I’ve got a tarmac SL6 disc with a 12x142 rear axle. I’ve been riding a different bike on my wahoo kickr, but I’ve been wanting to switch over to using the tarmac.
I noticed that all the recent generation specialized road bikes with thru axles have a recessed spot where the axle seats (its like a conical/cone seat). It doesn’t seem like the wahoo kickr standard 12x142 adapter works for this because it doesn’t have the same mating surface for the axle adapters.
Odd, I’ve had my SL6 on my kickr core without a problem. I’m 99% sure the inner part of the dropout is flat, where the axle meets the frame. If it weren’t, hub manufacturers would have to supply end caps that fit. The outside of the frame on the non-drive side is conical, where the the thru-axle sits against the frame, but that doesn’t have any influence on the hub end caps or kickr adapters.