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| Not sure where I wanted the bars on this bike, I decided to make an adjustable handlebar stem. The bars are easily pushed forward or back, and securely locked in place. Height is achieved by clamping this higher or lower on the fork steerer, with spacers above and below. It's rather heavy, at 3/4 lb. with the bolts. |
| I got the tubing from Aircraft Spruce, which quickly sends me whatever I need in a few days after ordering. The main stem is 7/8, .058. The clamp that fits the one inch threadless steerer is 1 1/8 .058. The short piece of cut tube that holds the handlebar is 1 /1/8 .049. The six 6mm bolts go thru short pieces of 5/16" .035 tubing, brazed perpendicular against the larger clamping tube. I cut a slit in the clamping tube with my sawzall. Then I used my grinder with a thin wheel on it, to open the slot a bit more. |
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| For the handlebar stem, I painted the sliding clamp assembly, and put a few coats of clear spray lacquer on the other part. A nickel (5 cent piece) is silver brazed onto the end of the extension tube, and filed smooth. Lacquer does not hold the rust back that long (at least a few weeks), but it looks cool since you can see the brass and the shiny steel, and this is supposed to be a temporary stem anyways. |
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| And how temporary it is. Below is the sequence of events I undertook to make my new custom stem. |
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| I used a 1 1/8 .049 tube for the handlebar clamp. This fits a Cinelli bar perfectly. On a 26.0 bar the "ears" may touch before it's truly tight, so it may need a bit of shimming (like a strip of aluminum from a soda can). The 6mm bolts to hold the bar go through the short piece of 3/16 .035 tubing that I'm holding in my hand on the left. I put it to the grinder to give it a cutout that would make it seat nicely against the handlebar clamp. Then, I brazed one each on the top and bottom of the clamp tube. The C clamp hold the small tube; otherwise it would slide off during brazing when things begin to get hot. |
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| The stem extension tube was made out of 7/8 .058 cromoly tubing. I don't know what other people use, but this seems plenty strong to me and I like the small diameter of it. There was quite a bit of time involved in getting the miter right, where it attaches to the clamp that holds the steerer. I went back and forth to the adjustable one that was on the bike for comparison. |
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| One thing I learned when making small parts is to be careful about cutting the tube to the required length prematurely. Here in the vise is the stem extension, with the collar that grips the steerer resting above it. I will tack braze it like this. Leaving it long allows gravity to help me in setting up the pieces |
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| Now I'm checking the miter I did for the handlebar clamp. Looks 90 degrees to me. |
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| Now the stem is brazed to the collar. Here, I am setting up the handlebar clamp/stem extension joint. Leaving the handlebar clamp long allows me to check for square: in other words, the bars must be absolutely level when installed, and perpendicular to the extension. I need to get this right, since I look at it every time I ride the bike. |
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| The hard way is to use a hacksaw to cut the slit in this collar/clamp. The sawzall makes quick work out of this job. This is one tool I consider a necessity, like a bench vise. |
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| Don't tell my wife, but this is a quick way to get the flux residue off. The hotter the water bath you get it in, the quicker it will totally come off. With boiling water, it only took a few minutes. |
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| I used a brass wire wheel on the other end of the grinder to finish the cleaning. |
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| Then I cut the handlebar clamp open. Here I could see how well the brass penetrated underneath the piece of tubing that the bolt will go through. Not easy to see in the photo, but brass is present under it, and built up along the sides. |
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| Any framebuilder can make you a custom stem. |
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