Is it possible to get an adapter to put Specialized S Works BB30 cranks into my non-BB30 Specialized SL2?
Or can you only get adapters that go the other way, allowing you to put Shimano type cranks into BB30 bottom bracket?
You can only go BB30 to Shimano. The opening in the BB shell of the threaded frame is not big enough to fit the BB30 bearings into. If the bearings go “outboard”, then the BB would be too wide for those cranks.
There might be a way to take the insert out of the frame. I’m fairly certain that Specialized does the same thing that Cannondale does as far as making their frames compatible for normal 24mm BB spindles - they use a threaded Al insert that is “permanently” loctited into the frame.
I have heard of a tool that used to remove the insert and I really don’t know how easily it is removed - but if you want to go BB30 with your SL2 this is probably your best bet short of buying an SL3 (or Pro frameset).
Nope. I’ve got an SL2 that came threaded for a normal BB and a SL3 that came with the BB30 crank. You can only go one way.
In the future they will only make the BB30 style with adapters to use regular cranks. In the past though they produced two different frames. One BB30 and one “regular”.