Question about changing tire sizes

[Vampire2800]

I have a 2005 YFZ 450 SE. The standard tires that come on the quad are Dunlop KT 355. 20x10-9. (Rear tires, that is). Very few companies make a 20x10-9, though. Has anyone changed to a different size tire without changing the rim? What I mean is this....... 21x10-9, 21x11x9, etc are far more available. What are the pro's & con's of doing such a thing & is it even possible? I know that the 1st number in the series is the width, the 2nd number is the sidewall height & the 3rd number is the rim size. ALso, what's the difference between a radial & non-radial? I'm unclear after reviewing this on Google. It says something about a weaker sidewall or some crap like that. Thanks in advance for your help.

[KEVIN300A]

first 20-10-9 are a pretty common size tire..... 20 is the height, 10 is the width and 9 is the rim size.... 21-7-10 is a common front tire size.... the only real dif. you will knotice by changing the tires size is more sidewall height and maybe a little more ground clearance. goodluck and if you look anywhere you can find the original tire size, motosport, ebay, etc.... goodluck

[Vampire2800]

Thanks, I've been looking on www.tiresunlimited.com. The 20x10-9 is hard to find on there. So it won't damage anything by going with a larger or wider tire, correct?

[k4f5x0r]

you wont damage anything no, maybe lose a little acceleration though.

as for tire sizes, your best off going with a 20-11-9. Its the same tire size, just a tad wider. yes, it will fit on the stock rims just fine. 20-11-9's are by far the most available tires you can get.

[yfzrider690]

What kind of riding do you do. If it's mostly trails I would go with a 21 inch tire to get a little more ground clearance. I am running 21x11x9 ITP GNCC's and I am using the stock rims. I have 22x7x10 Razr 2's in the front. I ride trails and dunes but have sand tires thats why I went bigger for the trails. I didn't notice much difference in acceleration but I have some motorwork done.

[Vampire2800]

Some trails, but mostly open field riding. My son has a little Suzuki Z90 so he likes to jump. We have a few small jumps, but nothing like ya'll do, I bet. I might need to do some motor work because I found out 3 days ago, when my quad got a bath, that I have a coolant leak somewhere. I started it & let it run for a little bit & noticed coolant dripping from the bottom of the motor underneath the oil filter. I tightened the 4 small bolts just above the leak & it slowed it down tremendously. However, it's still leaking somewhere. I filled the coolant reservoir up & after about 4 hours of riding it was just below the "LOW" mark. If I can't find the leak, I might just have someone tear it apart & start replacing stuff. I wouldn't know where to begin or what improvements I could do. A good start might be to try to get rid of this "bog & die" when I press the throttle in 1/16 of a inch. Oh well. Thanks for all ya'll's help!

[mbx5]

I am running 21" rears for more ground clearance...I do harescrambles and found that most of the tracks I ran on had some really deep rutted sections....so 21" tires helped a lot.... I am also running the ITP GNCC series....great treads, last a long time, and tough tires...awesome traction.

If you lose acceleration, drop your stock front sprocket to 13 tooth...works great.

[Vampire2800]

I'll give it a shot. Just picked up my 2010 yfz450r SE this morning & it comes with new tires on it, lol. Lucky me! It has the stock 20x10-9 on the back like all the new ones do. Thanks for the advice ya'll.