G'Day Ron, your bike is looking great mate, well done! On the subject of rim sizes, I just bought this project bike, built by Ken Piper, now a mechanical engineering lecturer at the Defence Academy in Canberra, but an old race bike builder from "back in the day" who built the 1987 Arai 500 winning Yamaha FZR750, and an FZR1000 for the 1988 Suzuka 800 race in Japan.
He fitted wide 18 inch alloy rimmed wheels front and rear (tires aren't a problem, it runs Bridgestone B45's fore and aft) and with the FZR1000 forks and brakes mated to custom triples, this thing handles like no CB750 I've ever ridden. If I could close my eyes and block my ears from the wail of that genuine Yoshimura 4 into 1, I could convince myself that I was on a 1970's Ducati or Laverda!
Now wheels size is probably more personal preference than logical choice, but I personally believe that a 17 inch rimmed (front and rear) CB750 or Z1, Suzuki GS etc doesn't look right, because there's too much air under the fenders, and not enough between the ground and the engine cases, so I'm glad you went with the 18 inch front. The other problem is that our engines are much wider and sit lower than the modern bikes, so invariably, with little wheels, you can almost use your alternator cover for a side stand.
Sure, the K7/K8 ran a 17 inch rear wheel, but it should also be taken into consideration that they also ran a much higher profile tire than what is available nowadays, so in fact their 17 inch wheels fitted with the rubber they were using at the time had about the same outer diameter as a standard 18 inch rear wheel on the CB750 K0-K6. Regardless, rims/tires are really a personal choice, and one benefit of running smaller dia wheels is the physical lowering of the bike's height, which suits those of us with short legs, at the expense of some cornering clearance. Cheers, Terry.
