Bicycle Definition and 308 Threads

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 105...

A bicyclist applies varied force and velocity on their pedals as it goes around one revolution. The power distribution over one revolution is like two waves with the higher power being made on the downstrokes. The push through the bottom/top produces the lowest power. The question is does...

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...

Hi there. I have a project I am working on now which is kind of like a bicycle which uses powder clutches. The main goal is to make the whole thing compact by reducing the use of shafts. My initial idea of part of the mechanism is in the picture below. I was planning on...

1. Static friction cannot do work (correct?). Yet that is the only external force acting on an accelerating bicycle. How can these two ideas jibe? My thought is that the human is like a battery with potential energy, which, while being depleted, is *redirected* in some sense by the static...

This is not really a homework, 1. The problem I just noticed this (weird we don't think about so many things and take 'em for granted) : When the Bike is moving forward( with some significant velocity ) it can balance itself, I couldn't come up with an answer how... 2. The attempt at a...

I'm working on a group project where we test a bicycle frame on ABAQUS. The test is as follow Where F is a static load. It was suggested for us to consider it as 4G*120kg to simulate a laboratory test. We're having a hard time knowing what is the maximum deflection (or stifness) we should...

Homework Statement A force F of 90N is applied to the cable and each calliper rotates about its hinge at B. With what force does each brake block at A push against the wheel rim? * Image attached * Homework Equations Moment_B = ( Distance from B ) x ( Force acting on calliper...

Hey guys, I read through the other two bicycle gearing threads and to be quite frank I'm not sure if my question was answered. So to put it in it's most basic element, let's assume there's only one change, the gearing. Same bike, same crank length, pedal input, wheelsize, chain length. And...

Homework Statement A simplified model of a bicycle of mass M has two tires that each comes into contact with the ground at a point. The wheelbase of this bicycle (the distance between the points of contact with the ground) is w, and the center of mass of the bicycle is located midway between...

Like almost every bicycle mine makes a clicking sound when the wheel rotates and you are not moving the pedals. I checked online and this video shows the source of the clicking sound (freewheel hub). It's a gear mechanism to transmit torque. I want to remove that clicking noise because I...

Homework Statement I'm only trying to answer the maximum deceleration possible question, not the rest. Homework Equations Not really sure which equations are applicable, I know the Maximum deceleration of a body in general will be a = μ*g. Although I would think that moments...

Hello, I am looking on building my own water bike after finding out that they start around $1700 like the one pictured in this thread. What designs / materials can make this better? I would like to also have transparent floats rather then the original colors that you constantly see...

The tires of a bicycle have radius of $13 \text{ in}$ and are turning at a rate of $\displaystyle\frac{200\text{ rev}}{\text{min}}$ How fast is the bicycle traveling in $\displaystyle\frac{\text{mi}}{\text{hr}}$ well my try on this is. $ \displaystyle 26\pi\text{ in } \cdot \frac{200\text{...

I have always been under the impression that I totally understood the mechanics working behind the stability of a bicycle i.e. i) the gyroscopic effect of the spinning wheel ii) weight of cycle and rider and iii) the centrifugal force acting on the CG when the bicycle follows a curve path. If...

A bike rolling down a hill will on average stay upright for longer than a free standing bike? I can't think of a way to explain why this is?

Hi You'all, Newbie here so no calculus or polysyllabics on the first date please. If I hold a bicycle wheel horizontally and spin it at the north pole, the torque from the Earth spinning and the torque from the bicycle wheel are along the same axis. Does this mean the wheel could float off...

Hey all, I'm looking to build a stationary bicycle generator as a fun weekend project but have a couple of questions I can't figure out the answer to. It will be a regular bicycle with the rear wheel elevated and fixed to a stand. A belt will be attached to the wheel and the shaft of an...

Hi, i am confused with where to start with. A cyclist is on a bicycle with a mass of 10kg rolls down a hill 150m high. with zero losses what is the velocity of the bike at the bottom of the hill? could some one please send me in the right direction with formulas

Hi i am currently studying a bicycle seat post suspension unit. It is one of the lower end of the range models which consists of a spring and a rubber dampener. Basic outline in cad below. http://imageshack.us/a/img407/1720/drawing1layout1.th.jpg I would like to know the calculations behind...

Hi everyone, I just completed my bachelor's in mechanical engineering and have taken up a small project which involves a pedal assisted bicycle operating on both torque and cadence values. Having completed the design and relevant estimations, I have now gotten stuck at a problem which...

Can I ask you about some opinions? We desired to build a bicycle. That is we convert our mechanical energy to electricity energy and stored in capacitor by dynamo. Then when it reaches certain value we discharge it and connected to the portable air compressor. The electricty drive the...

Homework Statement In a demonstration, a bicycle wheel with moment of inertia = .37 kg*m^2 is spun up to 14 rad/s, rotating about a vertical axis. A student hold the wheel while sitting on a rotatable stool. The student and the stool are initially stationary and have a moment of inertia equal...

In the bicycle industry, there is a lot of marketing saying that rotational weight is more important than static weight when it comes to accelerations and competition. I understand I=mr^2 but how do you compare differences. Keeping the the hub/spokes constant, how much advantage would you get...

I'm attempting to solve a mastering physics problem, but I've seem to run into a dead-end on this problem. I've worked out my solution and I'm certain I've rounded my sig figs correctly, but mp doesn't accept the answer. Homework Statement An 17-cm long bicycle crank arm, with a pedal at one...

Hi, (this is not a homework question) If I have a bicycle with COM, M (in line with the center of the wheels, C) on an incline, angle Φ, and the bicycle is NOT moving at all because the brake is on at B. I am trying to put in the forces acting on the wheel. I figure that the weight of the...

I'm trying to understand the angles and force involved with my current project of building a 3 wheel front loading cargo bicycle. The current design stipulations maintain that the rear wheel always remain inline with the cargo(There are a vast majority of designs that do not adhere to this)...

I am making my own 12v electric bicycle but have read that a starter motor is not acceptable because it is not designed for extended use. What motor could I use?

I have always had this question and I have received various answers from angular momentum conservation to gyroscopic effect. But I couldn't really understand the principle. Also, why it becomes easier to balance the cycle when you move the handle?

Last night I had a trailside discussion about how (or if) elevation differences could affect the performance of a bicycle shock. The idea was that air shocks should not be affected because the air spring is in a sealed vessel. Though one rider claimed his suspension acted differently at higher...

Homework Statement A wheel has bicycle of diameters 109.0 cm. The bicyclist accelerates from rest with constant acceleration to 16.3 km/hr in 16.5 s. What is the angular acceleration of the wheels? Homework Equations w=v/r alpha= w/t The Attempt at a Solution I think I'm...

First off, this is not a homework question. I am simply trying to figure out how to make a discrete time model into a continuous one. I don't expect anyone to work this out for me, I just want to start heading in the right direction. I have a model of a bicycle on a 2d plane that has a...

https://www.youtube.com/watch?v=V3UsrfHa4MQ So check out the above video. When the man flips the bicycle wheel over, the turntable he is sitting on starts to rotate. What I don't understand is, how is energy transferred from the bicycle wheel to the turntable?

Evening all, I am in the middle of trying to understand the physics behind how gear ratios work on a bicycle. I have a typical road bike with a rear 10 speed sprocket and 2 front chain rings. What i am trying to understand is when you switch to a larger cog in the back it becomes easier to...

I have a few statements/questions, as stated below. Would appreciate your comments on them. 1) The system is not in translational equilibrium because of a net leftwards force. 2) The system should be in rotational equilibrium based on logic; But based on the FBD, if I take moments about the...

Hello, I am a new member here and am having a problem as to finding the more effective way to power my el wire. For those that don't know el wire is a thin copper wire coated in a phosphor which glows when an alternating current is applied to it. My goal is to wrap my bicycle in about 5...

Homework Statement A spot of paint on a bicycle tire moves in a circular path of radius .33m. When the spot has traveled a linear distance of 1.66m, through what angle has the tire rotated? Homework Equations v=rw w=2∏/T The Attempt at a Solution 1.66=2∏/T 1.66T=2∏ 100∏/83

A bicycle is traveling along a flat straight road with a steady horizontal velocity of 4m/s. Assume the front and rear wheels have a radius of 0.3m and they do not slip on the road. a. How many rpms (revolutions/minute) do the wheels make?[1] -4m/s *60sec/1min = 240m/min Circumference...

Homework Statement A bicycle with tires 70 cm in diameter is traveling along a road at 25 km/hr. What is the angular velocity in radians per second? (the answer given in the textbook is 19.8 radians per second) Homework Equations A= 1/2r^2 ∅ l = (radius)(central angle)The Attempt at a Solution...

Homework Statement During paddling of a bicycle, the force of friction exerted by the ground on the two wheels is such that it acts (A) Front Wheel -----> Backward | Rear Wheel ------> Forward (B) Front Wheel -----> Forward | Rear Wheel ------> Backward (C) Front and Rear Wheels...

This is a future project, but I want to have everything once the weather warms up. Also, if this is in the wrong spot, please move it. The Plan: In the early summer I plan on going on a mini tour and would be camping along the way. I will use a tarp that's big enough to use as a pup tent and...

So, the classic scenario: Person on frictionless rotating platform, holding a spinning bicycle wheel with vertical axis of rotation. Flips it over, and the platform spins in the direction the wheel was originally spinning. Angular momentum is conserved. My question is: Is there any way to...

Homework Statement A 70-kilogram cyclist develops 210 watts of power while pedaling at a constant velocity of 7 m/s east. What average force is exerted eastward on the bicycle to maintain this constant speed? m = 70kg W = 210 J V = 7 m/s F = ? Homework Equations The Attempt at a...

How do I do any calculation when I want to know what kind of a dynamo I need to connect to my fitness bike to produce electricity? And then, what kind of batteries?

Hello Forum, let say we are on a bicycle at rest and in the lowest gear. We start pedaling and the bike moves. The applied torque on the rear wheel is equal the ground frictional torque and the bike moves forward by action reaction... Once we reach a certain speed on the bike, is the...

Homework Statement Assume there is a person sitting on a stool that is free to rotate, the person holds a wheel in which its center of mass is directly above the center of mass of the person plus the stool, then the person rotates the wheel counterclockwise at 6π rad/s. Suddenly, the person...

Looking to learn physics about how a bicycle works and if it effects projectiles because of the rotational inertia if a bike was to go off a ramp. any suggestions?

Homework Statement Consider a biker riding on level ground as shown. She wants to have the maximum forward acceleration possible, which means experiencing the maximum horizontal force without her wheels slipping. Draw the free body diagram for the bike accelerating forward. Homework...

Homework Statement A bicycle wheel has a diameter of 63.8 cm and a mass of 1.79 kg. Assume that the wheel is a hoop with all of the mass concentrated on the outside radius. The bicycle is placed on a stationary stand and a resistive force of 117 N is applied tangent to the rim of the tire...

Homework Statement a man of mass 70kg rides a bicycle of mass 15kg at a steady speed of 4 ms-1 up a road which rises 1.0 m for every 20m of its length. what power is the cyclist developing if there is a constant resistance to motion of 20N Homework Equations (P= F*V) , ( p= W/t) The...