Simkins Designs CDP brakes
Simkins Designs is the work of former bicycle racer whose day job as a mechanical engineer working for a Silicon Valley based medical device company has given him the skills and foresight to set out to redesign the humble brake caliper.
The fruits of his labour are the Coupled Dual Pivot (CDP) brake, which uses fewer parts than competing dual pivot brakes. The design brief was for them to be as aerodynamic as possible, and judging from the photos, they certainly are small and compact.
[Ed.'s note: viewed from 'in front', a conventional dual-pivot caliper has a Y-arm holding the left-hand brake block pivoting on the centre bolt and a C-arm holding the right-hand brake block that pivots on a short stub arm attached to the centre bolt. The Simkins design does away with the stub arm, instead using a lateral extension to the Y-arm to house the pivot for the C-arm... The movement geometry therefore differs from a conventional dual-pivot caliper, since the C-arm pivot arcs away from the wheel as the caliper is closed. This, in turn, alters the path of the brake block attached to the C-arm. There are two springs in the Simkins caliper, one of which centres it to minimise the effect of this movement path.]
That lack of parts [apparently including cable adjuster - ed.] also means the weight it is on the low-side at just 275g for the pair. They’re made from 7075 aluminium with stainless steel and titanium hardware, and pivots are sealed, with the ball bearings rolling in machined grooved races.
"The CDP Brake achieves a compact design without compromising on leverage by taking advantage of two pivots. The pivot placement, combined with the patent pending self centering CDP design results in a small, wind cheating brake."
The patent pending brakes are CNC machined in the US, and are available with polished or raw machined finishes. Cost is $239.99, and they’re available direct from www.simkinsdesigns.com.