For more information contact Paul Durfee at info@durfees.com or call 503-472-9196.
It all started back in 1968 when Earl Durfee picked up an old Indian Scout Girder and knew he could do better. You see the better part was easy for Earl because of two big factors.
(1.) By 1968 the popular girder design which was used by Indian Motorcycle Company and was the preferred front suspension design used by the majority of the European motorcycle makers had seen a lot of bad roads (or in some cases, no roads and even bomb craters, motorcycles were used extensively in both WW-1 & 2) and many, many years of hard use. Earl saw that “Road” and “Stress” tests on these old girders pointed out the strengths and weaknesses of the designs. (2.) Earl had spent the last 15 years working in the R&D labs for two well known aircraft and defense contractors, building by hand, the prototypes for the Polaris and Minute-Man missiles. The Metallurgy and welding processes fields in which he had studied, worked-in and knew, had supplied him with the knowledge and tools to bring the girder design up-to-date. Some of the old girders had flaws from the limits of materials and processes available in the 1920’s, 30’s, and 40’s, but by 1968 things had changed and we where in the middle of the “space race”, with all the knowledge and new materials that brought.
But even with the flaws, the good, far outweighed the bad because there are so many great things about girders, some ahead of their time, which convinced him that this was the way to go if you were after a good looking, incredibly strong, light weight and smooth riding motorcycle suspension.
Since 1970’s motorcycles were larger, faster, heavier, and more powerful than the old models that had come before, Earl brought the materials and processes he had learned from his years in R&D and redesigned the girder to handle the bigger loads and higher speeds by using things like aircraft alloys and T.I.G. welding. His redesign also included four hidden, internal adjusters, that could be firmed up for fast riding or adjusted back for a smoother ride. The new design also added components for disk brakes so the end result was lighter, stronger, visually cleaner looking, and a more safe Girder that helped make the Durfee Girder the one to have and to ride.
Now that Earl had updated the classic and proven girder designs it was time to see how his new model worked. Being a Certified Aircraft Welder, he was familiar with and believed in the value of testing. To be “Certified” is to have your work, techniques, and knowledge, periodically tested by independent labs to make sure that the airframe you just welded together doesn’t come apart on the pilot and crew in mid-air. Just down the street from the shop was a group of German Rocket Scientists (no joke, one a colleague and co-worker to Werner Von Braun) and Physicists so Earl gave them his Girder and to quote Robert Di Nero who said to Billy Crystal “Analyze This” they were off to do their thing. A 58 page “Stress Analysis” report was the result.
Earl then introduced his new physicist friends to some of his associates in the custom motorcycle business, Robert Paugh of Paughco, Joe Terresi of Easy Riders magazine and Jammer Products, Neil McNeil of AMEN, Joe Alphabet, Les Fitch, etc., etc. These guys and several more got together and formed the National Custom Cycle Safety Institute or NCCSI. The purpose of this organization was to test and certify their products through independent testing that would allow the builder and the various state vehicle inspection and licensing agencies to know that this was a safe product. The Structural Test Machine was the first project commissioned by this new organization.
The NCCSI test machine was a sadistic monster that used a 4 foot diameter steel wheel with bolted-on metal plates that can vary in size to simulate a road expansion joint all the way up to a huge pothole in the road. The wheel was powered to rotate from a crawl up to about 100 MPH. The front end is bolted into an adjustable, hydraulic neck that can simulate any rake and be rotated to mimic any curve that a motorcycle might lean into. The neck's hydraulic ram can apply up to 1500 pounds of downward force to push the tested component down onto the wheel, a weight which exceeds what an extremely heavy rider and motorcycle would weigh and the test part is run at it’s resonate frequency. The “Resonate Frequency” is the point at which that particular part looses control, the shocks or springs are at full stroke, all the way loose to fully collapsed and can no longer cope with the stresses on them. The resonate frequency was “Fatigue Phase” was part of 3 tests, Exploratory, Severe Loads, and Fatigue. Sensors on the tested part measure the forces at different points and strobe lights allow you to turn what is a blur of crashing metal into slow motion or can even completely stop the motion to see what is happening at any place on the front end.
Here are some quotes from Larry Kumferman who reported about the NCCSI test machine for Custom Chopper magazine in the April 1973 issue. “If you have you ever seen a fox terrier systematically shake a rat to death, you have a fairly accurate idea of what the newly completed National Custom Cycle Safety Institute structural tester does to a motorcycle component.” “The shaking the tester gives a bike component is so severe that it seems unfair . . .”Watching the test specimen is a trip and only seeing the test in person can convey the emotional feelings invoked by the sounds and sights of an assembly of metal being systematically beat to death. That any fork can stay whole through the test is a minor wonder to me.”
With the strobe lights set properly you can actually see the front wheel/tire assembly getting airborne after the tire has completely flattened so that the only thing separating the bare rim from the bumps on the tester are the sidewalls of the tire, you could also see the spokes flex and curve under the load and then spring back into shape. To give you an idea of the severity of this machine, a new Harley “glide” front end lasted less than 20 minutes before the fork seized and the glide turned into a broken, smoking paperweight. The Durfee Girder would take the normal 24 hour run, at resonate frequency, easily as part of the 100 hour complete test. As a matter of fact, the same Durfee Girder was mounted to the machine again and again whenever the officials from the National Highway Safety & Traffic Administration, California Highway Patrol or the German TUV (the Durfee Girder was one of maybe only two non-OEM suspensions that the TUV would allow on German roads) would show up. And after all that repeated beating, way past what the test required, when the Girder was torn down and inspected there was only mild wear on the replaceable pivot shafts!
Along with Walt Jaquith and Rick Anderson. Paul Durfee who has helped build the Durfee Girders since 1969, completed another mild redesign in 2005 resulting in an even stronger, better built, and better looking suspension, that can accept todays larger hubs, wheels and and dual-disc brakes.
Currently Paul, Walt, Rick and Paul's brother Mark Durfee are in the process of designing several new, completely different kinds of "girders" that we hope to let you know about soon. KEEP WATCHING THIS SITE!
It all started back in 1968 when Earl Durfee picked up an old Indian Scout Girder and knew he could do better. You see the better part was easy for Earl because of two big factors.
(1.) By 1968 the popular girder design which was used by Indian Motorcycle Company and was the preferred front suspension design used by the majority of the European motorcycle makers had seen a lot of bad roads (or in some cases, no roads and even bomb craters, motorcycles were used extensively in both WW-1 & 2) and many, many years of hard use. Earl saw that “Road” and “Stress” tests on these old girders pointed out the strengths and weaknesses of the designs. (2.) Earl had spent the last 15 years working in the R&D labs for two well known aircraft and defense contractors, building by hand, the prototypes for the Polaris and Minute-Man missiles. The Metallurgy and welding processes fields in which he had studied, worked-in and knew, had supplied him with the knowledge and tools to bring the girder design up-to-date. Some of the old girders had flaws from the limits of materials and processes available in the 1920’s, 30’s, and 40’s, but by 1968 things had changed and we where in the middle of the “space race”, with all the knowledge and new materials that brought.
But even with the flaws, the good, far outweighed the bad because there are so many great things about girders, some ahead of their time, which convinced him that this was the way to go if you were after a good looking, incredibly strong, light weight and smooth riding motorcycle suspension.
Since 1970’s motorcycles were larger, faster, heavier, and more powerful than the old models that had come before, Earl brought the materials and processes he had learned from his years in R&D and redesigned the girder to handle the bigger loads and higher speeds by using things like aircraft alloys and T.I.G. welding. His redesign also included four hidden, internal adjusters, that could be firmed up for fast riding or adjusted back for a smoother ride. The new design also added components for disk brakes so the end result was lighter, stronger, visually cleaner looking, and a more safe Girder that helped make the Durfee Girder the one to have and to ride.
Now that Earl had updated the classic and proven girder designs it was time to see how his new model worked. Being a Certified Aircraft Welder, he was familiar with and believed in the value of testing. To be “Certified” is to have your work, techniques, and knowledge, periodically tested by independent labs to make sure that the airframe you just welded together doesn’t come apart on the pilot and crew in mid-air. Just down the street from the shop was a group of German Rocket Scientists (no joke, one a colleague and co-worker to Werner Von Braun) and Physicists so Earl gave them his Girder and to quote Robert Di Nero who said to Billy Crystal “Analyze This” they were off to do their thing. A 58 page “Stress Analysis” report was the result.
Earl then introduced his new physicist friends to some of his associates in the custom motorcycle business, Robert Paugh of Paughco, Joe Terresi of Easy Riders magazine and Jammer Products, Neil McNeil of AMEN, Joe Alphabet, Les Fitch, etc., etc. These guys and several more got together and formed the National Custom Cycle Safety Institute or NCCSI. The purpose of this organization was to test and certify their products through independent testing that would allow the builder and the various state vehicle inspection and licensing agencies to know that this was a safe product. The Structural Test Machine was the first project commissioned by this new organization.
The NCCSI test machine was a sadistic monster that used a 4 foot diameter steel wheel with bolted-on metal plates that can vary in size to simulate a road expansion joint all the way up to a huge pothole in the road. The wheel was powered to rotate from a crawl up to about 100 MPH. The front end is bolted into an adjustable, hydraulic neck that can simulate any rake and be rotated to mimic any curve that a motorcycle might lean into. The neck's hydraulic ram can apply up to 1500 pounds of downward force to push the tested component down onto the wheel, a weight which exceeds what an extremely heavy rider and motorcycle would weigh and the test part is run at it’s resonate frequency. The “Resonate Frequency” is the point at which that particular part looses control, the shocks or springs are at full stroke, all the way loose to fully collapsed and can no longer cope with the stresses on them. The resonate frequency was “Fatigue Phase” was part of 3 tests, Exploratory, Severe Loads, and Fatigue. Sensors on the tested part measure the forces at different points and strobe lights allow you to turn what is a blur of crashing metal into slow motion or can even completely stop the motion to see what is happening at any place on the front end.
Here are some quotes from Larry Kumferman who reported about the NCCSI test machine for Custom Chopper magazine in the April 1973 issue. “If you have you ever seen a fox terrier systematically shake a rat to death, you have a fairly accurate idea of what the newly completed National Custom Cycle Safety Institute structural tester does to a motorcycle component.” “The shaking the tester gives a bike component is so severe that it seems unfair . . .”Watching the test specimen is a trip and only seeing the test in person can convey the emotional feelings invoked by the sounds and sights of an assembly of metal being systematically beat to death. That any fork can stay whole through the test is a minor wonder to me.”
With the strobe lights set properly you can actually see the front wheel/tire assembly getting airborne after the tire has completely flattened so that the only thing separating the bare rim from the bumps on the tester are the sidewalls of the tire, you could also see the spokes flex and curve under the load and then spring back into shape. To give you an idea of the severity of this machine, a new Harley “glide” front end lasted less than 20 minutes before the fork seized and the glide turned into a broken, smoking paperweight. The Durfee Girder would take the normal 24 hour run, at resonate frequency, easily as part of the 100 hour complete test. As a matter of fact, the same Durfee Girder was mounted to the machine again and again whenever the officials from the National Highway Safety & Traffic Administration, California Highway Patrol or the German TUV (the Durfee Girder was one of maybe only two non-OEM suspensions that the TUV would allow on German roads) would show up. And after all that repeated beating, way past what the test required, when the Girder was torn down and inspected there was only mild wear on the replaceable pivot shafts!
Along with Walt Jaquith and Rick Anderson. Paul Durfee who has helped build the Durfee Girders since 1969, completed another mild redesign in 2005 resulting in an even stronger, better built, and better looking suspension, that can accept todays larger hubs, wheels and and dual-disc brakes.
Currently Paul, Walt, Rick and Paul's brother Mark Durfee are in the process of designing several new, completely different kinds of "girders" that we hope to let you know about soon. KEEP WATCHING THIS SITE!