Re: British slang.
I even try to trip up potential posers on bike forums.
I'll ask them if it's a good idea to change out the mousetrap on my new Sportster by upgrading it from plastic to copper. The old hands snicker.
A "mousetrap" is a 'clutch booster' last seen on early panheads. They were never on a Sportster. The entire assembly is essentially a coil spring, and it cannot be made out of either plastic or copper.