From the club races I've seen recently there still seems to be as many first lap crashes now as there were before tyre warmers existed and I think the problem is still the same - it's the way the grid is formed, random or by ballot (ever noticed how there are less crashes when grid positions are decided by qualiying times or in finals where earlier finishing order determines the grid). This random nature of the grid means that a rider with a chance of finishing up front will have to make up positions quickly as club races just aren't long enough to wait a lap to start passing people, so there is always going to be some contact with 30 or so riders together with the faster ones deparate to get to the front.
Threaded Mode