Hi gentleman, just a quick question if you would.the size of the tire on my 85 k100rt rear,is a 130/80 17 58h, is this a stock size? what I've read is that stock is a 130/90 17. is this a taller tire? thanks

It would be 26mm larger in diameter thats 1 inch

G'day Ken , take a look at this link , you can use it to compare different tyre sizes , just fill in the stock tyre size ( as Rick stated 130/90/17 ) and then the tyre size you want to compare , I use it all the time

www.tacomaworld.com/tirecalc

John Re

Ken52 wrote:Hi gentleman, just a quick question if you would.the size of the tire on my 85 k100rt rear,is a 130/80 17 58h, is this a stock size? what I've read is that stock is a 130/90 17. is this a taller tire? thanks

Some people fit a 130/80-17 instead of the original 130/90-17 to get the seat a bit lower.

Al

I have a 140/80 on the rear instead of the 130/90. Bridgestone BT45.

Sometimes what is fitted will depend on your tyre preferences as not every size is available from every manufacturer.

The '80' or the '90' you're enquiring about is called the aspect ratio. It generally means that the tyre's 'height' is that percentage of the tyre's width. So, 130/90x17 is 130mm wide, the sidewall is 90% of the width x 17, the number of inches of the wheel diametre. In short, a smaller aspect ratio will mean a smaller rolling diametre, which is a 'shorter' tyre. The stock 'Y' five spoke rear K wheel takes a 130/90-17, however, many of us use 140/80-17 to get a slightly larger footprint without changing the speedo ratio too much. Same goes for the front wheel. Stock is 100/90-18, a good plus one size is 110/80-18.

Standard: 130/90-17
Radius 333mm
Circumference 2093mm

Small/Low: 130/80-17
Radius: 320mm (bikes sits 13mm lower than standard, with no other mods)
Circumference: 2011mm
Effect on gearing: Engine revs approx 4% higher than standard

Wide option: 140/80-17 (Standard on some later RSs)
Radius: 328mm (bike sits 5mm lower than standard, probably not even noticeable)
Circumference: 2061mm
Effect on gearing: Engine revs approx 1.5% higher than standard

Hope it helps

Al

I changed from a 130/90 rear to a 140/80. Not noticeable simply because the worn diameter of the 130/90 is so close to a new diameter 140/80.

There are many threads about tyre types so if you have preferences you will find that your preferred tyres may be limited in size options.
 
The change in revs is very minor but since I have a spare RS final drive I might swap out the RT final drive IF maintenance requires it. Otherwise its not really worth doing.