- Joined
- Feb 28, 2009
- Messages
- 45
dave M said:
If you like, we can take the personal attacks off line; that would be the polite thing to do.
You asked me to explain the differences; I believe I did that in an objective manner. In the spirit of this forum,let's stick to sharing experience and knowledge that contributes to the community. If I may digress for a bit - R&D costs, as well as production costs are a function of time and place. The TT unit is a product of 2001 knowledge and cost of labor. It is also a product that was developed to support my local economy, so when posed the question of where it could be made for the least cost, the decision was made to keep the work at home, rather than sent overseas. I see that as supportive of a cottage industry approach, hmm, where did that used to be a national way of life?
Now, to the experiences and the shared knowledge. I had a helluva time installing the DT unit simply because it did not fit properly to the frame of my '71 Roadster. Those who've fitted the unit know from personal experience that it is not a simple bolt on process. In some cases, depending on frame origin it will not clamp firmly, and it cannot be snugged far enough rearward for proper link alignment. More importantly, once one understands the benefits of the heim link, it is beneficial to then follow-through on the implications of its fit and function to the other joints - the isolastics.
Once one understands the geometry of the subframe, and its control of the rear wheel alignment, one will understand the benefits of a truly aligned frame and suspension. This cannot be achieved without having a perfectly aligned (vertical) engine. Much has been done by others - Stevan Thomas & Ken Augustine, Dr. Rob Tuluie, in analizing the faults, and describing the remedies, related to the production flaws in the Commando frame. It has been well established by many individuals that a heim link attachment will control, absolutely, the lateral and orbital gyrations of the original isolastic/motor arrangement. In a perfect world, the isolastics could be dialed down to an absolute minimal gap (pick your number) and the handling could be improved over the original manufactured bike. However, by virtue of the isolastic assembly's design some lateral (some would say excessive) movement is accepted; that's how the "isolation" is achieved without damage to the frame. It's interesting to note that the vast majority of Commandos on the road (not racing) use the oem headsteadies which are simply rubber donuts; and yet the vast majority of Commando riders will sincerely believe, often advocate, and frequently stridently defend, the idea that their particular Commando possesses "legendary" racing heritage quality handling. I submit that those who actually ride aggressively and push the bike to its limits will concede that the original handling of the Commando, in modern terms, is a poor, often dangerous, handling machine.
Regarding the heim link. You can obtain this product from a wide range of manufacturer sources, and in a wide range of qualties and price. Only one manufacturer, however, produces a "Heim" joint. All others are generic by name - Rose joint, Rod End, etc. That's how the marketplace operates - an individual invents and others participate in the evolutionary process. Would you prefer that each innovator who improved on the Heim Link concept had gone back to Mr. Heim and offered their ideas for improvement to him for gratis?
What led me to improving on the DT headsteady was the realization that certain compromises or concessions were made in its current form, for whatever reason, that prevent the unit from being "dialed-in" in situ. This is important if one wants to resolve the inherent misalignment of the motor/subframe/rear wheel assembly to the frame. Mr. Thomas points out that the best way to do this is to "blueprint" ,or reengineer, the frame in a machine shop via total disassembly and remachining of the mating surfaces. (see the articles, including "The World's Straightest Norton", by Thomas. My approach was to achieve a more reasonable compromised solution that can be achieved by those not so well equipped.
Based on my own prior experience with the Norvil headsteady (no aspersions intended), and the DT unit, it was clear that misalignment of the motor to the frame was the cause of early headsteady wear and subsequent loss of handling precision.
I can go on. I hope this helps to bring my purpose in this excercise back to a productive place. I have no intention to disparage Mr. Bob Trigg, Dr. Stefan Bauer, Mr. Taylor, Mr. Heim, "Mr." Norvil, Andover Norton, or any others who have contributed to the, hopefully, never ending PROCESS of advancing the performance of this cherished motorcycle. Anybody who has replaced the original cheese head screws on their Norton motor cases with stainless steel allen headed fasteners can clearly appreciate that this whole issue of "authorship" is a tempest in a tea kettle, or more precisely, a non-issue.
Respectfully,
Mark LaPierre
