tire size for rear

7 replies to this topic
  • ggamster

Posted January 15, 2014 - 05:13 AM


I have a new WR 450 F. It is time to replace the stock mx51. The stock size is a 120/80-18. Is that the size I should replace it with? I am riding in a rocky area but between the rocks there are areas of deap mud. I am looking at the Michelin s 12 XC.

Thanks guys


  • CBus660R

Posted January 15, 2014 - 06:21 AM


Yeah, a 120 would OK to stay with.  When you order it, make sure you get the correct tire since Mich sizes the S12 and M12 differently, you want to make sure you order the 140 tire on the S12.  That is equivalent to everyone else's 120 (including Mich's MS3 and MH3).

Edited by CBus660R, January 15, 2014 - 06:22 AM.

  • Pooley

Posted January 15, 2014 - 06:47 PM


I tried going up one size on my 426 and did not like the way it handled, and it also seemed to hit the chain quite a bit.  To be honest, I didn't notice the handling while I had the larger size, but when I went back to stock size it seemed to make a noticeable difference.  I'd vote for sticking with stock size.

  • RMK800

Posted January 15, 2014 - 07:21 PM


Interesting perspective. I went with a 120 on my 07 450 and I would never go back to stock. I really liked the larger footprint in the rocks. Im also enjoying the mx 71 over the Maxxis Dessert IT. A lot of difference opinion on tires, but I do like the bigger size. I also went one size bigger on the front, made a huge difference in the rocks and rough terrain and less washing out.

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  • RMK800

Posted January 15, 2014 - 07:24 PM


Maybe others can confirm, but I thought stock tire size was a 110. So your 120 is one size bigger, but I could be wrong.

  • ggamster

Posted January 16, 2014 - 05:06 AM


I honestly didnt check to see what was on it. I just pulled the info off of Yamahas spec sheet. I ended up ordering a 120 AT81. We will see how it does.

  • stevethe

Posted January 16, 2014 - 05:42 AM


You shouldn't hit anything. We always run a 140/80/18 on the rear.

  • markit

Posted January 16, 2014 - 05:49 AM


What ever stock is. Went through upsizing 20 years ago and just ended up finding the Mans size them for a reason.


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