# Thread: I propose that 650B be called 27.2

1. ## I propose that 650B be called 27.2

I posted this in another thread, but I'm annoyed with this 27.5 nonsense, so I thought I'd start my own thread.

26" ISO: 559
650B ISO: 584
29" ISO: 622

Difference between 29" and 650B = 622-584= 38
Difference between 650B and 26" = 584 - 559 = 25
Difference between 29" and 26" = 622 - 559 = 63
25/63= .4
38/63= .6
Imperial size of 650B = 26+(.4*(29-26))=27.2
So, if you're going to use 26 and 29 as the benchmark unit of measure, technically the new wheel size is 27.2

2. ## I propose that 650B be called 27.2

WFC?

"I ride my bike to ride my bike"- Zen proverb

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3. Sorry, no offense at all (!!!), but some People just care too much about a Size that´s slightly bigger than the one we all know for Years ...

... and I don´t think Schwalbe, Continental or anyone else using 27.5 instead of 650B is going to reprint their Decals for 27.2

4. Feel free, but don't get upset when you're the only one and you have to explain your reasoning to everyone you say 27.2 to...I don't think most people really care

5. I say we call it Vicky.

27.2 is a seat post size...

6. If we don't call it Juan Carlos, I'm taking my toys and going home..

7. ## I propose that 650B be called 27.2

Originally Posted by ohpossum
If we don't call it Juan Carlos, I'm taking my toys and going home..
+1. Juan Carlos FTW

8. I measured my tires very accurately and came up with a diameter of 27.45678352132436487459859297635374748755905745342 314263748596

So I propose we call it 27.45678352132436487459859297635374748755905745342 314263748596

Or Juan Carlos works too.

9. Johnny "Dangerously" Charles. This is 'Merica.

10. Originally Posted by ljsmith
So I propose we call it 27.45678352132436487459859297635374748755905745342 314263748596
That is funny, is this number like pi, an endless string of non-repeating numbers? We could have a Guinness BoR entry for the guy who can recite the most in a row, and put it on a T-shirt. Sweet.

11. BGE or FE0. That's alpha for 275 or 650.

I *WAS* in the 27.2 camp, but now I'm squarely Juan Carlos.

Do it for the children.

mk

12. 'Mericans hate accuracy

13. Originally Posted by dirtdan
Difference between 29" and 650B = 622-584= 38
Difference between 650B and 26" = 584 - 559 = 25
Difference between 29" and 26" = 622 - 559 = 63
25/63= .4
38/63= .6
Imperial size of 650B = 26+(.4*(29-26))=27.2
So, if you're going to use 26 and 29 as the benchmark unit of measure, technically the new wheel size is 27.2
Funny maths but all popular 650b tires measure at least 27,5" in diameter and some of them reach 28" so naming is correct.

14. I propose 100010011

15. Originally Posted by Koen
Funny maths but all popular 650b tires measure at least 27,5" in diameter and some of them reach 28" so naming is correct.
And 29ers measure 29.2-29.5. Are those named correctly?

16. My vote is Juan Carlos; maybe JC for short and to confuse the bashers..

17. ## I propose that 650B be called 27.2

Angry Singlespeeder is also annoyed:

http://reviews.mtbr.com/the-angry-si...d-toilet-paper

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18. When comparing tiny 1.8 XC race tires on each rim, yes, 26, 27.2, 28.7

Tire sizes vary. Now that there are multiple trail bike wheel sizes, I think labeling wheel size by the rims' bead seat measurement would be most accurate and agreeable, such as is done with motorcycles.

19. Originally Posted by dirtdan
And 29ers measure 29.2-29.5. Are those named correctly?
The difference in rim size between 27,5" and 29" is exactly 1,5" (38mm) so you are probably talking about the same kind of tires that turn 27,5" into 28".

20. Or just call it 650B and go back to calling 29ers as 700C as they actually are, and the 559 size just gets called cruiser size. Its too bad the 559 bead never had a french equivalent model code.

21. Just enjoy the ride.

22. All I want is Juan Carlos to take dirtdan and his thread somewhere that I'm not tempted to look at it. It's a good thing that I'm fortunate enough to get paid while wasting my time reading this nonsense. Otherwise, I would feel violated.

23. I propose you and DC get together. That way you would both have someone to appreciate your genius.

24. Originally Posted by Koen
The difference in rim size between 27,5" and 29" is exactly 1,5" (38mm) so you are probably talking about the same kind of tires that turn 27,5" into 28".
If this is true then the difference between the 27.5 and 26 is more like an inch meaning the difference between 26 and 29 is more like 2.5 inches and then my whole world gets completely turned upside down...

25. Originally Posted by dbhammercycle
That is funny, is this number like pi, an endless string of non-repeating numbers? We could have a Guinness BoR entry for the guy who can recite the most in a row, and put it on a T-shirt. Sweet.
The IT Crowd - Series 1 - Episode 2: New emergency number - YouTube

26. Originally Posted by dirtdan
'Mericans hate accuracy
No dirtdan, I think it's just a case of most cyclists that enjoy their ride, what ever it be, just get sick of people that keep crapping on about wheel size.

It's round and they go on your bike to let it roll, so just roll with whatever the f@ck it is, please.

27. I propose that 650B be called 27.2
Proposal rejected-thank you for taking the trouble to start a thread about it though...

28. I second SteveF's rejection.

29. Originally Posted by dirtdan
I posted this in another thread, but I'm annoyed with this 27.5 nonsense, so I thought I'd start my own thread.

26" ISO: 559
650B ISO: 584
29" ISO: 622

Difference between 29" and 650B = 622-584= 38
Difference between 650B and 26" = 584 - 559 = 25
Difference between 29" and 26" = 622 - 559 = 63
25/63= .4
38/63= .6
Imperial size of 650B = 26+(.4*(29-26))=27.2
So, if you're going to use 26 and 29 as the benchmark unit of measure, technically the new wheel size is 27.2
There's a big flaw in your logic. 26" and 29" are diameter measurements of the wheel + the tire. 622 and 559 are the diameters of the rims, or the wheel WITHOUT the tire if you prefer. So you're comparing apples to oranges. As other's have pointed out, a 650b wheel (584mm rim) with a large knobby tire does, indeed, measure roughly 27.5". 26", 29", 27.5" are all just marketting terms, because, of course, the actual diameter measurements are dependant on the size of the tire.

30. ## I propose that 650B be called 27.2

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31. The jingle is a nice touch, do 26ers or 29ers have a jingle?

32. Originally Posted by bolandjd
There's a big flaw in your logic. 26" and 29" are diameter measurements of the wheel + the tire. 622 and 559 are the diameters of the rims, or the wheel WITHOUT the tire if you prefer. So you're comparing apples to oranges. As other's have pointed out, a 650b wheel (584mm rim) with a large knobby tire does, indeed, measure roughly 27.5". 26", 29", 27.5" are all just marketting terms, because, of course, the actual diameter measurements are dependant on the size of the tire.
Yes, and a 29" tire with a large knobby tire measure 29.5"
No flaw in my logic.
The actual diameter measurements are dependent on the size of the rim + the size of the tire. If you use the same width tires on all the different size rims, the logic/ratio holds true.
If 559 + 2 inch tire = 26"
And 622 + 2 inch tire = 29"
then logically 584 + 2 inch tire = 27.2"

In terms of who cares about stuff like this? People who manage rubber departments at bike shops who deal with horrible misconceptions from consumers who are as clueless about tire size as they are about nuclear physics.

33. Originally Posted by emu26
No dirtdan, I think it's just a case of most cyclists that enjoy their ride, what ever it be, just get sick of people that keep crapping on about wheel size.

It's round and they go on your bike to let it roll, so just roll with whatever the f@ck it is, please.
So, you get sick of people who get sick of people using inaccurate and illogical designations for tire size that have nothing to do with math. We all have our pet peeves, right?

34. seriously though:
26", 27", 29"

no more "er" at the end please. thank you for your cooperation.

35. Originally Posted by bigfruits
seriously though:
26", 27", 29"

no more "er" at the end please. thank you for your cooperation.
I much prefer rounding down to 27 than rounding up to 27.5.
Of course, 27 is already a specific designation that is not the same ETRTO as 650B so that would make matters worse as well.
Realistically, people should just use the ISO/ETRTO number for tires/wheels and life would be a lot nicer for shop managers.

36. Originally Posted by dirtdan
Yes, and a 29" tire with a large knobby tire measure 29.5"
No flaw in my logic.
The actual diameter measurements are dependent on the size of the rim + the size of the tire. If you use the same width tires on all the different size rims, the logic/ratio holds true.
If 559 + 2 inch tire = 26"
And 622 + 2 inch tire = 29"
then logically 584 + 2 inch tire = 27.2".

559 = 22", 622 = 24.49", 584 = 22.99"

37. Comparing the differences between wheel/tires and then adding to 26" is flawed because so-called 26" wheel/tires are NOT 26". Even with a 2.1 tire, a 26" wheel/tire measures closer to 26.5" than 26". I believe that a 650B wheel and tire of 2.1 to 2.25" is actually quite close to 27.5". I can't remember just how close, but check for yourself. If anything should be renamed its the 26" wheel size.

That being said, the one thing that needs to be looked at or changed is the tire used to identify mtb wheel/tire combinations. People run anywhere from 1.95 to 2.4 on most common xc and all mountain bikes, but, it's safe to say that the most common average of sizes used to be 2.1 and now it's closer to 2.25. If people want to talk about wheel and tire sizes and names, it's time to include a standard tire size in the discussion. The tire size makes a noticable difference.

As you can see in the above comparison of wheel sizes by DeeEight, without tires, the 26" wheel is 1 inch smaller than "650B" and 29'er's are about 2.5" taller than so-called 26" wheel/tires. This makes sense because the 26" is really 26.5"...so add 2.5" and you have a 29'er. I actually have no problem calling 650B a 27.5 but as I mention above, we need to keep tire sizes uniform when comparing sizes. 650B with 2.1 vs 650B with 2.25 or 2.35 etc etc. Different. As long as the industry want to change names, I don't care, just standardize the language with regards to tires. OR, call them by their rim sizes.

Wheel sizes were named before we mtb'ers started using the larger tires we use today. Technically, the 650B wheel size was actually called a 26" wheel size years ago.

38. Why don't we just go with the -ish suffix designation.

What size wheel you got there?
It's ??-ish.

Or perhaps just go with rim size.

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