Wider Rims with Stock Hubs

Hi everyone,

I'm new to this forum, but I am currently restoring a 78' Kz1000A2 into a cafe racer style bike. I was wondering if someone can let me know what is the largest size of rim, front and rear, that fit with stock spacing, and without any mods to the rear brake or sprocket and carrier.

I've already read on here of someone going to a 2.15" rim on the front and 3" on the rear, but can you go any wider without using an offset gear and sprocket spacer?

I've seen a 4" X 16 rim on 78' CB750 with stock hub, but i'm really not sure where to look for this info or where to find the parts....

Any help is appreciated,
Andy

its the swingarm thats the limiting factor;)

Yes, the stock swingarm limits you to using a 130 mm X 18" rear tire. And this rear tire comes close to the front of the stock swingarm too. Sure, you can fit a wider rear rim like a 3.5" X 18" or even a 4.0" X 18" but you won't be able to fit wider rear tires on these wider rims because of the stock swingarm's limitations.

My '78 KZ1000A2 has a 2.15" X 19" DID rim and SS spokes on a 100mm X 19" tire while the rear has a 3.00" X 18" DID rim and SS spokes on the stock swingarm and a 130mm X 18" tire.

My '73 Z1-900 has a 3.5" X 17" Excel front rim and SS spokes and a 4.25" X 17" Excel rear rim and SS spokes on a '82 Suzuki GS1100E swingarm and a '77/'78 KZ1000 rear wheel hub.

thanks BohicaBob for the reply,


if you can go to a 3.5" with the major problem being the height or aspect ratio of the tire to the front of the swingarm, why not go to a shorter side wall if available? I know there are many 3.5 X 16" rims available for the rear and if side clearance is ok, why not on 140mm X 80-70 rear tire?

anyways 130mm or 140mm is all i'm looking for, alot better grip to put down the power. I figure I'm going to be close to the 100 rwhp with my bike. its got fully port head, 34mm carbs, oversized valves, decked head, and i'm considering the 1105 cc engine kit; that or new rings and a cylinder hone. should be a decent ride.

thanks again