I have spent a lot of time lately cruising the BF archive and the web in general to learn about 650B wheels. I can totally understand the desire for a ballonish tire that will give a comfortable ride while carrying some weight and having the benefit of fenders. What I can't understand is what is the driving force to revive an old standard rather than modify an existing one. A 650B conversion (either of an 700c road bike or 26 mountain bike) is expensive. 650B wheels and tires are significantly more expensive, and options are fewer than 26" wheels and tires. They are insignificantly different sizewise, and should not provide any different ride qualities. I understand that the 26" tires are often made for rugged conditions and don't have the supple sidewalls desired by 650B enthusiasts. Why isn't the drive to get 26" tire manufacturers to make supple tires in 1.5 or 1.75 widths? Seems like it would be the path of far less resistance. And it would allow one to simply change tires and be able to go from wide knobbies for the trails, to narrower slicks for the road.

To extend the question, why are conversions often of 700c to 650B? Isn't converting a 26" mountain bike far easier?

Regards,
Steve

Because people are dumb.

Not really. A frame for 700c wheels is bigger then one for 26" wheels, making the convert to 650b much easier.

Brake reach.

I believe that it a popular size in Europe. The rest of the world doesn't worry about we think.

700c makes more sense to convert for sure, I was calling the 650b "revolution" dumb. It kind of reminds me of when people tried to bring back bio-pace chain rings.

I would assume that there is some historical precedent for 650b as a road bike wheel size.
Bike technology doesnt always evolve in ways that make sense when seen from current context.

However the primary reason nowadays is probably marketing perceptions; 26" is for mountain bikes, you'll get looked at wierd on club rides if you have mtb wheels on your road bike.

Same reason 700c mountain bikes are called 29ers.



check out michelin WildRun'r 26x1.1 (559 mtb ertd) comes with pncture resistance

650b are slightly bigger than 26" mtb wheels is the only thing i can guess. plus the perception that 26" wheels are for mtb/cruisers like xenologer said

650b is actually making bigger inroads on the mtn side of bikes...

I get it, I don't mind choice, but I'll opt for 26 any time I want smaller wheels, 700/29 for larger wheels. I see bigger manufacturers going 650b for offroad bikes, but I've only seen custom and boutique bikes rocking 650b on a road oriented bike.

Telling: Surly LHT -- when they went for a smaller wheel size on the smaller models, they opted for 26" wheels, not 650b.

I think the marketing men's perception of 26" is skewed. There is no reason for 26" to be a "rugged" size, it's just a size. You can get 26" tyres down to about 1" (28mm) for roadifying MTBs. Personally I would like to see 650C folded in to 26(MTB) so, just like in 700c, you have a whole spectrum of widths for one diameter rim. You can have rugged rims and lightweight rims, racing, touring, commuting and off-road, all in one 26" diameter.

There seems to be a real gap in the market for lightweight commuter/touring bikes using a 26" rim capable of taking medium tyres (28/32mm). Who needs this? Only all the small people in the world.

Schwalbe ballon tyres such as Big Apple and Kojak are taking the role of French style 650B for urban riding. I ride Big Apples and they are really comfortable but efficient. They are still a niche product rather than mainstream.
650B revival is a bit odd but it is a boutique size for people who like to be different. Its a nice size but before we make 650B mainstream, I would prefer to see lightweight 26" (MTB) expanded.

Surly has offered 26" (ISO 559) rims on their small frame LHTs for quite a while and predate the current 650b fad. I assume they did it to achieve adequate toe clearance on small frames without distorting the geometry too much. The same reasoning Georgina Terry used for fitting 24" front wheels on her small bikes intended for women.

Many choices out there for 26 inch tires.

I'll at least defend 650B on being a pretty distinct size from the standard 26 inch wheel. A 650B wheel is 25mm larger than a 26 inch one, and 38mm smaller than a 700c wheel.

As for it's particular usefulness, why not? People tout the benefits of smaller wheels all the time; spend time on the folding bike forum and hear people talk about how fast to accelerate they are. Larger wheels also have advantages; talk about how well 29ers roll over things accounts for a good half of the volume of mountain bike publications these days. Why not split the different and have a wheel in the middle?

As far as 650b in particular, the only real advantage it has (over 650A, or any of the other similar sizes) is a romantic backstory.

I guess it is still a truism "those who do not study history are doomed to repeat it". So my thoughts;
1) You (we) are not taking 650B mainstream. It was mainstreams many decades ago. Amazingly a wheel is still a wheel. I have old tandems and touring bikes with 650B's and they are still quite ridable.
2) Bike wheels and tires are a lot like religion as it is impossible to get any complete agreement. It is better to figure out what you believe, rejoice in it, and leave others folks to their own path to happiness.
3) There is really nothing magic about a wheel diameter...it just is what it is. The differences do exist in terms of the fitness for really small frames, xlarge frames, beefy riders, and for heavy duty use (as loaded touring, rock climbing, tandem touring, bogg crawling, and extreme sports).
4) Changing an existing bike to a different wheel diameter can almost always be done. It is also a fact that doing so tends to burn through a lot of money; the result is not always that great; the resell value of the resulting bike will usually be lowered; and in many cases one would be money ahead to sell the "bad bike" you have now and use the money to just buy a bike that already has the wheels/tire size you are now fascinating on.
5) Relating to #4; does the world really need another "Frankenbike". Probably not.

Yeah, 650b has no actual advantages over 26" or 700c. It has gotten popular recently because the French constructeur bikes were often 650b, and developed a sort of cachet in the retro-grouchy crowd that wanted an Alex Singer but couldn't afford one. Kinda like the 700c wheel did to the 27"- there's nothing wrong with 27", but it got associated with cheap steel-rimmed junk. It's all image and very little function.

That being said, I am building up a Raleigh Portage, one of the few 650b bikes available in the US at the time, and I won't feel self-conscious about riding a bike with drop handlebars and fat tires when I do so. Most bikes built for 700 wheels won't accept larger tires and MTB frames have a different geometry.

You are correct about most but Surly has made a nice living selling road bikes that do take 700c wheels and clear fat tires.

I was with ya right up until this statement, which is very, very wrong--the world can always use another frankenbike; there aren't enough people spending heaps of money doing questionable mods to their bikes...

Appropos of nothing much except that we are discussing tires/wheel sizes, 26" rim with Schwalbe Big Apple 26 x 2.35 tire is .5" diameter larger than a 700 wheel with a 23c tire... which means a 2.1" tire would be just about the same. Usually this is what people advocating 650b are after, a smaller rim size so larger volume tires will equal out to the same diameter as 700 rim/tire combos. You can get there with a 26" rim, and if you enjoy BIG volume tires rather than those neither here nor there 650b tires, it's a reasonable way to go.

Bicycle Quarterly publisher is a Francophile .. been promoting his preferences,
for a long time.

Japan too has a lot of Francophile people too,, that is why you get French style racks from Nitto.

and light skin-wall 650B tires .. from Japanese manufacturers.

650B is French a size between US cruiser based 26", and French 700c, and slightly larger 27"

People want to do something with their old, freebie, 27" frames ..

Mconlonx +3 on that. If I could just keep those bolt tight that keep my head from falling off, I would be more willing to embrace Frankenbikes... {:-)]

I don't have a 650b bike but I'm considering one. I think one of the attractions is the possibility of new life for nice older frames. For example, I have a very pretty Bridgestone RB2, nice purple color, looks new. I have newer steel bikes that are lighter and ride just as well or better. The RB2 will only take 28mm tires, max. It would be more useful to me if it did something my other bikes didn't, such as have the ability to use fat tires for gravel, rail trails, etc. With a 650b wheelset and long reach caliper brakes I could have a bike that is functionally different from my others. I don't think there are calipers that would make the reach to 26, so that's a plus for 650b over 26. Wish there were some less expensive 650b rims available.

The 650b size has been a popular choice for tandem bikes for many years. They offer a slightly smaller diameter fatter tire for lower gearing and greater weight capacity.

Not that Steve PGN10 was suggesting converting a 700c bike to 26" but just to run some numbers, the conversion of a 700c bike to 650b involves a 19mm drop, (622-584)/2. That is doable with long reach caliper brakes or perhaps a brake bridge, a la Sheldon Brown. Conversion of a 700c to 26" involves a 31.5mm drop. Add 4mm for a 27" wheel to a 26" wheel - 35.5mm, (630-559)/2. Even if you found a caliper brake with a reach like that, you would be at a mechanical disadvantage compared to a shorter reach brake. This leaves you with a fugly brake bridge or disk brakes (or a coaster brake).

So, it would be a lot easier to just take a 26" bike and run 650b type tires on it. Conversion to a drop bar tourer is just a matter of finding the right frame and using drop handlebars, etc., whole thread on it here. The only problem with converting a mountain bike to a 650b-like tourer is the beefier and heavier frames on many vintage MTB bikes. With the right tires, though, this looks to me like an option versus a 650b bike.

Canti's? but added cost of braze-ons and new pc or paint probably around $200 minimum(for pc, paint most likey quite a bit higher) will hurt a bit.

Drum brake setup solves a lot of problems at the same time for not as much money as any solution which requires welding and repainting; cleaner than some bodged brake bridge.

Not arguing, just offering another alternative. I have an older Schwinn Super Le Tour which might get drum/650b treatment.

Thanks for running the numbers. When I posted I was confused about the actual size differences.

My deeper dive into learning about 650B conversions started when I was trying to get a MTB ready for a backup commuter for the winter. I had bought some Zefal fenders last year that gave unsatisfactory results when used with 26x2.1 tires. This got me to thinking about using some narrower slicks, and a google search of 26x1.75 (picked at random for a width) turned up the Compass tires that are being made on the same molds as the Paselas. What with superstorm Sandy bearing down on us, and a lot of hours at home, I spent those hours reading about 650B. Looking at the 26x1.75 Paselas, it was hard for me to wrap my mind around conversions when it seemed dead simple to use a tire like the Paselas on a MTB and get the goodness of balloon tires. This does not take into consideration those who prefer a road bike with balloon tires, but I don't know what that buys you in comparison with a MTB with balloon tires. I would find it interesting to hear from someone who has run 26" balloon tires on a MTB, 650B on a MTB, and 650B on a road bike and can give objective comparisons between them.

For the record, I'm going with the Paselas.