We did our homework on this cog and we think you will be pleased with the result! This 16t cog smooths out the cog to cog transition when using the GC and a standard 11-36 cassette. You should expect this to shift well and last as long as the rest of your cassette cogs of similar size.
Here are the transitions WITHOUT the 16t cog (4 tooth max jump):
Remove the 15t -> 11-13-17-19....
Remove the 17t -> 11-13-15-19...
Here are the transitions WITH the 16t cog (3 tooth max jump):
Remove 15t & 17t-> 11-13-16-19...
Compatibility - any cassette that is compatible with the GC40 or GC42
See detailed instructions on our tech page: 16T instructions
1. Remove both the 15t & 17t cogs on your cassette and the spacer between them.
2a. For Shimano cassettes, install the 16t with the tab that has two dots in the wide notch of the freehub body.
2b. For SRAM cassettes, install the 16t with the tab that has the single dot in the wide notch of the freehub body.