What does "profiled wheel" mean in "a sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a chain, track or other perforated or indented material"? Thank you!

2 Answers 2


If you look at the image below (which is from your wikipedia page):

enter image description here

You can see where it has (on the left hand side) two dimensions given: Do & Dp. You can also see on the tooth (in blue, at the top of the gear, shown at the left) is angled at the top, tilting in on each side. This is what is meant by profiled. It isn't a straight cut gear, but has a profile. This allows so the gear itself does not interfere with the chain as it rides along the teeth. It helps to keep the chain from rubbing on the gear. If the profile was not there, the outer edge would continually grate on the chain until something wears out.


I assume you know what a wheel is, so a "standard" wheel is, by definition, unprofiled. That means that its outer diameter is smooth and makes a circle.

When you add a profile to it, it becomes a "profiled" wheel. For example a CAM is a profile wheel since it's not circular but had an "egg" shape to it.

Similarly, a gear, sprocket, or chainwheel (all are similar but designed for different applications) has a profile on its outer diameter that matches with whatever it is design to mate with.

From the page you referenced:

Profiled Wheel

Note the teeth and valleys between the teeth. These are part of the PROFILE.

  • Thank you all so very much for your detailed explanations!
    – Maurice
    Feb 7, 2023 at 2:10

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