Road tyres for a 27.5" bike

amilne

I have decided to build a 27.5 inch bike, modifying a standard carbon 27.5 inch frame to suit my needs. One thing I want to be able to do is fit road tyres and tubes to the wheels, as I regularly go road touring when the same bike would be suitable and better fitted with a rigid fork and road tyres. I cannot seem to source road tyres. I have been confused by the availability of 650b/c tyres which it turns out are all actually 26 inch tyres. Can anyone point out a supplier of 27.5 inch road tyres?

njee20

I have been confused by the availability of 650b/c tyres which it turns out are all actually 26 inch tyres

You're still confused!

There are 4 different wheel sizes:

26": 559mm ETRTO
650c (was common on triathlon bikes and small road bikes, much less so now): 571mm ETRTO
650B/27.5" (the new standard - which you are proposing to use): 584mm ETRTO
29"/700c: 622mm ETRTO

Tyres are not interchangeable between different sizes.

650B being new and designed for MTBs I'm not aware of any road tyres, they may exist, but considering how limited knobbly tyres are I'd not be surprised if there aren't any yet.

You can fit road-tyre shod 700c rims in a 26" MTB frame, so that'd be the best, or just go 29er if you're getting a new frame, or stick with 26" if you want the selection of tyres.

amilne

Thanks for the quick reply. I have 700c as a fall back I think, particularly as I have already bought a lightweight second hand front wheel as I wanted a spare set of wheels for the 29er I originally decided on. As I'm only 5 ft 6in, I don't feel particularly comfortable on a road bike or 29er coming from a 20in bike, so recent 27.5 availability of carbon frames and wheels has driven me that way. I thought I would have to try the 29er wheels and a road tyre to see if it would fit. Perhaps I need to get a tape measure out or do the maths and research tyre sizes, which I have not done. Still hopeful for 27.5 road tyres, perhaps for next year only then.

nicklouse

why? it is a MTB lead thing and road have the 650c.

29 and 700c are the same.

note a 26" wheels is not the rim size, also a 29" is not 29" the measurement is the total wheel diameter with a "nominal" tyre.

All covered in depeth on Sheldon Browns pages.

amilne

Wow, there's a lot to research in this subject.
I've only just started, initially checking this out with the Schwalbe catalogue and the references above. It is clear that a 584mm ETRO wheel has been in use for some time, so there are other tyres available, which might fit but it is unlikely that they will be any use to me. I'll research further until I can get a good idea of the OD of possible tyres and whether any might be of use for a "road" tyre.
Thanks for the help.

amilne

I have now done my initial research into a "road" tyre for 27.5er, 650B with a wheel ETRTO diameter of 584mm. Thanks for the help in getting started. To say I was confused is a complete understatement.
There are quite a number of tyres which have mainly been available for several years, based upon a mainly French size of 650B cycle, a cycle tourer as opposed to a "racer" using 700c wheels. There is an enthusiast group trying to keep the wheel and cycles alive, unlike the worldwide bicycle industry. The tyres have a range of sizes in the main between 32-584 ETRTO designation (32mm wide) and 54-584. Many of these are old designs, heavy with wire bead core.
The 27.5 inch MTB style bike using the wheels has an increasing range of tyres available, around size 57-584 ETRTO, 27.5 x 2.25 inch, from 2.1" to 2.35", mainly intended for tubeless use, all "knobbly". I'll use these when fitted with front suspension forks, but I'll wait to see the 2013 ranges.
The 650b enthusiast group in France has recently collaborated with Hutchinson to produce a tyre called "Confrérie des 650" from the name of the group, a 32-584 tyre of modern construction but old looks and a treadless centre strip, 260g per tyre, for use with a tube, which is the closest I can find to a "road" tyre. It seems likely that this can be used not only on the road, but I hope also on tracks up to the point where I would prefer to have a front suspension fork on the bike. I have now ordered 2 to try, but my bike will not likely be ready until the end of October.
I calculate (hope) that my bike will be close to 8kg in weight without panniers or other tourer necessities in rigid fork configuration, but with 26" Dr sludge filled tubes (if they fit). It could be lighter, but at £ per gramme, not pence, so there'd be even more reason to question a new bike at my age.
I list below some useful sites to anyone interested in 27.5er tyres.
http://www.confreriedes650.org/pneu.php In French (French enthusiast group)
https://docs.google.com/spreadsheet/ccc?key=0AhJ3Eg2EndMUcFpsLUVBTm5XWWk3aGlEVXZfS2pvTHc&hl=en_US#gid=0 Spreadsheet for 650B outside diameters
http://www.cyclos-cyclotes.org/650/pneus_650.html In French Everything you need to know about 650B tyres
https://groups.google.com/forum/#!forum/650b Google Group

cooldad

Sounds like a lot of hassle to me. Why when there are perfectly good, readily available alternatives?

njee20

My thoughts exactly! 700c wheels would have fitted fine, with a vast range of slicks and they'd roll better. Keep the 650b niche for the knobblies.

Each to their own!

rockmonkeysc

Why buy a mountain bike and then kit it out for road? Why not just buy a road bike instead?

amilne

I have been researching my new bike for almost a year now, but was delighted that I could build a 27.5" rather than 29". I would need a 29er rear wheel to go that way, which increases costs and still gives me a full size bike. I will buy a lightweight 29 inch wheel, but try for second hand, and use this to go with friends on racing bikes. As I tour in France several weeks per year (presently without tube/tyre spares or problems), I might even be able to get spares if I have multiple tyre issues. As my main offroad use is solo in the Grampians on high and long distance routes, I'm done for on my 26" if I have a failure with no spares I can use, and the new bike will be much easier to carry/push, and I'll not be any worse off. The total conversion cost without tyres is around £100, and I couldn't get a light road bike to suit me for 10 times that, and I do want a tourer. It really is "Each to his own" and I have researched this and tried other peoples bikes to see what I want. I'm not a conventional offroader or road biker.

cooldad

That made no sense to me, but if you're happy...