hogman,
I've just fitted T bars on my bike and had a few problems to. It sounds to be like the riser bolts are longer than you need. unscrew one and see how far the bolt enters the old then check with the new one. I had crap in the right hand riser, a tap would have been handy. the only other thing I can think of is if the centre sleeves are missing from the rubbers.
Ductor
