27" to 700c? About what year did the industry make this change? Was it all at once? Different years for high end or low end? Different years for Italian or English or US? - Thanks, TF

The Euros were using 700c in the 60s and probably before, IIRC. Since Schwinn totally dominated the high end market in the US, the whole North American market was 27" with typical tire pressure ratings of 65 psi in a 1 & 1/4" width on a non-hook bead rim. In the late 70s, high pressure 27" tires came along with hook bead rims, with Schwinn and Specialized getting into the act. In the early 80s, the transition to 700c got underway, and was pretty much complete by the mid 80s. IIRC Trek was a leader in the conversion, but I could easily be wrong on that. 27" and 700c coexisted for a number of years, with 700c winning out when a lot of equipment started coming in from Europe and "racing" bikes built to the 700c size for tubulars demanding 700c when people switched to clinchers. I'm not familiar with the Euro situation, but I would have to wonder whether 27" ever had a dominant role there. The earlier 700c tires and rims coming from Europe were labeled 28" and this also suggests that 27" was not strong there. Sheldon Brown has a big tire article on his web site, but I don't know if it addresses the Euro market. I'm sure one of our UK or continental participants can clue us in.

Kerry is right on with this thought... but to expand slightly on it, the final nail in the 27" coffin really came in about 1988. That was about the year that the sub $500 road bike died. Schwinn was one of the last holdouts to try to produce low price recreational road bikes in the sub $500 range. Most companies about that time had made the switch to building mountain bikes in that price range. The benefits were numerous.... wider tires with lower pressure for comfort, stronger ATB wheels, upright seating position.... it all lead to the end of low price road bikes... and the higher end ones used 700c wheels because high end bikes of the day almost all had tubulars, and nobody (to my knowledge) made 27" tubulars, so most high end frames were all built around the 700c platform. Some companies that were selling Japan built touring bikes still held out, but those were few and far between... and the reason was the better clearance for fenders on touring bikes still allowed for 27" tires.

Russ

Actually, the 700c tire size dates back to at least the 1920's in France. As a size for Tubulars, it dates back to the dawn of cycling.

There used to be in Europe,the 650 tire, with the 597mm rim (sometimes called 26"), 700 with the 622 mm rim, and the 28" tire using the 635mm rim, used for large "roadster" bikes.

Sometime around the 1960's, british bike manufacturers wanted a tire size to fit in-between their 26" (which isn't the same as the French 26", btw) and the big 28" tyres. They came up with the 27" tire, which fitted onto a 630mm rim. Bigger than a French 700, smaller than a British 28".

Re Dave's comments about the 650-size rim: Rivendell has just released a new bike, called the Saluki, I think, with 650 wheels. Grant has all kinds of reasons we need yet another variable, and I'm inclined to chalk it up to marketing, but every idea of his I've tried up to now has worked, so who knows? If my wife is serious about getting back into cycling, I'm going to look at one for her. She's only 5 feet tall, and it might be easier to get a good fit.

Re Dave's comments about the 650-size rim: Rivendell has just released a new bike, called the Saluki, I think, with 650 wheels. Grant has all kinds of reasons we need yet another variable, and I'm inclined to chalk it up to marketing, but every idea of his I've tried up to now has worked, so who knows? If my wife is serious about getting back into cycling, I'm going to look at one for her. She's only 5 feet tall, and it might be easier to get a good fit.

I've never understood the 650 front and 700 rear for small bikes. Making them both 650 makes more sense to me. If a 56cm bike is proprtioned correctly with 700 wheels, why wouldn't a 48cm be correctly proportioned with 650 wheels?

TF

In (continental) Europe, 27" has never existed in any quantities AFAIK. In Britain things were different. The change happened in the early 1980s, prompted I think by Mavic's introduction of the Module E rim. This meant that you could get a light, narrow rim (and matching tyre) that would interchange with tubulars with no brake adjustment - a hassle if racing/training on different wheels. By 1982 it was clear that 27" was doomed in the UK for light wheels (it continued for a few years more for touring).

Sadly, I live in Oz, and 700C tyres were not readily available there at this time, so I (reluctantly) had a new frame made in the UK in 1982 to fit 27" wheels. (This was for PBP in 1983.) It took another year or two before 700C reached Oz in any quantities, at which point I switched over. (I think the timeline was similar in the USA to Oz; certainly things happened earlier in the UK and Europe.)

Nowadays, 27" is basically dead everywhere, with a few decent tyres still available from Conti (and maybe Michelin, IRC, etc), and rims from Velocity. The only sad thing about this is that the Poms ever came up with 27", and that it didn't die a lot earlier!

Your right ..... The British were the odd one's out and who knows why as they had 700c tubulars (sew-ups) in the 30's so made it tricky for themselves in accepting another diameter for wired-ons (clinchers, high pressure et al).

Europe at the time were using 3 different diameters, namely

700A - 640mm - tyre width 1 1/4"

700B - 635mm - tyre width 1 1/2"

and

700C. 622mm - tyre width 1 3/4

All 3 sizes roughly made out to a 28" diameter and things were pretty smart as one could use any wheel for any frame and simply use the generous, at the time, brake reach to adjust. Handling and clearance in terms of bike design was simple.

You can also see that the fattest tyres are on the 700c and the thinnest on the 700a which is contradictory to the 700c rim as we now know it. This all got reversed and mixed up because tyre manufacturers started making thin, medium and fat tyres for each of the rim diameters which made it a big puzzle and threw a good system out the window. Thus the decline of the above system.

Eventually the whole party came back in line and makers started using the ISO system which by luck landed with the 700c rim. From then most all rims and tires were quoted with the bead seat diameter and tire width in mm.... ie 622-23. Each tyre now made carries the marking. Still doesn't explain why the Brits sat out but there were always regional differences outside of Europe. British 26 x 1 3/4 is different to American 26 x 1.75 etc etc.

Some peeps mentioned above about 650 reintroduction. What is creeping in is not the 650c as you may be thinking but 650-B. A difference of 15mm in bead seat diameter and using very different tires and for different means. A 650b rim/tire is fat and will be much closer to the overall diameter as a 700c with a modest or thin tire (23-25c) and is far more comfortable. What you take away with rim diameter you then add on with tyre diameter. You can make a 700c bike with very fat (35c or Larger) tyres but then you have to stretch it out to make room not only for the fork and brake bridge but for toe-overlap and behind the seatube as well. It just adds more complications to otherwise tried and tested frame dynamics. It isn't what some assume to be used for smaller frames to aid in clearance but to offer more comfort and better ride for normal size frames without having to change frame design or have gearing changes due to a larger diameter 700c rim with a super fat tyres. Quite simply, you can ride your normal frame clearance bike with 650b's and and only need to adjust for the extra brake drop (canti's, and long reach centrepull's are ideal). A 650c rim/tyre is a smaller wheel/thinner tyre that is usefull for smaller riders ie sub 51cm frames - whilst it allows more options for better geometry it results in a harsher ride due to the smaller diameter and changes the gearing.

To me 650b (584mm + tyre) makes sense as it's only fairly recently that all bikes come with the option of 700C race rims, back then most bikes were built with comfort and utility in mind and the smaller rim/fat tyres help for average paced riding and bad roads and otherwise only racers used harsh and scant option of 700c race rims and the thin tire options available. Call it a niche, or marketing or whatever but it does make sense to a lot of people who aim to ride in comfort. Below is a bike made for regular 700c wheels of which its owner very smartly changed the wheels to 650b's and I'm sure he's happy.


http://folks.harbornet.com/kstagg/650b


That bike looks like it could be ridden for days. In case anyone is thinking of it there are now quite a few options for 650b tyres where a short while ago it was nearly extinct. It makes sense for us to opt for wheels in overall diameter rather than for one inside measurement (700c - 622mm) with the then countless wheels sizes for tyres from 19c - 52c but that would mean the death of the short reach brake caliper as the 99% option for brakes available for road bikes. Everyone should try a road bike with nice fat tyres .... the pic below explains it all - same bikes, same size, built with same specs for clearance but very different wheels to meet different ends. Hooray for more options with wheels !!!!!

Oh ..... Coz' I replied to a fellow Aussie i decided to spell "tires" the proper way ;)

ciao