Questions tagged [design]
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66 questions
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How did we get to traditional size pulleys and when exactly did they become a relic of tradition?
Over time in the development of rear derailleurs brought to market, we can see most of the players going larger in tooth count most of the time, for both mainstream off-the-shelf components and also ...
- 88.2k
5
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2
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832
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What was the engineering motivation behind each press-fit bottom bracket standard?
I've read all the differences between PF30, BB30, PF86/92, etc. I understand that it's easier to make carbon frames with press-fit than bonding in a threaded shell, and you save some weight, but I don'...
- 210
6
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5
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Is there any advantage to using brakes the UK style?
For a moment forget about the current downsides of preferring UK brakes living in a non-UK marketplace:
Hard to test ride bikes in stores
Rental bikes won't be set up that way
Some frames might not ...
- 210
2
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0
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295
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Bicycle chain roller diameter size chart?
I'm digging for a while now, and can not find any helpful chart for chain roller diameters e.g. Shimano 8,9,10,11,12 speed. It differs of course depending on the manufacturer and the purpose. We know ...
- 153
13
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2
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3k
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Rear wheels are dished. Why not "dish" the frame instead?
Most rear wheels are dished to make room for the cassette. They have the drive side spokes comming into the hub more perpendicularly, which weakens the wheel against lateral forces in that direction. ...
- 2,079
5
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2
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598
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Why are cheap bikes so heavy?
Is the excessive weight of cheap bikes (think Walmart and Amazon) entirely down to the use of lower grade materials, or are there also compromises in design that contribute? Is it that much cheaper to ...
- 2,696
6
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2
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2k
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Are rattling cables unavoidable with internal routing?
Someone shows you a bike with internal routing, and you marvel at all the advantages:
you're not upsetting the tension by lifting the bike from its top or down tubes,
there are no exposed sections of ...
- 10.3k
3
votes
1
answer
253
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Steering torque
What defines the steering torque? What is an average value for e.g. city bikes and downhill MTB?
Is the static torque largest for returning the steering to zero position, depending on (radial) load ...
- 301
1
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1
answer
132
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Why do steerer expander plugs have nesting threads?
I'm looking at expander plugs as I work on a modification for my new build.
I note that the M6 bolt that holds most of them - like the Enve on my desk - threads into a larger, internally threaded, ...
- 123
6
votes
2
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689
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Why do coil suspension forks have coils placed inside the stanchions, when the rear shocks place it exernally?
If you look at a rear shock which uses a metal coil, you'll always see a large visible coil sitting outside of the shock:
However, front suspension forks that use coil are visibly almost ...
- 14.4k
28
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8
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12k
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Why are male and female model bicycles different in the between-legs part?
Female bike:
Male bike:
Other than the basket in front, the only difference is that the female version is far more convenient to get up on and get back down from. And you never accidentally crush ...
- 289
19
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10
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10k
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Why are there no adult balance bikes?
After a decade of commuting and travelling by bike, I just learned about balance bikes. I get the sense that this is a fairly well-known technology, but for those like me who are just hearing of it ...
- 301
9
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2
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3k
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Standard forces on a bike frame
Let's say I was going to design a bike frame for a specific size of individual. I'd start with some basic frame geometries, then I assume I'd calculate the necessary member sizes, stiffnesses, etc. by ...
- 677
3
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2
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647
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Why have MTB tyres with strong front / back design disappeared?
Back a few years ago was easy to find tyres with a particular design based on their position, back or front, see this sample image fron a pair of Nokian Boazobeana:
Riding with those was pretty nice, ...
- 183
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2
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2k
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Is a chin strap with a cup safer than an under-chin strap?
Many helmets have chin straps to hold them on.
One design uses a split chin-strap, where the strap splits into two forming a cup shape, one going just below the lower lip and one under the chin.
In ...
- 151
0
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4
answers
578
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Upright bicycle efficiency & seat movement
The Kwiggle is folding bike that has been around for a while now (even though doesn't seem to be for sale yet): https://kwiggle.odoo.com/en_US/startseite
Apart from it's folding capabilities I was ...
- 1,025
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2
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406
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Why does a Bella cargo bike not act like a car driving in reverse?
This is crazy you could never make any vehicle have this kinda steering layout. You would imagine that it would be horribly unstable at high speeds +30 km/h. I can't see this being a good idea but it ...
- 475
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2
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785
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What is the function of these 'bulges' on the frame?
A friend brought me an old frame that he found on the roadside on bulky waste day (is that a thing outside of Austria and Germany?).
The rear wheel was gone, the front one bent beyond repair, but the ...
- 527
0
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1
answer
2k
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Does shorter shock stroke limit rear travel better than higher shock pressure?
I'm building a full-suspension XC bike for racing technical courses. My frame is built with a leverage ratio such that 45mm of shock stroke corresponds to 130mm of rear travel. 99% of the time, I am ...
- 173
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2D CAD library of bicycle parts [closed]
Does anybody know of a royalty-free, reasonably comprehensive source of 2D CAD files of bicycle parts? I use LibreCad so .dxf preferable, but most other formats possible. For personal use only.
4
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5
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2k
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Is there any reason for the rear frame and bottom bracket to be asymmetric?
I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be ...
- 41
32
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5
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10k
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Why are most bicycle gears designed to have so much overlap
For bikes with a front derailleur, I've noticed that the gearing ratios of most bicycles are not linear, and there is an odd "overlap" between those power ratios as you switch from one front gear to ...
- 597
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2
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How do I calculate the spring weight rating for my bike?
I have a home built bike design and the rear shock absorber that came with the part bottoms out so I want to get one that is more appropriate. But I have no idea how to calculate which one to buy as ...
- 475
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2
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2k
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Feasibility of bike frame design by a layperson
I'm sure for many bike builders, their ultimate dream bike starts with a frame that they designed themselves. And herein lies the problem: it seems that modern means of frame production (e.g., ...
- 1,067
5
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2
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596
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Are most bikes' paint jobs not as durable as they used to be?
I am asking specifics in a few posts so as to not get into discussions.
Consider this a continuation of bike quality for the price.
I find the paint job on my bike to be nice but very thin and fragile....
- 415
-2
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1
answer
260
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Is a bicycle wheel an indeterminate structure? [closed]
Does anyone knows whether a bicycle wheel is a statically determinate or indeterminate structure?
- 123
4
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3
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334
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Do mid-low end bike manufacturers only design their bikes to last 1000 miles?
When exploring a braking system, I noticed with surprise that they tested their brake actuations to match the 1000 mile quality life expectation of a comfort bike. This seems to imply that this is the ...
- 29.5k
-2
votes
1
answer
292
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Why is the single-rear derailleur that enables <= 12 speeds so popular?
All the high-end MTB, and road racers seem to have somewhere between ... 6 and 12 gears. NO derailleur up-front, only a few to scroll through in back. I get the KISS principle behind it; I like having ...
- 335
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1
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405
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Rickshaw physics
I wanted to know the physics behind the working of such a model. Specifically, the relationship between the force applied by the Rider and the weight of the passengers.
- 101
19
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4
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18k
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What freewheel mechanism designs are used in bicycles?
What are the various freehub mechanism designs that have been designed and or put into production? (doesn't need to have been made necessarily!)
A good post will contain:
A description of the design,...
- 2,001
6
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2
answers
3k
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Feasibiliy of KERS for bicycles (editor: likely Kinetic Energy Recovery System)
I want to know more about KERS for bicycles...
I have a question. What will happen if we attach the flywheel on front wheel? Does it make any difference?
Please reply me.. I preparing this as my ...
- 63
21
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3
answers
17k
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What is an asymmetric wheel and why would you use it?
Campagnolo advertises the Khamsin Asymmetric Wheel:
What is an asymmetric wheel and (given that we expect wheels to be symmetrical), why would one want an asymmetrical one? How is it related to dish?
- 29.5k
10
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1
answer
384
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Why not have the bearings in the forks themselves with through-axles?
Given that we're moving away from QRs to through-axles - partly driven by the torque needs of disc brakes, why not follow the natural progression and move the wheel bearings from the hub to the forks ...
- 29.5k
4
votes
2
answers
329
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Derailleur Configuration - Anyone ever seen something like this?
Can't find anything on Google because I guess I don't know what search terms to use.
I am wondering if anyone has ever seen a derailleur setup like I have drawn in the picture. It is NOT for ...
- 91
35
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1
answer
155k
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What is the difference between I.S., post, and flat mount disc brake mounting standards?
What is the difference between "I.S." (international standard), "P.M." (post mount), and flat mount disc brake mounting standards?
Does one have a clear advantage over the other and is there a ...
- 29.5k
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4
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3k
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Does anyone manufacture a seatless bicycle?
I need to stay fit and cycling is a great non-impact exercise. I don't see the point in sitting when cycling, instead I rather standing as such as it creates a better form of exercise. Are there any ...
- 133
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1
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Handling Stability Parameters [closed]
I'm building my first bike: probably steel (easy to work with). 2X26" road tires. Full suspension. Will be used on sandy dirt roads, and paved streets with moderate incline. Want hands free option, ...
- 11
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2
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2k
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Dynamic stability of a tricycle
I'm currently designing the "electric bike of my dream" (please do not laugh! it's for fun, nothing serious), and I came up after some though with a tricycle, where 2 rear wheels are supporting the ...
- 456
13
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1
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527
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Why do track bikes vary between events?
Watching the Olympics, I've noticed that track bikes seem to vary between events.
For example, in the Keirin, all the riders have bikes with a solid/disc rear wheel and a front wheel that has a solid ...
- 433
1
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1
answer
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2 wheeled trailer - wheel position/weight distribution
Two wheeled trailers usually have the wheels in the middle as far as I know. I understand this minimizes additional weight on the back wheel of the towing bike. But wouldn't moving the wheels back on ...
- 1,779
-4
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1
answer
405
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Is it useful to design a pedal with kickstand? [closed]
i am working on a project, trying to combine a pedal and kickstand.
It can provide temporary balance for the bike, and to take better bike photo easily.
Do you think you ever need such a product?
...
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0
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135
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Why do most mtb forks place the arch in front of the stanchions? [duplicate]
Similarly to the pictured below RS Pike, most fork manufacturers place the ark in front of the stanchions. This has proven to be a terrible solution when riding in muddy (or actually anything ...
- 14k
12
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6
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Are folding handlebars a good idea from an engineering standpoint?
A couple of Chinese stores have been selling folding handlebars:
At first glance this appears to be a great idea since the handlebar width is one of the reasons that carrying and storing bikes can be ...
- 29.5k
-3
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2
answers
3k
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how to design a shaft and gears for shaft driven bicycle [closed]
i want to know about the complete design and dimensions of the shaft and suggest me to give more efficiency to the bicycle
- 11
5
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1
answer
6k
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What are the advantages of handlebars with an integrated stem?
I was doing a bit of research for an upcoming handlebar purchase, and came across this strange piece of hardware -- handlebars with an integrated stem (or possibly a stem with integrated bars).
So ...
- 475
1
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3
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792
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Safe to shorten a dual-pivot caliper mounting nut?
I have a 2006 Specialized Langster. Unfortunately the brake bridge is not deep enough to insert the shortest caliper mounting nut I could find (10mm). The head of the nut should insert all of the way ...
- 393
3
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2
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677
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What are the technical differences between a bike for off-road touring and a mountain bike?
There are a lot of adventure touring bikes, or bikes designed for bikepacking, off-road touring and the like. But what is the difference between one of these and a standard mountain bike. E.g. what ...
- 2,964
2
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3
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444
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Pedaling in Rear Wheel design
I had built a bike similar to this one before. I think many would have this idea, too.
However, for some reason, not many of these designed are commercially marketed....
- 3,531
0
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1
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4k
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Use Raspberry Pi (and C#) in a bicycles [closed]
Any full source code sample projects about Raspberry Pi (or another) using it in bicycles ?
Maybe interesting for create a dashboard in bike for manage lighting ?
Examples:
live web bicycle (gps ...
9
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6
answers
15k
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Why do we need front brakes?
Most biking accident stories (ignoring collisions) that I hear about involve squeezing the frontbrake too hard and flipping over, often when biking on a downhill.
Read, for example, this fellow's ...
- 243