So if you took the same bike and had one with 26" wheels and one with 700c, would the 700c be noticeable faster?

If you didn't change the gearing, and if the 26" came with typical fat tyres and the 700 came with road tyres, then yeah.

If you adjusted for gearing and had identical tyres, then the only difference would be the negligible friction in the hub.

Given they're both pushing the same gear inches, I doubt it. Tri bikes use 650/26" wheels and roll just as efficiently....but of course also has the advantage of sitting a little lower than 700c rigs.

BUT... if you were to compare 26" & 29" fat tire bikes on dirt, yes, I think there is a diff.....the larger wheel will roll more effortlessly especially over technical terrain.

Yes, the same tire size.
Thanks, for the answers.
The reason I ask is because my measurements put me between two frame sizes; 56/58cm. The 56 comes with 26" wheels and the 58" comes with 700c. I think if I had to choose, I'd rather go smaller in frame size rather than larger. I think.

??? They put 700's on smaller bikes than that. I ride 56cm, and all the tires/wheels are 700.

haha, ya exactly.
That's the difference with Rivendell. They size the wheel to the frame.

I dunno about speed but There probably would be a brake problem....

That's not the issue here, but since you brought it up, no, these frames are designed for either 700c or 26" wheels depending on size...

Ha! When I saw that you were looking at a 56 or 58 and it was 26" or 700c, I knew right away that you were looking at Rivendell. They're the only ones psycho enough to run 26" on that large of a frame. Usually you have to at least hit 54/53 to get to 26" land. God love 'em.

I'll give you a different take: how available do you think the tires you want will be? 26" is just fine unless you want skinny ones.

700c... i don't know why you'd want any smaller tires at your size.

and like bostontrevor said, if rivendell is gonna sell you on 26" wheels make sure you can find tires your happy with... (there is a much wider sleection of "road" tires available in 700c)

Doesn't Rivendell also put people on larger bikes to begin with? I mean, riding a Rivendell 56 might be a person that others would fit to a 53 or 54. They have to make that work somehow.

Tire choice is no big deal. I run 1.5" specialized nimbus armadillos for commuting.
I was going to get a second wheelset so it can do double duty as a road bike on weekends but again, it's no problem to find 120psi 1" tires.

They do, but they accomplish that with lower bottom brackets.

The Surly LHT also uses 26" wheels on the frames smaller than 56". I guess 26" has some advantages for touring-like strength.
CPW

One thing that hasn't been mentioned is inflation. 700c tires typically inflate to much higher PSI than 26" tires, which will give you much less road resistance (and traction).


I personally use 26" tires for the smoother ride, though.

You have to compare like with like. A 1.5" slick at 90ps is roughly equiv to a 700c x32 at 90psi.

If you ride fast, the smaller total surface area will offer a slightly lower drag, and the smaller size of the wheel means the spokes are shorter, and thus catch less wind. Finally, the smaller size, all other things being equal, means a lower total weight for the wheel.

All of these factors should help raise the average speed, but if it's a factor in the real world, I don't know. 26" wheels should be at least as fast, anyway.

Theoretically, yes. IMO, no. I ride both an Atlantis with 26" wheels and a Kogswell P56 with 700C wheels. You notice a difference, but it's not so much speed as it is a gyroscopic effect - almost like the 700C wheels fight turns a touch. Very subtle. No big deal at all.

I've done rollout tests, I've timed my commute (20 miles each way) and I've got about 3000 miles on the Atlantis and about 1000 on the P56 this year. A toss up, assuming comparable tires. Not worth worrying about, unless you are after a *specific* tire that's not available in the size you want.

There are fewer skinny/high pressure 26" ties, but they exist and they are good. There are fewer wide 700C tires, but they also exist and are good.

You'll love the Atlantis, BTW. You'd love a P56, too. As a commuter, I like the Atlantis better but they are both great.

Being everything equal, the 700c is in theory and in practice faster. To which extent? It depends on the cyclist. Again, everything the same, 700c has lower rolling resistance and higher rotating momentum (both of them good for keeping high speeds, but not so much for accelerating); 26" has lower wind resistance (only for the front wheel; the rear one is behind wind drag of seat tube for all bikes) and weight, and lower center of gravity (better for quick and nimble swerves and wriggles). The outcome being that speed-wise the advantages of the 700c slightly outrun the 26"'s ones. I've ridden both, and the 700c is usually 1 to 2 mph faster with the same effort. Anyway, if you have to keep up with a group of fitness-matched people, wheel diameter won't matter much.

Tell you the truth i strongly suspect that many things in the cycling world including this one are theoretical.
We think the 700 c are faster generally but some tri bikes run 650's with good results. Rolling resistance is a factor of tire width and pressure but there's some conjecture about wheel size.
Conventianal wisdom is that a larger wheel provides less resistance but whether that outweighs the added weight of a larger wheel is debateable. Larger wheels also have more surface area and are arguably more flexable. Also the larger wheel takes more force to accellerate and changes the handleing...

All those factor which wheel should you buy.
If the 650 provides better handleing and a clean ride then the only question is tires and tubes. 650's are harder to find than 700's but you can find 26" mtb tires anywhere.
If it's a difference between 700c racing wheels and 26" MTB or city, the difference is weight vs durability. Depends on the weight you'll carry though it sounds as if your a smaller frame so it shouldn't be an issue.
Lastly, if your'e a creative, mechanical person that like to hommake things and push the mechanical envelope then you might like to get an 'off' size and experiment.

I've also seen smaller bikes and womens bikes with 700c rear wheels and 650 front (some frame geometry reason) and they rode well enough.

I am absolutely convinced of this. If the difference was even 1MPH, that would work out to about 4 minutes faster on my commute (which I do in the same time, pretty much down to the minute). There is no difference.

As long as its round it should be OK

Square works too if you're fast enough to keep them spinnin'.

The differance in real world commuting speed between a 700 and 26 inch wheel is nothing. Even gearing really doesn't make a differance unless you're a really strong rider and you're not in too much traffic. I avoid hammering on the commute because I have traffic, weather, darkness and lots of work related stuff on my mind. But here are a couple of real world things to think about.

I'd rather flat with a 26 in wheel with a 1.5 inch slick than a road bike wheel with a super skinny, high pressure tire any day.

26 inch wheels with 135 mm rear spacing are way cheaper than road bike wheels (700 with 130 mm spacing) As a general rule, MTB bike parts are cheaper and stronger than road bike parts (and heavier, I know)

For the money, 26 inch is better deal if your commute isn't too long. Think about a wide range MTB style casette in back and a double chainring up frount without index shifting. You would win any races, but it's a great commuting/touring set up.

But nothing's like hammering on a road bike

I have been expermenting with the difference in reliability over the past few years. riding MTB's, Cross or Hybrid's. When it come to general parts, they all wear about the same. Buit when it comes to wheels.....I hade greater reliability with 26" wheels and slicks vs. 700 c wheels. the combination of flats and broken spokes my problems with 700c wheels were about twice as much as they were with 26" wheel. I am only riding about 140k a week, but the overal maint that I have to put into wheels has been alot. It does not matter if they were hand built, x4 spoke pattern Mavic Open Pros or what.
I just have less problems with the 26".

I do about a 20+ mile round trip and hasve adjusted the gearing accordingly like other people have suggested. It is a tad slower.....but when I need to jup onto a curve when a SEPTA bus does not see me.....I do not worry about bending my rim