| PLYMOUTH RIM. | KUNDTZ RIM. |
This same Mr. H. H. Shepard (who, by the way, is a six-footer and bearded like a patriarch), in a lecture in New York City on wood-bending before the master mechanics of the Carriage Makers’ Association, placed his audience in good humor with him when he declared that his earliest recollections of bending were when, while a boy, his mother bent him over her knee to keep him straight. The Shepard is a one-piece wood rim of second growth white ash. The ends are butted together and an ovoid piece of hardwood is inserted over the butt ends on the inside of the joint. This insert extends about three inches each side of the butt-ended joint and is flush with the remainder of the rim. These rims are bent by compressing the inner surface in a hydraulic press without stretching the outer periphery of the rim. This method shortens the inner surface about six inches, thereby greatly toughening the inner surface of the wood. The average weight of the steel rim formerly used was about 24 ounces. The average weight of the wood rim used for a cemented-on tire as first made was about 14 ounces. The average weight of the wood rim in use today is probably about 18 ounces.
VARIOUS MAKES OF WOOD RIMS.
Another popular rim is called the Winona. The process of making the Winona rim is as follows: There is about six inches difference in the circumference between the inside and outside of the rough rim. The bars being straight before they are bent, it is obvious the inside must stretch or the outside upset. The process used prevents stretching of the outside fibre of the rim, and actually upsets the outside as well as the inside, thereby interlocking the entire fibre and doubling its original strength. They use a plain beveled dovetail joint. They also make a laminated rim, and what they call a screwed rim. This rim has screws at stated intervals running crosswise of the rim, coming just under the seat of the groove, as the greatest strain on the rims is caused by the spokes, which sometimes result in splitting the rim. They have undertaken to overcome this, or, rather, to strengthen the rim by putting in these screws. The illustration shows a sectional end view of the rim and the manner of inserting the screw from side to side. The Winona rims are made of butt cuts, and they use what is known as a second cut rock elm only for their rims. Rock elm has dark streaks running through and is dark in color, differing, therefore, from second growth white ash, which is very light in color.
A well known wood rim is that known as the [Plymouth], which consists of a single piece of rock elm bent, jointed and turned on a lathe. The joint in the Plymouth rim is so constructed that the ends come together square across. It consists of a series of tongues and grooves interlocking, the tension of the spokes making them tighter instead of straining them apart. One of the special features of the Plymouth rim is the fact that the spoke holes are eyeletted and are thus made waterproof. The illustration shows their reinforced joint.
The [Kundtz] is known as a double reinforced rim. It requires two rims to make one, and the manner of cementing one rim into the other, with a section of thin wood between them, which has its grain running crosswise to the two main sections, as shown in the illustration, produces one of the strongest wood rims made. Another improvement in this make is the fact that its glued joints are not exposed to the weather, which has been considered a detriment in building up rims of the old style.
One of the most popular rims is that which is known as the Fairbanks-Boston. A laminated wood rim is one, as is now quite generally known, formed of curvilinear maple segments, indissolubly cemented into perfect unity under enormous hydraulic pressure, which, because of this principle of jointure, remains perfectly true both laterally and in periphery, while the transverse grains of the adjoining segments or laminæ absolutely prevent splitting along the line of spokes in the impact of collision or shock. The fact that no single joint extends through the rim effectually overcomes any tendency to break off in any direction or manner. The makers use three curvilinear segments of Pennsylvania rock maple. Each segment is planed on both sides to a thickness of mathematical exactness throughout the entire length, thus insuring absolute unbroken contact when cementing to the adjoining segments.
The overlapping ends of each segment are by special machinery then “scarfed” to feather edges, obtaining laps equal in length tapering on an angle which experience has proven correct. By this process of bending the rims do not require steaming, which disintegrates the fibre of the wood, and in cementing the joints the three laps are placed at points of the circumference of equal distance apart, rendering the tensile strength absolutely uniform in all parts. In compressing the segments of the rim together hydraulic pressure is applied to the periphery of the rim after the application of the cement. An enormous pressure is applied equally at all circumferential points, and it is maintained until the cement has completely solidified the three independent segments into the form of a permanent circle. They also make what is known as a covered laminated rim, the enveloping fabric, which is a special quality of pure Irish linen, fitted exactly on the rim and secured permanently with liquid cement, and it is estimated that enclosing the rim in this manner imparts at least 30 per cent. to its strength, with a corresponding increase in is resiliency, and these rims are therefore recommended in damp climates, and for use on tandems and other multicycles. All the makers furnish their rims in a natural varnish, and also stained in imitation of rosewood and other woods, and many of the makers in addition to this furnish the rims painted and striped in different colors, in many instances matching the colors of the enamels used on the frames.
At the ’96 Cycle Show papier-maché rims were shown, for which great claims were made and a great deal expected, but none of the well-known manufacturers adopted them, and the company that brought them out has since gone out of existence. Trials within the knowledge of the writers proved that these rims as made then were not practical.