thanks for the welcome and the offer for assistance.
well I now have a digital angular guage for my metal work so I should measure it for you what I can do.
However I can tell you it will not do quite as well as a mountain bike but will do very well for a trike. The reason being the extra low gearing: 24 (soon 22) to 34 teeth, the huge 19inch trials tyre and rim, the 15kg total weight and the fact that the seat is just off the tyre for maximum weight on the rear wheel so therefore to have the most amount of traction possible.
However I have a fourth trike in the works that powers the front wheels instead, got a new thread on it too:
http://www.bikeforums.net/showthread.php?t=422139
I am working to have it be able to climb more than any other trike before it anywhere. Big aim but I am doing some serious things to get there.