e*thirteen has entered the aftermarket cog game with the Extended Range EX cog, a product designed to cater for the increasing number of mountain bikers who are looking to harness the advantages of a larger range of gears without needing a front derailleur.
The EX cog is designed to be retrofitted into an existing 34-tooth 10-speed cassette, which in turn replaces the 15- or 17-tooth cog within the cassette. Unfortunately the EX cog won’t work with 36t cassettes, as it will affect the drivetrain's timing between gear changes.
The Extended Range EX cog can be fitted to a 10-speed 34t cassette
Available in both 40- and 42-tooth guises, with specific ramping on the teeth for either SRAM or Shimano host cassettes, the new EX cog will be the icing on the cake for many a bike and should be a simple upgrade for many riders. It's available in black, blue or red.
e*thirteen claim the EX cog is compatible with some dual-ring setups, although a long-cage derailleur and a longer chain would be needed in such cases.
While not e*thirteen is not the first brand to offer an aftermarket cog such as this, its decision to add this product to its portfolio is further evidence of the demand for a revised, simpler gear setup. It's a trend we're excited to see and one that we think will see more and more mountain bikers giving up their front derailleur.
Three colours are available
Also included, is a new B limit screw for the rear derailleur, which is designed to deliver the required increased clearance with the EX cog in place. Installation instructions for the new EX cog can be found on .
The EX cog will be priced at £54.95 / US$69.95 and will become available from May.