I had something like this while learning. I found that my upper body was
twisted to the left, causing my hips (and the uni) to turn to the left.
It's just an idea, check that there is no rotation of the upper body
while riding straight.
>thanks
>
>Michael
>
>ps I'm sure this has been asked before but would trying on soft ground help
>me to learn to free mount? I'm nearly there but I tend to lose balance just
>after bringing up my balance leg on to the pedal i.e., just as I push off
>to ride. Would the soft ground slow down the process as well as easing my
>fall?
>
Try letting some air out of the tire also (not too much tho').
When learning I found that ~30 psi gave the wheel a bit extra
rolling resistance which made everything easier. Once you get
the hang of it, you can put the pressure back up (I use 50 psi).