Yeah 'cuz the R tail looks proportionate. It's the proper tail, that's why it went on to the 1125r :lol:
It went onto the 1125, both R and CR, because HD cut their budget so short that they had to pull from the parts bin. The whole backstory is no more surprising than anything else that went on with Buell during HD's full ownership.
Basically after the XB's were doing so well, Erik Buell said he needed a watercooled engine for the new bike. HD offered the V-Rod engine (which should have been Buell's to begin with), Buell said it was too heavy for a sportbike, eventually they gave him the ok to source an engine from another manufacturer (Rotax) under the conditions that HD wouldn't have to spend a dime on it, and it couldn't be bigger than the V-Rod's displacement at the time (1130cc).
HD even went as far as making him redesign another fairing for the 1125. The patent drawing clearly shows the radiator pods of the 1125 with the Firebolt fairing.