Installation of Super CNC 12/14T Strummer Pulley on Shimano 105 Rear Derailleur

In the video below, you can see the customer installing the Strummer Super CNC pulley on the Shimano 105 rear derailleur (with the long cage variant). On this rear derailleur (RD), it has 11 and 13T default gears, so the user decided to upgrade the size to 12 & 14T.

The pulley diameter is larger, so the bends in the chain are reduced. The black ceramic bearings on this pulley have low friction, so the rotation experiences lower friction. Both of these factors make the rear derailleur operation more efficient.

Hard alloy material, so this pulley is durable during long-term use.

Narrow wide design also helps chain retention (chain is less likely to fall off).

Note: The making of this video was not sponsored by Strummer. The purchase of the product and the making of the video were done on his own initiative.