Pulled from the Cyril Huze blog:
Harley-Davidson TriGlide Suspension Upgrade By Progressive Suspension
The Tri Glide, the remaining trike model from Harley-Davidson, is evidently a very heavy vehicle facing unique handling challenge due to the loads generated by the steering forces. Harley Tri Glide factory forks are those of a two-wheeler and cornering dynamic feels much more like when you drive a four wheel vehicle.
So, the Progressive Suspension engineers started to work on these issues and were able to think out a suspension solution to improve the oem chassis/suspension setup.
They are now able to offer a pair of high pressure gas charged Monotube damper cartridges with progressive rate springs tuned to the weight challenges (it’s heavy!) of the Tri Glide. The result is reduced brake dive, improved bottoming control and increased front end cornering grip, all in a tidy cartridge package that’s designed to last the life of your Harley trike.
Progressive has also developed a new set of shocks for the rear of the HD Trike. They’ve valved and sprung their proven 416 Series hybrid air/coil shock to suit the live axle on the Tri Glide and improved the ride height to help reduce dragging as well as increase ride comfort and improve bottoming control. The combination of their Monotube fork Cartridge kit and 416 Series Shocks will help the Tri Glide become the mile eating monster promised by Harley, without adding undue cost or complexity. Available separately as front and rear packages.