Questions tagged [bicycles]
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37 questions
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Why don't motorcycles have as good a turning radius as bicycles?
The question is about why are motorcycles not manufactured with handlebars that can turn to great degrees like a bicycle. In most motorcycles, you hardly have a steering angle of about 20-30 degrees, ...
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What are the technical obstacles for using flywheel-based regenerative braking on bicycles?
Is it possible to convert the energy you would normally lose when braking your bicycle to rotational energy by attaching an extra wheel which would start to rotate once you use your brakes? E.g., when ...
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What makes scooters unstable at high speeds?
Scooters and skateboards are obviously meant for slower speeds, below 5 MPH. Typically if you go faster than that, it becomes harder and harder to control the scooter, and you will fall off. An ...
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Clamping force of a bicycle quick release skewer
In brief: between a standard quick-release skewer and a bolt-on skewer, which will provide greater clamping force?
More detail:
Modern bicycle wheels are held in place by clamping skewers that run ...
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Calculate max deceleration without front wheel slipping (bicycle)
I am trying to calculate the maximum braking force/deceleration for a bicycle.
Note: the question assumes only the front brake is used
Free body diagram:
Typo: in the image above, "$F_{a,\ max(...
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Why is the open-front bike stem design so widespread despite that it may be inferior to the closed-front design?
Context
Even major bicycle corporations have the occasional
product recall on handlebars.
It's easy to see why. The bike itself is a gentle, light, and nimble ~10 kg (for a road bike) object, whereas ...
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How do I add magnets to the mechanism of my exercise bike?
I have an exercise bike that works by a (I'm assuming solid iron) flywheel and a 'horseshoe' of magnets that are moved in and out to set the difficulty.
I have attached an image of the same design ...
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Actual amount of reinforcement gained by adding gusset to welded steel tube construction
This question bothers me for quite a while and is about bicycle frame construction, specifically a BMX frame and even more specifically it's front triangle.
It is a heavy duty frame by definition, and ...
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1
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What is the impact toughness for some common bicycle frame materials?
I've been trying to compare popular materials for bicycle frames in terms of their mechanical properties. One thing I noticed is that it's hardly possible to find a data sheet specifying the impact ...
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How fast could a human pedal a car? [closed]
Suppose that we were to install bicycle pedals into a passenger car, say a civic coupe, in such a way that pedaling is as mechanically efficient as riding an ordinary bike. Further suppose that we ...
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Can epoxy bond two Aluminum alloy beams?
The bicycle component manufacturer Shimano makes crankarms named "Hollowtech".
Hollowtech crankarms are meant to be both strong and light. As the diagram below (source: Shimano) shows, the ...
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Why there is no piston style pedal bicycle?
I have interested in walking bicycle. For the concept is just bicycle that you don't cycling pedal but stepping or striding to drive wheel
Which leads me to think that is it better if we use linear ...
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Is the bicycle the fastest possible human-powered vehicle?
It seems to me that bicycles have proven themselves to be the fastest human-powered vehicle in common usage. By “human-powered” I mean it has no fuel or power source other than the inputs given by a ...
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With ebikes, is there friction from the motor when riding with the electronics turned off?
One may want to ride an electric bike with the electronics turned off. There are many reasons to do this, i.e. flat battery, fitness (who would have thought)
When riding an ebike conventionally, is ...
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Bike wheel sizes
I was passing by a row of motorbikes and mopeds yesterday, and noticed they all have really small radius wheels compared to bicycles. Not all motorbikes are equal (some motorbikes are literally ...
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Why is the rear wheel of the Penny-farthing so small?
I see a lot of people asking why the Penny-farthing's front wheel is so big, and I think I've read enough materials to understand why (at least, at the most basic level). But even so, I feel that the ...
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How to change the direction of a chain-sprocket system
I’m looking for a way to change the direction (90 °) of a motion transmitted by a basic chain-sprocket system. Is there such a thing as a chain-driven equivalent to straight bevel gears?
I’m planning ...
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heavy duty cargo bike - which direction to choose
I would like to build a heavy duty cargo bike. Heavy = approx 200Kg of load on the front rack.
I want 2 front wheels.
Basically, there are 2 options that I know of:
the front wheels are fixed to ...
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Is it possible to prove that applied forces to a bicycle top tube are worse than a seatpost when using a repair stand clamp? [closed]
This stems from the idea that you should use a bike stand clamp on a seatpost, if you can, for carbon fiber (CF) bike frames. Hopefully, this would avoid the cracking of a CF bike frame.
In order to ...
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Why aren't tricycles use cardan shafts?
All the tricycles I saw use chains. It looks far from being efficient comparing the regular bike:
Notice how long the chain is. They have to use 2 chain idlers. The back path is inside the curved ...
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Fabricating a Strong Hub Shell for a Bicycle
I'd asked this question over at SE Bicycles but they think this is more an engineering question.
The flange on my hub broke and I'm having to get one fabricated. The part is actually a cage that ...
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How are single tube bicycles prevented from collapsing?
From time to time I come across bicycles with a particular geometry (or rather a lack of). Most of them have no seat and a single tube which simply connects wheels and has the bottom bracket (if that ...
user12075
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Measuring Torque in a bicycle [closed]
How to measure torque in a bicycle?
how much newtons will produce by the pedal of the cycle ?
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How are sealed bearings assembled?
Sealed bearings are a common component on modern bicycles.
Even if you take off the plastic covers of sealed bearings, the ball bearings inside will not fall out.
How is such a part assembled in the ...
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Street like tyres on smaller bike? [closed]
Is it possible to get rolling resistance of best street tyres on smaller wheels say 20", 16" or way smaller like scooter or in-line wheels ?
Looking for best options for specials like ...
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Could radial bearings with brackets hold the weight and load of a large cart
Me and my partner are trying to build electric pull carts to assist elderly Korean women and men who collect paper boxes for a living. These boxes are sold for recycling.
They work virtually at every ...
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Larger battery from 18650 batteries - using a case?
I want to build a battery for an electric bicycle using 18650 batteries. But I'm not into spot welding so much. Would it be possible to build a large case for the 18650 batteries with these types of ...
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What is an advantage/disadvantage of difference wheels size in front and rear of a bicycle?
Suppose there is a vehicle with difference size of wheels in front and in rear. Specifically bicycle, There would be 2 cases that front wheel larger than rear wheel and vice versa
I would like to ...
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Fabricating a Strong Hub Shell for a Bicycle
I'd asked this question over at SE Bicycles but they think this is more an engineering question.
The flange on my hub broke and I'm having to get one fabricated. The part is actually a cage that ...
- 101
0
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1
answer
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How to slow down an electric motor for pull cart?
I'm trying to retrofit an electric motor (such as this) to a pull cart as depicted below. I got most things figured out except for how to slow down the motor to a pedestrian speed.
Could I slow it ...
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Working of planetary gear set in electric bicycle
For mid-drive electric bicycles where the motor is attached to the pedals, it provides helping torque which reduces the force that needs to be provided on the pedal.
So, how does a planetary gear set ...
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1
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How is forward motion initiated in this case?
Source:byjus.com
Do these forces cancel out each other? If yes, how is forward motion initiated?
Also, in this situation, since friction between the road and the wheels is enabling motion, which ...
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Why do instructions on creation of roller chain sprocket tooth profile require redundant measurements?
I'm CADing a tooth profile for a bicycle chainring model and I'm referring my measurements and formulas to these sources:
http://www.gearseds.com/files/design_draw_sprocket_5.pdf
https://data.epo.org/...
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How far can I drive an electric bicycle with a 250 watt engine using three serial connected 12 V motorbike batteries?
How far can I drive an (average sized) electric bicycle with a 250 watt engine using three serial connected 12 V motorbike batteries?
Trying to research the feasibility of this. I would like to ...
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Designing and fabricating custom gears and sprockets
I need to get a motor from an electric motorbike to drive a single-speed BMX Bike chain, and I haven't worked with bikes/sprockets before so I don't know where to start (I was only supposed to be ...
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How can wheels with spokes concurrent at the center be solid?
A traditional bicycle wheel looks like the left wheel in the image. The spokes are not concurrent at the center. They connect with the hub at a near tangent.
Given their length-to-diameter ratio, it ...
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What is the name of the type of diagram that displays all the forces that act on a moving bicycle so that it stays in balance and does not fall?
If I were to draw a diagram the system of forces acting on a bicycle at high speed in order to demonstrate that the bicycle does not fall over, what is tat type of diagram called?
