question about tire sizes

[sly409]

Hey guys,

I've been search tire sizes and stuff to see whats the largest I could fit on my bike and after a quick search I found that the largest tire sizes others have been using is 110/90x18 (4.00?) for front and 130/90x18 (5.00?) for rear. None of the threads really stated if that was the largest they could fit with or without fenders. I'm currently planning on running my bike without any front or rear fenders and no chain guard so I was wondering if its possible to go any larger than that.

For reference my bike is a 79 xs400f with disc brakes and mag wheels. My rim sizes are 1.85x18/front and 2.15x18/rear. Current tires on them are severely worn 3.00 front and 3.50 rear.

I'm trying to determine if largest tire size is dependent on rim size or clearance size or both?

Thanks for any input fellas.

 

[LuckyEight]

I'm also curious about the tyre sizes. I thought that maximal rear tyre size is 120 due to chain (or chain gauard?)

 

[16VGTIDave]

The narrow rim width is a bigger factor. Modern radial tires are built for wider rims than we have. This limits the choices we have.

 

[sly409]

I'm also curious about the tyre sizes. I thought that maximal rear tyre size is 120 due to chain (or chain gauard?)

I think 120 is max if you have chain guard still on. I believe people who've taken off or modified their chain guard are able to go up to 130. Thats kinda what I'm getting from reading other users experiences.

 

[Scorpio1963]

I wonder if thats why my chain guard is missing from my bike I`ll have to check the back tire size.Thanks for bringing this thread up.

 

[XSLeo]

On these bikes the wide tires is not the best handling, stay with the stock sizes.
Leo