Thanks for the responses.
Hmmm yeah I read a few bit and bobs about bottoming out, although what would the solution be?? Because I can't really go and buy new springs at, what, £60 each, plus I don't feel that there's a great need to at this stage, I mean it's not happening every time, just when I put maximum effort in.
I'll keep bocking and see how it goes I guess. Hopefully it won't mess up my back too badly.
I'm a little disappointed with
www.pro-jump.co.uk I suppose, as they could have given some better hints on which model to buy, but I thought buying ones about 5kg above my weight would be fine, if not a little stiff. It's not as though I'm using them more 'extremely' than anyone else, I just wouldn't have thought of buying the 80kg model, as I'm still lighter than 70kg!!
Never mind, hopefully I'll resolve it somehow!!
Thanks again,
Dom