That is back in my time of riding like 5 yrs after I started. In our area most had shifted to Brit irons for dirt riding & even street. A group of us were deep into most forms of competition & we had some of the first dirt comp irons from the UK along with modifications to street bikes so they were competitive in dirt comp & yes even road raceing. Yet a few times I saw an almost stock HD with crash bars front & rear to even saddle bags actually trying to compete in dirt comp. So VERY Club like & a maze of fun.
Riding gear was almost identical though by '48 I was wearing Brit Barbour & Sons waxed cotten m/c gear basically as a jacket while trousers were jeans or ex-army wool battle dress pants. Crash helmet was the "puddin' basin" thing in AMA & CMA events like flat tracking, dirt hill climbing , Scrambling (MX), Enduro, & Cross Country. YET often in hill climbing I would see older Americans wearing an O-L-D football leather helmet that would date back to the 30s!!!!!!!