Schwinn Sales West
Finally riding a big boys bike
Schwinn made many of their own steel rims at the Chicago factory. The tubular steel welded rims were one of the key selling features on the showroom sales floor quality board. They had a Schwinn rim cut in half, and a standard rim cut in half to demonstrate the strength of the Schwinn Tubular Rim. Not many know how these were made. Sorry I do not have any photos, so here's my memory details.
They were made on a tube mill, much like electrical conduit tubing is manufactured. They began with a flat roll of steel. It was loaded on to the end of a tubing mill. This machine was a very long series of rollers that bent the flat metal into a U shape, and then back over itself into the shape of the desired rim model. Looking at it in action, you would think "there's no way" that a straight metal flat sheet could be formed into a rim shape. Remember this roll of metal was hundreds of feet long, and the rims were a different shape as this single roll went through different stages of the machine. They had two serrated rollers that were positive/negative charged and they welded the inside edges of the rim to the outside edge. This made the Schwinn rims double thick in the high stress area with the spoke holes. The rim was still like a single straight pipe at this point.
After the welding process the "single pipe rim shape" went through a series of rollers that curved the rim into a circle and cut them off. If you ever watch, "How it's Made" on the Science Channel, they have a lead in with a machine makes springs. As they come out of the machine, they are sliced off, that's the way the Schwinn rims were cut after the curving process. Then they electric welded the cut ends together. In my mind it was like a giant spot weld. I can silver solder, braze, gas weld, stick weld, Mig weld, Tig weld, but I cannot truly understand what they called Electro Weld. Obviously, it was a production welding process that Schwinn used on many different applications over many years.
One of the problem areas for rim production over the years was final finishing the welded areas. Many were "undercut" or you might say they were ground with gouges. Not a big deal on a coaster brake model, but it was a PITA on any caliper brake equipped model with the thumping each time the welded seam went through the brake blocks.
At this stage, they were formed, coiled to the correct desired tire size, welded together at both the center seam and the ends. They went into a piercing machine that poked holes into the tubular section. These holes were on opposing sides (tire side) of the rims. Their purpose was to allow for air pressure to flush out the acid from the chroming process. Anybody that has had old Schwinn rims replated knows the importance of removing the acids which will ruin your new chrome if not fully removed. At this point, the rims went into a machine that drilled the valve hole and all the spoke holes at the same time. Finally, the rims went to the chrome line or the paint line for final finish.
Almost all of the wheel builders were women, and they were Smooth and FAST. It looked like a women's sewing circle with all of the talking and chatting while they were lacing the hubs/spokes/rims together. After the lacing, the wheels went into a oil pressure driven Holland Machine that automatically pulled up the nipples and trued the wheels. As a former Schwinn dealer, the factory had a different view than we did on what constituted a "Trued Wheel". I believe the factory standard was "if it cleared the fork legs, it passed". The dealers had to make the wheels straight enough to work with caliper brakes. They used to put small round yellow inspector tags on the spokes. Every time we had a dealer meeting someone would tell the Schwinn management that wheel Inspector Number 76 needed to have his eyes checked. The answer was always OK, we'll check it out, next question.
The completed wheels went to have tires and tubes installed. The tires and the tubes were already assembled when they came into the factory from the rubber supplier. That's why you find bikes with inner tubes even today that say Original Equipment. I was in Arizona, and all of our bikes were always ordered with the optional Thorn Resistant Tubes on Chicago built bikes. Dealer cost $1.20 extra, retail $2.00 extra. We were bummed as Schwinn moved to different sourcing because they no longer offered the ability to special order the thick tubes. We had to change the tubes on every new bike and always had hundreds of "new" take off tubes to get rid of.
Hopefully this answers some of your Schwinn Chicago rim questions.
John
They were made on a tube mill, much like electrical conduit tubing is manufactured. They began with a flat roll of steel. It was loaded on to the end of a tubing mill. This machine was a very long series of rollers that bent the flat metal into a U shape, and then back over itself into the shape of the desired rim model. Looking at it in action, you would think "there's no way" that a straight metal flat sheet could be formed into a rim shape. Remember this roll of metal was hundreds of feet long, and the rims were a different shape as this single roll went through different stages of the machine. They had two serrated rollers that were positive/negative charged and they welded the inside edges of the rim to the outside edge. This made the Schwinn rims double thick in the high stress area with the spoke holes. The rim was still like a single straight pipe at this point.
After the welding process the "single pipe rim shape" went through a series of rollers that curved the rim into a circle and cut them off. If you ever watch, "How it's Made" on the Science Channel, they have a lead in with a machine makes springs. As they come out of the machine, they are sliced off, that's the way the Schwinn rims were cut after the curving process. Then they electric welded the cut ends together. In my mind it was like a giant spot weld. I can silver solder, braze, gas weld, stick weld, Mig weld, Tig weld, but I cannot truly understand what they called Electro Weld. Obviously, it was a production welding process that Schwinn used on many different applications over many years.
One of the problem areas for rim production over the years was final finishing the welded areas. Many were "undercut" or you might say they were ground with gouges. Not a big deal on a coaster brake model, but it was a PITA on any caliper brake equipped model with the thumping each time the welded seam went through the brake blocks.
At this stage, they were formed, coiled to the correct desired tire size, welded together at both the center seam and the ends. They went into a piercing machine that poked holes into the tubular section. These holes were on opposing sides (tire side) of the rims. Their purpose was to allow for air pressure to flush out the acid from the chroming process. Anybody that has had old Schwinn rims replated knows the importance of removing the acids which will ruin your new chrome if not fully removed. At this point, the rims went into a machine that drilled the valve hole and all the spoke holes at the same time. Finally, the rims went to the chrome line or the paint line for final finish.
Almost all of the wheel builders were women, and they were Smooth and FAST. It looked like a women's sewing circle with all of the talking and chatting while they were lacing the hubs/spokes/rims together. After the lacing, the wheels went into a oil pressure driven Holland Machine that automatically pulled up the nipples and trued the wheels. As a former Schwinn dealer, the factory had a different view than we did on what constituted a "Trued Wheel". I believe the factory standard was "if it cleared the fork legs, it passed". The dealers had to make the wheels straight enough to work with caliper brakes. They used to put small round yellow inspector tags on the spokes. Every time we had a dealer meeting someone would tell the Schwinn management that wheel Inspector Number 76 needed to have his eyes checked. The answer was always OK, we'll check it out, next question.
The completed wheels went to have tires and tubes installed. The tires and the tubes were already assembled when they came into the factory from the rubber supplier. That's why you find bikes with inner tubes even today that say Original Equipment. I was in Arizona, and all of our bikes were always ordered with the optional Thorn Resistant Tubes on Chicago built bikes. Dealer cost $1.20 extra, retail $2.00 extra. We were bummed as Schwinn moved to different sourcing because they no longer offered the ability to special order the thick tubes. We had to change the tubes on every new bike and always had hundreds of "new" take off tubes to get rid of.
Hopefully this answers some of your Schwinn Chicago rim questions.
John
