Does it really matter?..As an ex DR said to me in Normandy..'If you wanted to have fun you'd take a **** or a ****, if you wanted to get there you'd take an M20'... ....Ian..(****..fill in as required )
As a Canadian veterans once told me: Norton went, where harleys wouldn't go.
Maybe the two motorcyclists are trainspotters: adding a braking motorcycle to the rear?
Nope, the Harley was equipped with fording tubes to stop water getting in and it had a decent sealed air filter, the Harley had already reached the other side and had enough time to get his camera out to take the picture!!!