Tire sizes, confused

[Gippslander]

Getting confused,

I'm looking for some new Michelin S 12 tyres, I want 110/100-18 and on one of the ads I see the following:

"Up for sale is a brand new Michelin S12XC 130/80-18 (110/100-18 equivalent)"

Can anybody explain that to me, thanks

(fixed my typo  on the size I typed 100 and it should have been 110)

[matcho mick]

yep,makes sense if your'e pissed ,

[JohnnyO]

Michelin measure their tyre width from knob to knob and most other brands measure the width at the carcass.
A 130 Michelin is equal to a conventional 110

[matcho mick]

O

[John Orchard]

Yeh I have a Michy 110/90x18 on the back of the Kawa 400, miles too small.

[Gippslander]

Thanks John, couldn't work it out at all, doesn't make sense why they would do that just confuses the crap out of people anyway will probably give them a go, am looking for new tires for the 77 KTM 250, 110 on the back is probably about right, and they do the same on the front they say 90/90 is the equivalent of 80/100, but that's even sillier anyway they don't seem to list anything else if you go on their website they don't have a Michelin S 12 in 110/100 x 18 80/100 x 21, time to hit the fridge

[Rookie#1]

Michelin measure their tyre width from knob to knob and most other brands measure the width at the carcass.
A 130 Michelin is equal to a conventional 110

Exactly, you'll find this on Michi and Metzler tyres, some others as well. I often get people who want to put a "130" on the back of their (insert any big bore here) and tell me it "has" to be a 130!! And "they're all the same", even after attempting to polite educate them often they're still walk out with tyre waaaay too small because "I know my bike mate" ? oh well who am I to argue, after all.....what would I know 

[Mick D]

Getting confused,

Boy your confused, don't get me me started, so many experiences and what I thought at so many times what may have been knowledge at least 2/3 of life time of confusion,,,and it ain't over yet
Best try to explain in a moment when I'm not so busy drinking

[Nathan S]

Sometimes you buy a Michelin that has a sticker on the sidewall that has the "normal" size on it.

Michelin 120/90 = everyone else 100/100.
Michelin 130/80 = everyone else 110/100.
Michelin 140/80 = everyone else 120/100.

[Mick D]

so the confusion still goes on,,
sounds like you got to carry some sort of a manufacturers-conversion-equivalent card with you
FFS

For  me the Confucius started way back in the 70's some where when I bought a 400x18 to replace a 400x18,,,,,,
and the new forker wouldn't clear the arm and chain

Oh yeah well that's the way it is mate,,,,
some manufacturers measure the total width of tread and some measure the width of case, then add the tread, forkers.

So yeah,,,,,,,,,,,,,,,,,,,is there still some sort of manufacturer BETA, VHS sizeing thing still happening ?? 

[SON]

Maybe there is an advantage in buying from a shop where the guy knows the back wheel from the front

[Gippslander]

Thanks Nathan, can you do a comparo chart for the 21 inch front wheel tire sizes 

Mick,  not sure I can laugh at the BETA VHS thing  because my memory goes back to when someone bought a cheap video player at the pub and went home beaming and the Mrs pointed out that BETA was  dead in the water

[Mick D]

 

Well at least you got me laughin

[JohnnyO]

Sometimes you buy a Michelin that has a sticker on the sidewall that has the "normal" size on it.

Michelin 120/90 = everyone else 100/100.
Michelin 130/80 = everyone else 110/100.
Michelin 140/80 = everyone else 120/100.

Yep that's correct..
It seems as though the enduro tyres use the different measuring system and the mx tyres the conventional way.
MH3 and MS3 are 100, 110 & 120 sizes

[Mick D]

Maybe there is an advantage in buying from a shop where the guy knows the back wheel from the front

Yeap, I reckon your right,,,
cant go past a fellow VMX racer and tyre specialist and all round good guy
http://www.localsearch.com.au/Warners-Bay,NSW/Two-Wheel-Treads-Motorcycle-Tyres/profile/uQ52

https://www.facebook.com/pages/Two-Wheel-Treads-Motorcycle-Tyres/136639919846671

http://www.whereis.com/nsw/warners-bay-2282/yellowId-14553213