I raced against one back in the early 90's when the Cycle Jam was at Pocono. It sounded great with a full system and did pretty good in D Superbike.
Iconic Motorbikes have all four of the 250cc, I-4 bikes for sale. Should be an upcoming Cycle World article featuring them.
I have put a dozen or so miles on one. Completely ludicrous and ridiculous. If I had the dosh I would own one, but I'm the type of motorcycle owner who doesn't deserve a nice bike. You rev the piss out of it, shift at the top, and when you grab the brakes you realize that you are only doing 50 MPH and the brakes make it just. stop. It slows down faster than you can downshift, so you are caught completely off guard on the road until you wrap your brain around the new paradigm. I also got to ride a TZR250 and KR1 on the same day, and the CBR was just as fun as the smokers. More road compliant than the KR1 by a long stretch, but that's not saying much, really.
A one off bike for sure, but this SIX cylinder small bore sounds most excellent. Built by Guy Coulon of Tech 3 fame. I'm sure if I heard this bike in person, I'd have a woodie - rare for a four stroke.
Did it go by you and make your eyes water from the smell and taste of Elf fuel? God I hate that shit....
I rode a GSX-R 250 many moons ago. 1989 or 1990 model, I think. That made 45 HP at 15K - didn't look nearly as cool as that CBR though. People automatically got mad when they heard a bike screaming like that, but their attitude changed when they realized that it was still at walking pace
I found out some interesting info on this bike, and its relationship with the CBR250RR. https://www.visordown.com/news/racing/general/what-does-guy-coulon-do-his-spare-time
