Boa Technology Inc., developed a unique reel system for lacing items such as sports shoes, buckles, ratchets, and Velcro straps. The company’s engineers designed all of the components for the S1 27 mm Reel Closure System for specialized S-works shoes.
The S1 Reel Closure System prototype is shown here with its single tie.
The final design has a glove-like fit with smooth, even closure and no pressure points. The device uses micro-adjustable reels that offer seemingly infinite degrees of fine-tuning and one-handed adjustment with a quick turn of the Boa dial. Because the closures are quick-on/quick-off parts they allow users to save time when seconds count. Once the reels are locked into place, they are fixed. A simple faucet or hose can be used to clean dirt and grime from the lace guides, which helps to extend the life of the system and assure it is ready for the next use.
From the onset of the product development process, Boa designers knew an innovative and competitive product was needed. Their goal was to produce a device that was nearly 40% lower in cost, could provide precise adjustment with only 1 mm of resolution per click, lower in height, smaller in diameter than previous low-power reels, and incorporate only one active lace (instead of two) to increase the overall strength of the system itself. The lacing system consists of four primary components: knob, spool, housing, and lace.
By meeting their own challenge, Boa was able to create a product that was far superior to the ratchets and Velcro typically used in cycling. The S1 Reel weighs less than older systems, provides secure holding power, increases breathability, and has much higher resolution than comparable products that offer 3-5 mm of incremental adjustment.
The company created several prototype iterations before finalizing the design. The original concepts, for example, used different types of reel mechanisms. Rapid prototyping parts were produced by ZoomRP.com through their online service. Boa used SolidWorks 3D software for the development of the final parts. From SolidWorks, they exported an STL file to upload to ZoomRP for part production.
All of the components were built through selective laser sintering (SLS) using a nylon material. SLS offers one of the widest ranges of materials to choose from, including filled thermoplastics. Overall capability of the SLS process includes layers at an average of 0.004-in. thickness. The process produces strong finished parts that come close to production-like materials. Since there is no tooling required, prototype parts can be produced quickly and at low volumes.
Because most of the clearance specifications on the needed parts were approximately 0.2 mm, part accuracy was important. The company only ordered parts that were wet/dry blasted. And, since they were prototypes used for testing, no color was required.
In this photo, the S1 Reel System from Boa Technology is used on a Specialized 2011 S-Works Road Shoe.
The most difficult part of the project was in the production of the components. According to Boa, it was difficult to build such small features. The largest piece of the S1 Reel Closure System was the knob, which was only 27 mm in diameter.
Today, the device is used on a number of shoes made by some of the largest sports shoe manufacturers in the world, as well as for medical braces. Pro cyclists, including over 100 pro peloton riders, have been wearing shoes with the S1 Reel System this year.