I'm new to dual-sporting (2010 KLX250S), and I had never seen tire sizes like 3.00 21 or 4.60 18 etc. but I went looking for some primarily street tires. Problem is it appears those sizes are being phased out and everyone is going to the sizes like 90/90-21. I've seen some conversion charts, but they don't all seem to agree..

So, I'm thinking of Pirelli MT90AT and wondering if these are the right ones for sure (just need a sanity check): 90/90-21 54S TT for front, and 120/80-18 62S TT for rear?

The rears are also available as 110/80 and 140/80. Would any of the rears work, and what would be the consideration of one over the other?

 

the 3.00-21 is between an 80/100 and a 90/90. I am running a 90/90-21 on both my 250 and 650. No problem.

The rear inch sizes can be weird, the 4.60 may be a 4 inch low profile or may actually be around a 4.50" tire. You can use the 110-120 without much issue, the 130-150 series is really overkill and requires more horsepower to rotate them. The 110/90-18 is roughly the same as a 4.10 and a 4.60 if it is the low profile, the 120 is more like 4.50 wide. You need to actually go to the manufacturer's site to get actual mounted widths and diameters, most have them somewhere on the site. That's what I did. I went to a narrower tire than the OEM. I went with a 4.10-18 which was about a 110/80 instead of the 120/80-18.

I like a lighter tire gving the bike a light motocross bike look , taking less power to rotate it, less unsprung weight, and the ability to break loose easier when I want to if in sand or mud or just doinking around on gravel roads to slide in corners.. There is one other reason I run the 4.10 versus the 120, a side benefit - $20 difference in price. I can buy three of the 4.10-18 for the price of two of the 120/80-18 in the same brand/model. So I get a lighter tire that takes less horsepower to spin and almost the same wear as the wider tire, but 1/3 less cost. Hard to beat.

 

thx, klx678

 

Side note:

A lot of riders like the look of fat rear tires, I have no problem with that. I just present why I run what I run. The Supermoto version runs a 130 road tire and that makes sense, off road and road needs aren't the same. The bike will pull the 120, obviously Kawasaki felt it would, but likely performs a shade better with the narrower tire. You aren't going to lack traction with the small horsepower of the KLX. But if you prefer the bigger tire, go for it.

If your choice does offer both 110 and 120, check the pricing. It may sway you one way or the other. It was a factor in my choice once I saw the difference. Although I did lean toward the small tire in the first place the price locked it in.

 

https://www.kawasakiforums.com/forum...re-size-38762/

 

klx678--pretty sound reasoning, I'd say

brienensac--thanks, link was informative and encouraging

 

I would not put a 140 on it. I ran a 120 on my KLR650 and it was fine. great tire btw (for a 90/10) I ran through a couple sets on my "road" wheels. kinda spendy but none better

 

 

I'm in the same boat with wasaki and have never owned a 4-stroke anything. I've owned 20+ 2-stroke mx & Enduro bikes for off roading and woods riding since 1976. I'm 58 years old with worn out knees, back & shoulders but just can't concede. When my KX got too hard to crank because of the knees a couple of years ago, I quit riding it, except around the house. Left knee keeps bending backwards when kicking with the right. UGH! I've been looking for a new bike solution for a while now and ran across a KLX250 with 2k miles and bought it. I know it's a drastic change from a KX250 2-stroke but Yeah! electric start.

The factory tire size is 100/100/18 dual sport tire but most of my riding will be off pavement. I've been looking at the D606 Dunlop (always bought 695's,) because it is a 90/10 tire. Only sizes I see are 120/90/18 and 130/90/18. My concern is with the wider tire and reduced HP of the KLX, how bad the affect will be. Very noticeable or not so much? I'm dropping the front sprocket to a 13T because I don't need the speed and am not concerned with gas mileage but want the grunt when necessary.

I welcome your suggestions. Thanks Firedog

 

I'd look up the tire on Dunlop's site and see just how wide the tire is. They have good information on all their tires. Compare it to others, there may be a fair amount of variance manufacturer/model to manufacturer/model. Not a whole lot of DOT knobbies out there. I looked and over all width is 4.80" wide and from a quick perusal of the other off road-only tires, the narrowest of the 18s available. To go narrower