When SRAM launched their RED Hydro 22 and S700 road hydraulic shift levers, they provided the world of road disc brakes with its first taste of legitimacy.
Never before had a major manufacturer offered a hydraulic brake/shift lever combination compatible with existing road groups, so disc brake adoption was reserved for those willing to go with mechanical systems, thereby missing out on the superior modulation and lever feel afforded by a hydraulic system.
Unfortunately though, SRAM’s initial design was met with several design flaws that could cause the brake to fail.
After investigation, it was found that the lack of circumferential machining on the master cylinder piston, paired with a manufacturing process that resulted in the cylinder bores in the lever body being slightly out of round were at the heart of the original failures.
Inadequate sealing materials, namely O-rings that lost their necessary performance characteristics when subjected to freezing temperatures only served to exacerbate these flaws.
This resulted in a series of brake failures at particularly frigid cyclocross races late last year, leading SRAM to contact the Consumer Product Safety Commission to initiate the recall process. (It’s worth noting that SRAM announced the recall ahead of the date dictated by the CPSC in order to keep riders safe, and off the brakes at the Indiana State CX Championships, a week before SRAM was supposed to announce the recall.)
Faced with the directive to condense an entire 9-month design cycle into just over 4 months, SRAM engineers at the Colorado Springs Development Facility were certainly handed a weighty task.
Successful in their efforts, engineers have developed entirely new machining process for the piston in the master cylinder and a new manufacturing process for the plastic composite piston bore within the lever body.
New seal materials have been used, and the entire system has been tested extensively in an environmental chamber under a wide range of temperatures and pressures.
Additionally, a reshaped bladder now resides in the lever body as well, no longer featuring a butyl rubber construction that SRAM found was introducing air into the brake system, much the same way a butyl-rubber inner-tube is permeable to air, slowly deflating over time.
Quite literally rounding out the changes to the new lever, are a few slight tweaks to the shape of the lever body itself, as it gains smoother, more rounded edges and a slightly taller profile.
According to SRAM North America Market Rep, Ed Nasjleti, engineers on the project put in a great deal of overtime and “lots of weekends” to make sure consumers affected by the recall weren’t left waiting too long for a replacement product.
With stock arriving at SRAM’s Indianapolis distribution center Friday, it appears that SRAM was indeed able to meet company founder and CEO Stan Day’s promise that a replacement lever would be available by mid-May, an impressive feat to be sure.