Tire Differences

karbon_dunn · Post by **karbon_dunn** » 11:08 am Mar 27 2005

My '93 KDX currently has a rear Dunlop D756 100/100x18 and a front Metzler Unicross 90/90x21. Buykawasaki.com has the factory of 100/100x18 rear and 80/100x21. In looking into getting new tires I am looking at a Michelin S12 front and M12 rear. The 100/100x18 I have not found anywhere yet so I am asking what the differences are in a definition sense of say a 130/18x18 and a 120/19x18. Is the tire descriptor the same as a car, my corvette has 275/35ZR18 front 325/30ZR19 rear and know that that relates to tread width, sidewall and rim. Also what would be a recommened generalized spec be. I guess I would ask what is the difference between a 130/18x18 and a 120/19x18 and same for front. Advantages disadvantages etc.

Thanks guys!

Post by **Indawoods** » 11:22 am Mar 27 2005

I think it goes width first and then height percentage to width. 100/80 is 100 wide and 80% as tall. I THINK !

Michelin Conversion Chart

Michelin size 120/80x19 = 100/90x19 Conventional sizing
Michelin size 120/90x18 = 100/100x18 Conventional sizing
Michelin size 130/70x19 = 110/90x19 Conventional sizing
Michelin size 130/80x18 = 110/100x18 Conventional sizing
Michelin size 140/80x18 = 120/100x18 Conventional sizing
Michelin size 90/90x21 = 80/100x21 Conventional sizing

Discussion was here: http://kdxrider.net/forums/viewtopic.php?t=335

karbon_dunn · Post by **karbon_dunn** » 11:24 am Mar 27 2005

Thanks Inda!

PhilJensen · Post by **PhilJensen** » 09:37 am Mar 29 2005

You might want to reconsider the M-12 rear. S12 rear works better and seems to last just as long.

HTH,
Phil

Post by **Indawoods** » 10:01 am Mar 29 2005

Yeah...S12 rear... M12 front.

Post by **fuzzy** » 12:04 pm Mar 29 2005

I prolly missed something, and could research it but I'm lazy. Why the M over the S on the front?

Post by **Indawoods** » 12:35 pm Mar 29 2005

farmerj wrote:
I hear most people put M12's on the front but I don't know why since you usually get 3 times the wear out of a front than a rear.

I've done a lot of searching re: "tires". What I understand is that people run the M12 NOT because it lasts longer...but because it grips better. The S12 has a "sideways knob" in its tread pattern & doesn't hang on as well as the M12 in some situations, according to reports - not my "real world" experience!

canyncarvr · Post by **canyncarvr** » 12:56 pm Mar 29 2005

re: 'I guess I would ask what is the difference between a 130/18x18 and a 120/19x18 and same for front.'

Neither of those are valid sizes. Typos? I don't know.

The tire sizing does fit/relate to automobile tires...namely width first, ratio second, wheel size third.

Where the confusion comes in is the 'old' vs: 'new' method of sizing. At least Michelin's sizing is different. Don't know about other european outfits..like Pirelli.

I finally found another rider (local shop owner..MX racer guy)that has the same opinion as I do regarding the S12. Traction is great...brakes like it's on snot. You actually speed up when you put on the binders! But, throw a roost? Oh yeah. About 10" wide!! Sounds like a newly sharpened rip profile chain cutting the air (chain saw). The thing actually moans!

Post by **Indawoods** » 01:24 pm Mar 29 2005

re:Braking

Again... different schools of thought on this too!

85% of effective braking is front and 15% rear. This is my school of thought and found this true of street and dirt. The rears have to have some effectiveness but not nearly as much as the fronts.

PhilJensen · Post by **PhilJensen** » 01:34 pm Mar 29 2005

I like the S12 front and rear. S12 seems better to me in the front than M12 too.

As for the breaking problems, never had a problem there, but then I like brake sliding almost as much as power sliding ;)

Phil

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Tire Differences

Tire Differences