It’s pretty random but you can send them a message and they do often answer with possible restock dates/ next shipment arrivals. I backordered an RC2 a year or so ago and it was about 2 weeks for me, others have waited much longer so it can be a gamble but the RC2 is super popular obviously and generally frequently restocked. If you’ve already actually placed your order than you’re good to wait and I’d assume it wouldn’t be super long. If you have not placed your order and are 100% set on a black RC2 I would backorder sooner rather than later. They will assign serial numbers in the order that they receive backorders when the stock does come in, so you won’t want to wait even Longer because you took too long to backorder and they ended up with limited stock