mrteeth

I'm considering a new road bike that can be ordered with either wheel size. The 26" wheeled version will probably fit me better and seems like a more "global" size, but isn't compatible with caliper brakes (which I prefer) and has a poorer selection of road tires than 700c.

Which should I choose?

JoelS

700c

Robert Foster

700c would be my pick as well for a road bike. Remember there are two ways to calculate gears and you have to take into consideration tire size. If you happen to be pushing a chainring of 50 teeth in the front and 12 in the back you will have to spin a lot faster to make the same speed with a 26 inch tire. I believe the 26 inch tire is a 650 for a road bike. You will have to spin faster with a 650 tire to reach the same speed as you would with the same gear ratio on a 700c. But if it is a size thing go with the 650.

mrteeth

So I'll use a bigger chainring. If that was a problem then we'd all still be riding pennyfartherings.

The real issues are tire choice and caliper vs cantilever brakes. Also I'm talking about the ERTO559 size; I would never consider 650s because, despite the good tire choices, the sources are not well established.

EatMyA**

Spining faster is a GOOD THING! Infact a higher cadence is the best thing you can do for your technique. It keeps you from injuring yourself, getting tired, and its lets you drive much further. In competition, if the OP has a higher top end and can push that same gear five miles faster than everyone else, he will win everytime. But all of this is off topic.

If you can find tires you are happy with, a 26" wheel would be a better choice if it fits.

1 its stronger
2 its lighter
3 it requires less effort to spin
4 the tires it uses are lighter
5 it experiences less air resistance
6 they draft a 700c wheeled cyclist SIGNIFICANTLY better than a 700c wheel

It its an improvement on all categories.

About the gears. The Op can always get a different cassete or chainring, but I doubt he will need it. Infact I think it would give him more USABLE gears, as the highest gears on a road bike are hardly used by us regualr folk.

rdtompki

I went through the same decision process in buying a tandem recently. There is a wide diversity of opinion out there and not much of what I would characterize as measured data. My not-so-scientific conclusion: go with 26" if your riding will consist of significant off road (gravel paths, fire roads or worse) or if the captain needs help regarding top tube height. Otherwise, 700c tubes/tires are everywhere and there are certainly tires available for 700c that can be used in mild off-road conditions. Our tamdem will take up to 38mm tires and the 40 spoke rims are pretty stout. Also, my wife didn't like the look of the 26" wheels!

There is the argument that for world tourers 26" gear is more available, but I don't know if that's important to you. In our case we're sticking to the US of A.

Velo Dog

As you've noted, gearing is a non-issue in wheel selection. I don't think tire availability is a significant problem, either--there probably are fewer choices in 26 than 700, but you only need one good one, and there certainly are dozens. i've been commuting on an old mountain bike with 26x1.4 tires, and it's no slower than my Atlantis on 700x35s.
I'd probably pick 700 because I ride a 64cm frame and the 26s would look tiny under it, but as a practical matter I don't think there's much difference. If you're really interested in 650s, Rivendell carries a selection and says it will keep them in stock forever: www.rivbike.com

stapfam

Sounds as though the 26" bike fits you better but have you tried a 700C in a different size?

If you never go on rough trails then the 700C would give you a faster ride that takes less energy to propel forward. But a 26" is more versatile and will take the odd bit of "Offroad" if that is what you are planning. And don't be worried about the brakes. The 26" probably has "V" brakes and they are very effective.

Its down to the shop and test ride. That will tell you which is the bike for you.

mrteeth

I think I'm going to go with 700c, just because that is the standard road bike size. Sure I can find 26" road tires and use v-brakes, but why swim upstream?

On this particular bike I don't think fit will be an issue, there is zero chance of me taking it offroad with fat knobblies, and it doesn't make sense to single out the tires for easy replacement in godforsaken places when there are even rarer parts subject to catastrophic failure.

Every manufacturer of road components designs them primarily for the 700c size. Why where a dress to the bar when I'll meet more women by wearing pants?

However, it's amazing some of the performance myths I see some of you touting about wheel size. Once you try a bike with 20" or smaller wheels you realize that any increased efficiency you experience on a 700c bike, in fact, has absolutely nothing to do with the wheel diameter.

ghettocruiser

But it's still nice to have wheels that don't hammer you off every pavement irregularity.

mrteeth

And, yet, between 26" and 700c people generally recommend the smaller diameter for rougher surfaces.

IMO, when we shake out all the "all else being equal" bologna and look at the best configuration for each rim diameter the only practical differences are in frame design and availability/compatibility.

ghettocruiser

What?

Who?

mrteeth

Everyone and, considering that surfaces don't get any rougher than off-road, even sheldon brown hints at it in the quote before delving into the "all else being equal" nonsense.

26" road tires are almost always wider than their 700c counterparts and rightfully so because wider tires are faster and the smaller diameter negates the weight penalty. That's the point of smaller wheels: to eliminate the weight and clearance issues created by larger wheels so you can use tires that don't "hammer you off every pavement irregularity". The problem is that 26" tires are also usually stiffer and more durable, which makes them slower. Now, of course, not every tire follows this pattern, but that's the standard.

jim-bob

Sounds like you've already made up your mind to go with 26" wheels.

mrteeth

Actually I'm leaning towards 700c because there are still more wide road tires in this size and I suspect that over the years I'm just going to have more trouble finding compatible parts that suit me for the 559 wheel....starting with caliper brakes, which would have difficulty reaching the 559 rim on this frame.

I'm not sure what the weight difference is between a caliper and a v-brake, but I'm guessing the v-brake braze ons weigh nearly as much as a whole caliper. And I'll be disappointed if I ever want to sample some exotic tires like these:
https://www.vintagebicyclepress.com/tireoffer.html
And then if I ever want to upgrade to a lighter rim, etc, etc.

I'm thinking, why go through so much hassle when I can just use the 700c?

ghettocruiser

Thus the popularity of the 29er, i.e. a mountain bike that uses 700c rims.

I'm not sure what you're driving at. All kinds of touring bikes can accommodate tires up to, and sometimes beyond, 700x40C.

And I think a 26" wheel with a 1.5" tire rides rougher on the road than a skinny little 700x23C. All else being equal.

mrteeth

Not as popular as 26". Wanna know why? Because apart from the constraints on frame design and component compatibility (and availability), wheel diameter is almost irrelevant. But it still matters greatly because to build a bike you have to choose a wheel size and, once chosen, that affects the way the bike is built, what it will be compatible with, dealer inventory, etc, etc.


Take it from someone that knows.

What I'm driving at is that not playing to the strengths of the format is foolish. Since a larger diameter compromises a wider tire by compounding the weight it's better complimented by a skinnier tire and vice versa. That way you get the most performance out of each format as opposed to serving ice cream off the grill just so you can claim "all else is equal" when you compare it to steak.

And I very sincerely doubt that you've accurately compared a 26"x1.5" wheel to a 700x23c wheel with all else equal. But if you're serious about trying here's a hint: if you exaggerate the wheel diameter differences then the other factors which you can't control as well will become relatively more "equal". Comparing a bike with 20" wheels to 700c will tell you more about the effect of a 26" wheel than comparing 26" to 700c directly because the "signal to noise" ratio is higher. If what you are saying were even remotely true then the highly respected 20" wheeled Bike Friday touring bikes would be nearly unrideable.

Sci-Fi

If you are looking for a ETRTO 559 tire size with a smaller footprint..i.e. 20-25 width..wheelchair tires is the way to go. Lot of people use them for bikes and they roll good/fast. As far as comfort, I don't know, just seen them...but haven't heard any complaints or durability problems from the people that do ride on them. For example Schwalbe has these to choose from:
https://www.schwalbetires.com/wheelchair/tires

Prices are reasonable too, many tread patterns/colors, and you can pump many of them up to 145psi. Have to buy wheelchair tubes though (Schraeder or Presta valve are available).

Robert Foster

Then the answer is easy, build what you want. Why follow the established choices? If your concern is getting the tire and wheel you prefer why not get a custom bike built? They will make you just what you want with the brakes you prefer and none of this decission making and asking of opinions.

ghettocruiser

Direct quote on the page you linked to

"On the other hand, the larger the wheel the better the ride by averaging road roughness. Riders who encounter cattle guards can best explain this. Don't try that with roller blades."

Alright. I had them on the same bicycle with no other modifications. You're right in that I didn't attach impact monitoring instruments. I just rode them for three or four years each.

Both Sheldon and Brandt spell it out to you. Multiple riders I know have totally abandoned 26" MTB rides for 29ers. Maybe we're all wrong and you're right. Who knows?

I'm not saying the difference is night and day. A slick-tire 26er can be a great-riding bike. So can a 20" compact. But smaller wheels give a harsher ride. End of story.

mrteeth

...and the wider the tire...and the more supple the casing, etc, etc, etc, and on and on it goes and if you add it all up you find that it's all a wash and the only thing that matters is compatibility with available parts, tires, and design geometries.

You don't need impact monitoring instruments. Like I said, just keep decreasing diameters until the bike becomes unridably harsh...except it won't because the fact is that decreasing diameter doesn't make it harsh if you optimize the configuration at each diameter. A little cleverness goes a long way in scientific inquiry. While perseverance is admirable, it doesn't matter how many years you test if your experiment is poorly devised.

Even if it's not night and day between 700c and 26", then it should be when you go to 20", or 8" or, roller blade wheels, except it's not. Hate to say you're all wrong, but when you say you observe black and then claim white, then how can you not be wrong? If a 20" compact can be a great riding bike (and you admit it can be) then the only possible conclusion is that wheel diameter does not in itself cause harshness. Period. End of story. Everyone's experiences support this conclusion including yours. The only difference is that some people are either too stubborn or stupid to admit it.

stapfam

[QUOTE=mrteeth;If a 20" compact can be a great riding bike (and you admit it can be) then the only possible conclusion is that wheel diameter does not in itself cause harshness. [/QUOTE]

There is a lot more to comfort on a bike than wheel size- tyre size and width- type of tyre fitted. Take the obvious and Suppleness of the frame- or stiffness if you put it another way. Then the Contact points and their stiffness. C.F. Seat posts and forks do take the sting away from some very stiff frames. And then wheel build. Radially spoked wheels will give a very harsh ride and if you couple this with 700x23 tyres at 140 psi then you had better have a good dentist.

So look at the "Pro" Road racers and see what they run. Not many do not use radially spoked wheels and Tubular 700x 23 tyres at very high pressures. Why?

Efficiency.

ghettocruiser

Yes.

Yes.

FAIL.


Sorry, I'll take their analysis over yours. Call me stubborn, or maybe stupid, if you like.

mrteeth

First of all, the UCI has gone to great lengths to ensure that the equipment choices of pro riders are irrelevant. Therefore, if they're halfway competent, and I believe they are, then the choices of pro riders have little to no bearing on performance. I don't see NBA basketball fans claiming it would be more efficient to hang our trash cans 10 feet in the air. So why do I hear the same kind of ridiculous nonsense from cycling fans?

Second of all, I take it that you're now trying to translate the argument into "in order to gain comfort smaller wheels have to sacrifice efficiency", which just isn't true. We could argue about the details until we're blue in the face, but the fact of the matter is that most of the fastest bikes in the world (record setting) also have smaller wheels. Of course at that level of performance it's mostly due to aerodynamic advantages, but if you consider the tradeoffs over the entire performance spectrum it all ends up being a wash...unless you can't get complimentary quality parts, which is the overwhelming difference between various wheel diameters.

All this means that the inherent differences in wheel diameters can't possibly amount to even fractions of a second for anyone whether it be my grandma or lance armstrong. That's why the 650b format is gaining traction with time trialists and randonneurs despite having a diameter only 11mm off of 26" mountain bike rims. Go talk to them. They'll tell you how much more efficient and comfortable it is...except it's not the diameter itself, but the changes in geometry and tire choice the diameter affords.

We have to be rational here.

Except that's not their analysis. Jobst Brandt spends the entire article claiming exactly what I'm claiming, yet you've decided to latched on to a single sentence thrown in as a theoretical concession. Sheldon Brown also couches his language in qualifiers like "tends" and "generally" because he knows it's not really the diameter itself, but the MTB format in "general" which is coincidentally characterized by a smaller diameter.

Brandt clearly explains what Brown delicately avoids. Are you stupid if you can't understand the meaning? You tell me.

I agree with them.

ghettocruiser

What part of Brandt's article supports your argument that wheel size does not affect ride quality?

The article is short. Quote the part.