pdxtex

anyone know if there has ever been a quantified test to compare long distance effort on a single speed bike versus a geared bike? ie, is there a ratio of single speed to geared miles or a caloric expenditure difference? example, given the same road course, would a rider expend more calories and on a single speed bike then on a geared bike? they must, but how many? i ride both and personally, i max out at about 85 miles a week riding a single geared bike. on a geared road bike, i could easily do over 100 plus before id like to take a break.

RollCNY

I ride SS 95% of the time, and an SS is less work than a geared bike. I do not ride fixed, but that should be very similar. Anyone who tells you otherwise is selling something.

pdxtex

you think its less work? the derailleur optimizes output, with one gear you are subject to increased torque as the grade increases. ok, its a 12 mile time trial with a 4 percent constant grade, do you still think a ss would be easier? thats like driving a car in first gear the whole way....does not compute.

caloso

Dare I suggest a powermeter?

wphamilton

Maybe you're not going as fast on the single speed as you would with the geared bike. That would mean less work.

on the path

If the speed was identical over the same course, I believe the amount of work done would also be identical. Hoping the physicists and engineers will chime in.

FWIW, today I did a 34 mile loop with some pretty good hills on my SS. I won't reveal the stats but my avg speed was very good and I don't think I could have done better on my lighter multi-speed bike. Not today anyway...

hueyhoolihan

in general, being able to climb with a big gear (and the bigger the better) will result in less or no appreciable difference.

riding the same hilly route with a SS over a number of years and recently converting one of my SSs back into a geared bike, and riding that one over the same route a few times, i have found that i gain no speed advantage with the lower gears.

however, due to the fact that the power of a pedal stroke is not linear, it is possible to stall the bike at low speeds, in any gear, if the terrain is steep enough. this will happen, of course, with a bigger gear first, all things being equal.

hueyhoolihan

maybe we should stop burning so much coal and oil in our power plants and just outfit them with derailleurs to maximize output.

RollCNY

I do not have a power meter, but nudged someone who may have data from both.

From HR data, I know that I can't push my HR as high on my SS as I can geared (course dependant).

OP, break it down into pieces:
On flat ground, at your self selected comfortable all day cadence, the SS requires less work: straight chain line, less chain length, no spring tension in chain return side. But this difference is tiny, like fractions of a percent.

On descents, you spin out quickly, and coast. Less work.

On hills, you have choices. Low rpm grind, high force. But speed dictates wattage, so whether you use gears to pedal fast or grind, 6 mph requires specific wattage regardless of gearing. Or you hammer on your SS to stay in the cadence sweet spot, but you've increased wattage. You could use gears to match that speed, and have the same wattage.

The biggest thing with an SS is you can't push hard all the time, so there is a huge amount of recovery time. I have done two day, 250 mile trips on both SS and geared, same roads, and was far more fatigued on the geared bike. I was also faster.

alexaschwanden

Have fun with your bike.

RaleighSport

The only way SS is less work is if it's fixed gear.. IMO. Even then, it has to stay relatively flat for that to be true.

Elvo

It depends on your power output.

wphamilton

I already did It's almost as simple as that. It is possible to have a lower average speed (ie, velocity) and expend more energy, depending on how you budget your power, but I think that in general the total time taken will roughly correspond to how easy it was. I don't have a single speed, but it's reasonable that the tops of the speed spikes in powered motion are chopped off, meaning the ride is probably slower and having less total effort.

I can imagine a counter scenario, and maybe a single-speed rider can say if it's likely. If you're periodically spinning it hard on hills, and coasting downhill, you could wind up with a higher average speed and lower total work done. If in contrast with your geared bike you take it easier uphill and concentrate on your top speeds, because with the geared road bike faster is more fun. But it might feel "harder" on the single speed because you burned all your matches. This would be an exception to the first paragraph, but as I said I don't know how common that is.

JohnDThompson 

The human body is most efficient over a fairly narrow range of rpms; having a variety of gears available allows you to stay within that range in a variety of conditions: hills, winds, etc. That said, riding a fixed gear is a lot of fun, too, and trains your body to widen the range of rpms through which it can deliver power efficiently. In fact, I just got back from 50 miles on the road on my fixed gear bike...

on the path

The only way I can think that your last paragraph would hold true is if the end point of the course was at a lower altitude than the beginning point.

How hard it "feels" and how much work is done are 2 things not directly related to each other, not in the sense of physics. A geared bike contains many simple machines (essentially levers). Since you are "the guy" I'm hoping you'll confirm that simple machines do not reduce the amount of energy required to do specific "work", but rather they spread the work out over a longer distance and/or time period thus requiring less momentary force.

on the path

You got that right. It seems having only 1 gear ratio helps you work on your spinning AND your mashing. But let's keep this to ourselves. Shh...

Dean V

There are too many variables to compare. Terrain and your physical conditioning being the main ones.
Power meter won't help as pushing 300w up hill in the "right gear" is much easier on the body than grinding up there at 300w but 25rpm on your fixie. Same goes for when you are at the upper end of the cadence range.
Just taking notice of how tired you are during and after the ride will be as good a comparison as you will get.

wphamilton

You're forgetting that higher speeds take more than proportional power. V cubed. Also if you were easing up the hill because you've got the gears for it (taking a long time on the hill) you could sprint like Cavendish on the rest of it and still not finish in less time than if you had kept a good pace on the uphill.

Yep. If you burn your matches with a few intense efforts your muscles will feel knackered, but you probably won't wind up with as high an average speed (nor as much power over the duration) as if you'd taken it steady.

Oh - yeah, if the work done by the machine is the same, you have to put the same work in no matter what the machine is.

Brian Ratliff

BS. That's all I have to say about that. Geared bikes were invented for a reason, and it's not some conspiracy as to why. Human muscle output has a relatively narrow range of force it can reproduce repeatedly. Geared bikes keep torque on the pedals relatively constant for a given power output, regardless of terrain. SS bikes require a large torque range, from very tiny torques (and huge RPM) on downhills to very large torques (and low RPM) on uphills, to keep power constant over varied terrain. This is not a hard question.

Also, to avoid confusion, if your speed is constant, regardless of terrain, you are putting the same amount of work energy to the road. This is, then, purely a question of human body efficiency. Yes, derailleurs and chain line introduce a small component of drag. This is way overwhelmed by the increased body efficiency of a multigeared system. The utility of multiple gears is an old question that was put to rest when a woman amateur rider on a multi-geared bike beat a bunch of pro bike racers on single speeds over a hilly course a very long time ago.

RollCNY

Brian, I didn't say its less work for the same speed. Its less work because you go slower (depending on terrain). How many threads do we have to have this argument in?

Here is a hypothetical:
You are on flat ground, and your SS is geared at your self selected cadence. Is a geared bike more work, less work, or the same work at that moment?

Brian Ratliff

So we are on flat ground with the perfect gear now are we? Trivial. PDX (OP's haunts) has some sustained flat areas, but not many. Hills are the problem and is really the only topic worth mentioning when comparing SS to geared. Otherwise, on your hypothetical ice rink-flat world, there is no real difference between SS and geared because they are exactly the same thing. But then you forget there is usually a lot of wind in a flat world, which means SS loses again; head wind, like hills, forces a change in torque to the road to maintain constant power at a lower speed. This is most readily facilitated using a multi-gear drivetrain.

Come on. Be real. Half my road riding is on fixed gear, training for track. It's pretty obvious which drivetrain is most efficient. The only way you can make the argument otherwise is if you take the rider out of the equation and consider just chain drive efficiency. But... nobody cares! The only zero loss drivetrain ever made was the penny-farthing, and you don't really see many of those around now do you?

Brian Ratliff

Also, I can pedal pretty much any gear at my self selected cadence. The question is whether I want to go fast (with lots of work), medium (with medium work) or slow (with little work). I can do any of those speeds on any of my gears with my self selected cadence on my road bike. You seem to believe that, because you have to gear a SS for hills/wind, that you'll work less on the flats because you go slower. Well... I can go slow on a road bike too.

krobinson103

I have to say that my geared bikes are easier than a single speed/fixed gear. I like to tour and climb steep hills with a heavy load. Theres no way on earth I could do that without walking on a SS. I can match the exact gear on a ss by selected the correct ratio and just not shifting.... exactly the same thing.

RollCNY

You have no idea what I believe. My hypothetical was posed to your original post, which got edited out. I did not say you go slower on the flat. I asked the hypothetical question (which you didn't answer) because in my experience, I go the exact same speed on flat ground regardless of SS or geared, provided my SS is geared to do that. I go slower on a course.

But you were too busy answering yourself to have an intelligent conversation. I am sure you can quote this multiple times in response to yourself.

RollCNY

I have light toured on my SS. 257 miles in two days. It is up there in the best two cycling days of my life.