Not your daddy's Tire question. TIRE SIZES

[muaymendez1]

Hey guys . time has come for me to purchase a rear tire. I found the brand that i would like to try, my question is about reading tire sizes.

I would liek to fit a taller tire to try and get more clearance on my 96. Leveling links wont work for my year RS.

Manual says 150-90/15 as the size for the rear Is there any size that would be a taller tire.

Also IS it possible to run a 140/90-15 . This would give better turnout but will it be safe on the rim and since the second number is an aspect ration of the first will a 140-90/15 be a shorter tire.

I wish i could stand 4 tires up to each other to see the difference.

has anyone tried a size other than whats listed by the manufacturer.

As far as measuring aspect ratio 150x.9= 135 mm high which converted to inches is roughly 5.31" so thats 20 inch wheel

140x.9= 126 mm 4.96" so thats 20 inch wheel give or take 1/2 an inch

Edited March 23, 2011 by muaymendez1
measurements added

[MiCarl]

Ok, in your 150/90-15 tire:

 

150 is the sidewall width in mm.

90 is the sidewall height aspect ratio (.9x150 = 135mm)

15 is the wheel diameter in inches.

 

If you run a 140/90- 15 your sidewall height is (.9X140 = 126mm). You lower the bike 9mm, or just under 3/8 inch.

 

Your don't need to include the wheel diameter in your calculation unless you want to know the absolute axle height. In this case you're only interested in the change. (BTW, in your calculation you mixed wheel diameter with tire height to get effective diameter. You needed to double the tire height. With the 150/90 tire your effective diameter is 25.6", not 20")

 

I don't think anyone makes a 150/100 street tire. You usually only see those tall ratios in dirt bike tires. You're going to have to find a different way to lift it.

[skydoc_17]

Hey Jose,

The only way to make the tire taller, is to go wider. The problem you have with your bike is, it is shaft driven, which means the drive shaft tube runs from the back of the engine to the Final Drive on the left side of the rear tire. So a wider rear tire, (to make the tire taller) could rub the drive shaft tube. The second problem you have is, 4th and 5th gear in the tranny of the Second Gen. bike is overdriven. If you go to a taller tire on the rear, you will basically be driving around in 4th gear ALL THE TIME. In 5th gear, the engine will be running at such a low RPM that the bike won't be able to get out of it's own way in 5th gear. My suggestion would be to make a "shock extension" to elevate the bike, and put the stock tire on the rear. If you would like help with this project, feel free to PM me.

Earl

[muaymendez1]

A shock extension sounds interesting. But what I got out of this is that either way you change the tire not only will handling change but bike charecteristics.

So getting a narrower rear wheel may help in cornering but will lower my ground clearance.

oh well i think its back to stock for the old girl.

[bongobobny]

Yah! I was gong to suggest either stiffening your rear suspension with a progressive spring or fabricating a spacer to keep your suspension at the same softness as it is now...

[muaymendez1]

I am still fooling around with the shock settings. I am having a stiff ride now but I have more ground clerance.

On my last ride I was planning to soften if up for the next 50 miles but i never did.

next long ride I will change them between stops to see the difference.

I just may not be used to the bike yet with only 300 miles in.

[putzhunter]

Hello All,

Does anyone know the rear maximum tire clearance width is on 2007 RSTD. I'm considering Avon or Pirelli

170/80-15 as the tire height is about the same. Appreciate any info. Thx.

[Squidley]

Hello All,

Does anyone know the rear maximum tire clearance width is on 2007 RSTD. I'm considering Avon or Pirelli

170/80-15 as the tire height is about the same. Appreciate any info. Thx.

 

The stock size tire is as big as you can go, any bigger and it will rub the driveshaft.