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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 ...

There are some bike hubs containing an electrical motor inside. If you google "bike hub motor" and take a look at the images, you'll get the idea. I think these ones are ideal since they require minimal changes to the overall bike structure, allowing for normal riding if the motor is not working, and they don't burn evil oil: you just plug the bike to the ...

Your question is simple but a full answer is complex. The simplest answer is to point to Part 2 (especially chapter 4) of Wilson and Papadopoulos (2004), or the recent review by Debraux et al. (2011), or the paper by Martin et al. (1998). However, even these papers do not cover approaches that take better advantage of the data available from modern bicycle ...

According to the FAQ on their website: Note: PowerTap hubs must be laced with a minimum 2 cross pattern to avoid damage to the hub and maintain the warranty." That suggests that making the non-drive side radial could lead to warranty issues. Radial lacing does stress the flange more than tangential lacing so many hub manufacturers do not allow it. To ...

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 ...

I found this image of the first SRM power meter interesting: The crank is rigged up like a lever (rotating around the spindle) - the more forcefully you push the pedal, the more the strain-guage bends, the output of which is used as part of calculating wattage (as is better described in the other answers!) Many modern power-meters are essentially ...

If you could find several long hills of different but relatively constant (and not too steep) slope, then determine the slope and your terminal velocity on each hill (assuming that velocity is below some safe speed), you should be able to do the math to determine aerodynamic drag (working on the reasonably valid assumption that rolling resistance is ...

I will presume you are asking about the types of trainers that one mounts one's own bike onto, and not a dedicated "bike" trainer such as a Monark ergometer or a CycleOps Indoor Cycle (ergometers such as these are used in exercise physiology laboratories and can be calibrated to be very accurate). Consistency and Accuracy of Speed Measurement Accurate ...

Take a look at TrainerRoad.com to see if your trainer is on their list and you may be able to use a Speed/Cadence sensor with an ANT+ USB stick in your computer to use what they call "Virtual Power". They don't actually measure your power output, but based on known power curves of the trainer at given speed/cadence they run through some formulas to give you ...

MY first thought was MTFU and get fitter pedalling further. It might not be as hard as you think once you get used to it. However, for a 20k commute, definitely go with an electric hub motor. Loads available off the shelf. Easy to fit and use, very economical and reliable with low/no maintenance. Also nice and quiet.

Jan Heine & crew at Bicycle Quarterly recently reported the results of their wind tunnel research. A summary is available online, but the full results are only available in the printed journal.

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 ...

I have built a Sheldon Brown POWerwheel to a home-made recumbent I have (photo). Although the idea seems a bit absurd (two leading spokes for each trailing spoke), it worked great for years without any issue, gave a very discrete visual (you only notice it is a powerwheel if you look close), and in the end it is possible that it actually MAKES a difference ...

I believe you are asking two different questions: the first, how to use Coggan's Power Profile; and the second, given power at one duration, how to extrapolate and predict power at other durations. But first, an historical aside: Coggan's Power Profiles pre-date the publication of his book with Hunter Allen so really should be thought of as Coggan's own. ...

As others have pointed out, this is unlikely to bear any resemblance to the actual resistance at 80 rpm, but if you wanted to turn your numbers into watts, the formula would be: P[W] = F[N] * l[mm] * w[rpm] * 2 * pi / 60,000 P[W] --> Power [in Watts] F[N] --> Force [in Newtons] l[mm] --> Crank length [in mm] w[rpm] --> Cadence [in rpm] For ...

I find that my 8 minute TT outdoor tests always result in a higher wattage average. Even comparing PowerTap to SRM will result in some differences, but if the trainer gives you repeatable wattage's (as well as always pumping the tire to same psi and set same resistance of trainer to your tire), then you can do your indoor training based on those numbers ...

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 ...

There is a new website/download/software package called TrainerRoad that will allow you to train with Virtual Power for the price of a Trainer, ANT+ stick, Speed/Cadence sensor and $10/month subscription. Checkout the compatible hardware page (linked on the main page) to see if you already have a trainer on their list of known power curves. If not the Kurt ...