it may just be us brits have been riding motocycles for 100years or more,we may have parents grandparents or even great grandparents that rode bikes,in the 50s alot of families got about by motocycle/side car and there was probably more bikes than cars on the road so its deeply ingrained in our culture. it may just be that british citizens from other ethnic cultures just dont have such a long history with the motorcyle so the interest and desire to ride a bike is just not there