Investigating Aerodynamic Factors in Cycling Performance

[australianschoolkid]

Hello all,
This year once I go back to school, (late January) I will need to complete a piece of assessment called an extended experimental investigation (EEI), I was terrible in a similar assignment last year and was lucky to just pass. This is my last year of schooling and most important. I want to try and get the best possible mark, and as this is a major piece of assessment I want to start early. So I am writing for ideas, hopefully I want to investigate something very interesting, I love maths so the more equations the better, so any ideas?


An EEI has these characteristics:

·It is extended. An EEI occupies considerably more time than the usual physics practical. An EEI may continue for months and will continue in the background of your normal Physics lessons (as well as your other subjects). You will still be expected to do homework, study for exams, carry out practicals and complete other forms of assessment while the EEI is underway.

·It is experimental. An EEI requires you to conduct an experiment and to collect data. The data will be qualitative or quantitative observations of some particular phenomenon made by you (not by someone else as is the case for a purely book or internet researched project).

·It investigates some phenomenon in the physical world. You will be expected to analyse your data and to draw conclusions. You will discuss whether your results support your hypothesis or not.


Please any questions please ask, my friend is very much into cycling, so maybe some sort of experiment to do with cycling?


Cheers Matt

 

[chroot]

Cycling actually could lead to an enormous number of experiments. (I'm also a cyclist.)

Perhaps you could do some physiological experiments with a heart rate monitor, like measuring power output at various heart rates. You could do physics experiments, like measuring drive train power loss, or determining whether or not wheel weight or aerodynamics really matter. You could design, build, and test a better bicycle headlight and battery system. There are many possibilities -- I'll try to think of some more.

- Warren

 

[andrevdh]

If you don't mind to be up and out while others are sleeping. Have a look at the Amateur Reseach link.

http://skytonight.com/resources/internet/3304931.html"

 

[australianschoolkid]

Wow thanks for the ideas Warren. My cyclist friend has roller's (I think that’s what they're called, so a bike can be ridden in the one spot) and I am forever selling heart rate monitors at the local sports store where I work. In particular like the idea of looking at the measuring power output at various heart rates. One variable could be the gears of what the bike is in, I’m also looking at another variable, maybe I could look at the participants, and have a large person and then a lean person. How could the power be measured? We have briefly brushed over power early last year I remember that it all has to do with work, which may be able to be found by looking at force and distance. I really like this idea. Could you go into any more detail of what could be expanded on? I also am a keen physical education student so this sort of topic seems right down my ally.

Thanks
Matt

 

[australianschoolkid]

I was also thinking we could include the participants body temperature.

 

[chroot]

Well, if you look at the design of commercially available power-meters -- the kind you can mount on a bike, like the PowerTap -- they work by measuring torque and wheel speed. Torque times RPM = power. You can probably build the same kind of apparatus (though it won't look as well-engineered as a PowerTap) with fairly modest components.

On the other hand, your power meter doesn't have to be mounted to the bike, so you can make things quite a bit easier. You already have a trainer (rollers), which already includes some kind of resistance device to load the cyclist. All you really need to do is calibrate this resistance device -- make some measurements to find out how much torque it requires to spin at a specific RPM. After you've calibrated it, all you have to do is look at the RPM of the cyclist's wheels, and you know how much torque he's producing, and therefore how much power he's producing. You should be able to use any rear-wheel mountable cycle computer to measure wheel speed, so it's a pretty simple matter once you've calibrated your trainer.

The calibration would be the hard part -- you need some way to apply a known torque and measure the resulting RPM. First, check the trainer's manual -- it might even have a torque/RPM curve in it! If not, you might have to think of some clever ways to make this measurement. The one that comes to mind immediately is to use an electric motor to drive the trainer's resistance. You can measure the motor's current consumption, and calculate its torque. Unfortunately, you'd have to spend some money buying the motor and so on. You might be able to scavenge a suitable electric motor from an old blender or vacuum cleaner, however.

A mechanical engineer can probably come up with a better, easier way to calibrate your trainer, so perhaps one of them will chime in.

- Warren

 

[berkeman]

Do you perhaps have access to a wind tunnel that would hold a cyclist? If so, there was an extremely interesting program on TV back during Lance Armstrong's final Tour de France win that showed all of the aerodynamic work that the team did before the Tour to fine tune all the parts of the bike, rider postions and apparel to minimize the wind drag. Really fascinating what-all they came up with. And they kept saying that this little bit of drag reduction here corresponds to a 5-minute (or more) faster time in the XXX km race...

You could gather data on the bike rider in different positions, and wearing different gear, etc. If you're interested, I could try to see if I could find a link to the show.

 

[australianschoolkid]

Well, if you look at the design of commercially available power-meters -- the kind you can mount on a bike, like the PowerTap -- they work by measuring torque and wheel speed. Torque times RPM = power. You can probably build the same kind of apparatus (though it won't look as well-engineered as a PowerTap) with fairly modest components.

On the other hand, your power meter doesn't have to be mounted to the bike, so you can make things quite a bit easier. You already have a trainer (rollers), which already includes some kind of resistance device to load the cyclist. All you really need to do is calibrate this resistance device -- make some measurements to find out how much torque it requires to spin at a specific RPM. After you've calibrated it, all you have to do is look at the RPM of the cyclist's wheels, and you know how much torque he's producing, and therefore how much power he's producing. You should be able to use any rear-wheel mountable cycle computer to measure wheel speed, so it's a pretty simple matter once you've calibrated your trainer.

The calibration would be the hard part -- you need some way to apply a known torque and measure the resulting RPM. First, check the trainer's manual -- it might even have a torque/RPM curve in it! If not, you might have to think of some clever ways to make this measurement. The one that comes to mind immediately is to use an electric motor to drive the trainer's resistance. You can measure the motor's current consumption, and calculate its torque. Unfortunately, you'd have to spend some money buying the motor and so on. You might be able to scavenge a suitable electric motor from an old blender or vacuum cleaner, however.

A mechanical engineer can probably come up with a better, easier way to calibrate your trainer, so perhaps one of them will chime in.

- Warren

Well no unfortunately we don’t own a power-meter and my friend tells me he don’t think we will be able to afford one either. As for making one I think I might struggle, but it could be an option. Calibrate the resistance of the trainer I think sounds like the way to go, as I think I could go into the physics theory behind this, rather then just using a meter type device. I am seeing my cyclist friend tonight so will ask about his trainer.

So next problem - Calibrate the resistance of the trainer.
I have a rear-wheel mountable cycle computer, so that can be used once we can calibrate the trainer. As for an old motor I think I may be able to get my hands on one, will have to go looking!

I am going to look up torque so I know a bit more of what I’m talking about.

Thanks for your ideas again! You are a great help!

Matt

 

[australianschoolkid]

Do you perhaps have access to a wind tunnel that would hold a cyclist? If so, there was an extremely interesting program on TV back during Lance Armstrong's final Tour de France win that showed all of the aerodynamic work that the team did before the Tour to fine tune all the parts of the bike, rider postions and apparel to minimize the wind drag. Really fascinating what-all they came up with. And they kept saying that this little bit of drag reduction here corresponds to a 5-minute (or more) faster time in the XXX km race...

You could gather data on the bike rider in different positions, and wearing different gear, etc. If you're interested, I could try to see if I could find a link to the show.

Thanks for the reply, I don’t think I would be able too get access to a wind tunnel unless there is one at the local university, and even so I think it would be a bit too complex for me.

Thanks for the interest anyway
thanks
Matt