1. B

    Mechanics of a front wheel on a bicycle

    I am working on a project where I am supposed to find some ways to get constraints on some of the components (rim, hub and spokes) to use these for parametrization. So far I have thought that the constraint for the rim is that it can't buckle from the pre tension of the spokes (here I am...
  2. Evanish

    Misc. DIY - Replacing my bicycle tire with recycled plastic

    So the rubber on one of my bicycle tires has worn out to the point it needs to be replaced, and I was thinking I'd prefer a solid tire this time. Rather then buying one like a normal person I was thinking if I could make my own out of recycled plastic. Here is the plan as it currently...
  3. D

    A Bicycle tire width vs. pressure for identical comfort

    Here is what I want to know specifically: if I replace my 5cm wide rear tire with a 6.25cm wide tire, how much can I increase the inflation pressure to obtain the same comfort? I realize "comfort" is not a quantifiable measurement, maybe shock absorption characteristics is better. Perhaps it...
  4. Qwerty42

    I Forces applied to a leaning levitating bicycle

    Hi! So I'm building an electromagnetic bicycle where the frame is levitating over the wheels, thus reducing the rolling friction to almost zero by removing the bearings. Magnets have also been placed alongside the wheels to provide side to side stability. Black is the frame, red are the magnets...
  5. Kraken_Head

    Power of a bicycle accelerating up a slope.

    Hello everyone :alien: I have been assigned to create a physics problem involving bicycles. I thought up the following, but I had questions regarding if it was properly made / worked out. A cyclist is accelerating constantly up a slope at 1 m/s ^-2 The slope is at a 15 degree angle and is 30 m...
  6. F

    Comparison of 20" and 26" bicycles uphill

    Let's say you've got two electric bicycles both powered by identical 250W motors. Both are fixed gear. Both weigh about the same and have riders of the same weight. Both riders contribute no force to pedalling - all the work is done by the motors. The only difference is the first bike has 20"...
  7. SkyblueEagle

    How do I calculate forces acting on bicycle axle?

    Hey everyone, I am trying to figure out how to calculate how much total force is being applied to the wheel axle on a bicycle. I'm focusing on the rear wheel for the moment. For the sake of simplicity, let's say that the bike and rider together weigh 100kg and that 60 percent of that is going...
  8. MichaelWReed

    Expandable Gear CVT

    Hi there, I started working on an idea for an expandable gear CVT about 3 years ago, while out of work for a few months. I had some exciting progress on an idea that I think might be worth pursuing more, but I now have 2 kids, 2 jobs, and no time. I have brought up the project idea with a few...
  9. doctorwho55

    Relationship Between Bicycle Tire Pressure and Speed

    Hi, I have been tasked with finding a way to relate a bicycle tire's inflation pressure to its speed in travelling 160 meters. Data was given showing that as the pressure increased from 70 to 90 psi, the speed increased marginally. No equations were given. I think that it may have to do...
  10. M

    Pneumatic bicycle help

    I wish to create a pneumatic bicycle but not sure if i should use high torque low rpm or higher rpm with lower torque. I am thinking that a low rpm with high torque will use less compressed air and make better use of the PSI.
  11. R

    Powering electromagnets with bicycle power

    Would it be possible to operate an electromagnet using the power produced by pedaling a bicycle? The electromagnet would need to be strong enough to lift up the training wheels of a bicycle.
  12. N

    Rolling Friction of Bicycle Tires

    1. Homework Statement Two bicycle tires are set rolling with the same initial speed of 3.30m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi and goes a distance of 17.3m ; the other is at...
  13. M

    Bicycle Crank Power Meters and Round and Non-Round Chainrings

    One of the debates in part of the bicycling community is whether elliptical or non round chain rings cause a crank based power meter to over report power beyond the power meters accuracy rate when velocity is only measured once per revolution. Average and weight average of the velocity per...