Design & Technology
Steering is a very important part of your motorcycle trike riding experience. How your trike handles on various road conditions may determine your level of enjoyment. All motorcycles, when converted to a trike, have a certain amount of steering stiffness when cornering as well as a small amount of "headshake" at low speeds. We recommend raking the front forks of your motorcycle trike with a triple tree to ease the steering in corners and give you a power steering effect. By altering your steering geometry, you alter the rake and trail, which determines the ease of handling of your trike.
Rake & Trail
Rake is the angle measured between the steering axis and vertical. The steering axis is the line about which the steering system turns. Although the angle of the fork tubes from vertical is often the same as the rake angle, they are not always the same.
Trail is the distance measured from where the steering axis meets the ground to where a vertical line drawn though the front axle meets the ground. It can be thought of as the distance that the front wheel "trails" the steering axis.
The effects that rake and trail have on steering performance can best be explained using a shopping cart front wheel as an example. The front wheel of a shopping cart is a castor that has a vertical steering axis that is in front of the wheel. The vertical steering axis results in zero rake, and having the pivot in front of the wheel results in a significant amount of trail. This results in the front wheel tracking directly behind the pivot regardless of the direction the cart is pushed. If the vertical pivot axis were directly above the wheel axle, the wheel would not track directly behind the pivot. In this case both the trail and the rake would be zero resulting in a wheel that has as much possibility of turning sideways as it does going straight. This is a very unstable condition for both a shopping cart and a motorcycle.
Motorcycles and trikes both use a certain amount of rake and trail to ensure proper handling and steering response. In general, more rake provides greater straight-line stability, less rake makes the bike more responsive. This is why the forks on a sport-orientated motorcycle are more vertical than those on a cruiser or touring motorcycle. In short, smaller rake values result in quicker steering, while larger rake values result in slower steering.
Installation of a Lehman Trikes Triple Tree kit improves the trike riding experience by reducing the steering effort required to turn the trike, while making the steering more responsive. The triple tree kit modifies the fork tube angle moving the front wheel further out in front of the trike, reducing the trail.
Lehman Trikes has experimented with a variety of different triple tree angles and has determined the optimum angle for both the Honda Gold Wing and Harley-Davidson Touring models. The angle chosen reduces the steering effort and improves steering response while maintaining the stability required at higher speeds.
Suspension is the only component that separates the driver and/or passenger from the ground. The suspension in a trike helps absorb harshness in the road. There are basically two common suspension systems currently in use on trikes today. They can be identified as either "independent" or "solid axle." Lehman Trikes offers both our traditional "No-Lean" solid axle suspension and a high performance version of independent suspension, which we call our LLS (Limited Lean Suspension).
Lehman "No Lean" Suspension
Lehman Trikes "No-Lean" refers to the Lehman proprietary design, which minimizes flex in the swing-arm and rear-end system. This design features a differential rear-end with internal solid axles. The Lehman "No Lean" philosophy begins with a solid, one-piece swing arm that is designed to be the most sturdy and inflexible in the industry. What this does is completely minimize the Trike's ability to sway or roll to the outside of a corner. The noticeable benefits are increased stability and easy steering, especially at highway speeds. This is our simple "No Lean" philosophy that is responsible for the best handling Trikes for almost 30 years!
"No Lean" Suspension models include: Renegade for Harley-Davidson FLH, FLT, FLS.
LLS -"Limited Lean Suspension"
Lehman Trikes LLS "Limited Lean Suspension" is designed with light-weight aluminum components and dual coil-over shocks to provide a smooth and supple ride. The Dual H-Arm suspension provides proper geometry, giving you consistent handling and precise control in corners, down the highway, or around town.
Independent suspension allows each rear wheel to move vertically, independent of the other. The left and right sides of the suspension are connected by an anti-roll bar. The anti-roll bar ties the left and right wheels together and limits the amount of lean the trike exhibits when cornering. By optimizing the anti-roll bar design, the Lehman Limited Lean Suspension is able to deliver both a smooth ride and a confidence inspiring feel when cornering.
LLS models include: Renegade LLS for Harley-Davidson FLH & FLT, Trinity LLS for Harley-Davidson FLH & FLT, Monarch II LLS for Honda GL1800 & F6B
For more information on Lehman Trikes contact us today.