Hard-Tail Vs. Soft-Tail Chopper Frames: The Primary Differences
Hard-tail or Soft-tail
I am often asked about the differences between hard-tail and soft-tail frames. So here is a quick comparison between the two explaining their primary differences, including a quick reference chart.
Hard-Tail or Rigid Frames
Hard-tail frames have been around a long time. Their simple construction has made them the popular choice of chopper builders. Most “old school” builders consider hard-tails the epitome of the chopper spirit. The chopper, after all, was meant to be inexpensive, lightweight, fast, and free of all but the essentials to get the bike down the road.
Relatively simple construction gives the hard-tail some unique characteristics. The first is the lack of rear suspension. The axle is mounted directly to the frame, so the only suspension is achieved through the tire. This translates to more “road feel” being felt by the rider. Many riders consider this a positive trait, while others prefer a smoother ride.
With the lack of suspension, the upfront costs of building will be reduced. It also means fewer moving parts to install and maintain. This makes the hard-tail more attractive to rookie builders, and makes the frame attractive to those looking to reduce weight.
Apart from the ride, the lack of suspension has some drawbacks. Handling characteristics will suffer. Suspension acts to keep the tire in contact with the road. With no suspension the tire is more susceptible to bounce or chatter, reducing contact with the road surface when the going gets rough.
Soft-tail is the term used to describe a motorcycle frame with an active suspension. Whether it’s an A-frame or swing-arm configuration the principles are the same. The suspension is fastened to the frame via a horizontal axle that allows it to pivot (see soft-tail Illustration). This type of frame is favored by those riders who prefer a smoother ride.
The active suspension is dampened with the use of shock absorbers. Shock absorbers can be mounted in different configurations, from horizontally to vertically. Shocks can differ from hydraulic, to coil-over, and even air-adjustable.
Because the soft-tail utilizes an active suspension, it has the added benefit of increasing the handling capabilities of the chopper. Suspension lowers the amount of bounce associated with rough road, therefore keeping the tire in contact with the driving surface. This also reduces vibration the rider feels.
The downside of soft-tail frames is the expense and maintenance of the additional moving parts. Shocks and axles must be inspected for damage and structural integrity. Also, consideration must be given to the mounting of the rear fender and passenger seating. All this correlates to added weight.
Reference: Chopper Fundamentals 101, © 2007