Back in the old days-uh, the early 1980's and deeper-most front suspension was essentially a pogo-stick. Mush down, bounce up-hey, it was better than mush-down-clunk-up which described many 1960's front-ends. Obviously, the newer the bike the more sophisticated the suspension. On older bikes, and indeed the majority of the applications are for bikes from the 70's and 80's and through the 90's, progressive springs may make a noticeable difference during more aggressive runs. On newer bikes the difference will likely be more subtle.
Progressive springs were developed to be a little stiffer than stock under load, e.g., when riding hard and fast; yet provide a smooth and comfortable ride under normal conditions. Not precisely for racing applications, they're simply meant to broaden the overall suspension performance of a street-bike.
Weight is a factor. Personal human weight, that is. Heavier riders may get more out of a progressive spring, and these could in fact help prevent bottoming out the fork in extreme circumstances such as potholes or hard stops. Riders over 200 pounds may reap the benefits of progressives whereas lighter riders might never employ the full action of the spring. The addition of a passenger will of course affect spring (re)action, as well.
Installation of a progressive spring is about a six on a scale from 1-10, depending upon the make and model of bike. Some installs require complete removal of the forks from the frame, and very precise trimming of internal fork spacers. Your local bike shop can easily install them if you'd prefer a professional tackle the job.
The price isn't prohibitive, and if it improves your ride and/or handling, then you win.
Progressive Suspension also makes a custom-tuned air shock kit.
Find these Progressive Fork Springs:
Find this springs on eBay:
| Traxxas Stampede Green Heavy Duty Progressive Springs Rustler Grave Digger 2x 4x US $10.49 ![]() Auction Ends: 25d 21h 41m Make it yours... |
| Progressive Suspension fork springs Triumph T140 750 1973 74 75 76 77 78 79 82 US $83.00 ![]() Auction Ends: 47m Make it yours... |
| Traxxas Slash Stampede Rustler Monster Jam Matt Black H D Progressive Spring Set US $8.99 ![]() Auction Ends: 27d 19h 29m Make it yours... |

