The latest version of my expanding chain ring idea is called VECTr, short for Variably Expanding Chain Transmission. How does it work? Find out here: https://vectr-gear.com/how-it-works/.
The key to the design is the simple locking mechanism which performs two functions: (1) holding the gear segments in the desired radial position while they are engaging the chain, and (2) unlocking from that position and moving to a new one when the rider moves a gear shifter. The current design has a simple pin going through the gear segment and into a locking notch on the base of the device.
Simply by being rotated as the rider pedals, the pin hits a curved control plate, gets unlocked, and slides along the contour of the control plate moving the gear segment to a new position. When free of the control plate, a spring pushes the pin back to lock the gear segment in place so it can transfer power once again.
As you can see from previous posts, simplifying the design was not a very simple process. I have found that the first, or most obvious (to oneself), way of solving a problem is seldom the simplest. I tried to envision what I wanted my device to do, imagine a means of doing it, and then try to eliminate as many parts as I could while allowing the device to function. The result of this long, meandering process is VECTr.
VECTr is a simple design that really works. The video on my website shows a very basic working model to illustrate proof of concept. The next step in this process will be to develop an actual prototype that can be safety tested. But, there is a little tweaking here and there that remains to be done. VECTr is patent pending and has attracted over 9,500 views on its You Tube channel, and has received some very positive feedback so far.
Now you know the long and winding path that led to VECTr. From here on out, this blog will feature updates on this work in progress. Share your thoughts on VECTr, and join the ride!
VECTr - Variably Expanding Chain Transmission 