The majority of our kits are built in-house to guarantee quality control. All manufacturing is done by our experienced team, using state-of-the-art equipment. Lehman trike conversions retain the factory drive and suspension components of your motorcycle, making service and maintenance simple and convenient. Upgraded suspensions are available for most conversions and recommended on some models. To complement the suspension, premium quality wheels and tires are included to deliver the smooth ride, stability and exceptional handling you’re looking for.

All Lehman original body designs are built to a 54-inch width and crafted to complement and enhance the style of the host motorcycle. Installation is a simple bolt-on procedure with bodies finished in sanding gel coat, ready for your custom paint design. As an option, and at your request, bodies can also be provided painted to precisely match the original factory color scheme. In either case, your Lehman conversion kit will be created by our highly skilled and dedicated staff. We’re motorcycle people - it’s our passion. It’s what we do.

Lehman trike conversion kits are designed, engineered and manufactured to provide superior handling, performance, and durability of your Threedom Machine. Lehman engineers design our trikes to eliminate stresses to the host motorcycle that it was not designed to withstand. This commitment to original thinking and leading edge design has resulted in such developments as the famous Lehman "No Lean" suspension, which offers exceptional high-speed handling and confidence inspiring maneuverability. Lehman Trikes offers the most effective trike braking system that has been tested and complied with D.O.T. specifications to date.

Every part of our kits are checked and double checked before they leave our 30,000 square foot facility in Westlock, Alberta on its way to you via one of our friendly and service-oriented dealers throughout the United States and around the world. Soon after delivery, it will become your personal expression of Threedom!

Lehman trike conversions offer an exceptionally stable ride and nimble handling characteristics. Ideal for touring at highway speeds. You will enjoy unmatched versatility and convenience, with more storage space and a greater safety margin when pulling a trailer. Add to that, supreme comfort and the exhilaration of the open road and you have a Threedom Machine.

There are a limited number of suspension systems used on trikes today. They can be placed into two general categories - conventional suspension and independent suspension. Conventional suspension refers to the wheel hubs being bolted to separate axles on either side of a differential, which uses a swingarm suspension system. Independent suspension means that each wheel is bolted to separate axles utilizing individual suspension components. Trikes built with less rigid swingarms will perform much like those with independent suspension.

Trikes perform best when there is no flex within the swingarm or suspension components. Flex is undesirable because it translates into what the rider feels as body roll or sway. When this occurs, the trikes ability to corner is affected, as it tends to lean outward in the corner. As the body rolls, the trike becomes unstable in the corners and forces the rider to counteract these effects. Trikes manufactured with independent suspensions and those with more flexible swingarms all suffer from this problem. For example if cornering to the left, centrifugal forces and momentum cause the trike to lean to the right. When it leans to the right, the trike wants to travel to the right, therefore making it more difficult to corner to the left. This is manageable at low speeds but gets progressively more difficult as cornering becomes more aggressive. In most cases, the riders’ speed must decrease when cornering on a trike with independent or less rigid suspension. Cars with independent suspension also lean outward in corners but are stabilized by the outside front wheel.

Some manufacturers have tried to obtain a medium between conventional and independent suspensions, with little or no success. The addition of sway bars and/or air bags to trikes with more flexible suspensions does not eliminate the dangers listed above. The only solutions are to build an extremely long and wide trike, or one with an inflexible swingarm. For these reasons, Lehman Trikes, Inc. has patented the “No Lean” suspension.

The Lehman “No Lean” suspension is designed and manufactured to be the most inflexible in the market. Through reinforcement of the original motorcycle frame combined with added bracing of the swingarm, there is little sway or body roll. The Lehman suspension is manufactured with the minimum amount of moving parts possible, therefore decreasing the need for maintenance and adjustment. Air is located only within the shock to adjust for load variation, not to compensate for swingarm design. This allows Lehman trikes to corner more solidly and with less physical effort from the rider. One side of the suspension will not compress relative to the other side, so the trike will remain closer to the horizontal. This allows the rider to maintain his speed throughout the turn.

At Lehman Trikes, Inc. we feel that performance and safety should not be sacrificed upon converting to a trike. With over fifteen years of research and development, Lehman Trikes, Inc. has a knowledge base that is second to none. We use this knowledge to build the world’s safest and best handling trikes.

1. What is “No-Lean” suspension?

The single greatest factor that determines how a trike performs is swing-arm design. No other single component has such an impact on handling and ride quality.

“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 swing-arm is a one piece reinforced design, specially constructed to reduce all torsion effects.

2. Why should the swingarm be so rigid?

Performance. The way to maximize stability and improve handling is to use the most rigid one-piece swing-arm possible. Using a rigid swing-arm ensures that while cornering, all three wheels remain firmly planted on the ground, while the center of gravity stays where it belongs – centered over the rear end. Flex within the swing-arm would cause the trike to lean resulting in decreased stability and heavier steering.

3. How does “No-Lean” suspension compare to independent suspension systems?

“No-Lean” is the exact opposite of independent suspension. Independent platforms are designed to allow shock compression on one side of the trike while allowing extension on the opposite side. For this reason, body roll or “sway” must be expected. Body roll shifts the center of gravity to the outside wheel in curves and creates a less stable condition. To compensate for this, the rider must slow down or the trike may tip over. In effect, a trike with independent suspension will tip easier and faster, due to the center of gravity shifting towards the outside of the trike. The addition of anti-sway devices simply limits this tendency by restricting the independent movement, which also limits the smooth ride benefits.

Translation:

No other motorcycle-trike conversion is as stable or handles as well as the Lehman “No-Lean” Trike.

There are three main components to a basic drive shaft system:

1. Front universal joint

2. Drive shaft, and

3. Rear universal joint

The purpose of the shaft is to transfer power from the motorcycle transmission to the differential. The universal joints are required because the differential is offset and at an angle to the transmission.

All universal joints are designed to have a minimum of 1/2 degree of working angle. This angle is necessary in order to keep the needle bearings contained in the caps rolling. At angles less than 1/2 degree, the needles stay locked in the same position and wear into the cap, causing vibration and eventually failure.

All universal joints vibrate. This is a property due to the design of the joint.

So the next question is: "If universal joints vibrate, then why does my car not vibrate?"

When a drive shaft is designed for application in a car, the joints are always in pairs. When there are two joints, they can be phased so they cancel each other out and no vibration is felt.

The universal joints work as follows:

When the output shaft turns, the two caps of the front universal joint must turn around the center of the output shaft.

When we look at the opposite side of the universal joint the other two caps on the universal joint must turn about the center of the drive shaft.

Because the drive shaft is at some angle to the output shaft, the cross of the universal joint must wobble back and forth to allow the bearing caps to trace these circles out while rotating.

This causes the rotating speed of the drive shaft to fluctuate on every turn, at first speeding up slightly faster than the output shaft, then slowing to slightly below the output shaft speed. If this effect is not counteracted with a second universal joint, it will create vibrations.

At the other end of the driveshaft, there is a second universal joint. This joint is timed to the front universal joint in order to be exactly opposite to it. When the drive shaft speeds up from the action of the front universal joint, the action of the rear universal joint slows it down, and vice versa. This produces a constant shaft speed at the differential shaft.

Automotive drive shafts are not straight for the reasons explained above. The rear end moves up and down, so the drive shaft can never be perfectly straight.

There is always lots of discussion within the trike community regarding raked triple trees and how they affect steering. Following is a short analysis and explanation of these steering kits and how they affect trike performance.

Rake is the angle of the steering neck tube from the vertical. It is NOT the angle of the fork tubes, although in many cases these angles are the same. Rake is measured in degrees, and is a frame specification. Increasing the rake will move the front tire farther from the bike. In some applications the angle of the steering neck tube and the angle of the fork tubes may vary. One of the most common ways of achieving this is by changing the angle of the fork tubes through the triple trees. This provides an appearance of rake without modifying the motorcycle frame.

Trail is the distance that the front wheel is being pulled down the road. To understand this think of the castor on a shopping cart, these have zero rake but lots of trail. The wheel axle is located behind the pivot point, which causes the wheel to follow the pivot no matter where it’s going. As the cart is pushed forward the wheel swings into line behind the pivot. If the wheel axle was directly underneath the pivot you wouldn’t be able to keep the cart in a straight line as the wheel would have as much possibility of turning sideways as it would for going straight.

Trail is measured in inches and is determined by measuring the length at ground level between a vertical line intersecting the front wheel axle, and a line through the steering neck tube (or rake). Therefore, trail is not a fixed value. It will vary based upon lean angle, fork tube angle, and even the diameter of the front tire.

In general, more rake provides greater straight-line stability, less rake makes the bike more responsive. This is why the forks on a sport bike are more vertical than those on a cruiser. At large angles, the rake can cause the trail to become negative, creating a very stable, unresponsive condition. In short, steep rake = quick steering, while laid back rake = slow steering.

The more trail you have, the greater the high-speed stability. However, the trade off is that steering gets heavy and slow at lower speeds. The longer the distance, the more stable but the heavier the steering; the shorter the distance, the lighter and more twitchy the steering. This is why the trail on sport bikes is less than that on cruiser or touring models. It doesn’t mean that cruisers don’t go around corners or that sport bikes don’t go in straight lines, but it does affect how easily they do both. Short trail = light steering.

The steering kits offered by many trike manufacturers are a way of increasing the fork tube angle. These slightly decrease the rake of the trike due to the lowering of the front-end. However, they provide for quick and easy steering but result in decreased stability at higher speeds.

Therefore, the greater the angle of the steering kit, the lighter the steering and the less the stability. Lehman Trikes has experimented with a variety of different steering kit angles and has determined that the optimum angle for both the Honda Gold Wing and Harley-Davidson Touring models is three degrees. This provides for a “power-steering” effect while maintaining the stability required at higher speeds.