I posted this q in this forum because I thought it would have the best audience.

I've got a 26" hybrid- basically a rigid mtb with slicks- and I like having a tough, durable bike for errands and fitness. I've begun to wonder if my 26" wheels are "slower" than an equivalent bike with 700c wheels, though.

The question- if you compare two hybrid bikes, one with 26" wheels and the other with 700c, all things being equal including their flat handlebars, frames/rigid forks and gearing, with the tires being of the same width/weight/pressure and the wheels having the same spoke count, which one would roll with less resistance? In other words, which one would be "faster"?

Last, I understand that with flat handlebars, both bikes will not be aerodynamic so the rider & bike aren't going to set any land speed records.

Roll with less resistance, or "faster"? All things being "equal" as you say, the 26 in wheel bike will require more pedaling and faster pedaling to equal the same wheel-inches of the 700c bike. But in reality, things are never "equal." You might not want to pedal a 700c bike in as high a gear compared to the 559mm (26") bike. Smaller wheels=less rolling resistance (the principle behind Moulton's 18-in wheel bikes). So the smaller-wheeled bike might seem just as fast. Moulton uses large front chainrings to compensate, sometimes as large as 60t, and you could also with your MTB, if your chainstays will not interfere. Most MTBs have relatively small "largest" rings, usually 44t or 46t, so the top end on a typical 26 in MTB usually cannot match top end on a typical 700c road bike.

If the tires are the same width, I don't think the speed would be that much different. Most people run a skinnier tire on their 700c bikes than their 26 inch bikes. In that case, the 700c is faster.

I like how Surly specs the Long Haul Trucker. 26 inch wheels for the smaller frame sizes and 700c for the larger ones. Makes sense to me.

All things being equal there is probably a small rolling resistance advantage for the 700c wheel, very small. Moultons 18" wheel size was based on an aerodynamic advantage rather than a rolling resistance advantage.
Ofcourse gearing will be different but that just means you will use a lower gear to go the same speed with the same effort on the 700c.
Another small difference is the selection and availability of tires for your bike. The selection has improved in recent years but in general the availability of street tires for either style may not be the best. Fat cruiser and knobbie tires are easily available for 26" and skinny racing tires are easy to find for 700c but good width, high quality commuting tires will depend on you LBS. Thats why I usually order my commuting tires online.

Craig

The fitter one, with bigger thighs.

Yes. In theory 700c = less rolling resistance. 26" wheels are more aerodynamic and more rigid. Assuming you end up with the same gearing and same tire width, the difference will be negligible. Like was said finding skinny tires on 26'' mountain wheels is tougher (not so for 650c) but I like being confy so I'd take 700x32 or 26x1.25".

As noted in this thread, I think the speed differences on smooth pavement will be questionable.

However on rough pavement, the larger wheels will run more smoothly, and in my experience a noticeable speed gain may result from this.

This is ignoring factors like spoke/fork compliance, suspension, and tire size/pressure that are commonly different on 700c vs 26" bikes

Yeah, Surly considers the frame geometry more important than the wheel size. The reason Surly uses a smaller wheel size on the <50cm LHT is so they don't have to compromise the geometry of the frame. The would have move the seat tube to fit in a 700c wheel on the smaller sizes.

Hi, I have both a 26" and 700c wheel bikes. I find that the 700c bikes is better for going downhill and for cruising a long distance while sustaining a good speed. The 26" wheel bike is better for accelerating from a stoplight and for climbing a hill. In an urban setting with stopping and starting at intersections there is no clear advantange of one over the other to me as far as speed.

If you are riding long stretches of road where you can cruise the 700c wheel and getting aero will help greatly to move at a good speed. If you are haulilng 30lbs of cargo or more then, speed goes out the window. Many tourers use 26" wheel bikes (check the touring section) for the bigger tires and lower gearing.

Determine what your needs are then find the right bike for you.

Taking your question head on, that is assuming a 'hybrid/mtb' riding position,and assuming that you equalize the gearing, roughly same speed for the same effort. One of the best discussions of this I've seen is by Andy Blance on the Thorn (UK) website: yes, 700c has a slight advantage in rolling resistance over 'bumps' BUT 26" with, say, wider 1.5 tires at lower pressure have less rolling resistance over ever-present small road surface imperfections -- probably pretty much balances out. 700c 'wins' at sustained, 'racing' speeds due to aerodynamic advantages and other factors (e.g. narrow tires at high pressures), 26" at more usual touring/fast touring speeds due to comfort (wider tire, lower pressure), relative wheel strength, and (importantly) ability to accelerate slightly more quickly. As others have said, figure out your priorities, best fit, and choose accordingly.

I have a similar setup. It's an old diamondback rigid MTB with slicks 26x1.25". And then I have a 2006 Trek 1200 road bike with skinny 25mm tires. At the end of the day my average speed is about dead even between them over the course of 29 miles.

The rolling resistance really isn't THAT much worse on the hybrid's slicks. They're heavier, but eeh.

The gearing doesn't matter that much because I never top out the gearing on my road bike. I do sometimes approach wringing out the hybrid, though.

The aerodynamics do make some difference but only at higher speeds, and I "tuck" on both my hybrid and my road bike on downhills. Sure, the roadie's a little more aero when tucked

Commuting isn't always about speed and performance. It's about finding a compromise -- a balance that meets your needs as best as possible. In my situation, I prefer the road bike because it's shiny and new, and it's got the rack and panniers on it. It's a little more reliable with better components as well. In a bind, though, I'd happily ride either of them to work, and I have.

I've tried both and much prefer 700c. I find that no matter what my gearing there is a "dead spot" in my pedal stroke that will not go away with 26".

Every other controllable variable being equal, which wheel has less rolling resistance? The smaller wheel, since it encounters trivially less atmospheric friction.

The larger wheel, however, falls trivially less far into depressions and trivially better irons out surface irregularities, which exactly compensates for its greater rolling resistance.

The effort, measured in time and expense, to replace one wheel size with another (every other controllable variable being equal) will put you trivially closer to the grave.

Better to go out for a lovely ride this afternoon on the wheels you already have.

My 54cm LHT has a gargantuan head tube, which shrinks again for the 56 and 58 (2 smallest 700c frames), then is basically the same for the 60cm one. No chance of toe overlap whatsoever, and I could pretty much mount a water bottle on my front fender if I wanted to as well.

Theoretically, again, 26" allows similar wheel strength w/ fewer spokes (for weight weenies) or, more along my style, tandem wheel level durability from a regular 36 spoke hub!

In the real world the 700 would probably be 'faster' because the gearing would be slightly taller and it would probably have skinnier/higher psi tires. Realistically though,there would prolly be other differences as well. The only bikes I can think of that actually come in both 700 and 26 are the Scott Sub series;they have two of each model with either 700's or 26's.

If you live somewhere that doesn't get snow and has smooth roads,700cc wheels will give you the advantage of being able to easily find skinny,high pressure tires. If you have bad roads and/or snow;26ers will allow you to run wider tires for comfort and proper knobbie/studded tires for snow/ice.

Even gearing doesn't matter much really.
according to my cateye computer setup stuff:

700x20c = 2086mm (like my boss's road bike commuter)
26x2.35 = 2083mm (like my mtb commuter running big apples)

3mm really is "slightly" taller gearing!

What is the difference between 700x28 and 26x1.5?

My sigma documentation calls my 26x2.0 apples a 2114 perimeter. Says 700x28=2149, 26x1.5=2026. The 30+mm discrepancy between cateye and sigma (and 2.35 vs 2.0 at that) is greater than the difference between 26x2.0 and 700x28 on the sigma doc, and if my sigma doc went out to 26x2.35, the real discrepancy would probably put the 700x28 and 26x1.5 pretty close together too.

Actually the sigma doc has 26x2.0=700x20, so there are some equivalencies that the algebra-minded could use to extrapolate the discrepancy among the documentations...

+1
I was going to mention Thorn myself. When I looked into this I came to the conclusion that the most meaningful difference is the bigger selection of slick, skinning tires available in the 700c size. I don’t think the speed difference would be realized unless you are a very fit athlete in a time trial.

+1 - it ain't the bike it's the engine.

1ply:

My cateye documentation shows
700x28 = 2136mm
26x1.5 = 2010mm

a difference of 6.3%

With a 48 tooth front, that is a little less than a tooth different in the back. (48:15 vs 48:14 = 7.1%)

Thanks.

On my ride to work and back I think I have nothing to worry about. If it takes me 2 minutes to get there with the same effort, I'll take the cushiness of the bigger tires.

Correct. The difference between 559mm rims and 622mm rims with the same width of rim/tire is tiny. That much of a difference might make you want to use slightly different gearing to compensate but other than that, it is indeed trivial.

Yes, I've finally concluded this as well. There seems to be few slick 26" tires on the market that can be pumped over 100psi, they're hard to find- even on the internet, and even when they can be found, they can be pretty expensive

I'm trying to figure this out too. I'm trying to decide which bike from the following two, would best suit me for city commuting, I can't decide:

https://www.edinburghbicycle.com/ebwP...c002910m005710

OR

https://www.edinburghbicycle.com/ebwP...c002910m005724

same bike, (mostly) same components, different tyres. what do people think? (sorry to hijack the thread!)