SRAM 12t X-Sync pulley for 1x drivetrains

cults3d

There are numerous jockey pulleys available on Thingiverse, but most of them feature the older 11t design. Recently, I managed to damage two SRAM jockey pulleys, despite the derailleur functioning perfectly, and discovered that replacement pulleys cost $30 - this led me to decide it was time to contribute to the growing collection of Thingiverse jockey pulleys. For some reason, SRAM believes that jockey pulleys require a narrow/wide design that is excellent for chain retention on chainrings. I'm not convinced it makes much difference, but I matched their design as closely as possible. I have included the raw model, along with a split version that can be printed in halves and then glued together using superglue. After experimenting with supports, I found them to be quite difficult to clean up, so printing the pulleys in halves has proven to be a more practical approach. This design is centered around the 626 bearing used in SRAM's X-Sync pulleys, and includes two press pieces for removing the old bearings and installing new ones. However, it appears that the 626 bearing is less common than other options, so I plan on creating a version utilizing the more widely available 688 bearing. Unfortunately, this will not be compatible with SRAM hardware, making the original design still relevant. Update: After eight months and over 1750km of riding through various seasons, I removed the lower pulley printed in PLA and cleaned it up - it was in excellent condition. The photos show some wear, but it's minimal. The only issue was that the bearing bore had expanded slightly, causing the pulley to shift side to side and resulting in noticeable wear on the face. I plan on redesigning the pulley in Fusion 360 and addressing the bearing fitment issues in the new design.