After a spot of mechanical advice if possible.
I was out for a ride yesterday and went OK until my chain started slipping when there was much force put into the peddles.
I stopped and realised that the chain was VERY loose and then noticed the rear mech seemed to have very little torsion. The mech was still able to chain the gears though.
Today I checked it over and all looks to be ok with the gear cable etc but the mech cage appears to be in a strange place i.e. at least 45 degrees forward when normally it should be vertical. It seems to me as if the spring in the rear mech has gone but having said that it still springs back into position. I was thinking it might be that the chain stretched but I dont have a chain ruler and I just changed it 5 weeks ago.