Hey all I'm a newbie and just got my 08 ninja 250 this summer. I love it so far. I use it to commute (80 mi per day) and haven't had any issues.

My question is does anyone know how large of a rear tire I can upgrade to? The stock one is pretty small.

 

you cant go much wider than stock, and there isnt much need to unless you are looking for a high performance tire that will not hold up to commuting. you can go with a 140-70r17, bit its a tight fit. switching to a radial will help ALOT, but going to a wider tire will do nothing.

 

i'll ask my supplier. i overheard him talking to one of hs customers about the availability of a certain size and said alot of 250 owners uprade to size X.. i'll find out monday evening and post up. (hopefully.. if i remember.. A.D.D. is a ***** )

 

Ok so here is a dumb newb question - why is the radial better?

 

the way its wound and how it handles, basically.. the "technology" in the tire far exceeds the performnce aspects of the bias-ply tires. carcass flex and belt postioning (and other tire stuff..lol) all make it worlds better..

ok.. answer
the stock bike comes with 130/70-17 and a 110/70-17 (R, F)

alot of guys looking for more tire options are simply bumping up 10 on their aspect ratio. this allows them to also get not only the stock Dunlop tires, but a tire from pirelli that is not available in the stock size on the bike..

so,they're getting a 130/80-17 and a 110/80-17 if they want the pirelli tires. i think theres a few other manufactures out there as well covering this size, but evidently dunlop is the only one making the 130/70 and 110/70 tires.

as far as if you're considering a 140 tire, basically, unless it you actually do it, you'll never know. i'm pretty sure i can fit a 200 on my bike, but until i get bored and set a date with the tire machine on a slow night at the shop (and a spare tire.. won't BUY one unless i NOW it'll work..) i'll never know for sure..


if you get a 140 and it fits, awesome! if not, sadly, you'll have to eat the cost as probably 99% of suppliers don't refund on tires. unlss you sell it to a friend for value and get your money back then..

correction/edit.. i re-read the whole thing.. i see that you CAN fit a 140, but remember... the wider the tire is on a stock-sized rim, the more you abnormally flex the tire's contour. you're laterally squeezing a 140-wide tire to fit a 130 rim. that bows the sidewall, compromises bead seating and also contorts the contact patch.

it won't be bad on just going up 10 on the width, but any more, cances are you'll adversely affect handling. the bike will feel like i wants to "fall" into a cornering lean..

quick solution: get a wider rim for a wider tire. naturally, you'l have to bumpthe swingarm as well.. might not be worth all that, unless you have a 230HP 250R that NEEDS a wide tire.. lol

i'm trying to pin down a 250 for a racebike, i'll also post my own experiemtns and stuff on that if and when i get it..

hope that little bit of info helps!