Technical > Wheels, Tyres and Brakes
Are 26" tyres an endangered species?
Vintagetourer:
To those of us with 26" wheeled bikes such as the Thorn Sherpa, the thought that 26" tyres not be available in the future is slightly disconcerting. I haven't seriously started stockpiling 26" tyres...well not yet. Well may be just a few extra tyres ordered just in case.
Any thoughts on what is happening, or will happen with 26" tyres? Will they go extinct? Harder to get? Less range of available types and widths?
Danneaux:
Hi Graham,
Having already lived through the demise of the 27in touring tire -- and the first death of the 650B* -- nothing really surprises me anymore.
I don't mean to sound cynical, but as the market share decreases, designers often seem to do something to obsolete established old standards in favor of generating interest in and sales of the "next best thing" -- even though that often means dredging up innovations that have already come and gone decades before. Sometimes these things work better, sometimes the same or worse. In any case, it all seems new and has the effect of being backwards non-compatible, which stimulates the purchase of new stuff -- and the unfortunate retirement of the old stuff when maintenance and replacement parts become hard to obtain.
Among such things...
Rear dropout width...I have bikes ranging from 120mm OLN (Over Lock Nut) measurements to 124, 126, 130, 135 and 145mm (the last my tandem). I cannot swap rear wheels between these bikes.
Bottom bracket shell dimensions.
Rear derailleurs that used no cable housing so the frames produced for them had no cable stops (the last was the SunTour Superbe Tech L: http://www.disraeligears.co.uk/Site/SunTour_Superbe_Tech_L_derailleur_4800.html ).
A whole slew of handlebar stem clamp dimensions -- 25.2, 26.0 and now more commonly 31.8mm. Not a stopper for frames, but can make interchanging parts a bit more difficult when changing stem length or handlebars.
Quill stem/threaded steerer versus clamped stems/threadless steerers....and threadless steerers in various diameters. Anyone remember 1in threadless? Kinda hard to find a headset now...almost as difficult as 1-1/4in threaded oversize. Now we have tapered steerers and sometimes head tubes as well.
Various kinds of integrated headsets...and the specialized frame head tubes meant to house them. I recall some that used the frame's head tube as the mating bearing race, a notsogood idea.
French component frame dimensions (headset, BB, quill stem diameter)...and the rear derailleur hangers intended for them.
U-brakes...and replacement pads for them; they have slightly oversized shafts and the posts are too high to retrofit with cantilevers or v-brakes.
Steerers with a flat instead of keyed kerf for cable stops. Anyone seen a front brake cable stop with a D-opening for flats recently?
"Big" and "Little" 20in rims and tires...one is 451mm BSD (Bead Seat Diameter) while the other is 406mm and though both are nominally 20in, they don't interchange. I have the same problem with my late father's 1938 Hercules coaster...it has 26in tires (571mm) that do not match contemporary (559mm) 26in diameters...or bead design. I use tires intended for period Schwinn cruisers and their old Leviathan tandem.
Chainring and cog width...and the width of the chains intended for various sizes...and the quick-links for them. Not a stopper in itself for frames, but the number of speeds correlated with rear dropout spacing and that can make for upgrade problems.
...and so on.
--- Quote ---Any thoughts on what is happening, or will happen with 26" tyres? Will they go extinct? Harder to get? Less range of available types and widths?
--- End quote ---
Fortunately, there is a large installed base of fat road-oriented tires in the trekking bikes market and I think this will ensure a steady supply for some time, likely the same for knobbly MTB tires.
--- Quote ---I haven't seriously started stockpiling 26" tyres...well not yet. Well may be just a few extra tyres ordered just in case.
--- End quote ---
I tried that with 27inchers with mixed luck. I stored them in cross-matched plastic garbage bags with the air pulled out using my ShopVac, then stored them in a cool, dark closet. I found they were still good after 20-off years but with something odd: They deteriorated much sooner once out of their little nests than if they'd been new. It was like accelerated aging. Gum/Tan/Skin sidewalls were where it showed first, with the surface becoming cracked very quickly from age, UV, and ozone exposure once they were mounted. Tires with black sidewalls (really, the tread material molded onto the sides) were much more resistant. A wholebuncha Avocet Duro 20s and 30s did fine until ridden on rainy days and then the sidewalls just sort of dissolved, turning white very quickly and then appearing to lose any sort of latex coating before the threads in the weave came apart. Most disappointing. Some old 700C silk sewups (tubulars) did pretty okay, but the rubber tread glazed much more quickly than the clinchers did once released from captivity. You might have similar luck or better or worse. The outcome depends on a lot. I still have some 27inchers in storage and this is a good reminder to take a look at how they're doing. Some have been sleeping for over 25 years in my gear lockers.
All the best,
Dan.
*In 1995, the Brotherhood of the 650B was founded in an attempt to resurrect this tire size which had fallen from favor among mass-production bike manufacturers and so were sometimes difficult to get as replacements. I remember placing a 650B tire order at a local shop for a friend's bike in the early 1980s. We were only able to get some really old, sun-rotted Wolbers after a nearly 8 week wait. Pitiful. I followed the Brotherhood's mission with some interest. You can go back through their archives here:
http://confreriedes650.org/nos-randonneuses/
Google English translation here: https://translate.google.com/translate?hl=en&sl=fr&u=http://confreriedes650.org/nos-randonneuses/&prev=search
...and a bit of translated history and a mission statement here: https://translate.google.com/translate?hl=en&sl=fr&u=http://confreriedes650.org/nos-randonneuses/&prev=search
Vintagetourer:
Dan as a proud owner of a working 1979 Falcon Olympic Ernie Clements 27 wheeled bike, and a small hoard of 27 tyres, I dont know whether to be alert or alarmed by your astute and well informed post.
I rode the Falcon for 30+ years.
Surely my newish 26 Thorn Sherpa should be rideable for at least as many years. Tyre availability shouldnt be the end of a working bikes life. So unfair :)
martinf:
--- Quote from: Vintagetourer on April 23, 2018, 06:45:21 am ---Any thoughts on what is happening, or will happen with 26" tyres? Will they go extinct? Harder to get? Less range of available types and widths?
--- End quote ---
A similar sort of thing happened with 650B (which I have been using since at least 1983). At first, I had no trouble getting decent tyres, even in a special, very durable tandem-specific model. Quite soon, the range of available tyres reduced, but never completely disappeared. At one stage, the only tyres easily available were cheap, low quality and a bit narrow for the family bikes (35 mm true width instead of the 650x44 the bikes were designed for, which were 42 mm true width). A bit later, with the rise of Internet, I was able to find a suitable model in the Schwalbe catalogue, and get my friendly LBS (alas, just recently closed) to order some better tyres.
Just recently, there has been a lot of choice of good quality 650B tyres, because of the "new" 27.5 wheels, which have the same bead dimension.
Unfortunately, all the new 27.5 rims are for disk brakes. 650B rims for rim brakes are still very rare, the only ones I found were old stock Ambrosia Keba rims resulting from an initiative by the 650B user group mentioned by Danneaux. The Keba are a trifle narrow for fat tyres, but they do work OK, I have hoarded two of them, which I hope will be enough. They are, at the present time, still available from 1 mail-order outlet in France.
I don't think the same thing will happen soon with 26", there are just too many bikes around with 26" rims. If it does, I expect there will be initiatives to get batches of good tyres made, as Thorn/SJS Cycles has done with their special order of Dureme tyres.
Danneaux:
--- Quote ---Dan as a proud owner of a working 1979 Falcon Olympic Ernie Clements 27 wheeled bike, and a small hoard of 27 tyres, I dont know whether to be alert or alarmed by your astute and well informed post.
I rode the Falcon for 30+ years.
Surely my newish 26 Thorn Sherpa should be rideable for at least as many years. Tyre availability shouldnt be the end of a working bikes life. So unfair
--- End quote ---
<nods> I feel your pain, Graham! It really is a pickle when tire sizes change and bikes must -- or cannot -- change with them. 700C rims have a diameter 8mm smaller than 27in...which means the brakes much reach another 4mm (radius) downward to the rim. Doesn't sound like much until they...don't. :(
On two of my 1983/84 tourers, I was able to fit a different brand of cantilever brakes and reverse the mounting hardware on the rear so the pads could reach the smaller 700C rims. Up front, I had to partially section a brake pad to do the job with the new brakes. My 1970 British tourer was built with very generous clearances and the rear brake is already the longest centerpull made by Weinmann/Dia-Compe...but won't.quite.reach a 700C. If I convert, I have several options:
1) Make a drop bolt for the present centerpull brakes. I don't really like the idea of the extra braking torque on the rear bridge, which is not super-robust.
2) Fit a sidepull caliper to a Dan-made drop bolt. Same concern as above.
3) Braze on some cantilever posts and repaint. I have the posts and am well experienced as a hobbyist framebuilder, but I'd really hate to toast the paint on the seatstays and fork blades, as it is still almost perfect even after 48 years.
4) Those stored Avocets were meant to save the day (or postpone the inevitable for awhile) but soon I must go with an alternative. I live in Eugene, Oregon USA about 180km south of a major bicycle tire specialist in Portland and they list several alternatives in 27in, some of which have tan sidewalls for "historic aesthetics"; the rest are blackwalls or dark brown in the case of some Contis:
Cheng Shin Super HP (comes in colors only[!]. Cheng Shin Tire is the parent company of MTB tire brand Maxxis. I really liked their CST917 and got phenomenal mileage from them...)
Cheng Shin Super HP Tire with Puncture Protection - black tread/black sidewalls
Continental Gatorskin - dark brown sidewalls
Continental Gator Hardshell - dark brown sidewalls
Continental SuperSport Plus - blackwalls
Continental TourRide - blackwalls
Continental UltraSport II - blackwalls
Kenda K35 (cheap and cheerful with good reviews)- tan sidewalls
Kenda K40 (same) - tan sidewall
Kenda K161 KrossCyclo (knobbly cyclo-cross tire) - tan sidewalls
Panaracer Pasela (my most likely choice for the bike in question and for my sister's truly lovely 1984 mixte) - tan sidewall
Schwalbe Marathon - black sidewalls with reflex strip
Schwalbe HS159 Puncture Protection - tan sidewalls
Vittoria Zaffiro - black sidewalls
Hopefully something from this list will give hope a little longer for your Falcon, Graham. They all can be ordered by your LBS and are presently available (as of April 2018).
All the best,
Dan.
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