Rear rim width/ Tire selection

[zio]

Can I put a 120 on the stock 18 rim, or do I need to stick with a 110? For example, Maxxis' website lists the width of their 120/100/18 IT rear as 5.3", and a rim width of 2.75", whereas the 110/100/18 has a width of 5.0", and rim width of 2.5".

I did a search & found a few folks who said it's not improtant, but I'm ordering a tire for DW & don't have time to make a mistake.

I have a 130/80/18 M12 on it now, and can't find the info on Michelin's website, nor can I find the rim width for my stockers.

 

[BigBore]

If you've already got a 130/80 on there, then the 120/100 should fit.

 

[zio]

Thanks!

 

[dirt bike dave]

The Michelin 130 rear is the same size as most other makers 110's. If you liked the size of the Michelin, I'd stick with a 110.

 

[zio]

Gotcha. So most folks run 110's on their 250's? Any disadvantage to trying a 120? Any particular advantage?

 

[BigBore]

I stand corrected. I forgot that some manufacturers measure the width of the tire from different places. Its been my understanding that some measure from sideknobs to sideknobs, while some measure sidewall to sidewall.

 

[zio]

Well, I can change my order before the end of the day, but I've already called Cyclewerkz & Jeanne has confirmed my Maxxis IT front & 120/100/18 rear will be there. I don't care about anything, as long as it fits.

 

[dirt bike dave]

I've never felt the need to run a different tire than a 110 size on my 250, so I cant' give first hand information on how a larger 120 width tire would work.

Most folks do run 110 size rears on their 250's and 300's. Seems to work well. FWIW, I compared a Michelin S12 130 x 18 in the store next to a Dunlop 756 in 110 x 18 and the Dunlop was just a hair larger. As a rule, deduct 20mm from the Michelin rears to compare with other tires.

The 120 size tires (140 in Michelin speak) are intended for big bores and are going to be heavier. Clearance and rim fit might be a problem. More rubber might offer additional traction in some situations, but the heavier tire might have an effect on engine and suspension response.

 

[zio]

I'll give a report after DirtWeek. However, my adrenaline will be pumpin' through my body like a firehose up a monkey's butt, so I doubt I'll notice much.

 

[el presidente]

i have a 130/80/18 Michelin S12 on my 200 exc and i love it, great traction and sticks the corners very well. my friend has a 400 exc and he has a 140/80/18 Michelin S12 on his, but i don't believe that the 140 will fit on my 200.

 

[bud]

When I had a 140 s12, I had trouble with it hitting the plastic chain guide and silencer. It wore slightly better (due to less wheelspin?), hooked up better in some conditions, with really low pressures - 3psi - but that also sapped power. With normal pressure it didn't hook up any better, and hindered turning at times. Overall any advantages a bigger tire offers are outweighed by the disadvantages at least on a 250 imo.

 

[fremontguy]

Zio, good choice on the 120 size. Haven't tried the Maxiss line yet but would like to. I've used only M5b and S12 in 140 size on 300e and Xr400 and like the meaty hook up. Bigger nobs stretched farther out around tire was the way it was explained to me.

 

[jeb]

I've used the 140 S12 on my 98 380, 99 250, 01 400 and run it all the time on my 03 450. I always remove that plastic thing between the tire and chain as part of my new bike prep so I don't know if it hits that or not. It for sure does not hit the silencer on any of those bikes. Great tire, BTW.