AAAAGGGGHHHHH!
I have this wheel that needs an adapter, to make it 142×12…

can’t bloody get it right, can I! I’ve tried these adapters and the wheel doesn’t fit.

I know it’s not the gold ones, they came with the wheel and are the boost adapters, the red ones aren’t much thinner – both of these are too wide for the 142mm dropouts, and the black ones are a mystery – i’ve no idea how they fit onto the axle.
Could anyone offer some advice? I’ve nearly spent as much on adapters as I did on the wheel!
thanks muchley

If it came as boost then it probably won’t ever fit as the whole hub shell will be wider.

What nixie said. If it’s a boost wheel then you can’t adapt it to fit a 142 frame.

if it’s boost, wouldn’t it be 148x12mm as standard? without any adaptors?

I didn’t realise that it might be boost flange spacing, I bought it new, off eBay as a 135/142 hub.
… that would mean the disc rotor would be off too…bugger! 🙁

The adaptors are end caps. You need them to help protect the bearings and also provide a larger clamping surface. Was it the whole wheel you bought? Time to talk to the seller or sell it on as the correct description.