If you're taking your tire off, could you measure some things for me?

[Rabbitbunny]

I've come up with an algorithm that I think comes pretty close to correct. If you happen to have your tire off in the next couple days, Could you measure these for me? My LBS is closed for the winter and I don't really want to wait.

The rim width is the inner measure, where the tire mounts. If your rim is not in this list it is not ISO, but the numbers can help.
The tire section width is the two digit part of your ISO tire size, If yours is not on this list it is not ISO, your numbers cannot help.
The mounted height is the distance from the bead to the ground. Please measure this without the tire actually on the ground.
The mounted width is the widest part of the tire. Please measure this without the tire actually on the ground.
The carcass width is from bead to bead of the tire when off the rim and laid flat, this is a very important number.

Also, your tire needs to be at ISO pressure, 200kPa(29psi) above 25mm section width, and 300kPa(43.5psi) below.

These are my calculated values;
Rim Width -- Tire Section Width -- Mounted Height -- Mounted Width -- Carcass Width
13 -- 16 -- 16.67 -- 16.01 -- 35.09
13 -- 18 -- 19.22 -- 18 -- 42.02
13 -- 20 -- 21.6 -- 20 -- 48.68
13 -- 23 -- 23.53 -- 22.22 -- 55.92
13 -- 25 -- 25.83 -- 24.25 -- 62.45
13 -- 28 -- 27.79 -- 26.51 -- 69.7
13 -- 32 -- 33.73 -- 30.57 -- 82.61
13 -- 35 -- 36.99 -- 33.6 -- 92.2
13 -- 37 -- 37.91 -- 34.89 -- 96.29
13 -- 40 -- 41.15 -- 37.93 -- 105.87
13 -- 44 -- 45.4 -- 41.96 -- 118.58
13 -- 47 -- 48.56 -- 44.98 -- 128.1
13 -- 50 -- 51.69 -- 47.99 -- 137.59
13 -- 54 -- 55.85 -- 52.01 -- 150.23
13 -- 57 -- 58.95 -- 55.02 -- 159.7
13 -- 60 -- 61.04 -- 57.35 -- 167.04
13 -- 62 -- 63.11 -- 59.36 -- 173.35
15 -- 16 -- 17.47 -- 17.02 -- 35.09
15 -- 18 -- 19.99 -- 18.9 -- 42.02
15 -- 20 -- 22.33 -- 20.83 -- 48.68
15 -- 23 -- 24.22 -- 23 -- 55.92
15 -- 25 -- 26.5 -- 25 -- 62.45
15 -- 28 -- 28.45 -- 27.25 -- 69.7
15 -- 32 -- 34.39 -- 31.28 -- 82.61
15 -- 35 -- 37.64 -- 34.3 -- 92.2
15 -- 37 -- 38.56 -- 35.58 -- 96.29
15 -- 40 -- 41.79 -- 38.61 -- 105.87
15 -- 44 -- 46.04 -- 42.63 -- 118.58
15 -- 47 -- 49.19 -- 45.64 -- 128.1
15 -- 50 -- 52.33 -- 48.65 -- 137.59
15 -- 54 -- 56.49 -- 52.67 -- 150.23
15 -- 57 -- 59.58 -- 55.67 -- 159.7
15 -- 60 -- 61.68 -- 58.01 -- 167.04
15 -- 62 -- 63.74 -- 60.01 -- 173.35
16 -- 16 -- 17.91 -- 17.58 -- 35.09
16 -- 18 -- 20.38 -- 19.37 -- 42.02
16 -- 20 -- 22.72 -- 21.27 -- 48.68
16 -- 23 -- 24.58 -- 23.41 -- 55.92
16 -- 25 -- 26.85 -- 25.39 -- 62.45
16 -- 28 -- 28.78 -- 27.62 -- 69.7
16 -- 32 -- 34.72 -- 31.64 -- 82.61
16 -- 35 -- 37.97 -- 34.65 -- 92.2
16 -- 37 -- 38.88 -- 35.93 -- 96.29
16 -- 40 -- 42.11 -- 38.95 -- 105.87
16 -- 44 -- 46.36 -- 42.97 -- 118.58
16 -- 47 -- 49.52 -- 45.98 -- 128.1
16 -- 50 -- 52.65 -- 48.99 -- 137.59
16 -- 54 -- 56.81 -- 53 -- 150.23
16 -- 57 -- 59.9 -- 56 -- 159.7
16 -- 60 -- 61.99 -- 58.33 -- 167.04
16 -- 62 -- 64.06 -- 60.34 -- 173.35
17 -- 16 -- 18.38 -- 18.17 -- 35.09
17 -- 18 -- 20.81 -- 19.87 -- 42.02
17 -- 20 -- 23.11 -- 21.72 -- 48.68
17 -- 23 -- 24.95 -- 23.83 -- 55.92
17 -- 25 -- 27.21 -- 25.79 -- 62.45
17 -- 28 -- 29.12 -- 28 -- 69.7
17 -- 32 -- 35.06 -- 32 -- 82.61
17 -- 35 -- 38.3 -- 35 -- 92.2
17 -- 37 -- 39.21 -- 36.29 -- 96.29
17 -- 40 -- 42.44 -- 39.3 -- 105.87
17 -- 44 -- 46.69 -- 43.31 -- 118.58
17 -- 47 -- 49.84 -- 46.32 -- 128.1
17 -- 50 -- 52.98 -- 49.33 -- 137.59
17 -- 54 -- 57.12 -- 53.33 -- 150.23
17 -- 57 -- 60.23 -- 56.34 -- 159.7
17 -- 60 -- 62.31 -- 58.67 -- 167.04
17 -- 62 -- 64.38 -- 60.67 -- 173.35
19 -- 16 -- 19.44 -- 19.51 -- 35.09
19 -- 18 -- 21.73 -- 20.96 -- 42.02
19 -- 20 -- 23.95 -- 22.67 -- 48.68
19 -- 23 -- 25.71 -- 24.7 -- 55.92
19 -- 25 -- 27.96 -- 26.62 -- 62.45
19 -- 28 -- 29.83 -- 28.79 -- 69.7
19 -- 32 -- 35.75 -- 32.75 -- 82.61
19 -- 35 -- 38.98 -- 35.73 -- 92.2
19 -- 37 -- 39.87 -- 37 -- 96.29
19 -- 40 -- 43.1 -- 40 -- 105.87
19 -- 44 -- 47.35 -- 44.01 -- 118.58
19 -- 47 -- 50.5 -- 47.01 -- 128.1
19 -- 50 -- 53.63 -- 50.01 -- 137.59
19 -- 54 -- 57.78 -- 54.01 -- 150.23
19 -- 57 -- 60.88 -- 57.01 -- 159.7
19 -- 60 -- 62.95 -- 59.33 -- 167.04
19 -- 62 -- 65.02 -- 61.33 -- 173.35
21 -- 16 -- 20.7 -- 21.1 -- 35.09
21 -- 18 -- 22.75 -- 22.17 -- 42.02
21 -- 20 -- 24.86 -- 23.71 -- 48.68
21 -- 23 -- 26.54 -- 25.64 -- 55.92
21 -- 25 -- 28.74 -- 27.49 -- 62.45
21 -- 28 -- 30.58 -- 29.62 -- 69.7
21 -- 32 -- 36.46 -- 33.52 -- 82.61
21 -- 35 -- 39.68 -- 36.48 -- 92.2
21 -- 37 -- 40.56 -- 37.74 -- 96.29
21 -- 40 -- 43.79 -- 40.73 -- 105.87
21 -- 44 -- 48.02 -- 44.71 -- 118.58
21 -- 47 -- 51.16 -- 47.7 -- 128.1
21 -- 50 -- 54.29 -- 50.69 -- 137.59
21 -- 54 -- 58.44 -- 54.69 -- 150.23
21 -- 57 -- 61.53 -- 57.68 -- 159.7
21 -- 60 -- 63.61 -- 60.01 -- 167.04
21 -- 62 -- 65.68 -- 62.01 -- 173.35
23 -- 16 -- 22.2 -- 23 -- 35.09
23 -- 18 -- 23.91 -- 23.54 -- 42.02
23 -- 20 -- 25.87 -- 24.85 -- 48.68
23 -- 23 -- 27.42 -- 26.64 -- 55.92
23 -- 25 -- 29.58 -- 28.42 -- 62.45
23 -- 28 -- 31.36 -- 30.49 -- 69.7
23 -- 32 -- 37.2 -- 34.32 -- 82.61
23 -- 35 -- 40.41 -- 37.25 -- 92.2
23 -- 37 -- 41.27 -- 38.5 -- 96.29
23 -- 40 -- 44.47 -- 41.46 -- 105.87
23 -- 44 -- 48.7 -- 45.43 -- 118.58
23 -- 47 -- 51.84 -- 48.41 -- 128.1
23 -- 50 -- 54.96 -- 51.39 -- 137.59
23 -- 54 -- 59.1 -- 55.37 -- 150.23
23 -- 57 -- 62.19 -- 58.36 -- 159.7
23 -- 60 -- 64.26 -- 60.68 -- 167.04
23 -- 62 -- 66.33 -- 62.68 -- 173.35
25 -- 16 -- 23.79 -- 25 -- 35.09
25 -- 18 -- 25.26 -- 25.13 -- 42.02
25 -- 20 -- 26.98 -- 26.12 -- 48.68
25 -- 23 -- 28.37 -- 27.72 -- 55.92
25 -- 25 -- 30.46 -- 29.4 -- 62.45
25 -- 28 -- 32.18 -- 31.4 -- 69.7
25 -- 32 -- 37.96 -- 35.15 -- 82.61
25 -- 35 -- 41.15 -- 38.04 -- 92.2
25 -- 37 -- 41.99 -- 39.28 -- 96.29
25 -- 40 -- 45.19 -- 42.22 -- 105.87
25 -- 44 -- 49.4 -- 46.16 -- 118.58
25 -- 47 -- 52.53 -- 49.13 -- 128.1
25 -- 50 -- 55.65 -- 52.1 -- 137.59
25 -- 54 -- 59.78 -- 56.07 -- 150.23
25 -- 57 -- 62.87 -- 59.06 -- 159.7
25 -- 60 -- 64.93 -- 61.37 -- 167.04
25 -- 62 -- 67 -- 63.37 -- 173.35

If you'd like to see the code, I've put it at Lua pastebin - collaborative debugging tool You'll note there is no license attached. You can have this code to do whatever you want with it.

 

[alienator]

What is the goal of this? I don't see what useful information it provides.

 

[Rabbitbunny]

Well, with real world data I can find how close my equations are for the sizes I don't have. Once the equations are right I will be able to calculate the traction of any tire on any rim, on a known surface. Then, I can find the best rims and tires for my velomobile, and as a bonus I'll post the equations so you can find the best tires for your cycle. No more opinion, No more manufacturer recommendation. Fact.

 

[alienator]

Well, with real world data I can find how close my equations are for the sizes I don't have. Once the equations are right I will be able to calculate the traction of any tire on any rim, on a known surface. Then, I can find the best rims and tires for my velomobile, and as a bonus I'll post the equations so you can find the best tires for your cycle. No more opinion, No more manufacturer recommendation. Fact.

So, the manufacturer's are going to give you the coefficients of static and kinetic friction, eh? Because you'll need that, since traction is just friction. Of course you'll need that for road surfaces, petroleum covered surfaces, water covered surfaces, and etc. Moroever, traction--which varies very little among all bike tires--isn't the only data point that cyclists are interested in. Coefficients of rolling resistance can vary greatly, and they do have an impact on performance. Also, you'd have to consider aerodynamics of the wheel/tire system. At the end, there is one very large intangible metric that no equation can predict: what the rider "feels" on those tires and/or rims. There is no way to define "best."

 

[frenchyge]

Once the equations are right I will be able to calculate the traction of any tire on any rim, on a known surface.

Similar to what Alienator said, I can't say I've ever ridden on a "known surface." Things like bumps and imperfections in the road surface, dirt or grease buildup surface, etc. are going to have a bigger effect on traction then tire brand.

Seems like the modelled traction values would be on par with the manufacture's data in terms of lack of real world usefulness.

 

[alienator]

As a reference, motorcycle and auto racing teams don't have a "traction" value. The have various compounds--soft, medium, hard, qualifying....--and the try 'em to see which works best at a given track, in given conditions. There are enough variables that it's not worth the effort of trying to calculate which is the best. You're better off just trying various tires. It's also worth noting that the rubber compound isn't isotropic, and the assembly of tires isn't done on a lab bench.....so there are variations in tires of the same model. One tire can be quite a bit different than others that are supposed to be the same.

 

[Rabbitbunny]

Oh, it's impossible. Assholes.

 

[alienator]

Oh, it's impossible. Assholes.

What kind of response is that? No one flamed you. And again, since you can't seem to understand: there is no single best tire. What's best depends on given conditions and more importantly, personal preference.

If this for some academic work, particularly graduate work of any kind, do your own damned work, Trixie.

 

[taniwha]

Oh, it's impossible. Assholes.

What is "it's" the possessor of? Without knowing that, how can we judge whether it's impossible, or not?

Maybe I missed the point here. Is "Oh" a being or object? If "Oh" is an object then grammatically you're correct. But then that begs the deeper question, what is 'Oh"?
If "Oh" is a being, then you're being grammatically incorrect as they should be assigned a gender, either he or she will do.

Or maybe "Oh" is a friend that you are addressing, telling them it's impossible, which bring's us back to "it's"

So, what's "it's" to be?

 

[Rabbitbunny]

I didn't ask for your opinion, simply verification of my numbers.

I did the work. I even offered my results to the community.

 

[Rabbitbunny]

What is "it's" the possessor of? Without knowing that, how can we judge whether it's impossible, or not?

Maybe I missed the point here. Is "Oh" a being or object? If "Oh" is an object then grammatically you're correct. But then that begs the deeper question, what is 'Oh"?
If "Oh" is a being, then you're being grammatically incorrect as they should be assigned a gender, either he or she will do.

Or maybe "Oh" is a friend that you are addressing, telling them it's impossible, which bring's us back to "it's"

So, what's "it's" to be?

I hope you're being ignorant to be funny. " its' " is the possessive form. " it's " is a contraction. If you're going to try to be a grammar nazi, it helps to be correct.

 

[taniwha]

I hope you're being ignorant to be funny. " its' " is the possessive form. " it's " is a contraction. If you're going to try to be a grammar nazi, it helps to be correct.

I'll take the ignorant part, thank you. No grammar nazi business here, after all I could have a field day pulling myself to bits, then to start on all the other posts...a better man than me would die trying there.

No, I was merely musing upon the deeper philosophical meaning of your post.

So, what's it to be?