Tolle patented these famous adjustable triple trees in 1986. Their Number One advantage is that they allow you to adjust the fork angle to achieve the optimum trail. Nobody knows exactly what the correct trail is, guideline for rigid frames is between 2" and 4" (50 and 111mm), where frames with rear suspension need a trail between 3" and 6" (75 and 152mm). You can adjust these triple trees from zero to 17 degrees, allowing you to change to the optimum trail, no matter if you use short or long forks. Tolle adjustable triple trees are CNC machined in aircraft quality aluminum and have a mirror shine polish finish. Lower triple tree plates have open slots in the rear, to properly secure the tubes. OEM triple trees do not have this unique feature. Available as 220mm pitch Mid-Glide triple tree, or 250mm pitch Wide Glide. Both are suitable for 1 5/8" (41.27mm) diameter fork tubes. These triple trees can also be used with 39mm fork tubes as found in XL, FXR and Dyna when you also order 39mm adapter bushings and fork plugs. Steering stop kits and adapter bushings as well as other related triple tree parts are separately available.