Mechanical Design

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One of the questions we often receive at Skylock is “Why is Skylock so expensive?” We feel Skylock is reasonably priced for the features we are providing. To explore the question we need to analyze both the mechanical and electrical components.

Mechanically the Skylock shackle needs to be cut twice in order to break. It needs to be cut twice because there are two locking pins that engage the shackle, rather than the traditional single side locking mechanisms. This is by default more secure than the Kryptonite Evolution series and most other steel locks out on the market.

For example, the New York Kryptonite Fahgettaboudit Ulock has an 18mm shackle. The area of a circle (cross section of the shackle) is πr², so for the lock mentioned above the cross sectional area is 3.14* 9² = 254mm². The cross sectional area of Skylock is 237mm² (we calculated the area of two circles and the space in between). The diagram below indicates cross sectional areas:

Skylock cross-sectional area vs Kryptonite Fahgettaboutdit

While being comparable in shackle cross section area to the Fahgettaboudit lock, the differentiating factor about Skylock is its shape. Most bike locks have a cylindrical shape which makes cutting pretty easy. Bolt cutters have all of their load concentrated on two points (see image below). Knowing this, we designed Skylock to have a teardrop cross section because it spread the load of a cutter across a larger surface, effectively lowering the stress. This teardrop shape is what gives Skylock its sleek look and also what makes it stronger than its competitors. Truly form meets function.

Distributed loads on Skylock shackle versus point load on other shackles

At the time of this post the cost of the Kryptonite Fahgettaboutitlock is $111.95 at REI or $96 at Amazon with no electrical components (a ‘dumb’) lock. While no lock is unbreakable, a good lock should serve as a deterrent.