What size tire do you guys usually run?

I run the Mitchelin S12 (140/80/18) on my CR500. When time came to replace it, I decided to try it out on my WR450. Decided to leave it on the WR and buy a second S12 tire for the CR. The WR should have come with this size tire. Still spins but what an improvement on acceleration especially out of soft corners!

what do the size numbers represent. "ie" 100 110 19

100mm wide, 100%height of the width (90% would be a lower profile tire) and 19 is inches of the diameter of the rim

does that s12 140 fit the stock rim for an 06 wr450?

if not, what does the stock 06 wr450 max tire size?

Thanks.

I have the S12 140/80/18 on a 05' WR450. I would guess the 06' is the same size rim. I still have 1 inch of clearance on either side of the swingarm and close to 2 inches to the mud guard. I will go with a 150 on next go around!

I can't believe how quickly the stock tires wear out on the 06 wr450, m ine onjly have 52 miles on them and have more wear than my Maxxis desert IT on my XR 250 with over 500 miles!

I have to go hillclimbing with the bike before assessing what tires to get, right now I love the way it can slide around.

I use 110/100-18 Dunlop tyres on my WR 450 and they work just great!

100mm wide, 100%height of the width (90% would be a lower profile tire) and 19 is inches of the diameter of the rim

So let me get this straight. If you currently have 110/100 -18 and then you go to a 130/100 - 18, the tire will be higher correct, because you will go from 110 mm height to 130 mm height. Not a great plan for the vertically challenged like myself. So if you go to a 130/80 - 18, then the height is 80% of 130, so 104 mm. Hmmm. I think I like that idea.

So you guys who see a bit more mud/clay, do you like the wider tires in those conditions?

And then I guess the next question is, are the prices significantly higher with these less common sizes?

It is called aspect ratio, and you have part of it right.

if you had a 100/100/18 your width (first number) would be 100mm (nominal) your side wall height (second number) would be 100% of the width, so in this case you would have a 100mm height. If you changed to a 130/100/18 your width would be 130mm and height would be 100% or 130mm. if you used a 130/80/18 you would have a 130mm wide tire (nominal) and a side wall 80% of the height or roughly 104mm side wall height. Keep in mind these are actually average height and will vary slightly from manufacture to manufacture,

Some thing else to keep in mind is the rim width. a 450 has a 2.15 inch rim width and a 250f a 1.85 rim width. so if you put a wide tire on a skinny rim the math will not work out completely due to the side walls being pulled in and inversly if you put a skinny tire on a wide rim, the tire will actually widen the profile and shrink in diameter.

There are many set ups and changes that can be made.

Also, some interesting things start happening when you start changing tire sizes. Remeber the 130/100/18 as the example, this tire is taller in overall diameter than a 110/100/18 and will effectively change your gearing (like taking away a tooth from the rear sprocket, I didn't do the math, just an example) just like if you used a 110/80/18 in place of the 110/100/18 it would effectively add a tooth to your gearing (again just an example and I did not do the math, just a reference point to show effect).

Next you have weight and kinetic energy (someone out there could compute this, i wish not to). we all jump and some more than others, but remember brake checking? a tire with more weight will have a greater effect when doing this due to more energy, same as when you shut off the throttle.

Now more to think about, those people out there that lower the radiators on thier bike to lower the center of gravity, can to a slight effect do the same with tire combo's.

Next the weight will effect to a point the suspension due to it being what is called unsprung weight.

I kind of got off tangent here, and I guess my point would be that there is more to the tire issue than just width and height and tread design. these are the things people care the most about, but as you change them up, you change many other things at the same time. In all honesty like anything it is preference and what will work for a person.

Now that said for a long time I ran a 1.85 (250f or 125) rim with a 110/90/19 combo. worked great in the woods as it allowed me to more effectively use the rear brake steer method in the tight nasty woods (the ass would slide better).

:thumbsup::devil:

It is called aspect ratio, and you have part of it right.

if you had a 100/100/18 your width (first number) would be 100mm (nominal) your side wall height (second number) would be 100% of the width, so in this case you would have a 100mm height. If you changed to a 130/100/18 your width would be 130mm and height would be 100% or 130mm. if you used a 130/80/18 you would have a 130mm wide tire (nominal) and a side wall 80% of the height or roughly 104mm side wall height. Keep in mind these are actually average height and will vary slightly from manufacture to manufacture,

Some thing else to keep in mind is the rim width. a 450 has a 2.15 inch rim width and a 250f a 1.85 rim width. so if you put a wide tire on a skinny rim the math will not work out completely due to the side walls being pulled in and inversly if you put a skinny tire on a wide rim, the tire will actually widen the profile and shrink in diameter.

There are many set ups and changes that can be made.

Also, some interesting things start happening when you start changing tire sizes. Remeber the 130/100/18 as the example, this tire is taller in overall diameter than a 110/100/18 and will effectively change your gearing (like taking away a tooth from the rear sprocket, I didn't do the math, just an example) just like if you used a 110/80/18 in place of the 110/100/18 it would effectively add a tooth to your gearing (again just an example and I did not do the math, just a reference point to show effect).

Next you have weight and kinetic energy (someone out there could compute this, i wish not to). we all jump and some more than others, but remember brake checking? a tire with more weight will have a greater effect when doing this due to more energy, same as when you shut off the throttle.

Now more to think about, those people out there that lower the radiators on thier bike to lower the center of gravity, can to a slight effect do the same with tire combo's.

Next the weight will effect to a point the suspension due to it being what is called unsprung weight.

I kind of got off tangent here, and I guess my point would be that there is more to the tire issue than just width and height and tread design. these are the things people care the most about, but as you change them up, you change many other things at the same time. In all honesty like anything it is preference and what will work for a person.

Now that said for a long time I ran a 1.85 (250f or 125) rim with a 110/90/19 combo. worked great in the woods as it allowed me to more effectively use the rear brake steer method in the tight nasty woods (the ass would slide better).

:thumbsup::devil:

Wow, Thanks for that information Mkporn. :smirk: :smirk: :bonk:

Definitely lots of things to keep in mind. I can see how there could be some unexpected ramifications of making a big change all at once. But like you said, it is a preference and one a guy can only learn about from experimenting.

The bottom line is that a guy should expect better traction from a 130 than a 110, assuming everything else is equal, correct?

I just pleasure ride and I have the stock front and I think a 739 Dunlop rear. Its pretty much the same tread just harder.

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