If you think wide range cassette adapters are just for mountain bikes, think again. Relic MTB showed off this 40-tooth cog that slips onto the back of a Shimano 10 or 11 speed cassette. It comes with an 16-tooth intermediate cog to replace the 15 and 17 usually found in the lower third of the cassette. But if you think that’s big…

This demo unit shifted from the stock cassette to the oversized one surprisingly smoothly, and it works because they’ve knocked off the Goat Link, which gives the chain the necessary space between the derailleur’s upper pulley and the cog…and allows for enough chain wrap.

It works with 10-speed cassettes with a 28t big cog, and 11-speed cassettes with up to a 32-tooth cog. Weight for all three parts is ~92g.

Just in case SRAM Eagle’s 50-tooth isn’t enough, there’s this 52-tooth cog. Like the Road 40T, it slips onto the back of a Shimano cassette and comes with a 16t intermediate cog and a spacer to go between the largest stock cog and the oversized piece.

System weight is 146g for all three parts with the 52-tooth cog, and there’s a 50-tooth cog kit that’s 2g less. Pricing wasn’t set, and the parts are promoted on their homepage but aren’t yet listed in the product section.

RelicMTB.com