Tire / wheel fitment question

I am nearing the end of a new build. EX500, R6 front end, ninja 300 swinger and 4"' rear wheel.

Am I risking certain death trying to run a 160 slick on a 4" wheel?

Do I need to try and find a 4.5" wheel I can make fit or should I just stick to a 150 DOT type tire on the 4" wheel?

 

Front wheel size please?

 

R6 front wheel, 17x3.5". Running a 120/70 front tire

 

I would say that 4" is a bit narrow for a 160. Having said that, I do have a 160 on a 4.5" on the back of the RGV at the moment.

 

A 160 on a 4.o pinches in the beads too much which changes the profile. It's just like a 200 on a 5.5. Preferred tire on a 4.o is a 150 and Pirelli offers 2 compounds to choose from.

But wait Joey Superfast with the yellow plates that only does trackdays once a year will contradict this in about a hour or less.

 

You rang?
My first street bike, GSX-R750, came with a 140 rear. I took it racing (first big bike race) and the only available tire on short notice was a 170. Yeah, I ran that bitch.

 

Ok, lets take this a step further. The chassis geometry works out a little better with a taller rear tire than the 150/60 provides. Assuming the 160 on a 4" wheel is a no go, what about the 140/70 Pirelli slick as opposed to the 150/60 dot? Is the 140/70 slick still available?

 

Go put a new car tire on your FJR and ride out of here will ya

 

A 160/60 is designed for a 4.50 to 5.00 rim. And you're starting things right by measuring first.

140/70 is 628mm diameter and 140mm wide on a 3.50
150/60 is 615mm diameter and 149mm wide on a 4.00

And the new small bike slicks aren't out yet so I don't have the tech specs, and I'm not sure when they will get to NA.

 

I did't realize the small slicks were a new offering. That explains why I have been unable to find any in stock. Looks like I ma just need to stick with the 150 rear and raise the shock a smidge until the new sizes are available.

 

You better call your Vendor before just showing up to the track....

 

Not a bad idea since in some regions the little bikes aren't that popular.

 

This was 1987. It was either that 170 (ME1 CompK w/ corresponding ME33 Laser CompK) or the OEM Bridgestone Cyrox Radials at Rockingham and Slippery point.
I knew nothing about geometry, but I understood traction...and in the case of the OEM tires, the lack thereof.

 

Man it didn’t take long to turn this into a dark sider thread lol

 

I didn't realize we were in "tech".
My apologies.

 

I don't know if it would be a hoot to try and run a small tire like a 140 on a modern 600/750 or just terrifying. I only say that because when I read it I instantly imagined a new bike then figured it was older.

 

It was, afaik, the first time a MFG mounted a radial tire. They were scary.

 

And it was a 3.5" X 18" rim. Multiple layers of scary.

 

Really? I don't remember. I figured at least 4".
What's that make the front, 3"?
I think it's coming back to me, 3 and 3.5 sounds vaguely familiar.
Dayummn.

 

The 160 isn't going to fit the 300 Ninja swingarm anyway. The Dunlop Alpha13 150 barely fits and will tear the crap out of your tire warmers if you're not careful.