You cant currently buy this pulley from ALTA. They have plans to make them available again. Below is an actual conversation with ALTA. (thanks to Sarag from MU)
→Hi, do you guys still sell the R56 Lightened crank pulley? Can't seem to find it.
Customer Service 4: Thanks for asking! Let me check
Customer Service 4: we used too, but not any longer
→Aw, alright, thanks for checking!
Customer Service 4: You are the third person I have spoken to this week that wanted one
Customer Service 4: I will mention it to production to likely poke the button on some more of them
→Lol, maybe that means ALTA should get them back!
→Yes! Thanks so much
Customer Service 4: yeah I see no reason we won't actually
Customer Service 4: so expect 4-6 week and they will be back
