On the late 1930,s works TT machines there were travel limiters fitted to the forks clearly visible in a press photo to prevent denting the tubes on full extension. So the works were aware of the issue as were Velocette on the girder forked KTT, racers. In the late 30,s In Ontario the Sparks Brothers fitted Norton rebound check springs their very fast TT. Replica.
The ones on the left?