We seem to always be searching for ways to increase the efficiency of our bikes. Weight reduction is one way, better gearing and faster tires is where so many of us spend piles of money. The commercial manufacturers seem to have gotten the state of the art carbon or titanium bikes down to less than 20 lbs. but more than 15.

What is the most efficient bike you've ridden? What feature about it impresses you the most?

That Boreas I have is about as efficient as I can get it----For me. 15 1/2 lbs- Wheels that stay true and coupled with the tyres roll well- Bars that fit perfectly whether I am in the drops- hoods or on the flats. Brake levers that just fall naturally for the hands and the change levers are just natural. Saddle and 50 milers and I don't even feel it and the crankset is just right on Crankring difference for my cadence and Crank length is perfect. All I have to do is get me working efficiently and it would be perfect.

So why is it that the TCR- that is set up with the same components- same position and setup just doesn't work quite as good?

Check out the human-powered vehicle races. Those guys can go a lot faster than regular racing-style bikes because they are free of the UCI restrictions (especially for aerodynamics, which is more important than weight most of the time). 80mph has been achieved over short distances.

You can focus on this aspect too much. Bikes are very efficient. I recall reading an article in Scientific American about Bicycle Physics years ago. They had the then standard professional racing bike. With their standard rider (a certain weight and certain horse power), the bike went something like 32 mph. The most tricked out bike available at that time went 33 mph with the standard rider. The perfect bike which was weightless, frictionless and had no wind resistance went 34 mph.

The biggest limit on bicycle top end speed is wind resistance and most of that is caused by the rider. Putting the rider into a faring and prone is about the best thing to do, but it does not seem to be very practical for riding on the road.

Some years back, I used to ride with a fast group. Almost every bike in the group was Dura Ace with a few Campys. I was riding 105 which was viewed with disdain. The guy who was easily the strongest rider in the bunch was riding Tiagra.

Training and keeping your weight down will have far greater effects then spending $$$$$$$$ on the bike.

Now if you are an elite cyclist and are competing against other elite cyclists, the small gain you get from a really high end bike is well worth it. I don't bother because I sort of suspect that if I have not made the Tour de France by now, it ain't happenin.

The rider will be the most important factor to improve efficiency: training, diet, weight, life style, etc.

What's most efficient will depend on the test criteria. On the flat being more aero at the expense of weight is more effective. Going up hill, lighter is more efficient. Look at what the pros ride; light climbing bikes, TT bikes... Those are the most efficient bikes within the technical constraints of the sanctioning bodies.

Yup, as above, its the Indian, not the Arrow!

I like the Specialized Tarmac in SWorks trim for efficiency. As a climbing bike I can't think of a better production frame. I don't have one though I may be getting an SL4 soon. It's not the bike that makes me go but every bit helps. I agree the lower trimline groupsets shift quite well. I do believe that DA does have a better tactile feel, smoother, with slightly less effort required to activate. But as far as moving the chain, there isn't too much between the low end and the fancy stuff.

I was most impressed with deep carbon wheels I borrowed for a century ride. I'd love to have a set though I find the cost prohibitive.

"The most efficient bike" will have to propel its rider the most distance on the least fuel; so, it must be light AND sturdy. Light, to take less energy to pedal; sturdy, to last long enough to to recoup the initial investment.

Bicycle: $80-15,000.
Food/Fuel: variable, anywhere from $0.15 for a pack of ramen noodles to $1000 for a political fundraiser.
Joy of riding: BEYOND priceless!

So, my answer is, my Jamis Dakar XLT 1.0; 34 lbs., 5.7" suspension travel, 27 speeds, dual discs, and never less than 2.0 wide tires. For over four years, it carried me through joy and pain, sunshine and rain, everywhere I needed and wanted to go. When the frame died, I cried.

I may come up with a different answer, but your reasoning is flawless, IMO.

In the motorcycling world young guys are constantly asking what modification will make their bikes faster. The answer is always "learn to ride it." Nothing better than a track day for motorcyclists. +1 on the training, diet, weight, life style thing.

To answer the question, a time trial bike is the most efficient bike that can be purchased at retail. Some recumbents are also very efficient. However, you give up very important performance and comfort needs to get a small gain in efficiency.

As someone pointed out the most efficient bike CANNOT be restrained by rules set up by the UCI and other cycling organizations. They only hold back and cater to big money in the manuf arena. The simple fact is that the most efficient bike is a recumbent streamliner.

xizangstan, What a simple question, but one that could branch off in a dozen or more directions.

Just another way to look at the question:

If one's looking to convert X amount of power into speed, an aero'd trike is hard to beat.
If one needs to haul large and heavy loads, then an extended tail utility bike has to be near the top of the list.
If one is looking to go downhill in the shortest amount of time an engineless hybrid mix of a motorcross motorcycle/mo ped, sans engine, is the formula.
When constrained by some set of rules, then it's the rider that has to become more efficient... which is is the best path to follow anyways.

As diamond frame bicycles and recumbent bicycles are basically an engineering compromise on the two wheeled theme, perhaps the most efficient bike is that middle of the road CX bike. It can carry a load, perform roadie duties and work well on non technical off road romps.

Brad

IMO, there are two manufactures who have public information that does a good job of framing the answer to the question - Cervelo for frames https://www.cervelo.com/en_us/enginee...presentations/ and HED for wheels https://www.hedcycling.com/aerodynamics.asp .

On the Cervelo link click on the aerodynamics. They discuss their aero and climbing bikes and discuss the tradeoff. I own a Cervelo R3. For my terrain and power, a lighter bike is better than a more aero bike. What is interesting is the break point where lighter bicycles are better than heavier more aero bicycles. For professional and elite cat 1,2 cyclists it is an 8% grade. For 250 watt cyclists, it is a 5% grade. Since most riders here are under 200 watts, the climbing advantage will be greater on shallower grades.

Therefore, a lighter and more aero bicycle will provide the weakest riders with the most advantage on a percentage basis. The same is true for wheels. Which is why I think recreational cyclists feel more impact from better equipment.

IMO, I have the most efficient bicycle for my terrain and riding style and I put on different wheels depending on the conditions to further optimize the results.

The find "The most efficient bike available" it is necessary to design a bicycle with the least rolling, mechanical, and wind resistance possible.

That said, I envision a bicycle that is not to comfortable to ride. Humans don't bend like that!

Based on the Cervelo white paper, I should be on an S series, as the toughest climbs here average no more than 4%. But nothing will have near the impact of increasing my FTP/Weight. I raced this past year at 195-197#. I'm thinking I will keep myself under 190# for next season, and that I'll still be able to increase power while doing that.

That depends on the road, on a baby bottom smooth freshly paved road, the most efficient bicycle looks very different then it does on a muddy cow path, and that looks different from a bike that is built for gravel or chip seal.

Duh.... But we are not talking about rider weight. This is about bicycle efficiency. IMO, lowering rider weight and improving the engine is a given and obvious.

Where is Blazing Pedals?

My Gunnar Street Dog, that I had built eleven years ago. The fixed gear is very efficient, but I will agree with anyone who says it is not for everyone. As I have stated before, I don't get to ride as much as I would like, and riding a fixed gear gives me a workout that I would get from a multi-gear drive train.

I know, I know,,, I'm tempting the "fixie bashers". So be it.

That makes no sense. With no friction and no wind resistance there is no practical limit to a bikes speed except gearing and cadence, because there is no resistance slowing the bike down you can basically accelerate nearly effortlessly until you run out of gears.

You still have the aero drag of the rider, which is the largest single factor at speeds above 15mph. However, the 32, 33, 34 data points are questionable.

Me too! Improving the power to weight ratio of the engine is the best way to improve efficiency.

Marc

Of course... no argument.. and you are the expert when it comes to any type of efficiency. I'm just saying I have a ways to go before the decision between whether my bike is a bit more aero, compared to being a bit lighter, will be a big factor. The percentages gained in either area are very small for me, as I weigh comparatively a lot and am not yet very aero. My size probably gives even more of an edge to aero over weight. I believe I can increase my aero efficiency a greater percent than I can decrease bike weight as a percent of my total weight. The paper points out how small the percentage gains are compared to rider influences, but I'm not saying they aren't important. If you want to win, then any advantage or disadvantage is important. And the paper doesn't take into account the amount of time a rider might spend in the wind compared to the average. If you get dropped a lot, you need aero!

And I have a week to decide whether to participate in a team buy. Big discounts on either the Scott Foil, the Cervelo S5 (or R5), or an ultralight Guru Photon in team paint. The Cervelo geo suits me better, but of course I wouldn't get a chance to ride any of them in a size close to what I need.