question over tyre sizes

[x9 rider]

hi there,

my amalfi's rear stock tyre size is 140 / 60 / 14. any side effect if i replace it with the following sizes ?  

1. 140 / 70 / 14

2. 150 / 70 / 14

[jimc]

Either should fit - but the 15/70 might get a bit near to the shock springs.  Both will give a more rounded profile, the 150/70 very much so.  They'll make the overall diameter of the wheel+tyre greater, so reducing acceleration a bit but possibly increasing top speed - though the latter didn't happen on my Fuoco when I changed to a 150/70 from a 140/70.

[loonymoon]

I'm changing the rear tyre on my X8 400 from a 140/70 to a 150/70 too, wonder what effect it'll have on the X8 - hopefully similar to the fuoco i.e. no noticible difference in acceleration (don't really want to lose any there)!!

[Dave Milnes]

The CVT tends to adjust the gearing so balancing out any increase in diameter.
Top speed will be increased slightly as the transmission runs out of gearing long before that point so the increased diameter has a direct affect. Don't expect a huge increase though, you probably won't even notice it. It is probably less than the difference between an old belt and a new one.

[loonymoon]

Thanks again Dave, very interesting info. I'm not too bothered about an increase in top speed on the 400 as I rarely reach it anyway but on a 250 (which I'm guessing the OP has) it might be of more interest.

[x9 rider]

thanks guys. i'll go for 140 / 70 / 14 . higher sidewall = more ride comfort .