Friday, February 20, 2009

Elliptical Chain Ring???

For some reason my new Kabuki has a chain ring that is not round.  It is not stretched or something.  It's elliptical for some reason.  For more Kabuki pictures, click on the picture and you'll go to my Flickr site.  


Rat Trap Press said...

That's really interesting. I didn't realize that they put biopace chainrings on anything other than road and mountain bikes. Cool bike!

David Hembrow said...

Except... that one isn't "biopace" (a Shimano trademark for a particular type of ovalised chainring), but a Bridgestone oval.

Lots of people have made oval chainrings in the past. These people will make one for you of any size and shape you want.

In the past there has been much debate about the supposed higher efficiency of differently shaped rings. Like many such improvements for cyclists, there is no clear evidence of them being truly more efficient. The problem with cycling is that you can easily use all the power your body can produce with normal chainrings, legs only etc. So anything which claims to get more energy out of your body probably isn't going to do so.

2whls3spds said...

That is interesting. I have the Sugino ovaliod rings on a couple of my bikes, but I have never seen a single ring like that.

I think they were supposed to help keep the power stroke smooth over the full revolution. I can take them or leave them, but have heard that some people find they help relieve some types of knee pain, supposedly by smoothing out the power application.