what we are doing.
[Linked Image from i175.photobucket.com]
The turn ration on the black bike is something like 1:21 the final drive being the silver disk at the front.

der Großvater