Exclusive: Cranklock technical drawings
The Cranklock is a brilliantly simple idea that offers speed, safety and security benefits to cyclists by allowing the rider to lock the pedals at will - and our article and podcast on the subject has generated lots of interest over the past week. So we know what it does, but how does it do it? Led by Steve Briggs, the company's engineering team has left no stone unturned in finding the right solution and many patent applications have been filed covering different versions of the mechanism. While exact details on the final production model are still under wraps, Cranklock inventor Chris Toal has given us a peek at early technical drawings from a couple of the patent applications to provide an insight into how the Cranklock will operate... plus the first pics of a new downhill prototype.
We spoke to Chris about the various approaches taken in the patent applications - here's a summary:
Figure 1 - This drawing shows a spring-loaded drop pin mechanism (yellow) inside a tube (blue) which would be housed internally in the bike frame. The mechanism is controlled via a cable running from the handlebars and can be spring loaded in either direction.
Figure 2 - This sliding mechanism approach consists of a conventional crankshaft with a spline and a sleeve (yellow) which sits inside the crank tube. There is a keyway on the outside and a second cylinder (orange) with an internal spline locks the crank when it slides across. Chris points out that this is one of the designs which could be packaged as a simple retrofittable kit for standard bikes.
Figure 3 - The third sketch also shows a sliding mechanism, but with a very different approach to how its controlled - instead of a cable this design uses an electronic switch. Here round pins (pink) are slid into grooves on the crankshaft housing to lock the pedals, but instead of a mechanical slide to lock them in place, this approach uses a collar made from high tensile alloy that contains highly charged magnets (white). The coils at either end (orange) are a reversible polarity throw, so moving the collar into a locked position is controlled electronically. Although not shown, there could also be a small generator integrated into this system to keep the battery charged - very clever.
Stay tuned for more images and video of the Cranklock being put through it's paces in coming weeks, and check the gallery for sneak look at Cranklock's downhill prototype bike and a new image showing the pressure the Cranklock allows you to put on the rear tire at any angle - an eye-opener for stunt bike riders we suspect.