I recently converted an old rigid steel frame to a suspended 9 speed mountain bike. When I was cleaning out my garage this weekend, I came across the rigid fork, and held it up to the frame with the 100mm suspension fork. The unloaded suspension fork was several inches longer than the rigid fork.
Here is my question: Are there any tricks to estimating the head tube angle?
I spent a little time with an angle finder and a level, but It was a framing level, and the whole thing was a little cumbersome. I am plannign on spending more time with it this weekend. I am interested in knowing how much I may have affected the frame geometry, and if I should be worried about the stress on the frame/headtube. The bike is pretty streched out, it is very stable and fast on technical descents, but it is a little sluggish on climbs (it could also be the engine).
I would also like to know at which angle I should begin to worry about fatiguing the headtube?
Thanks in advance for your comments.