I can only tell you that for wired-on tyres as opposed to tubs, when I started cycling in the late 1950's with some pretty ancient stuff, there were only two common sizes 27 x 1¼ on 'lightweight' bikes and 26 x 1⅜ for utility bikes.
I think 26 x 1 1/4" came before 27 x 1 1/4" and was the choice of the "Clubman" until the late 50's early 60's when 27 x 1 1/4" became prevalent for "lightweights". 700C falls nicely between the two
S.O.S - Save Our Steel! 1971 Raleigh Mercury 2010 Condor Fratello 1980 Peugeot Tandem 1989 MBK Aventure MTB 195? Viking Severn Valley 1951 Raleigh Lenton Sports See them here http://tinyurl.com/Mikewsmiths-Bikes
There is only one dimension that the tyre and rim share, this is the tyre bead diameter, which is also the rim bead seat diameter. This is used in the ETRO (European tyre & rim organisation) system of sizing. So 622 bead diameter is 700c (nominally 700mm. overall diameter), and 559 is American 26", (nominally 26" overall). Of course the actual overall diameter varies with the tyre width).
So 559 was what was available in fat tyre sizes (on American "cruisers") when the Americans were "inventing" mountain bikes, so it became the standard size.
Now for some history, which is from memory, ie probably wrong!
When England was the "workshop of the World" and exported manufactured goods everywhere, the common sizes were 28x inch and a half, and 26x inch and three eighths. (I think!!) When other countries manufactured their own bikes, these sizes got translated to 700 and 650mm , but it didn't stop there. Somebody (French?) decided to make a range of bead diameters so that fat and thin tyres had similar overall diameters, so you had 650a, 650b, and 650c, and the same for 700. However, that was far too difficult, so they settled on the most commonly used sizes, ie 700c and 650b. (occasionally 650a) (the joke is that 622 was originally the fat tire bead diameter for a 700mm overall diameter, now it fits skinny tyres, and they are way under 700mm overall)
But bike racing is a European thing, and British racing cyclists looked to Europe for their fashions. So a bigger, narrower wheel was needed to look similar to the European racers 700c wheels with tubs.(tubular tyres). So rather than making it an exact 700c, it got translated (again ) to 27", so you had to adjust your brake blocks when swapping between 27" (high pressures, as we called wire ons then) to 700c, for your tubs. Why make it different? I suspect it was trade protectionism, it was much harder then to buy stuff from foreign countries, make it unique and you have the home market sewn up. I believe 26xone and a quarter inches was "invented" by Dunlop (?) for similar reasons, ie to corner the market, you really dont need a separate bead diameter to account for one eighth inch width difference.
So 622 was originally (English) 28x one and a half inches, which got exported and translated to 700mm, and re-imported translated to 27", long after the original 28" wheels had died out.
andrew_s wrote:I wonder how many more Guv'nors Pashley would have sold if they hadn't made the somewhat perverse choice of a 635mm (28") rim?
dunno, but don't knock 28" or 29" till you've tried it. the comfort over bridlepaths, cobbles and the like has to be tried to be believed.
I'm not knocking the comfort of large wheels with reasonably fat tyres, just the availability of replacement tyres and rims. How many places will sell you a 635-38 tyre, or a replacement rim (28"x1½" or 700b)?
I'd have considered it if it had had 700c with fat tyres - eg cream Fat Frank
andrew_s wrote:I'm not knocking the comfort of large wheels with reasonably fat tyres, just the availability of replacement tyres and rims.
the tyres are available at lots of places. i think my 42-635 contis were £12 each. as for the rims, i can't see ever needing to replace them given that there's 42mm of tyre, 36 spokes and drum brakes however, mine came from a shop in berlin at under £50/pr, posted.
Tonyf33 wrote: Not correct, they came in 27" size before 700C
Are you sure? I'd have put my money on andrew_s being correct.
THERE IS ACTUALLY NO SUCH THING AS A "27 INCH" TUBULAR.
That's what SB has to say on the subject and the capitals are his, although I agree it's written in the present tense.
Well if the venerable SB says it is so, however I was looking for 27" tyres at the time I wrote my response and there were more than a few references to 27" tubulars, so why are some tubs referred to as 27" then?
