Bike Definition and 189 Threads

I watched a video of a rail bike and if I had to I would have guessed that what I saw in the video was not a stable mechanical system, stable to the rear wheel coming off the railroad track. Please watch from 1:54 to 2:30 to understand the setup of this rail bike below, I would have guessed...

Hi, I recently bought a folding bike and it turned out over time that its weak point is the main hinge where two bolts (vertically placed) are located. I've had the lower bolt break twice during a ride, leaving a part of it stuck inside the hinge thread. It's clear that the forces applied were...

I am a bit overwhelmed with your forum site. I was not sure where to post my question...Here goes- Full details…I have an e-bike. It weighs about 55 pounds. I have ridden it for the last year with a canvas bag attached to the rear flat book carrier. The canvas bag measures 19” long, 9” tall and...

When a cyclist rides off a ‘drop’ (an abrupt step in topography, ranging from a curb to a cliff), the front wheel starts falling before the back wheel, so that by the time the back wheel comes off the drop, the bike will not be horizontal. The front wheel will be lower than the back wheel by...

Find the question below; For part (a), i used the graph to find ##t=22## For part (b), i considered the points; ##(8,20)##, ##(13.333,20)## and ##(0,0)## it follows that, Area=##\sqrt {25.454(25.454-21.54)(25.454-24.036)(25.454-5.333)}## ##\sqrt {2842.58}##=##53.31## There may...

So...I have a home spin bike which unfortunately lacks the sensors of some of the more expensive models. What I'm trying to do is work out if I can dynamically calculate my power output. The spin bike itself has: - An 18kg flywheel of radius 30cm - Direct drive between the crank and the...

Hey Guys, I found this thread about the proper size dimension of a torsion spring for upholding a kickstand in the right position. I have to develop a kickstand for my Omnium Cargo bike. I have been thinking about using the same choice of spring type for my product, but I've also been...

So there's this idea in mountain biking that keeping your weight over the tire contact patch equates to more cornering traction. What I mean is instead of leaning with the bike, you lean the bike under you while staying mostly over the tires (see the right "Bike more than body" image below)...

Take for example earth. Earth has angular momentum about its own axis. However, if we ignore the orbital portion, the angular momentum of the Earth relative to the sun's axis is the same. Another example is the spinning bike wheel/person holding it in a chair. It has angular momentum about its...

In the classic example of a person holding a spinning bike wheel, as they flip the wheel over, angular momentum is conserved by the person/chair spinning with 2x the angular momentum of the initial wheel. Not questioning that. However, I thought ang momentum is always conserved about a...

Summary:: I have an assignment that is looking at how a bicycle pump is used to push air through a turbine to generate energy. I need to determine the energy input and energy created. I'm hoping I can get some direction on where to start. The concept is straightforward. A bicycle pump of...

I am currently facing a problem with my quad bike handlebar starter switch. When i am turning it on it does humming but it seems as if it is not getting the power to its alternator

going off the summary I want some feedback and any opinion that may improve this project, please and thank you.

can anyone tell me the method by which the aspect ratio for the motorcycle tire can be decided given that load capacity of bike is known.

<< Multiple threads on the same subject merged, Thread moved to the schoolwork forums, and the OP has been reminded to show more effort on their own schoolwork questions >>[/color] I want an investigation/research that is simple to experiment practically (I don't have fancy equipment. My main...

My task is to analyze a frame's strength of a specific motorcross using different loads, and to do this i decided to focus on vertical fall from various heights, since this will probably give the largest forces on the bike. The one can also experiment with different types of landings, i.e...

Hello, what is the consensus on using super capacitors to power a 500w electric bike motor. cheap and innovative alternative to li-po batteries or explosion between thighs waiting to happen? the plan is to create something like this: i will use a 24V motor...

Hello, I'm currently constructing an electric bicycle using a 500w 24v motor, 2X24v 7ah batteries (maybe 4 later on). I bought a 24v 30a dimmer switch to use as a "throttle". During the intitial test (on a table, not on the bike!) It worked absolutely fine for 2 minutes, but then began to smoke...

Hi, It's my first post here on the forum and I'm just looking for an answer to a basic kinematic movement equation. This is the text of a problem: "A bike accelerates uniformly from rest to a speed of 7.10 m/s over a distance of 35.4 m. Determine the acceleration of the bike." Now, in the...

Why do softer brake pads stop a bicycle faster, and wear faster, and harder brake pads stop a bicycle slower, and wear slower? Thanks Much in advanced!

I am trying to figure out the power required to lift a hover bike that would have four propellers and would weigh around 400-500 kg. how can i select an engine and find the required shaft power, rpm, engine cc and thrust required.

Homework Statement A stuntman drives a dirt bike on a curved track with a radius of 7.50 m. If he starts from rest and accelerates at 2.35 m/s2, at what time will the magnitude of the total acceleration of the bike be 5.02 m/s2? (Hint: the tangential acceleration will stay constant at 2.35...

Homework Statement A power plant operator on a bicycle is pedaling at uniform acceleration of "a", when his initial velocity "u" m/s. After 6.2s, and 9.3s, the bicycle had moved 23.5m & 39.7m respectively. Find the value of "u" & "a". Homework Equations s=ut+1/2at^2The Attempt at a Solution...

Homework Statement To calculate the resultant pedal force from the variables given: Crank (degrees) measured clockwise from vertical, spindle (degrees) measured anti-clockwise from horizontal, tangent force (N) applied to the pedal surface, normal force (N) applied to the pedal surface and...

Can there be a system that utilizes mechanical energy to produce kinetic energy, but "storing" the mechanical energy to be used at a different time for kinetic energy? Like a bike where you pedal but don't move; that mechanical energy is waiting to be "released" by some mechanism *** exclude...

I have been working on some projects, I build a glass grinder, faceter with a 120v induction AC motor. Its not possible to effectively change the speeds with electronic controls being a single phase motor. It is using belts and pulleys for now. So I am wanting to build several tools, rock...

A bike turns when you turn the front wheel, and the front wheel only turns in the direction it's aligned in. The pedaling motion provides a force in the up, or +Y direction. If the wheels are aligned up, the bike moves along +Y. If the front wheel is turned 90 degrees, the bike won't move. If...

Hi everyone, My roommate and I were talking about which would win in a short downhill race (with no pedaling from either rider), a bike or a skateboard. Assuming the bike stays in the same gear (2, and 4), and has a wheel diameter of 27", and the skateboard has a wheel diameter of 2.4". My...

Do different sized bicycle wheel spray differently? I was asked this question recently and have got myself confused with an answer. To expand on the question a little, when riding through mud at the same speed, which would spray the mud further, a 26 inch wheel or a 29 inch wheel? My thought...

I'm an avid bike rider and a first year physics student. A couple days ago a friend of mine told me about how his friend was going downhill on her bike, used her front brake, and went over. I would like to determine what the minimum speed for a given slope angle is for the biker to do a full...

Hi All, I am working on a project that mounts an accelerometer to the bike pedal, and requires me to calculate the power that the sensor experiences as the bike is being ridden. However, I am having some trouble understanding the forces that the pedal/sensor experiences. Essentially, I need...

Homework Statement I think that the equation for the force someone exerts on their bike pedals or the force forward is stated below. can anyone confirm this is true? Homework Equations Fapplied by rider = (weight of rider) (Radius Crank /Radius Tire) (Gear Ratio) The Attempt at a Solution

Homework Statement Hi there, I am doing a project for my physics class where I am attempting to calculate the amount of force and work required to go up a 10% grade hill in a variety of different gears and I am running into a lot of issues. I have already collected my data and have calculated...

Is a 6.5kg/cm torque motor enough to move (let.s say at 6km/h) a small go cart and a kid (total w. about 45kg)? this is the motor: http://www.amazon.com/dp/B00T48KC1Q/?tag=pfamazon01-20 PS: this is not for a homework but for a for-fun project.

Hi, I saw a video of a guy who made a hover and figured; hey, I should try making one too. I've a general design in my mind. His design had two propellers, one on the front and one on the rear. I wanted to make a bike with more than 2 propellers( assuming more the propellers, greater the...

I have been reading up on electric bike motors, there are a few things regarding size and wire gauge that have me confused. I have seen disassembly videos of around 300 watt electric bike motors with planetary gears, and I can't see how anyone can push through 300 watts through the wires without...

Hi, I'm trying to figure out the minimum specs of each components of the new party bike I'll be building to make sure nothing fails prematurely, but I also don't want to over do it because of cost and weight. This is our current bike, for reference. We will use a similar design as a starting...

So is a Bike driver stable when the bike is running because the bike wheels has a certain moment of inertia about the horizontal axis ,which might alter(mi gets lesser) if the direction of the axis changes ? Thanks in advance

Homework Statement You are traveling on a bike, moving at a constant speed of 20,0 km/h. You just finished eating an apple, and you wish to pop the core into a trash bin located by a busstop.The bin is 3,00 m from the edge of the road (where you are biking). You throw it at a point 4,00 m...

< Mentor Note -- OP has been reminded to use the HH Template and show their work in future posts... >[/color] A man fires a bullet into a swimming pool. There is a distance of 6m from the gun to the bottom of the pool. Does the bullet have enough force through the water to break an average...

Hello Folks! I want to find the maximum applicable force on a full suspension mountain bike and i will use this force on a FEA software structural analysis for a uni design project. This bike has a rear suspension with 400 lbs/in spring rate.Also rear wheel vertical displacement(travel amount)...

Fantastic :smile:

Homework Statement We model a dirt bike as a rod of mass (M) 100 kg, and length (L) 2 m to which are attached two wheels of mass (m)=40 kg kg, and radius R=0.5 m. The bike goes off a spine ramp with angle ##\phi=1deg.## to the vertical on either side (see diagram below). Our question is, at...

Greetings! I have been thinking about creating a Gasoline electric bike. The reason being is that good batteries are very expensive. In fact more expensive than a good quality gasoline motor. I don't want a direct drive gasoline motor do to it being less stealthy and more cumbersome running...

Hi, I've been thinking up a project on harnessing the kinetic energy to use for charging or powering small deviecs around the house firstly my laptop and smart phone. I have a basic idea of what I'm going to use and have some of the things needed. My idea was to use a small brushless or maybe...

Hi Folks I am looking for some help in a calculation if possible. I am looking at a bike design where the handlebars are clamped in place in the stem using only 1 bolt - see the picture attached or link below for an example...

Okay, so I'm new to this forum, but I'm hoping I can get some help. I live in the United States, and I'm having trouble converting from metric to standard with the build plans given. I want to build the open source Spaceframe recumbent bike which the build plans can be found...

Homework Statement Hi all, I race bikes in my spare time and someone asked this on a cycling forum: How much time could you save on a 40km race on a flat course, riding at 40km/h if your bike was one pound lighter. Let's say the weight of the rider and bike together is 80kg. There was a time...

Homework Statement Bicycle wheel is at rest, and can rotate frictionlessly about a fixed axle. A dart travels at velocity v (in plane of wheel) parallel to a line that goes through the centre of the wheel. It hits the rim of the wheel and sticks. What kinetic energy, if any, is lost during...

Hello, I am looking to modify/convert a Quad Bike and make it remotely operated and was wondering if anyone had any advice (from a Mechanical Engineering view) on where to start my research or any other advice they could think of with regards to getting the project off the ground. Any help...