Honda CBR 750RR Fireblade Prototype

Back in the late 1980s, the sportsbike market was very different than it is today. Sure, there were 600s and 1000s, but bikes like the GPZ600R were more budget all-rounders than the high-end race-replicas of 2011 while large-capacity bikes like the GSX-R1100 were incredibly fast, but heavy and erred towards stability over agility. The race replicas of the period were the 750s — GSX-R, OW-01, ZXR — but Honda’s entry into that category was the etherial and expensive RC30. How could Honda combine power and handling for the street at an accessible price? Enter this Honda CBR750RR, a never-before-seen prototype that eventually birthed the Fireblade.

“It was in 1989 and I was riding with a group of Honda engineers on some of the competitors' machines,” Tadao Baba told Kevin Ash back in 2000. “There was a Suzuki GSX-R1100, a Yamaha FZR1000 and our own CBR1000F. I was thinking, 'How can these be called sportsbikes when they are so very big and heavy?' They didn't deserve the name.”

Baba-san, of course, is the legendary engineer who fathered the ‘Blade. But, before he got there, this 750 was his proposal for a something that deserved the sportsbike monicker.

Legend has it, that when Baba-san pulled the wraps of the CBR750RR in a secret meeting with Honda management, one executive was bewildered by what he desribed as a “small bike and full of holes.”

The production CBR900RR.

You can see a lot of what would eventually become the CBR900RR in 1992 in this 750. The huge aluminum beam frame defines the bike, while the windsheild, mirrors, fairing brace and tank could have come straight off the ‘Blade. The seat shape draws influence from that RC30 — a bike it was eventually decided the CBR shouldn’t pilfer influence from. That huge swingarm evokes race track performance, but was watered down into a likely-more-affordable, braced design for production. That 16-inch front wheel — something spec’d to speed steering, but that would come to plague the ‘Blade’s reputation with instability — is clearly present.

Because the intention with the CBR was to create the ultimate road-going sportsbike rather than build a World Superbike replica, it was eventually decided that the racing-dictated 750cc capacity wasn’t necessary, leaving Baba-san free to find the best compromise between weight, size, flexibility and outright power available at the time, stroking the 750 mill out to 893cc.

“Originally we started with a CBR750RR but we already had the VFR, so perhaps make it a 1000? No. We also had CBR1000F,” Baba-san told Visordown. “Instead we saw that if we took the dimensions of a 750, use base motor but keep same bore and increase stroke it came to 893cc — so a new class was born, the 900 class.”

That left the CBR750RR as a footnote in Honda’s history.

Source rideapart.com