Major Softie wrote:Rob wrote:Were Lesters designed to run tubeless?
No
YES!!!
Tubeless was the intention of their design. This was ground breaking stuff back in the early 70's. They don't meet today's standards, but, as I said before, breaking the bead on these solid wheels requires so much force, It's not on my radar as an issue. The wheels are very tough too. I've hit some nasty rocks and pieces of metal on the road that have bent my fellow rider's rims badly. Read the article.
"On January 14, 1976, a patent was filed by Thomas Lester for cast motorcycle wheels. On September 13, 1977, United States Patent 4047764 was issued.
Patent 4047764 was for "Composite motorcycle wheel construction " described as follows.
"Lightweight composite motorcycle wheel construction characterized in that it comprises a wheel unit casting including concentric outer and inner rim and sleeve portions integrally connected together by angularly spaced spokes; and a hub unit casting having an interference fit within the bore of the sleeve portion thus to frictionally retain the hub and wheel units together against relative angular and axial movement while the bearing receiving bore in the hub unit is located and held coaxially of said rim portion, the wheel and hub units additionally being welded together to prevent relative angular and axial movement despite application of torque and axial loads exceeding the frictional resistance of the interference fit."
Within the patent application, Lester describes various problems with spoked motorcycle wheels, including this little gem..
"Wire spoke wheels, however, have certain disadvantages such as the necessity of using a tire inner tube, the necessity of periodic tightening of the spokes to avoid unsafe riding and handling conditions of the vehicle, the abrasion of the tire inner tube, and the danger of puncturing the tire inner tube by the head of a broken spoke. "
This reference does not mean that Lesters were meant to be tubeless, only that a cast wheel would not cause the same problems for tubes as spoked wheels.
And then..
"Porous metal is weak and prone to cracking or yielding in the high stress areas of the rim or in those portions of the hub which support bearing races, etc. Porous metal is further unacceptable in the rims of
wheels used with tubeless tires since the sealing compounds normally used on rim surfaces do not seal this type of porosity. Moreover, porosity is unacceptable in any portion of the wheel which must be threaded to receive cap screws or other threaded elements."
A hint that he was considering a tubeless tire for the new rims? Read on..
"Nonetheless, there is great inducement to equip motorcycles with wheels formed from lightweight metal castings because there is a great need to reduce the unsprung weight of motorcycles. For example, a cast aluminum alloy wheel according to the invention can be substantially lighter than a wire wheel of the same tire size
and permits the use of a tubeless tire. The elimination of the inner tube results in a further ten to fifteen percent reduction of total wheel weight."
And then, the holy grail...
"The radially outer surface of the center wall 14 of the rim has the usual drop center cross sectional contour for enabling the removal of pneumatic tires. The rim 6 is centrally apertured through a radially inwardly extending boss 21 having an opening 22 through which a valve stem is normally installed. The sidewalls and center wall of the rim form an impermeable barrier to air. With a valve stem installed in opening 22 and a tire mounted with its beads in airtight contact with the inner surfaces of walls 11 and 12, the air is retained by the tire on the rim without the aid of an inner tube, an important innovation in the use of motorcycle wheels."
"The foregoing description is intended to point out those features of wheel structure which render the motorcycle wheels described herein substantially advantageous over the prior art motorcycle wheels, especially wire spoke wheels. Wheels such as described will result in the elimination of inner tubes from the motorcycle tires. This will not only reduce cost but render the sidewalls of the tires more flexible with greater road gripping capacity. The wheel herein described is greatly improved over prior art devices with regard to the overall strength of the wheel especially in the spoke and rim construction. The side wall construction of the rim is of particular interest. A wheel as described herein holds great promise for substantially reduced manufacturing costs on a mass-produced basis."
So there you have it. Thomas Lester invented the Lester Cast wheel specifically to eliminate the use of tubes in motorcycle tires. I hope you have enjoyed reading this little bit of motorcycle wheel trivia as much as I enjoyed researching it. We may now bury the kitten, as we like to say around here. Now if finding the answer to the best oil were as easy..
I would like to thank Dale Adams for his excellent biography of Thomas Lester."
