Is this tire okay for my 2006 klx 250s?
 

DUNLOP D606 REAR TIRE - 130/90-18 | MotoSport

What front tire do you guys recommend? I heard the Dunlop 606 front tire is terrible.

I think the 130 is too much for the 250 to handle. I would not go more than the 120 if I were you.

I wasn't sure what size would be best. I want to get the most performance out of the bike.

Clearing the chain and the swingarm are what you need to worry about. I'm running a 4.6" wide rear tire. That's between 110 and 120.

The D606 130 fits, and I didn't really notice any loss in power or performance with it on (I'm not a very sensitive guy though :) ), but it costs more than the 120 and it really didn't seem to give an advantage anywhere. One slight negative I noticed, was that the bike leaned over farther when on the kickstand. That is because the 130 tire is taller as well as wider. I have a pic of 130 vs 120 somewhere .
Dan

OK heres the pic.
My bike is on the left with the D606 130 on it, and my buddys bike on the right has the D606 120.
Dan

Attachment 14943

every time i see those pics from the bucky, i say to myself "geez i need to get out more". That was a great ride.

I wont be in the mud too much so the issue of whether the bike is too big for bike to handle is obsolete(or so I think). I am about to purchase this tire:

Dunlop D606 Dual Sport Tire | Rocky Mountain ATV/MC

Is this the right size?

If it's the 120/90x18 then yes, it' the correct tyre. (your link doesn't go to a specific size, just the generic tyre)

130 will fit, but it will raise your gearing and make the bike handle like a tw200, but if it floats your boat go for it.