I’m looking at getting a new crank, Sram eagle gx, there are a few good deals kicking around, the bike has a 73mm bb shell and I believe I need a boost crank is that the 53mm gx crankset or 49mm ? Or can you have a non boost 53mm crankset and if so what’s the blinking difference? It’s making my brain hurt.

For Sram cranks, the crankset is all the same, but the spider 9or direct mount ring) provides the offset to make it boost/non boost.

49mm would be non boost, 53mm boost – confusingly, SRAM also do 156mm and 168mm cranks, that refers to Q-factor (width between the pedals) of the cranks

Many thanks for the clarity. Think the term ‘standardisation needed’ spring to mind.

But those are the standards aren’t they? 😉