Hot answers tagged performance
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The Pedaling Technique of Elite Endurance Cyclists: Changes With Increasing Workload at Constant Cadence was published in the International Journal of Sport Biometrics 7:29-53, 1991. However, it seems to come to the conclusion that they don't really make any difference as far as pedaling efficiency goes.
"...while torque during the upstroke did reduce the ...
11
Presuming you are doing a standing start and coming to a complete stop at the top of the hill. The simple requirement is you need energy to move your from the bottom to the top. Most of the energy required will be to raise potential energy of the payload (you and the bike). Essentially you will be creating kinetic energy (moving the bike) by converting ...
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Jan Heine performed some wind tunnel tests of "Real World Aerodynamics" a few years ago. A link to a blog post (and the results published in Bicycle Quarterly) can be found here. Those tests cover only one component (the aero drag component) of commuter-type bicycles vs. "racing" bikes.
If you want to make your own apples-to-apples comparisons of ...
8
The case for/against clipless, or even straps, is sort of summed up in this piece from the Rivendell Bicycles website. They mention studies, albeit without citing the exact source, that actually pulling up on the pedal is extremely unlikely, except maybe on short uphill or sprint bursts, and so being attached to the pedal is far from being a must. And they ...
5
I'm a commuter who has to carry things like books, a notebook, food for the day, bike lock, etc. I should say that it makes a striking difference whether you carry stuff on your back or on a bike rack -- a heavy bike is not as bad as a heavy backpack, in other words.
Another thing that I've noticed is that my performance decreases if I ride five days a week ...
4
Some factors that affect day to day athletic performance are:
the degree to which your muscles have recovered from previous strenuous work. It is impossible to push the pace everyday, and hit a consistent performance level. Day to day consistent performance is only possible (far) less than maximal effort.
symptom-free infections. It's possible for your ...
4
If I on one ride add 1 kg of weight to the bike, how much slower (in time) will I be?
Assuming that you and your bike mass 100kg (in round numbers), an extra 1kg causes a 1% increase in weight, i.e. a 1% increase in the potential energy associated with climbing the hill.
If your power output is constant, that implies a 1% increase in time.
However ...
3
It's not a study per se, but the Wattbike gym machine has a useful power output meter which shows the power being applied by each leg (explained in more detail on their website).
The basic premise is that by smoothing out the push and the pull you can see a visible effect on the power curve on the display. The real key (from personal anecdotal experience) ...
3
Alloy would save a tiny amount of weight. I wouldn't expect it to make any difference to wheel stiffness, so long as you lubricate the threads when building it (alloy nipples are stiffer to turn otherwise, so it's harder to get the tension right). Brass is stronger, but you shouldn't have to rely on that to get a stiff wheel.
But long term, alloy is more ...
3
A Wikipedia definition is pretty much applicable. Stiffness is how much things resist bending.
Stiffness is measured by measuring how much stuff bends when lateral force is applied. So, in the example of frame stiffness, you could put one end of the frame in a vise, horizontally, then hang a known weight from the other end and measure how much it sags.
...
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I'm late to this thread, sorry, but ...I've tested out all the folding bikes at my local bike shop, Dahon and schwinns mostly and ended up buying the Citizen Gotham Large frame. It's a 7 speed 22lb street cruiser, aluminum frame, with all the bells and whistles. I got the seat upgrade for $29 and makes a huge difference for long distance riding. All in I ...
2
There are two additional things that haven't been mentioned yet.
First, road rash is actually made worse by hairy legs. We all know that when you hit the pavement it acts like sandpaper scraping a layer off your skin. However, if you have hairy legs the hairs get pulled out by the root as well. This makes the road rash deeper where your skin actually comes ...
2
A "light" bike these days is around 16 lbs. Getting down to that kind of light weight involves a lot of optimizations-- it is not just the frame, but also the wheels, cranks, handlebars and everything else. The end result is something that is very nice but quite expensive. You won't want to leave a bike like that alone on a public street even with a good ...
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Stiffness is a frequent point of debate in cycling circles. For instance, touring bikes tend to still be made of steel rather than aluminum, because (among other reasons), for equivalent strength, steel is more flexible, and will absorb road shock better. A common complaint against early aluminum frames was that they were too stiff and rode too "harshly". ...
2
A Joule is a Newton-meter and is also a Watt-second. Gravity is about 9.81 Newtons/kilogram.
Raising 1 pound 1000 feet would be raising 0.4536kg 304.8 meters. So that would be 9.81 * 0.4536 * 304.8 = 1356 Joules, or 1356 Watt-seconds.
Your peak sustained energy output is probably in the general range of 300 watts (and "cruising" would be somewhere ...
1
Foot retention, in some form, has been around since the dawn of cycling.
There are multiple reasons for it:
Having a foot slip off the pedal during a hard effort is dangerous (especially on fixed gear bikes, but also during a race in close quarters). This isn't a risk at slow speeds, but at high cadences, it can be hard to stay on pedals without ...
1
I think you could take this technique pretty far, but probably not all the way (at least usefully).
I see a lot of use for the first part of your plan: taking multiple pictures and reconstructing a 3D model. If you try this for multiple postures I think it should be possible to determine an optimal position for you on your bike based on just looking at the ...
1
As already pointed out by the other answers, an additional kilogram is rather negligible when concerning purely the additional potential energy you need. But there are other factors where it may have a more or less larger effect.
Firstly that your body does not necessarily respond linearly to higher load. As long as you are in a region where you can do the ...
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Stiffness is important when you have long tubes as in a tandem or elongated recumbent and your frame is made of a flexible material like steel. The frame can flex, especially with the pedalling of a strong or heavy rider which can lead to metal fatigue over time and can be disconcerting to the captain. For upright singles it's a non-issue.
1
Allow my rather anecdotal answer, as for the third point in the question.
I used to ride a stock Trek VRX 400, did XC riding along with some jumps and drops. I was 18-22 years and I think my weight was around 120 lb. At that age the bike felt perfect, I loved that bike, I felt the bike very responsive, and each time I wanted to learn some new move, I felt ...
1
When I select a new bike setup i don't tend to look at the weight of the bike complete. If you want a faster bike for less money get a cheap 2nd hand frame and group set then swap out the "heavy" wheels that came with it and get some lightweight wheels.
There are a number of reasons for this.
1st, the heavier the wheel specifically the rim and the stuff ...
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