-5

For a broad spectrum of riding my answer is Yes. Here's my logic.

There are 5 major principals to consider in no particular order. Air resistance, drag, weight, rolling resistance (centrifugal or rotating mass) and Friction.

In all of those 5 principals, the single speed has an advantage. So much so, that you'd quickly find that you need a bigger gear ratio to maintain the same optimum cadence, thus maintaining a higher speed given that same cadence.

The breakdown. Geared bikes carry more weight. They also create more air resistance and drag. The derailer carries more weight, air resistance and drag. The derailer also creates more friction from the pullie cogs themselves and the action of the derailer adding the tensions involved. Granted, a single speed drivetrain also has tension and friction, but only over two points of contact, not four. The friction and tension over those extra two points of contact while small, in combination with other elements, becomes significant. Rotating mass plays it's part as well. The mass of the cassettes, the larger hubs and it's internal parts, the derailer pullies, all of it, adds rotating resistance. The chain being longer and heavier also adds weight and rotating mass thus creating resistance. The hubs, cassettes, derailers (front and rear) and chainrings and chain length, all create extra points air resistance and drag.

Add all that up... to a lot of deficits. Having gone from 22 speed to 1X 7,8,9 to SS to Fixed and back to SS. Here's what I've found:

My Commute times drop by 7 minutes on my 16 mile commute and 3 minutes on my 6 mile commute going from geared to SS. Why? Because for the same cadence I'm in a bigger gear ratio so my average speed is higher overall. On the hills I don't have a lower gear ratio to drop to, so I accelerate to the ascent and hold my cadence as long as possible. This does two things, I start the ascent at a higher speed and cadence and it forces me to power on to maintain the cadence. Without the lower gear I find I crest the hill faster as long as the grade isn't such that I fall out of my personal powerband. With gears I drop to lower ratios, so while it was easier to pedal up the hill, I was also doing so at a slower pace, much slower in fact. If you're not going up mountain hills constantly why would you want to stay on the hill any longer than you have to? The faster you get up the hill, the faster you get off the hill! I find I save more energy this way as well as saving time. Hills add the most time to a route. If I spend 20 second's on a hill SS and 30 seconds geared? I mean I could power up the hill geared but it would still be a lower ratio than the SS because of all of the power sapping deficits. I'd still get up the hill faster!!! And then I'd accelerate down hill. Granted if the hill is really long I might be able to catch myself.... Maybe. Sometimes. Most times no. I've tried. I have to work hard to do it though, meanwhile I'm resting on the descent on SS...10 seconds ahead.

But overall? Same cadence and higher gear ratio equals higher average speed. Descent speeds on average are more than nullified by ascent speeds and flats. Again this is as long as your hill grades aren't too steep. Then of course you're going to pass me by. It's also why I don't recommend Fixed for long commutes with hills, you don't get to rest and your decent speeds are drastically reduced unless you feel comfortable unclipping or unstrapping or skidding a lot.

And last but not least, Single Speeds make you a much stronger rider, physically. I'm always amazed at how much stronger I feel going back to geared, especially when climbing. You've just built up so much power.

Disagree? Let me know, why.

James McClellan ZEXX3S
  • 3
  • 1
  • 3
  • 4
    OK, now try climbing a hill. Or cycling into the wind (or with the wind, for that matter). – Daniel R Hicks Dec 28 '18 at 19:36
  • Well in the wind, you'll want to drop a gear. But you don't. You have to power through. I do it all the time. As for hills, read the whole explaination, I cover that. I ride hills all the time and blow by quite a few people dropping into smaller ratios while I'm powering up it. Again as long as the grade isn't crazy. If you have torturous, grades stay in your geared bike. I have hills but nothing I can't power up in the ratio I used. – James McClellan ZEXX3S Dec 28 '18 at 19:41
  • And wind? Really? If you can't power through the wind you're likely not as strong a rider as you think. – James McClellan ZEXX3S Dec 28 '18 at 19:43
  • 5
    April Fools Day isn't for another three months. – Daniel R Hicks Dec 28 '18 at 19:52
  • Oh really? I didn't realize? Gee? I thought it was next year already! Wait New year's Eve is Monday! Gee Whiz what was I thinking? – James McClellan ZEXX3S Dec 28 '18 at 19:54
  • Oh and you haven't explained how I'm wrong, if I'm wrong. Short rides and medium grade and length hills? I think I'm right. I know I am, as I've done the math, I've applied it to the real world changing through ratios and have seen the results. I currently ride either 44-16 in the winter or 46-16 during the summer. On weekends I ride my nicer bike at 48-16 and during events 50-16. I could go 48-15 but that requires a specialized hub and concurrent wheel builds and if I'm going there (I eventually will) I'm likely to get an Onyx hub and they are upwards of $450 to $500 alone. – James McClellan ZEXX3S Dec 28 '18 at 20:16
  • 1
    @JamesMcClellanZEXX3S You are misled because a) in the first half of your post you do not use any hard data, only your qualitative reasoning, which is as good as anyone else's reasoning until real-world data is available; b) in the second part of your post, you do provide some sort of data, but only for one data point — yourself. That data proves your statement for that point, and has nothing to do with the general statement you are trying to defend. – Grigory Rechistov Dec 28 '18 at 20:25
  • 1
    In the scientific method, one observes the world and makes a hypothesis about the nature of observed events (in this cases, dependency between bike's speed and gears). To check the hypothesis, one then conducts experiments in a controlled environment meant to minimize effects of factors non-accounted in the hypothesis. If the hypothesis still holds after that, one needs to check it many times in real world cases, preferably by many independent observers/experiments. Only after that a statement may be considered a theory with verified reasoning. You only did the first step. – Grigory Rechistov Dec 28 '18 at 20:31
  • 2
    I'm voting to close this question as off-topic because its not constructive – mattnz Dec 28 '18 at 20:40
  • 2
    You have to power through. Ummm. Yeah. Sure. Go get yourself a USA Cycling license and do a real race or two. Then try saying that. Hint: it don't work that way. – Andrew Henle Dec 28 '18 at 20:48
  • Single speed bikes appear a lot faster than geared bike because the peloton slows down and lets them ahead, hoping to a chance to turn of an loose them forever. If the peloton speeds up, the single speed is behind and sees when they turn off and follows like a bad smell. – mattnz Dec 28 '18 at 20:49
  • 1
    You're overthinking this. If you have access to both kinds of bikes, then try them out on the same route. – Criggie Dec 28 '18 at 21:00
  • 1
    @James : Comments are for clarification of questions, not arguing about them. Please take the tour https://bicycles.stackexchange.com/tour – mattnz Dec 28 '18 at 23:10
  • 1
    This is not a question, this is an argument masquerading as a question. – Adam Rice Dec 29 '18 at 01:04
  • 5
    I'm voting to close this question as off-topic because it is not a question asked in good faith. – Adam Rice Dec 29 '18 at 01:05
  • @JamesMcClellanZEXX3S did you read the [tour] ? Looks like not. Note that SE is a Q&A format, not a discussion forum. Opinions are unavoidable, but this looks to be the sort of topic where facts can be found to fit all opinions. Can your question can be asked more specifically? – Criggie Dec 29 '18 at 01:51
  • 1
    I think a power meter on both kinds of bikes might show you interesting numbers - I'd bet you're putting in more power on the singlespeed, and therefore less able to endure. – Criggie Dec 29 '18 at 01:52
  • Possible duplicate of https://bicycles.stackexchange.com/questions/1983/why-ride-a-single-speed-bike – Criggie Dec 29 '18 at 09:07

3 Answers3

5

I strongly suspect you are faster on your single speed on your commute because there is a psychological effect of being on the single speed bike that makes you work harder or cycle more effectively.

You cannot say that the single speed forces you to be in a higher gear than the geared bike on hill. I'm sure the geared bike has the same approximate ratio available the single has (an higher), so if you have the power to ride up a hill in a higher gear just do that on the geared bike.

Update to make this a real answer rather than what should have been a comment...

For a rider to be fast, what we care about is absolute power at the rear wheel not efficiency. A more more powerful rider on a slightly less efficient bike is still faster than a less powerful rider. What derailleur gears do is enable the rider be more powerful on average, over a range of resistance levels (aka hills) by allowing them to ride at their most powerful cadence for a given resistance.

Argenti Apparatus
  • 75,665
  • 4
  • 86
  • 188
  • Argenti. No the same power output and cadence with the same ratio on a Geared bike is not the same as on SS. The power drain from the 5 principles says it is not possible. Friction and rotating mass alone should tell you immediately that this is so and that the drivetrain of the Single Speed is more efficient. – James McClellan ZEXX3S Dec 28 '18 at 20:48
  • 3
    @JamesMcClellanZEXX3S Friction losses at any decent speed on any decent bike are negligible compared to aerodynamic drag. "Rotating mass" vs "non-rotating mass" is bogus - mass is mass. And the difference in mass of a fixed vs a geared bike isn't all that much. – Andrew Henle Dec 28 '18 at 20:52
  • Argenti. Umm what you just said goes against just about every principle if Physics. It's why lighter wheels tires, tubes or lack of tubes is important. The principle doesn't up and die because it's not on the wheels themselves. Crank circumference & weight, cassettes and how many cogs, their circumferences & weight. The chain, its length & weight multiplied by crank and cog circumference and so on... It takes energy to move anything. With wheels, the bigger the wheel and the greater the mass dictates how much energy is required. That is the principle of centrifugal forces - rotating mass – James McClellan ZEXX3S Dec 28 '18 at 21:20
  • Also I didn't say the greater efficiency forces you into a greater ratio. But if you want be as efficient with your cadence and power output you increase your ratio and thus gain a higher speed. But it's your choice to do so. – James McClellan ZEXX3S Dec 28 '18 at 21:28
  • 1
    Comparing different forces and neglecting those that are very small in comparison to others certainly does not go against "any principle of physics". This approach is approximation and it is at the very core of anything but ab initio approaches to the most fundamental problems. – gschenk Dec 28 '18 at 21:31
  • @JamesMcClellanZEXX3S It takes energy to move anything. With wheels, the bigger the wheel and the greater the mass dictates how much energy is required. That is the principle of centrifugal forces - rotating mass Do the actual math on the amount of energy "consumed" by rotating mass vs non-rotating mass. Others have - the links are in my answer. The difference is literally something like two or three orders of magnitude smaller than the energy used to push the bike and rider through the air. It simply doesn't matter - and it's been measured not to matter. That's also in my answer. – Andrew Henle Dec 28 '18 at 21:38
  • @Andrew Henle It does matter. Singularly no it's miniscule. Add that miniscule number to a bunch of other miniscule numbers you start getting a lot of numbers. And they all take share of your performance away. Aero frame, wheels, derailers, cranks, seats, handlebars, etc. And now it's dimples like on golf balls and cars under trays. That's just aero. Cars also use lighter wheels to lower unsprung mass and rotating mass. 1/4 here 1/8 here and there adds up when converting to watts. And friction is a big one too. Stiffness in the bottom bracket and cranks. All of it gets considered. – James McClellan ZEXX3S Dec 28 '18 at 22:34
  • You can't leave it out because it doesn't fit with the argument as a whole. You both choose singular instances ignoring the rest. When as a whole and in combination they do count. One wouldn't be a very good team captain for a bike team or any racing team when such things are taken into consideration. Just because it's not a race doesn't mean it doesn't count. They all count. And they are noticeable. I've researched it and ridden both. Back to back over a week back and forth. It really doesn't take that long though. You know immediately. – James McClellan ZEXX3S Dec 28 '18 at 22:38
  • "Comparing different forces and neglecting those that are very small in comparison to others certainly does not go against "any principle of physics". This approach is approximation and it is at the very core of anything but ab initio approaches to the most fundamental problems.". – James McClellan ZEXX3S Dec 28 '18 at 22:41
  • "Comparing different forces and neglecting those that are very small in comparison to others certainly does not go against "any principle of physics". This approach is approximation and it is at the very core of anything but ab initio approaches to the most fundamental problems." ROFL! You can't be serious! Comparing different forces and ignoring those that are small does go against all principles of Physics. You must consider everything. That is the most untrue thing of all the arguments so far. Especially when talking about physics. Your wattage modifiers isn't just aero alone! Seriously? – James McClellan ZEXX3S Dec 28 '18 at 22:51
  • Anyways. Gotta hit the bar. Useful information on both sides. I saw another article where the author said that fixed gears don't have brakes.... SMH! – James McClellan ZEXX3S Dec 28 '18 at 23:24
  • 1
    Argenti, you should add a definition of "power". I suspect that Opie misunderstands that concept. – Daniel R Hicks Dec 28 '18 at 23:35
  • @JamesMcClellanZEXX3S I saw another article where the author said that fixed gears don't have brakes.... SMH! That's because they don't: "1.3.025 Freewheels, multiple gears and brakes are not permitted for use on the track during competition or training." And as I noted, often good riders will ride a fixed-gear track bike in competitive group rides - for the express purpose of riding a slower bike and getting a tougher workout. – Andrew Henle Dec 28 '18 at 23:45
5

This deserves to be up front:

The bike with the faster rider on it is faster.

But...

In general, a geared bike will be faster than a single-speed bike.

Friction losses and weight differences are negligible - if they exist. A single-speed bike can very well be heavier and lose more power to friction than a geared bike. And on good bikes of either type, the losses are negligible anyway.

Assuming such a thing as "optimal cadence" exists, it should be obvious that gearing enables a cyclist to ride at optimal cadence for the best power generation over a much wider range of terrain.

So, does "optimal cadence" exist?

Yes it does.

Some of the many peer-reviewed, published scientific research on cycling cadence:

Optimal cadence selection during cycling

Effect of cadence selection on peak power and time of power production in elite BMX riders: A laboratory based study

Determining optimal cadence for an individual road cyclist from field data

The relationship between cadence, pedalling technique and gross efficiency in cycling

And yes, rotating vs non-rotating mass is a bogus differentiation:

The influence of flywheel weight and pedalling frequency on the biomechanics and physiological responses to bicycle exercise

... Measured physiological, subjective and biomechanical indices did not change significantly with flywheel weight. ...

More on "rotating mass"

Rotating mass, the math and the myth...

he effect of the rotating mass on a bike is less than 2% of the energy required to accelerate to a reasonable speed the masses involved

and

Wheel Performance

...

In summary, wheels account for almost 10% of the total power required to race your bike and the dominant factor in wheel performance is aerodynamics. Wheel mass is a second order effect (nearly 10 times less significant) and wheel inertia is a third order effect (nearly 100 times less significant). ...

Like I said - mass is mass. Rotating or not simply does not matter.

And finally:

Good cyclists who want a harder ride will show up to group rides on their single-speed bike instead of their geared bike.

Andrew Henle
  • 10,539
  • 1
  • 22
  • 37
  • I have never said that optimal cadence doesn't exist. I've mentioned that it does several times. As for the articles you speak of. If all of that took into consideration all that I have said then velodrome long distance races would be done on geared bikes. They do not. Fixed gear and single speed drivetrains are always more efficient. Rotating mass is real. Otherwise you wouldn't be buying those $3000 rims for those $15000 bikes. – James McClellan ZEXX3S Dec 28 '18 at 21:39
  • Rotating mass is used to measure and dictates how much energy is needed to complete a rotation. That energy is taken into consideration in the most advanced power meters used today and make them much more accurate. – James McClellan ZEXX3S Dec 28 '18 at 21:40
  • 2
    @JamesMcClellanZEXX3S Otherwise you wouldn't be buying those $3000 rims for those $15000 bikes. I'll quote the research again: "In summary, wheels account for almost 10% of the total power required to race your bike and the dominant factor in wheel performance is aerodynamics." That's what you're paying for with $3,000 wheels - aerodynamics. – Andrew Henle Dec 28 '18 at 21:41
  • 3
    @JamesMcClellanZEXX3S Rotating mass is used to measure and dictates how much energy is needed to complete a rotation. That energy is taken into consideration in the most advanced power meters used today and make them much more accurate. Again - do the math. It's simple physics. The energy difference in accelerating rotational mass vs non-rotational mass is measured in the low-single digit watts. As in like two or three. And you display an alarming misunderstanding of inertia - once those "rotating masses" are accelerated to a steady-state speed they don't use more energy. – Andrew Henle Dec 28 '18 at 21:44
  • And to say that it does not matter is nuts. Yes aerodynamics is prime with regards to overall speed with the wheel. It's the leading edge of the bike and creates drag and thus turbulence for the rest of the bike behind it which then dictates the shapes of the leading edges of the bike itself. Not disputing that at all. We are talking about drivetrains efficiency and where your power is first directly influencing the bicycle before the wheels even becomes a consideration. Bottom bracket stiffness, crank arm stiffeness, crank weight, chainring, chainring weight, rear cog, cog weight etc – James McClellan ZEXX3S Dec 28 '18 at 21:48
  • @JamesMcClellanZEXX3S Again, I've posted links to research that actually calculates those things. I've posted links to research that actually measured the differences those things might make. And they all point to: the differences are negligible by calculation and can't be measured by experiment. And you have what? – Andrew Henle Dec 28 '18 at 21:51
  • And then you get into aero deficits with the whole geared assembly. The weight. The friction. The two latter being more involved before aero even is a factor. – James McClellan ZEXX3S Dec 28 '18 at 21:51
  • Put it this way. Identical bikes wheels and all except one is SS and one geared. If design is less effected by specification then less mass effected by aero should say the SS is more aero. On the SS the wheelset on the rear will be lighter, theirs no gears so that makes the bike lighter overall and the drivetrain is more efficient. I'll ride 49/16 or 46/16 depending on terrain. If I was Geared I'd be riding 38/12 or 14 or 54/18 or somewhere around there most times on the flats. Geared my ratio is actually lower. On rises, Geared I'd drop down. SS, I accelerate and stand up. 20 miles? Faster. – James McClellan ZEXX3S Dec 28 '18 at 22:05
  • 1 or 2 Watts is a lot dude! If all aero is equal with the same wheels. And that's just the wheel. They equate 4 Watts of lost power from just the friction of the derailer assembly. How far is that would you say over a hundred miles with say. 250 Watts of power and a cadence of say 100 to make it easy. Take 4 Watts away and look at the time. – James McClellan ZEXX3S Dec 28 '18 at 22:11
  • 2
    @JamesMcClellanZEXX3S -- You said Rotating mass is used to measure and dictates how much energy is needed to complete a rotation. Bullshit. Rotating mass affects acceleration, but it has nothing to do with the energy required to complete a rotation. – Daniel R Hicks Dec 28 '18 at 22:30
4

An ability to formulate a seemingly non self-contradicting yes/no-typed question does not make that question answerable with a "yes" or "no".

It is like that 1/x = 0, find x math problem is not answerable with a numerical x.

You might expect that for your title question, one would argue that exactly one of three possible outcomes is true:

  • single speed bikes are faster than geared;
  • single speed bikes are slower than geared;
  • single speed bikes are as fast as geared.

The reality is, none of these alternatives is true.

There are certainly cases when single speed is faster: all track competitions in closed venues are done on single-cog fixes. Single speed is also faster with your legs on your bikes on your commutes if you believe so.

There are certainly cases when geared bikes have speed advantage. The major road race and mountain bike competitions have all competitors on geared bikes. And they are not disillusioning themselves — a lot of money is on stake, and a lot of professionals prepare bikes and athletes to be the fastest. Let me remind you that historically, the first Tour de France were done on single speeds, simply because competitors had no other choice. But as soon as geared options become available, and despite certain resistance of the race organizers, competition moved to geared systems.

There were situations at downhill competitions when a bike with a broken and lost chain won the first place. There are benefits to lack of chain, like better operation of rear suspension. But I assume no one would argue that chainless bikes are "faster" than their chain-handicapped counterparts. After all, it was the rider's skill that brought a victory.

All in all, I am happy that you have so much fun on your single speed bike, because I enjoy mine also, and they certainly are a lot of fun, even if faster/slower/whatever.

Grigory Rechistov
  • 14,297
  • 2
  • 29
  • 59
  • Yes, but the pro bike races you speak of are really long races. Even the shorter stage time trials their ratios are single step and many only use 7 cogs and many pros sit in only one ratio the entire stage in those. But for short 5 to 20 mile rides with minimal hills? I'm not talking your weekend 50 mile or century rides where yes you'd likely do a little better with a geared bike considering the terrain. Buy I've done those around her in the Washington DC metropolitan area. It's not flat by no means and I've done them single speed I was fine. – James McClellan ZEXX3S Dec 28 '18 at 20:20
  • 3
    Your original statement and reasoning says nothing about the distance. If distance plays a role in definitively answering your question (which, I reiterate, has no answer), then what is the distance limit when single speed becomes worse/better than something geared? 10 miles? 20 miles? Or maybe it should be kilometers? If such limit exists, then there must be a mathematical equation that allows to find it. Do you know such formula? If you state that something exists, the best proof is to show it. – Grigory Rechistov Dec 28 '18 at 20:34
  • As for how I worded the question, it was in response to a previous similar question that I read here where the question was inadequately answered, but because of the rules regulating this forum I couldn't add my own answers to. The wording itself? What's the big deal? Is it a pet peeve of yours? It's a simple question. There are many answers to it and it's been asked many times. I've made points and gave my pros and cons. And none or exaggerated or untrue. The 5 principals differing SS from Geared are known and scientifically provable by yourself and have been proven otherwise. – James McClellan ZEXX3S Dec 28 '18 at 20:34
  • @JamesMcClellanZEXX3S yes, it is a simple question, and I believe I answered it. – Grigory Rechistov Dec 28 '18 at 20:36
  • Well distance is a factor mainly in calculating for what is most efficient over long distances. If the surface is smooth, no hills, your own personal strength/ endurance you could calculate your power output over a distance and gauge whether fixed, single speed or geared bike would be more optimal. What gear ratios were optimal... everything. It could be calculated easily with power meters and split times. With hills it would be the same. There would be no impediment if you wanted conclusive and undisputable evidence. But personally, you'll know your own body and be able to tell on your own. – James McClellan ZEXX3S Dec 28 '18 at 20:42
  • Put it this way. Gears only make you more efficient going up or down a hill when considering a rpm you are trying to keep to. That Rpm can be modulated given the length of the ride and the hills one needs to climb or decend. But on a flat surface their is no way a geared bike is faster. It's heavier. It has more friction. It has more drag. It has more air resistance. It has more rotating mass. Period. On average given your own personal strength, as long as the ride doesn't have too many high grade hills and isn't very long in length for you personally, a SS is better. – James McClellan ZEXX3S Dec 28 '18 at 20:58
  • 2
    @JamesMcClellanZEXX3S But on a flat surface their is no way a geared bike is faster. It's heavier. On a flat surface, even if the geared bike is heavier, that minimal weight difference simply does not matter. Speed on a flat surface is pretty much determined by power vs drag. It has more friction. Where does a geared bike have more friction? Pedals are the same. Wheel bearings are the same. Crankset bearings are the same. Chain losses? Again, the same. I want you to explain where a single-speed bike has less friction losses than a geared bike. It should be good. – Andrew Henle Dec 28 '18 at 21:23
  • 1
    The derailleur and cassette might increase drag. Drivetrain friction might also be slightly higher. Increased weight likely increases friction losses in hubs and rolling resistance. However, as you said before, we are talking about very small reduction in efficiency that may easily be outweighed by biomechanic gains from close to optimal gear ratios. Including a more aero position. – gschenk Dec 28 '18 at 21:46
  • @AndrewHenle I'll give him that there is more friction in a derailleur system - smaller sprockets, longer chain going around jockey wheels, and chain off a dead straight chainline. Still small compared to drag though. – Argenti Apparatus Dec 28 '18 at 22:45
  • 1
    @James. Comments should only be used for clarifying answers. If you do not like the answer, you down vote it, and/or post your own answer and let the community decide. – mattnz Dec 28 '18 at 23:10
  • I think he already included his own (wrong) answer in the question. – ojs Dec 29 '18 at 12:13