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Making handle bar grips from a bowling ball containing Vulcanite Plastic or from other materials

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mike cates

I live for the CABE
Things I've learned and done along the way to restoring bicycles:

The introduction of Vulcanite, also known as Ebonite or hard rubber, was the next phase in the evolution of plastics. Vulcanite is derived from natural rubber from India which is hardened through the addition of sulphur. It was formulated by Charles Goodyear in 1843.

"Vulcanite" was the first plastic used for bicycle grips as early as the late 1870's and were found on Columbia and other brand high wheel bicycles.
Most unrestored bicycles of the high wheel to TOC eras that had Vulcanite plastic grips now look a brownish color from decades of oils left on them from the rider's hands and from the natural aging process and the locations the bikes have been stored or found in. At fist glance it looks like wood and can fool you.
Over the years when wanting to find some authentic material to make some hand grips out of I found out information on my own by trial and error about vintage bowling balls that struck my curiosity back in the 1970's. Bowling balls, over their history of development, are made with layers of different plastics. with he outer layer being more abrasion and chip resistant and the more denser plastic being at it's core. Each manufacturer like Brunswick, Ebonite, AMF, etc experimented for decades with different layers of plastics to get the best rolling mass possible in their bowling balls to stay ahead of their competitors.
Vulcanite, the same as used for bicycle hand grips, was one of these plastics used in the centers of very old bowling balls and still can be found today. I have literally found very old bowling balls from bowling alleys for a few bucks each that have have had them taken out of service due to damage on the balls and they've been in storage for decades collecting dust. Also they turn up at garage sales, thrift stores, flea markets, swaps, etc so keep your eye out for them.
Once you think you have a very old ball, take a electric hand drill and a long drill bit say about 1/4" to 1/2" in diameter and drill into one of the finger holes until you feel you have drilled about 1/2 of the depth into the ball. Watch the color of the chips from the drill as you go. The outer layer(s) of the ball may be gray or other colors than the black color of the Vulcanite core you are wanting. When the black chips start to emerge from the flutes of the drill bit, stop drilling and feel the chips. If they are rubbery and stringy, then the center is not Vulcanite. If the chips are somewhat hard and brittle then they are probably Vulcanite and you can proceed to making a slicing jig to save the cuttings from the Vulcanite core.
You can make a jig to cut the bowling ball in half safely by cutting or purchasing a square plate of 1/2" thick aluminum that is the same length and width as the bowling ball diameter. At the center of the plate drill and tap for a 3/4" or 1" pipe thread and install a "close" plumbing pipe nipple in this threaded hole.
Now tap one of the drilled finger holes in the bowling ball with the corresponding pipe thread and assemble the ball tight to the square plate.
Using a vertical band saw position the edge of your aluminum plate, which will now be standing vertical, on the band saw table with the diameter of the ball also touching the table. The vertical aluminum plate should be to the left of the blade when cutting so "if" the ball starts to spin, it will tighten the right hand pipe threads on the close nipple connecting the ball and plate while cutting and not untighten them as if the aluminum plate were put to the right side of the blade. The square edge of the aluminum plate will aid in keeping the set up from not spinning but hold everything firm with pressure down onto the table and also into the blade all the way through the cut. Start cutting through the ball at it's center line. Use a low speed and feed into the blade as you don't want the blade to wander within in it's depth of cut through the ball and also not create heat from friction of the blade. At the end of the cut BE CAREFUL as the outer half of the ball becomes unsupported and it would help if you had someone else manning the blade stop switch when you cut completely through. If you try to hold the ball by hand and cut it in half, WHICH I DON'T RECOMMEND, the blade will catch the ball when cutting and you can't stop the ball from spinning by your hands and more than likely you'll have a bad accident. Remember the ball is not as important as your fingers or hands!
Once the ball is cut in half, remove the half affixed to the aluminum jig plate and you now have two equal halves that can safely be laid flat on the band saw table. Lay out some parallel lines over the sphere just larger than the diameter of the finished grip size you want to end up with. Slice both halves up so you have some extra material to work with for future grips or make extras for your use or sell/trade them off to other collectors, might as well as the Vulcanite is a dusty and sulpher smelling stinky mess and you should use a vacuum/dust collector pick up and should wear a mask during the cutting operation. You'll definatrly get black hands from all the dust so wear gloves as it is the devil to get your hands clean and not smelling like sulpher.
A coarse pitch wood cutting band saw blade like a 4 - 6 tooth per inch blade is best so the blade will not clog up going through the thicker spherical sections and will clean itself as it rolls over the upper and lower band saw wheels. Use your hands to push the material to a point of safety than switch to a push stick.
Now cut the width of these strips you just cut oversize of the grip diameter you want.
You now have square strips that can be cross cut to an oversize length of the grip you want.
Mark the centers of each end and use a 60 degree center drill and drill each end of each piece on a drill press with a table vise to keep the material perpendicular to the drill press table.
These pieces can now be chucked up in a 4 jaw chuck of a metal lathe and the center drilled end can be supported by a live center in the tail stock.
By repeatedly turning the outside to an oversized diameter, you will now have round bar stock that can be chucked in a 3 jaw chuck of the lathe and can be drilled and bored to the handlebar diameter to an appropriate depth or have a through hole for the handlebar diameter. Also any end step shoulders can be made for ferrules and end caps at this point.
You can fabricate a stub mandrel or end mandrels that would support the grip from it's inside diameter and turn outer arced radius to suit what you need.
Filing, sanding and polishing can also be done on the lathe at this point.

AGAIN.. if you are not a experienced machinist/woodworker PLEASE USE CAUTION WHEN USING MACHINERY, IT DOESN'T KNOW YOUR HANDS/EYES ARE THERE AND CAN HURT YOU. Seek out a machinist/woodworker that can help you and they might find interest in this quirky project!

FERRULES can be searched out from fishing maker's supply houses AND by finding old fishing rods for their parts. Ferrules for hard tire safeties with smaller tapering handlebars can be made from brass pipe solder-on caps by opening the closed end to the proper handlebar clearance diameter. These are found at plumbing parts houses, Home Depot, Lowe's, Menards's and local hardware stores. all these fittings can be nickle plated or buffed up to look great!

Black DELRIN plastic rod purchased from McMaster-Carr or a plastics supplier can also be used but does not have the surface hardness that Vulcanite does and will not polish up shiny black like Vulcanite was originally.

If hard to find wood is desired, try Tropical Exotic Hardwoods of Latin America in my home town of Carlsbad, California as they carry many species of rare woods. Try to talk to Mitch Talcove (the owner) as I know him from my being a founding member of the California Surf Museum in Oceanside, CA and he collects early wooden surfboards as well and this is how we met. Great guy and if he doesn't have it, he will find it. Their phone number is: (760) 434-3030

Have FUN!
Mike Cates, CA.
 
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mike cates

I live for the CABE
Sorry, the grips I made years ago are long gone on bicycles I sold. They look exactly the same as the original Vulcanite grips and have the same "feel".
The bowling ball material also lends itself well to making lathe turned knobs for STAR high wheel safeties for the end of the hand brake lever. I also made a knob for a 1884 Columbia three track adult tricycle that was mine and it turned out just as well. There is an article written by me titled "Reproducing missing brake lever and knob" for this tricycle in a Wheelmen Magazine published some years ago.
Mike Cates, CA.
 
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