e*thirteen has jumped into the oversized cog cassette adapter fray with two solid looking and well priced options.
The new EX Cog comes in a 40-tooth size for use with 34t max cassettes, in Shimano tooth profiles only. There’s also a 42-tooth cog to go with 36t max cassettes, with ramps and profiles timed for either SRAM or Shimano, helping ensure they work as well as possible with each brand.
Bonus number one: They come in colors – red, blue and black, to be exact. Bigger bonus? You won’t have to blow your bonus to get one. Retail is set at just $69.95 each. Beyond all that, they’ve gone out of their way to make it easy to upgrade your existing 1×10 or 2×10 setup by offering cassette compatibility charts and extensive how-to instructions on their website.
Cogs come with longer replacement B-limit screw for derailleurs since the stock screw could easily get maxed out, particularly on the 42t setups. They say it may not be needed on some 40t installs depending on dropout shapes and angles.
The compatibility chart not only covers cassettes, it also shows which 2×10 drivetrains can work. Chain wrap capacity will be an issue when used with some double cranksets. They also do not recommend using the 40t with 36t max cassettes – best to stick with the 36-to-42 and 34-to-40 upgrade patterns. Why? The ramp patterns aren’t optimized for transition between the two.
Like the other brands’ offerings, you’ll need to remove the 15t or 17t cog in the middle. And ideally you’ll have a medium or long cage rear derailleur. Charts, instructions and more here. Shipping to stores May 15, 2014.