Tire options and what those number mean...

[Kenstogie]

So I pillaged this from bikebandit and I don't claim to be a tire expert (at all) but in the interest of knowing more (aka learning) about it here it is..... my hope is that we all can pick the tires we want/need...

PLEASE CORRECT ME if you see something wrong! and give me your opinion also! Thanks!!


SEE THE PIC BELOW
The metric system has five main components, and they are all printed on the tire sidewall. Some are strict measurements, others are codes that indicate something, so we’ll explain them all. It's strange to me that they have inches and MM on the same tire....

1-Section Width: (120 on pic) measurement of the width of the tread, in a straight line from one side to the other. .
MY THOUGHTS -There has to be a range here but if you get to big it could rub on things, not to mention additional traction and drag, do some measurements

2-Aspect Ratio: (70 on Pic) the ratio of a tires width as a percentage of its height; the higher the number, the taller the tire. Usually a two-digit number.
Hint: to determine the exact height of a tire, simply multiply the width by the ratio expressed as a decimal (so a ratio of 60 would be converted to 0.6.) So with a 130/90 tire, multiply 130 X 0.9 to arrive at 117mm.
MY THOUGHTS - this is the height of the tire and is a formula... there is also some range here too. To tall a tire can throw off your speedo some.

3-Speed Rating: (Z on pic) an alphabetical code designating the speed a tire is designed to run at safely, when properly inflated and loaded, from J-Z. Not always ordered alphabetically, and can be a little confusing (see manufacturer information.)
MY THOUGHTS -I don't think the chinese tires even have a speed rating)

4-Radial Construction (R on pic)
MY THOUGHT -not on the chinese tires we have that I saw

5-Rim Diameter: (17 on pic) measurement of the rim, from one lip to the other, in inches
MY THOUGHT- at least there is one straight forward number on the tire, rejoice....


The TAO Motors TBR7 Tires/Rims Example.....


FRONT
STOCK FRONT TIRE (2020)
Front Tire reads the following #'s
90/90-19 M/C First 90= Tire width in MM Second 90 means aspect ratio 19 is the rim size M/C means Motorcycle
RIM 2.15x19 Tire width x Tire Diameter??

JIANGSO General Science Technology Co (manufacturer)
CELIMO Brand name (?)
Tread 2 plies (2 layers of material on tread?)
Sidewall 2 plies (2 layers of material on sidewall?)

58P 6PR - no idea what these mean
Load Range C TUBE TYPE
MAX LOAD 236kg(520 LBS) at 280kPa(40PSI)

Front Rim Reads
19x1.85 (rim Diameter x Width?)
19 08 (manufacture date?)



REAR
STOCK REAR TIRE (2020)
Tire reads
110/90-17 M/C
--110 is the Tire width in MM and is a straightforward measurement

--90 is the sidewall height but is not a straightforward measurement. this is represented in an aspect ratio
of tire width (the first number)
90% (thats the second number shown) of 110 (first number shown, tire width)= 99mm
99 mm is the sidewall height

--17 is the rim size diameter in inches

--M/C means Motorcycle

NYLON
TREAD 3 PLIES (3 layers of material on tread?)
SIDEWALL 2 PLIES (2 layers of material on sidewall?)
RIM 2.50x17
JIANGSO General Science Technology Co (manufacturer)

BACK Rim Reads
17x2.15 (rim Diameter x Width?)
19 08 (manufacture date?)



So that's what I have on tires...... Would someone explain to me how this helps pick what the options are for a tire??

[Megadan]

The oversimplified explanation.

Don't worry about the load ratings as these bikes are so light you won't come close to exceeding them unless you weigh several hundred pounds. That said, it is simple a coding to describe the axle weight capability of the individual tire at maximum pressure. You can easily look up the weight if you are curious.

The number of plies in a tire is actually just another weigh to judge/rate a tires construction or work capability. More Ply = tougher or heavier tire. Yes, the number of plies is just layers essentially.

As for the rest of it, the metric measurements are simply there to help you judge the size of the tire. How does it help you select what tire to get? Simple, there are limitations as to how wide or narrow a rim can be for a given tire size, swing arm, etc.

As far as the Aspect ratio, you are correct. It is essentially the ratio of sidewall height in relation to tread width. That information is also capable of telling you the overall diameter of the tire.

110/90-17 = 110mm wide. The sidewall is 90% the dimension of the width or 99mm.

To get the diameter we need the size of the wheel, which is 17 inches, Next we take the sidewall measure and double it (Tire is on both sides of the wheel ) which gives us 198mm. Next we convert the sidewall measurement to inches by dividing by 25.4, which then gives us 7.8 inches rounded up. For total diameter you add the 17 inch rim diameter to the 7.8 inches of sidewall, and you get a tire diameter of 24.8 inches.

How does that help you? Well, lets say you can't find a 110/90-17 in the tire you desire, but maybe they have a 100/90-17. You know the tire is 10mm narrower, but you can also figure out it is only 24 inches in diameter. That change in diameter will allow you to possibly make adjustments to your speedometer readout, or if it were a rear tire, change your sprocket(s) to compensate for the change to the overall final drive ratio of the bike.

[Kenstogie]

mega dan making sense of stuff.... i am on the hunt for 50 50 tires for the TBR7....


i did some searching and stumbled upon the Shinko 805 130/80-17 - Bias Ply - Tubeless - 65 - T

Here's my thought process....

--130 is 20mm (0.787 inch) wider than the stock tire

--sidewall height is 104mm ....an additional 5 mm (0.197 inch) from the stock tire (80% of 130=104mm)

--17 inch diameter that simply has to match rim diameter

....so i stick my head and tape measure in the rear tire area of my bike and make sure there is enough room.... (plus some extra) AND make sure there is ample clearance factoring any movement of the rear swing arm is covered.

--in this case it's a tubeless tire but you can run a tube in tubeless tire .....however it is somewhat of a PITA so maybe a tire designed for a tube might be a better option...