[TexasSP]

The 3905 tranny has no more rotating mass than the gorilla single speed as it is single speed as well. The 3905 tranny has fixed the issues with the old tranny so there is really no need to spend money on something else. It holds up fine to my neu 1515/2.5d and is doing well for many others. In fact I have not heard of any tranny failures on the 3905.