Tyre size GSX750 1981

[Troy74]

Hi 

I just acquired a 1981 GSX 750 - cannot for the life of me make out the tyre sizes - tyres probably original as it was a barn find and the sidewalls are worn down from being flat I guess - were they just standard tyre sizes on these that someone will know or were there variants ? 
thanks in advance 

[Gixer1460]

I'm not near my Workshop manual but 100/80 x 19 fronts and 130/70 x 18 (or 19) sounds familiar.

[TonyGee]

3.25 x 19 and 4.00 x 18

[Gixer1460]

10 hours ago, TonyGee said:

3.25 x 19 and 4.00 x 18

He's not far wrong LOL.

From the manual 3.25H 19 4PR and 4.00H 18 4PR. And scribbled beside (as those harder to find in '85) 100/90 H19 & 120/90 H18, so nearly right !

[Troy74]

Thanks for the input guys ! I found a manual and it corresponds with what you said so I guess I can't go wrong if I go get tyres at those specs ! Thanks 

[Troy74]

Can I just check this is a suitable rear tire - check out the link 

 

https://se.mynetmoto.com/shop.cfm/mnm000005968/continental-120-90--18-(65h)-conti-go!.html

[Gixer1460]

More than likely - you ain't going to be spoiled for choice in those sizes these days!

[TonyGee]

this is one of the reasons we fit big fat wheels for modern tyres   plus it looks the dogs danglies  

[Poldark]

I ride same model (82).  110/90-19 front and 130/90-18 rear.  Those are one size wider than the recommended, but I've not had any adverse issues. I wouldn't go larger though.