EricGorr
Super Power AssClown
- Aug 24, 2000
- 708
- 1
125 INVADER: BACK TO THE FUTURE OF DIRT BIKING
Heres some good humor for you guys to ponder. Back in the early 1980s we took a lot of flack for our experiments in new dirt bike designs, but the funniest cracks came from a magazine whose name I won’t mention but its initials are MXA. They featured the only published photo of this bike in an article titled stupidest bikes of all time or ugliest bikes that never made it or something equally moronic. And people wonder why we’re so negative about they’re influence on the engineering side of our sport?
Just for the record, here is a list of some of the things that we experimented with and were first to deploy on two-stroke dirt bikes. Many of these ideas were incorporated into production dirt bikes or exploited by the aftermarket.
1) First example of a mass centralized dirt bike, with the fuel tank relocated to a free space above the right side engine cover. Suzuki and Honda adapted the idea for their supercross factory bikes soon after. Now all modern dirt bikes feature this idea.
2) First use of a fuel pump in order to prevent float bowl foaming and subsequent bogging when landing from big jumps. Honda used a similar set up on Donnie Hansen’s factory supercross bike.
3) First use of louvers on a radiator. We mounted the large single radiator on the left side of the engine and used the plastic body work to form ducting to route the air in and out. The result was a much narrower profile. We copped the idea from Ferrari’s F-1 car. In 1983 Yamaha introduced it on production Yzs.
4) First use of a full length seat that extended up to the steering head. Back then you could’nt slide forward on the seat because the fuel tanks were so wide and high. This bike enabled a new type of riding style which has become the defacto standard in dirt biking.
5) First use of crankcase effects, with a vaned crank and static diffusers positioned in the crankcase. This idea inspired many copy cats who misused the idea for fun and profit.
6) First use of a pulse-charged intake device. The Patent for that item was referenced on a series of Patents by Honda R&D, Toyota, and Yamaha for applications on four-stroke intake manifolds.
7) First use of plastic body work that enabled unobstructed movement of the rider across the motorcycle. The swept-back side number plates nearly got the bike banned from the NMA nationals because tech inspectors thought they were too sharp and a hazard. Back then Kaw had round number plates molded into the rear fender and they used to accumulate weight in mud. Ten years later the idea was revived by UFO and Acerbis but they failed to incorporate our ideas on ducting and the result was a body panel that contained the heat and carb overheating. Now all dirt bikes have swept back number plates and seamless sides.
8) First use of a triple clamp brace. This idea was later incorporated into triple clamp designs by WP and Paoli.
9) First use of a flat top piston on a 2-stroke dirt bike. Rich carved that thing up on the lathe and added gas ports to improve ring sealing. Now companies like Wiseco offer flat top pistons for a premium price.
10) First use of a dual spark plug ignition.
11) First use of thermal barrier coatings on the piston crown and combustion chamber. Rich found some ceramic epoxy that was good up to 3,500F and carefully applied it to the piston crown and head. It all blew off eventually but we thought it was cool. In later years Swain-Tech mastered the process with technology adapted from cookware.
12) First use of an insert in the head pipe to enable an additional reflection point for the compression wave in the mid-rpm range. Now its routine for manufacturers to include this idea into the exhaust manifolds.
13) First use of lightweight shock linkage struts with Heim joints. Back then RM and KXs used heavy steel tubing with dry bushings and funky off-sets. Rich got the bright idea to mount the struts in a straightline to reduce the need for a heavy strut. He threaded the rod with Heim joints to make it like an adjustable tie rod. This enabled quick changes in the attitude and pitch of the bike. Of course we made Rich ride the bike first since he was the heaviest and if it broke it would only hurt him! Later on this idea evolved into shorter or longer pull-rods, marketed by companies like DMC, PC, and White Bros.
14) First use of an air flow bench to aid in balancing the transfer port flow rates. Companies like Superflow now offer two-stroke test adapters for their line of benches.
Overall the bike was a blast to experiment on. Although it didn’t finish a lot of races, it raised a lot of eyebrows and scared the hell out of our competitors. The long term goal was to sell custom built motorcycles of all brands. The company that we worked for eventually went broke because of the impending recession and a massive downturn in off-road motorcycle sales. Efforts to borrow money were squashed. Rich went back to being an auto mechanic and I got a job as a carpenter, keeping my little porting business alive on a part time basis.
In hindsight I think that if we had taken our ideas to England we could’ve overcome the main obstacles like access to publicity in the dirt bike magazines, venture capital for business development, a motorcycle component manufacturing infastructure, and a growing motocross racing market.
When Rich and I were first clued in by the REV! guys about they’re mass customized concept bike we were really excited because that bike has so many features that we’ve been promoting for years. The REV! team has so many more advantages than we had at the time and that’s why we’re such strong supporters of theirs here on DRN. Best of luck to those dirt bike pioneers!
Heres some good humor for you guys to ponder. Back in the early 1980s we took a lot of flack for our experiments in new dirt bike designs, but the funniest cracks came from a magazine whose name I won’t mention but its initials are MXA. They featured the only published photo of this bike in an article titled stupidest bikes of all time or ugliest bikes that never made it or something equally moronic. And people wonder why we’re so negative about they’re influence on the engineering side of our sport?
Just for the record, here is a list of some of the things that we experimented with and were first to deploy on two-stroke dirt bikes. Many of these ideas were incorporated into production dirt bikes or exploited by the aftermarket.
1) First example of a mass centralized dirt bike, with the fuel tank relocated to a free space above the right side engine cover. Suzuki and Honda adapted the idea for their supercross factory bikes soon after. Now all modern dirt bikes feature this idea.
2) First use of a fuel pump in order to prevent float bowl foaming and subsequent bogging when landing from big jumps. Honda used a similar set up on Donnie Hansen’s factory supercross bike.
3) First use of louvers on a radiator. We mounted the large single radiator on the left side of the engine and used the plastic body work to form ducting to route the air in and out. The result was a much narrower profile. We copped the idea from Ferrari’s F-1 car. In 1983 Yamaha introduced it on production Yzs.
4) First use of a full length seat that extended up to the steering head. Back then you could’nt slide forward on the seat because the fuel tanks were so wide and high. This bike enabled a new type of riding style which has become the defacto standard in dirt biking.
5) First use of crankcase effects, with a vaned crank and static diffusers positioned in the crankcase. This idea inspired many copy cats who misused the idea for fun and profit.
6) First use of a pulse-charged intake device. The Patent for that item was referenced on a series of Patents by Honda R&D, Toyota, and Yamaha for applications on four-stroke intake manifolds.
7) First use of plastic body work that enabled unobstructed movement of the rider across the motorcycle. The swept-back side number plates nearly got the bike banned from the NMA nationals because tech inspectors thought they were too sharp and a hazard. Back then Kaw had round number plates molded into the rear fender and they used to accumulate weight in mud. Ten years later the idea was revived by UFO and Acerbis but they failed to incorporate our ideas on ducting and the result was a body panel that contained the heat and carb overheating. Now all dirt bikes have swept back number plates and seamless sides.
8) First use of a triple clamp brace. This idea was later incorporated into triple clamp designs by WP and Paoli.
9) First use of a flat top piston on a 2-stroke dirt bike. Rich carved that thing up on the lathe and added gas ports to improve ring sealing. Now companies like Wiseco offer flat top pistons for a premium price.
10) First use of a dual spark plug ignition.
11) First use of thermal barrier coatings on the piston crown and combustion chamber. Rich found some ceramic epoxy that was good up to 3,500F and carefully applied it to the piston crown and head. It all blew off eventually but we thought it was cool. In later years Swain-Tech mastered the process with technology adapted from cookware.
12) First use of an insert in the head pipe to enable an additional reflection point for the compression wave in the mid-rpm range. Now its routine for manufacturers to include this idea into the exhaust manifolds.
13) First use of lightweight shock linkage struts with Heim joints. Back then RM and KXs used heavy steel tubing with dry bushings and funky off-sets. Rich got the bright idea to mount the struts in a straightline to reduce the need for a heavy strut. He threaded the rod with Heim joints to make it like an adjustable tie rod. This enabled quick changes in the attitude and pitch of the bike. Of course we made Rich ride the bike first since he was the heaviest and if it broke it would only hurt him! Later on this idea evolved into shorter or longer pull-rods, marketed by companies like DMC, PC, and White Bros.
14) First use of an air flow bench to aid in balancing the transfer port flow rates. Companies like Superflow now offer two-stroke test adapters for their line of benches.
Overall the bike was a blast to experiment on. Although it didn’t finish a lot of races, it raised a lot of eyebrows and scared the hell out of our competitors. The long term goal was to sell custom built motorcycles of all brands. The company that we worked for eventually went broke because of the impending recession and a massive downturn in off-road motorcycle sales. Efforts to borrow money were squashed. Rich went back to being an auto mechanic and I got a job as a carpenter, keeping my little porting business alive on a part time basis.
In hindsight I think that if we had taken our ideas to England we could’ve overcome the main obstacles like access to publicity in the dirt bike magazines, venture capital for business development, a motorcycle component manufacturing infastructure, and a growing motocross racing market.
When Rich and I were first clued in by the REV! guys about they’re mass customized concept bike we were really excited because that bike has so many features that we’ve been promoting for years. The REV! team has so many more advantages than we had at the time and that’s why we’re such strong supporters of theirs here on DRN. Best of luck to those dirt bike pioneers!
