Understanding Harness (Suspension) Systems

Paramotor harness systems can be categorized by their in-flight hang point: low, mid, high, or hybrid. Only judge a machine while its hanging, not sitting on the ground. A high hang point (or attachment point) is where the risers attach above the pilot's shoulder, low hang point is where they attach below, and a mid attachment is near shoulder level. A Hybrid suspension moves after launch. For a comparison of each system's vice and virtue, check out Hang Points: High or Low?. Pivot point is where the risers, carabiner and any strap the carabiner attaches to, pivots on the frame or harness.

Attachment Point: Hard or Soft

When carabiners attach to the harness webbing it is a harness (or soft) attachment as pictured far left. When the carabiners attach to a frame part or short webbing that attaches to a frame part, it is considered frame (or hard) attachments such as the 2nd picture at left, a Walkerjet. All low hook-in machines such as the Pap, Miniplane Weight Shift, Fly with weight shift kit, Airfer, HE, and others have hard attachment points where the carabiners either attach to a frame or to a short piece of webbing that attaches to the frame. The significance is that the pivot point (described below) is usually the frame and not harness webbing.

The original style Fresh breeze, pictured far left, is a mix of soft and frame attachment systems because the carabiner attaches to a floating metal piece that serves as a spreader bar. Since that bar is not attached to the motor frame, the effect is that it behaves like a harness attachment system. A new (introduced 2006) Fresh Breeze harness is more standard, having soft attachments and better torque handling.

The SD, pictured 2nd above, is a high hook-in, frame (or hard) attachment system where the J-bars are able to pivot up and down. Nearly all original paramotors had fixed J-bars that the carabiners attached to and these, too, are frame attachments.

Spreader Systems

Almost all paramotors employ some method of pushing (spreading) the front harness webbing away from the pilots chest while under power. That prevents motor thrust from pushing you uncomfortably against the front of the harness. Distance bars, comfort bars, underarm bars, J-bars, etc. are all way to accomplish the purpose.

Only the most basic and low powered machines do not use spreader systems such as the now-rare Fly 70 and Adventure F1.

Bars that pivot up and down are usually intended to improve weight shift (better termed riser shift). Bars that pivot outward (they must never pivot inward) are intended to improve egress/ingress. When mentioned here, pivoting bar refers only to those that go up and down.

Sliding strap refers to systems where the front webbing can slide up and down through a slit at the end of each bar. This is done primarily so the seat bottom can go flat against the frame while running but it also allows weight shift in flight. Fly Products and the Comfort-Bar Fresh Breeze use this method.

J-Bars. Early machines all came with overhead J-bars to better distribute the heavy motors of the time. So the term J-bar now means over-the-shoulder J-bar whether pivoting or fixed.

Trikes

Nearly all wheeled machines use high hang points. They frequently use the paramotor's harness (like the Paratoys quad unit shown at left) but sometimes hang from a frame. The frame mount method allows the pilot to sit lower while keeping the pivot point above the thrust line for stability.

All tandem trikes that I'm aware of use a frame mount since the frame is used as a spreader system. They must balance the weight of the passenger and allow moving the hook-in point to accommodate varying pilot/passenger weights.

Riser Shift (Weight Shift)

The purpose of weight shift is to move the risers differentially to help turn. For a left turn, the left goes down and the right goes up. All machines have some weight shift ability but not necessarily by design. Any machine that allows less than 3 inches of riser shift with normal effort is considered to non weight shift.

The swing arm is another name for vertically pivoting bars.

The white Sky Trike is a harness mount system while the tandem Lamouette "Barney" trike is a frame-mount with adjustable holes to accommodate different pilot weights. Photos by Kevin Kanarski.

Low hang point (hook-in)

Low hang points are used to achieve a feel more akin to free flight. It's involves trade-offs because motor weight requires the hook-in point to be moved back towards the motor. These machines, when coupled with pivoting bars, usually allow significant weight shift. 

Low hang point models are a bit more challenging for new pilots to master launching and move around more in response to turbulence, especially fore-aft tilt. Some pilots find them to be more comfortable in flight due to the lower hand position.

• Fixed underarm bar. Non weight shift.  Examples: Bailey 4-stroke, Original Walkerjet, Flattop. These almost always have a slightly higher hook-in point than the pivoting bar type described below. These could also be called Mid-Low hang point styles.

• Pivoting underarm bar: The pivoting bar is made to improve weight shift. Additionally the hook-in points are usually lower than the fixed underarm bar models, making their weight shift even more effective. PAP was the first to popularize this. Examples: PAP, Airfer, HE, Free Spirit.
  
  The Miniplane with Weight Shift improves modifies the pivoting underarm bar by pivoting it up high on the frame but then curving it down under the pilots arm and up where the carabiner attaches. That puts the carabiner pivot point high enough to completely eliminate thrust-induced tilt and also dramatically reduces the fore-aft tilting felt on other low-attachments systems.

High Hang point (hook-in)

High hang points reduce the amount of movement felt by the pilot from turbulence. Many of the sport's most prolific instructors have found they are easier for new pilots to launch.

They are frequently more erect in flight although that can be adjusted on most machines at some expense in launch ease.

• No bar: The harness geometry has webbing going from the top of the frame, over the pilots shoulder and down to the seat then back to the frame. Examples: Fly 70, Adventure F1, Few other direct drives.

• Fixed underarm bar: A fixed, usually curved bar, goes from the frame forward. Examples: Miniplane, Sky Cruiser, I-Flyer, Blackhawk, Adventure.

• Pivoting underarm bar: A bar, hinged on the frame, goes forward to the front harness webbing. Examples: Weight shift versions of the Sky Cruiser, Older Blackhawk, Paracruiser, Phantom.

High hang point machines. 1) Fly Products Trike, 2) Phantom PPG

The original Paramotor brand with fixed J-bars. It was modeled after the La Mouette.

• Sliding web underarm bar: Fly Products, Phoenix PPG, Fresh Breeze (Comfort Bar system only).

• Fixed J-bar: To my knowledge there is no current production machine using this method. Past examples: Paramotor, Lamouette

• Floating J-bar: Fresh Breeze

• Pivoting J-bar: SD

Hybrid Hang point

There is only one machine that I know of where the hang point changes in flight—the Mantis. I've had a few flights on it with the dealer present and it took a couple tries to get used to the action. There will eventually be a review on it.

The intent is for the hang point to be high and centered during launch then move forward in flight while keeping the thrust line pointed in the right direction. One problem with many low hang point machines is that the motor leans way back in flight. That's comfortable but reduces climb and exacerbates torque.

Tandem

Here is an article on Tandem Paramotor suspension systems.

The Mantis during launch above. Photos courtesy Air-X.com.

At left is Jaro Krupa just before a flight.