1987

What is the story of 27 inch wheels?
There where already several common sizes near 630 (622 and 635 mm). Was 27" just an effort to create a new fad and make more money? Or is 27" much older?

I usually get annoyed by them. Though I have one bike with 27" and it's fully ok, just a bit difficult to get new tires (at least in the shops around here). The good thing is that frames made for 27" usually have bit more room and of you convert to 622, you can run wider tires.

John E

"I just love standards, because there are so many to choose from."

It would have been nice if 630mm rims had never been invented, just as it would have been nice if the U.S. had followed Ben Franklin's recommendation to make the American Revolution complete by adopting the French metric system and overthrowing Imperial weights and measures.

I remember the early 1970s, when 700C/622mm was the hard tire size to find.

Bianchigirll 

I think they did it just to keep you awake at night.

rhm

It was a proprietary size introduced by Dunlop, who made both the rims and the tires. I'm not sure exactly when this was; late 1930's I guess. The idea was to corner the market. It worked for a while.

The Golden Boy 

I think it's interesting that even as late as 1991 touring bikes were made with 27" wheels with the theory that in the middle of the sticks, it'll be easier to find 27" tires. The dominance of 700C is a relatively recent thing.

awfulwaffle 

Interesting indeed. Last time I had my Cannondale with me at the LBS, the fella behind the counter absolutely refused to believe that a bike made in 1990 came stock with 27" wheels. I almost feel as though they were using up the 27" wheels they had backstocked from the previous decade, as my ST400 came with 27" wheels but the ST600 and ST1000 of the same year came with 700c.

Doohickie

This.

When I started riding again in 2008 after 20+ years away from cycling, I had never even heard of 700C tire sizes. If you scoured my early BF posts you'll probably find a few from me asking what the heck a 700 tire is and how it compares with 27". To make it more confusing for me, I also acquired an old Raleigh DL-1 around that time that has 700B tires (aka 28 x 1-1/2).

See also.

1987

Good answers. Thanks.

For me it's fully enough with 349 mm (Brompton etc), 650B and 700C.

Here is a list that is larger than Sheldons tire size list:
A guide to tyre sizes

1987

Interesting that 27 was so wide spread in US. 700B = 635 is the classic size for utility bikes in Scandinavia. The size is obsolete, so no new bikes are made in that size. But it's still very easy to get new 635 tires here.

I have an almost antique bike, with the largest tire size ever made for safety bikes. 642 mm, a total nightmare to get a new pair. They are probably still made in China. I've seen them in one online shop in Australia.

rando_couche

Or to put it another way, the bike industry loves standards - that's why everybody has their own.

SP
OC, OR

Ex Pres 

And mountain bikers are making it even stupider
29er = 700c, so why did they need a new term?
and worse again are the new 27.5" wheels (what we know as 650b).


So a 29er is smaller than a 27" tire
and a 27.5" is smaller than not only a 27" tire, but also a 700c

1987

Yes, it's ridiculous.
But I guess marketing are trying to make more catchy phrases.

What rim diameter are those moonlander fat bikes using? I can add them to my list as well. Looks like a total dream to ride of road.

Wogster

I think you will find that the standards have changed over time, it seems that there are so many standards in cycling, because bicycles can last many decades. Unlike many other technologies where items themselves only last a decade or so, look at computers. Try finding an 8" floppy for example.

1987

It's more like that there where a lot of sizes, but now we have agreed to a couple of practical sizes. But the industry doesn't like balance.

I would like to see a computer calculated best size, inertia, wheel and bike weight, rim diameter, tire width, tire pressure, etc.

Very interesting to read Bicycle Quarterly about 650B x 42. It's almost as if narrow tires = high speeds is a myth.

nfmisso

More to the point; why isn't everyone using ETRTO designations? In automobiles, trucks, motor vehicles - just about everywhere else, tires are designated by the bead seat diameter (BSD). It would a great deal less confusing for everyone if bicycling followed the same standard.

1987

Yes, I also prefer ETRTO designations. Especially when I order something online.
349, 559, 584 and 622 mm will do it for me.

But 650B looks amd sounds better and is easier to remember than 584 mm. And that's probably why it lives on.

Sir_Name 

I think there are far too many variables for a "one size fits all" best size. Best for what?

1987

No I didn't mean that we should end up with one size. Rather one size for each category/purpose.

NormanF

There used to be a bewildering variety of tire sizes but they seem to have sorted themselves out into more or less five categories:

406 mm for folders, mini velo and bmx bikes, 559 mm for cruisers and standard mountain bikes, 584 mm for mid size mountain bikes and older French touring/city bikes, 622 mm for road bikes and 29er mountain bikes and 635 mm for path bikes and roadsters.

DiegoFrogs

When I moved from the US to Sweden this winter (because I'm so good at making decisions... ), despite knowing that there's no particular advantage to 700c wheels over 27" wheels when all other things are kept constant, I dumped my last 27" wheel and its unused partner in part to upgrade to a double-walled rim and modern cassette hub, but also because I didn't want to rely on a tire size that might be difficult to find here. Looking at inventory in shops here, I know I made the right decision. Though, I only brought two bikes that were special to me.

I also bought a Finnish city bike that was probably 20 years old or so, with a plastic cantilever brake and lever to complement the rear hub's coaster brake, after I got here and before my stuff arrived. It came with really nice, single-walled Belgian rims in great shape, both 700c! I'm still beating the tar out of the rear rim and haven't had to get out the spoke wrench once despite the brutal flogging it takes. Go figure!

GrayJay

Fat bikes use standard 559mm (26" mtb tire size) rims that are really wide (65-100mm width) combined with a huge tire to achieve tire outside diameter that is very close to a 29'er mtb tire. While they are cushy, fat tires/wheels are really heavy, feel slow on the road and they have some weird self-steering characteristics when used on hard surfaces.

GrayJay

Dont forget 507mm for 24" kid MTB's, 571mm for 650c (26" narrow road tires) both are fairly common. There are also a couple of other 20" wheel sizes that all use different rims. I
nterestingly, the outer diameter of the tire for both 507mm and 571mm are very close. I converted a 24" mtb frame into a road bike for my daughter by switching it to 650c wheels and fork and drilling the frame bridge for a road brake on the rear tire.

NormanF

I had in mind commonly accepted sizes for adult riders. As you mentioned, there are sizes for children and smaller riders as well.

1987

Thanks. Would like to try them off road.

nlerner

You forgot 630mm, which started this thread. Me, I'm partial to 597mm/EA1.