Earles Forks
The Earles fork was a variety of leading link fork where the pivot point was aft of the rear of the front wheel — this was the basis of a patent for the design. Designed by Englishman Ernest Richard George Earles, this triangulated fork actually caused the front end of a motorcycle to rise when braking hard — the reverse of the action of a telescopic fork. It was designed to accommodate sidecars, and from 1955 to 1969, BMW used the fork even though most of its motorcycles were sold as solo bikes.
Perhaps the greatest benefit of the Earles fork in sidecar use was its adjustability for rake and trail. The swinging arm pivot had two positions. Moving it to the forward position reduced trail, allowing the bike to turn with less effort when a sidecar was attached.