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I'm new to the bicycles scene and was trying to 3D draw a bicycle.

I'm currently trying to draw an 11 speed 11-30T cassette but I quickly noticed that the design of the teeth of the gears are quite advanced and thus that piqued my interest.

From a friend I hear that there are books and papers that discuss the shape of the teeth and they also have equations used to determine the shape using the pitch and roller diameter dimensions from the chain.

I tried looking for these books or any relevant information on these teeth designs but to my surprise, it seems that this info is really hard to find on the internet.

So my next strategy to find this information is by asking others! So if anyone has any information on this or has a website/book/technical report where I can find more info about this topic please let me know.

Thanks in advance!

  • Hi, welcome to bicycles! Have you tried searching for free CAD files? I found a primitive 6-speed Shimano cassette in a quick search, but that might be old enough not to have the ramps you're talking about. – DavidW Mar 19 at 21:45
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    While shapes can be observed, measured and copied, the reasons behind them is complex. Much of the information you are looking for will be propitiatory knowledge keep secret by the manufacturers. – mattnz Mar 19 at 21:46
  • @DavidW Hi, thanks for the reply and welcoming! i have actually searched for some online but sadly have not found file formats to see how they actually drew the gears (i use autodesk software). However i did find this link that details formulas and stuff on motorcycle teeth design and this is exactly what i would like but then for bikes ofcourse – cooldanietje Mar 19 at 21:52
  • @mattnz i was thinking that aswell :( i may have to reverse engineer some of this then :/ – cooldanietje Mar 19 at 21:54
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    Frank Berto's book The Dancing Chain has a few pages on sprocket designs and means to improve smooth shifting, such as Shimano's HyperGlide (p.366-368 in the 2013 update). My guess is that for disclosure of the fine-detail you have to search the patent literature, which is usually awful reading. Try Google's patent search. – mathieu van rijswick Mar 19 at 23:26
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I hear that there are books and papers that discuss the shape of the teeth and they also have equations used to determine the shape using the pitch and roller diameter dimensions from the chain... if anyone has any information on this or has a website/book/technical report where I can find more info about this topic please let me know.

This is a huge topic I'm going to bucket the conversation into two groups.
1. Information on products currently being manufactured.
2. General roller sprocket and roller chain design - this is the best source of detailed information. Google and/or search Amazon books "roller chain design" or "roller sprocket design".

1. Information on currently manufactured products.
Bicycle drive train makers (Shimano and others) have spent a great deal of money trying to make chains and cogs that shift better in hopes of giving them a competitive advantage in the market place. The details of their design are proprietary and patented. They will not publish enough details for you to re-create their designs.

There are people who have spent the time reverse engineering products.

For example:

Peter Verdone has a page that details a Shimano hyperglide 9 spd cassette interface.
enter image description here

Konstantin Shemyak spent some time examining the teeth of hyperglide sprocket teeth and has posted his findings.
enter image description here

GRABCAD has drawings of cassettes and chains.
enter image description here enter image description here

Here is a deep dive into some Shimano chainring designs using information from the patent office from BIKERUMOR!.
enter image description here

Chasing the patent trail - Google has a nice patent search engine. Here is an example of a "bicycle sprocket assembly"
enter image description here

2. General roller sprocket and roller chain design
The roller chain / roller sprocket drive mechanism is over 100 years old. If you look for information that is not specific to current bicycle drive trains and generalize to sprocket and chain design you can find a world of technical information on the web an machinist handbooks like this document on Gears Educational Systems.

Or an article on designing a single speed cog as just two examples of the mountain of information available.
enter image description here

| improve this answer | |
  • 1
    +1 for quantity of information and underlying 'here, let me Google that for you' vibe. – Argenti Apparatus Mar 20 at 16:09
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    @ArgentiApparatus Thanks. Searching can be frustrating if you don't know what words to use. My goal was to be helpful. – David D Mar 20 at 17:43

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