Cycling UK Forum

I'd note that the geographical range of unfashionability of 26" is probably far larger than the range in which 26" persists as the default option from pre-MTB days. But it is only fashion and some day, 26" might come back (but probably displacing 584/650B/27.5" if so, rather than 622/700C/28"). You could go for the disc Trucker and swap wheelsets at will (requires investment, obviously).

Bmblbzzz wrote:622/700C/28"). You could go for the disc Trucker and swap wheelsets at will (requires investment, obviously).

Are they interchangeable? They make two different frames for the wheel sizes.
The latest Thorn Nomad is supposedly designed for all three common wheel sizes, though it might be with two forks. I haven't tried one, but have doubts it could be optimal for all three.

Checking the geo shows they're actually separate frame sets. The 700c version has greater bb drop, lower standover, longer fork and a few other minor differences. So there would be compromises depending on what you're doing but it does seem common enough practice. Probably easier to fit 26" (or 650B) wheels in a frame made for 700c, in terms of clearances, and be aware of the possibility of pedal strike if off-road.

26" etrto 559 is still I think the world's most popular bicycle wheel size and is used on the majority of bikes sold in the world, those bikes may be low price models but still they will always need replacement tyres. I guess it's down to what tyres you like, many premium brands may stop doing 26" but you'll never have a problem getting some sort of 26" tyre unlike 27.5" in the world.

26" is the strongest most abuse-able wheel size of the larger sizes or can be much lighter for the same strength with less spokes etc. So a lot of positives for them. They are likely more efficient for stop and start cycling in city traffic etc just a bit more vulnerable I guess to road imperfections and pot holes as they will drop further in. If you are using thicker 26" tyres you may have more braking and contact surface and reduced tyre wear compared to a similar weight 700c wheel using thinner tyres so both improved safety and reduced costs. An other wise identical bike would have lower gearing making hills easier but slower top speed with 26" wheels. I feel there are a lot more positives to 26" overall but then my perspective may be different from yours. I think ultimately 26" can lead to a more robust bike that needs less maintenance if you use the reduced wheel size to use thicker tyres which can improve comfort and protect the spokes and rim. The heavier the rider or load the more sense it makes to go 26" as well. As ever many variables to allow for in the decision.

The choice of 26" road tyres, and rim-brake compatible rims seems to be decreasing - at least in the UK - as 27.5" and 29" become the new standards.

In terms of efficiency, I have two 700c-wheeled bikes and two 26"-wheeled bikes, and I usually feel the larger wheels are more efficient. It's not a totally objective comparison, but I can compare my steel-framed commuting bike (weighing ~33lbs and with 1/3" slick tyres) with my winter bike, a steel Dawes (weighing ~27-28lbs and with 32mm tyres) and the latter feels easier to ride over a day's ride.

I can also compare my 26"-wheeled Ribble (aluminium-carbon, 1.3" slicks) and summer bike (an aluminum-carbon Giant with 700x28mm tyres) and the Giant is definitely faster and requires less effort, but it is quite a lot lighter than the Ribble.

A fair comparison would require the same bike and same tyres but with 26" or 700C wheels.

Brucey wrote:...you can fit 584 (aka 26 x 1-1/2" or 650B) rims and tyres in disc braked bikes...38 x 584 tyres would go nicely in a 26" LHT

My 26" wheel Disc Trucker rides on E.A.3s (ISO 38x590 a.k.a. 26 x 1 3/8 a.k.a. 650A). Nice bike, rides and handles fine.

bgnukem wrote:
A fair comparison would require the same bike and same tyres but with 26" or 700C wheels.

This. Various comments here saying that 700c feels faster than 26". I would suggest that what feels faster isn't necessarily so. The larger wheel may or may not be faster using the same tyre in the same section but only more objective testing can determine this. People often report that their bike feels faster with the tyres inflated at higher pressures when proper testing can prove the opposite to be the case.

iandusud wrote:

bgnukem wrote:
A fair comparison would require the same bike and same tyres but with 26" or 700C wheels.

This. Various comments here saying that 700c feels faster than 26". I would suggest that what feels faster isn't necessarily so. The larger wheel may or may not be faster using the same tyre in the same section but only more objective testing can determine this. People often report that their bike feels faster with the tyres inflated at higher pressures when proper testing can prove the opposite to be the case.

I can say with absolute certainty that, taking the tyre out of it for a moment, a large solid wheel rolls better than a small solid wheel over imperfect surfaces. And the reason is obvious. Larger wheels don't descend as much into the low points of the imperfections in the surface as small wheels do. But the difference between a 26" wheel and a 700c wheel is not so great that you would notice this effect too much.

26" wheels are still the best choice for lugging a really heavy load but they are fast becoming less popular everywhere else. The effect of all this is that the choice of 559 rims and tyres is diminishing at a rapid rate.

I'm really interested you said this. A couple of years ago I wrote about this viewtopic.php?f=5&t=128452&p=1333981#p1333981 Cycling UK picked it up and used my original post as a letter in the magazine, without permission but with a rather patronising comment something to the effect that I had nothing to worry about (can't find the letter unfortunately).

pwa wrote:

iandusud wrote:

bgnukem wrote:
A fair comparison would require the same bike and same tyres but with 26" or 700C wheels.

This. Various comments here saying that 700c feels faster than 26". I would suggest that what feels faster isn't necessarily so. The larger wheel may or may not be faster using the same tyre in the same section but only more objective testing can determine this. People often report that their bike feels faster with the tyres inflated at higher pressures when proper testing can prove the opposite to be the case.

I can say with absolute certainty that, taking the tyre out of it for a moment, a large solid wheel rolls better than a small solid wheel over imperfect surfaces. And the reason is obvious. Larger wheels don't descend as much into the low points of the imperfections in the surface as small wheels do. But the difference between a 26" wheel and a 700c wheel is not so great that you would notice this effect too much.

You are of course correct about the effect of larger solid wheels but we are talking about wheels with pneumatic tyres, and in the case of use on paved roads I suspect the tyre does most of the work of absorbing the imperfections.

iandusud wrote:
You are of course correct about the effect of larger solid wheels but we are talking about wheels with pneumatic tyres, and in the case of use on paved roads I suspect the tyre does most of the work of absorbing the imperfections.

the tyre is a bit of a red herring; as a 'thought experiment' imagine a solid wheel rolling along an inflated sausage laid on the road surface. It is fairly obvious that very small bumps (small in relation to the diameter of the sausage) will not be 'felt' by the wheel regardless of wheel size. It is also obvious that bumps which are on a longer pitch will still cause the wheel centre to go up and down as it runs along the sausage, and that the smaller diameter the wheel is, the more this will happen.

So tyre or not, the same kind of thing happens, just to a different extent. You are always better off with bigger wheels; even if you have suspension it still gives the suspension less to do.

FWIW frames/forks for 26" wheels are very often quite a bit stiffer than those for larger wheels. 10% difference in wheel diameter is no big deal but 10% difference in a cantilever bend (such as a fork) is. The result is that on most of the (many) bikes I have had with 26" wheels, I only get comfortable when the tyre size is a fair bit larger than bikes with lighter built, less stiff frames and larger diameter wheels. So typically I find that riding 32mm-35mm tyres on a 26" wheeled bike is quite a lot like riding 25mm-28mm tyres on a bike with larger wheels.

cheers

Yes, many framesets for 26" wheels are beefed up for offroad use. Mind you, forks for disc brakes seem to be pretty harsh and stiff regardless of wheel size, plus straight-bladed 'road' forks in carbon fibre are not necessarily very comfy, if my Giant is anything to go by!

Some rigid forks fitted to 'offroad' framesets are 'suspension-corrected' to allow for suspension fork travel and so have quite long legs similar to those of a 700C fork, but are likely to be stiffened up for disc brakes.

Given that the contact patch of a 26" tyre will be shorter than that of a 700C tyre, given equal pressures, tyre widths and ride weight, higher pressure would be needed in the smaller tyre to avoid greater sidewall flex in the contact patch (to give a wider contact patch and thus equal contact area) which would increase rolling resistance. In practice though I guess most people run wider tyres in 26" than they would with 700c allowing equal or lower pressure.

Even in the MTB world there has been some movement towards larger wheels than 26" because of the advantage of larger wheels on uneven surfaces.

bgnukem wrote:Given that the contact patch of a 26" tyre will be shorter than that of a 700C tyre, given equal pressures, tyre widths and ride weight, higher pressure would be needed in the smaller tyre to avoid greater sidewall flex in the contact patch (to give a wider contact patch and thus equal contact area) which would increase rolling resistance.

What are you keeping constant in that comparison?

Jonathan

I think he has said 'contact patch area' and that stays about constant at fixed tyre pressure.

cheers