Bike Definition and 192 Threads

I have an electric motor that I want to use with a bike chain and not the small chain that is already on it. Using cad and getting a custom sprocket made might be the way to go, but finding a site that sells them would be more than likely be cheaper. I found that it is called a dual-d boreand is...

Homework Statement A cyclist intends to cycle up a 8.2^\circ hill whose vertical height is 180 m. The mass of the bike and the cyclist is 95kg. If each complete revolution of the pedals moves the bike 4.7 m along its path, calculate the average force that must be exerted on the pedals...

If a bike is running at v=0.866c, and it travels path of length L in time T, when observed from the stationary frame, same path will have length L/2 and be traveled in time T/2 in his, moving frame (because gamma=2 for v=0.866c). Now, what I don't understand is: If the bike is not...

Hi Guys, I've made an amphibious bike, shown below. Basically, it's a bike which you can use to cycle along the road, down the slipway into the water with litle/no changeover, and then pedal off through the water. It all works, and floats, but I'm struggling to find a way to propel it in...

I need to clarify the forces acting on the bike in the first fig is the 10N force spinning the wheel anti clockwise? hence the bike is moving backwards? Do the answers match the diagrams?

Hi friends I have a little doubt on the gear ratios of a bike like a mountain bike which have front sprockets also. It's clear that we get maximum RPM and min torque out of a bike when the chain is on smallest sprocket at the rear and largest at the front(highest gear ratio). But i read...

O hai. http://laughingsquid.com/the-worlds-largest-lolcat-invisible-bike-mural/ I found this freaking hilarious, even if it is old. And for those of you who don't know what LOLcats are (shame on you!), here's a TVTropes explanation: http://tvtropes.org/pmwiki/pmwiki.php/Main/Lolcats...

1). Shawn and his bike have a total mass of 45.0kg. Shawn rides his bike 1.80km in 10.0 min at a constant velocity. What is Shawn's kinetic energy? m=45.0kg (Shawn+Bike total mass) t=10.0min-->600sec d=1.80km-->1,800m K=1/2mv^2. so...K=1/2(45.0kg)(?)^2 I'm assuming v=3m/s...

I got a small 16inch folding bike weight 13kgs and managed to shed it down to 9kg and working in weight reduction further... eg using hollow shaft at the peddle and using clips at the axles and replacing to 14inch rims and redoing the frame in lighter stainless 201 - these are my next to-do...

Hi everyone, happy christmas I am working on a project looking into the inertial feel of a bicycle. The overall aim is to calculate the inertia of a bike and rider and to consider how this inertia feel can be recreated in an exercise bike and to quantify the differences through testing. In...

If you're riding a bike on ice with no friction and the wheels are rotating just as fast as they normally would when you're riding, will you fall down? (Since you're riding on frictionless ice you have would no linear momentum) I think that, due to conservation of angular momentum, the...

I have made a dinamo from my motor which I attached to my bike's tire and I placed the magnet on top of my motor. I give a good spin and then I measured the Voltage and it showed up to be 2.5 Volts at normal speed. The problem that I am having is that I can't get my small light bulb to work...

In the beginning scene of the film One Eight Seven, Samuel Jackson's character has one of his students hold a bicycle while sitting in a chair, and pump the pedals until the wheel got up to around 180 rpm. When he told the student to tilt the bike to the right, the chair started rotating...

Hi, I am trying to learn more about electromagnetic induction because I want to build a generator for a wind turbine. I am a bit confused about something, hopefully someone out there can help me! I recently opened a bike dynamo. It contains a permanent magnet that can rotate, and the...

Homework Statement Bike has leaned, passing via corner. Centrifugal forces ( m*(V*V/R)*sin(alpha) ) are trying to upright the bike, gravity forces ( m*g*cos(alpha) ) to lean it further, so the balance lean angle comes tg(alpha) = V*V/R/g, where V is bike speed, R is curve radius, g is...

I’d like to get many opinions and suggestions about possible configurations for a solar powered bicycle. Currently, my plans are to purchase an electric bicycle with 200-400W motor. There are many of these available on the market and many use a 24V/10A onboard battery (Typically NiMH) mounted to...

I'm planning on building a mountain bike light. I thought it'd be a good little project to get me into understanding electrical circuits and I want to know if my parts are compatible. Can anyone see any flaws? Light Specs Supplier WelchAllyn Part Number M10P004 Cost $46.00...

I'm working on a design for an electric bike. I need a free sim I can download to develop it: test it, see it work and compare varations. God bless and thank you in advance, -Hip PS, I looked for a "search the forums" feature, but was unable to locate it, it needs to be more prominant if...

I was discussing this with a friend: Say you are doing a tailwhip on a bike (bike spins around pivot at headtube) Simpify this by looking at it as a bar pivoted at one end, with a wheel mounted to the bar with the radius in the direction of the bar. We want to spin this around the pivot in...

I know this sounds crazy, but hear me out. My plan is to attach airfoils to my bike. I know it would be very hard to actually take off, but what if I got enough lift to counteract most of gravity? I could then jump my bike or go off a ramp and theoretically fly much farther and longer than...

I am trying to determine the forces exerted on a bicycle pedal crank by the rider so I can analyze the fatigue. I believe that I understand how to conduct the fatigue analysis but I think that the forces on the bike crank are more complicated then I have assumed them to be so far. I know...

Ok. Folks, first off this is my first post, and I am looking for some answers to some questions I have. I hope someone has the time to answer them :) First off, I'm no expert in physics. I know a billion times more than any of my friends but believe me that is not saying much. I have never...

greetings all here is my question: Starting from rest, a cyclist coasts down the starting ramp at a professional biking track. if the ramp has the minimum legal dimensions (1.5m high and 12m long), find the acceleration of the cyclist, ignoring friction. i am having a hard time figuring...

Hi, I was discussing cycling with my dear friend, Tim, and in no time at all we were at loggerheads with regard to weight savings as it relates to performance increases. Tim is of the opinion that "mass is mass" no matter where on the bike/person it is (controlling for aerodynamics etc.) but I...

Homework Statement You have your bicycle upside-down for repairs. The front wheel is free to rotate and is perfectly balanced except for the 16 g valve stem. If the valve stem is 34 cm from the rotation axis and is located 32 degrees below the horizontal, what is the resulting torque about the...

Homework Statement I am currently tring to work out the torque that is required to lift a bike seat of mass 2kg at a rate of 10mms-1 with a given screw thread and nut. how would i go about this? Also is it possible to calaculate the shear force experienced by the thread of the screw and...

I'm trying to calculate the torque i would need to pedal when in the highest gear on my bike to sustain a constant speed on level ground. Basically i just want someone to review my calculations and make sure they're correct. I leg press 270 pounds and therefore each of my legs can supply 135...

Hi all, I was wondering if there was such thing as a heat creating exercise bike. Made for the purpose of creating heat. It's really cold and the power bill is going up and I am wondering if this idea is stupid or has it already been tried. I would buy one. Any thoughts?

OK, a Man on a bike - leans into a corner to make a turn. How does he do that? Don't the laws of physics say that it's impossible for him to shift his center of mass from side to side? There's nothing for him to push against (side to side) It's like being up in space. and he shouldn't be...

I love Gizmag, and they've presented a challenge. (Actually, Honda presented it; Gizmag is passing it on.) The link shows a Honda concept bike that appears to have no tires, suspension, or drive train. I can think of a few ways that the suspension, steering, and power system might be done...

what wind has more force the wind of you standing on top of a car doing 200mph or you standing still and a 200mph wind hitting you?

A bike has wheels with diameter 0.6m. The bike moves along the road at 6m/s. Determine an equation for the height of the the speck on the tire above the road as a function of time in t seconds. I think that the amplitude is 0.3 and my period is 0.6pi (circumference). Would there be any phase...

So I am heading out to Arizona for grad school and my primary mode of transportation around campus will be by bicycle. I don't know jack about bikes. I am looking for something practical for a means of transportation, but I want something reasonably capable for riding trails also. I was...

On another forum i offered a guy from Canada the use of one my bikes to use to go to the Isle of Man TT on, he took up the offer with some glee. Now i thought the bike just needed a (once over) to be ready but, i have found several problems that have to be fixed before i hand the bike to him...

There's a video going around on the internet with a motorcyclist coming out of a corner and just letting go of the bike - ghost riding. The bike continues on and wobbles while the rider gets back up and runs and catches the bike. You can find the video (since there's a restriction for posting...

Well I am one step closer to getting my bike license, I have registered for a riding course and am now two days in. I am picking up lots of good tips and also learning about some bad habits I had. I got in trouble today for putting my right foot down at a stop instead of my left foot, they also...

I currently have a set up where I have attached a permanant magnet dc motor to a bicycle. The motor is attached through a diode to a 12v regulator and then to a 12v to 240v inverter. Everything works fine and I can power up my devices. But I have been told that if I connect my 12V lead acid...

Well, let's say we have a bike and we wanted to see the maximum speed that the bike would reach down a hill. Let's say that the combined weight of the rider and the bike is 210 lbs. The diameter of the wheels is about 20 inches and the hill is 45 degrees steep. The hill is smooth and has just...

Homework Statement How is the angular speed of the rear wheel (Wr) of a bicycle related to that of the pedals and front sprocket (Wf)? That is derive a formula for Wr/Wf. Let Nf and Nr be the number of teeth on the front and rear sprockets respectively. The teeth are spaced equally on all...

Greetings all! There is a bit of a debate in the world of mountain bikes, concerning the conventional 26" wheel diameter versus the rising popularity of the 29" wheel size (nominal diameters). One of the popular beliefs is that the 29" wheel requires a larger brake rotor than a 26" wheel...

[SOLVED] Bike Vectors Homework Statement A student bikes to school by traveling first d_N = 1.00 \rm {miles} north, then d_W = 0.400 \rm {miles} west, and finally d_S = 0.100 \rm {miles} south. If a bird were to start out from the origin (where the student starts) and fly...

Homework Statement There is a bike odometer that measures distance traveled for 27" wheels. So what heppens if you use it on a bike with 24" wheels? Will the odometer show the same, a larger or smaller distance traveled? Explain. Homework Equations The Attempt at a...

Homework Statement A bicycle has wheels of radius 0.29 m. Each wheel has a rotational inertia of 0.091 kg·m^2 about its axle. The total mass of the bicycle including the wheels and the rider is 79 kg. When coasting at constant speed, what fraction of the total kinetic energy of the bicycle...

http://www.youtube.com/watch?v=VyzVtTiax80&mode=related&search= How do they do this?

How would you recognise that someone have talent in racing in road bike competitions? What criteria would you use?

Homework Statement Tony (45kg) coasts on his bike (5kg) at a constant speed of 1 m/s, carrying a 5kg pack. Tony throws his pack forward, in the direction of his motion, at 5 m/s relative to the speed of bike just before the throw. What is the bike speed immediately after the throw...

What do you people think of this bike? http://www.bikes.com.au/p/289268/2007-diamondback-criterium.html Would you call it an entry level bike? What is the difference between entry level and non entry level road bikes? Is the only difference in speed? What type of bikes do climbers ride (i.e...

After waiting a week and a half she's here! http://photos-004.ak.facebook.com/photos-ak-sf2p/v78/133/69/5736845/n5736845_34678004_5514.jpg http://photos-005.ak.facebook.com/photos-ak-sf2p/v78/133/69/5736845/n5736845_34678005_5782.jpg Oh yeah, its Ultegra components...

http://s158.photobucket.com/albums/t83/knightcote/?action=view&current=Image1.jpg She is finished :biggrin:

Homework Statement The dynamo (generator) of a push bike is made to turn when the bicycle wheel turns. The generator provides energy to light the bicycle’s lamp. Would a cyclist coast further if the lamp connected to the generator were turned on or off? Why?Homework Equations The Attempt at a...