In the next couple weeks I will get some new tires for my NC31, but I'm in a bit of a dilemma finding the right size.

When I first got the bike it had a 160 rear tire, but since I had no previous experience with the another CB400, I didn't had any benchmark to compare it too. It was a Dunlop, don't remember which model but it was a lot stickier than the next set of tires I got (Dunlop GT501F).

When I got the new tires (GT501F) I decided to go with the stock sizing both rear and front (140 on the rear). I felt the bike much more nimbler and easier to lean on turns. But maybe that was because the tires were new and round.

Even though I commute on my bike daily, I'm always hitting the twisties, canyons and the occasional track day, so I would like to know if a wider rear tire would give me any advantages on cornering, I've read that a wider tire, while harder to initiate turn-in, will be more stable on a turn, is this true? What size are you guys running on your CB's? I'm debating whether getting a 140 or trying out a 150...but I'm also trying to use another brand/model of tyre (Feeling really inclined for the Pirelli Sport Demon).

Thanks! :D

I've got a stock 140 fitted (bridgestone bt 45) but this will be replaced by a bt090. I think I'll go with the standard size. I have no experience with bigger tyres. So can't help you there. I don't know if it's a problem that a wider tyre will be much rounder because the rim is made for smaller tyres.

everything ive read always seems to state that going wider than standard sizes ends up with shitty handling, so id be interested to know peoples ideas/opinions on this too. i did once put a rd350lc rear tyre on my rd125lc back in the 80s (yes im 40 now ) it only just cleared the swinging arm each side lol.. as for handling? i was a kid i didnt take much notice tbh i just wanted to look kewl with me metzlers on there hehe.

I had an oversized rear tyre on my VFR750 (a 185 instead of a 170 IIRC) and it totally upset the handling. The bike turned in too quick and felt as though it was going to fall over in low speed turns. Horrible!

I went back to the 170 and it felt light and nimble again (well, as light and nimble as a VFR750 is ever going to be!)

Personally, I'd stick with the standard set-up, unless you can afford to experiment a little

I'm due for some new tyres soon, and will stick to the original sizes. I will hunt round for something better than the Dunlops that are on it now though. I don't like Dunlop tyres.