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BBSHD Build on Trek Hybrid UAV-1

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    BBSHD Build on Trek Hybrid UAV-1

    I used my old Trek UAV-1, which in the mid 90's had been my commuter bike, until it was replaced with a road bike and became the tag-a-long captain part of the ersatz daddy-daughter(s) tandem rig. II had been toying with the idea of selling it, but knowing I wouldn't be able to get anything that for it that was worthy of its (sentimental) heritage. I'ld gotten the bike for what I thought was a good combination of weight, robustness and sleek looks. Over the years, everything got replaced with increasingly road bike like components, but for the e-bike conversion, I turned back to some of the beefier components to support the higher speeds and minimize the times I might end up doing on the road repairs and show up to work covered in bike grease - the motor would no doubt make the extra watts needed for those couple of pounds trivial.

    The build process was mostly spent on getting the old bike to the point that I wanted. The installation of the BBSHD, battery and controller presented a couple of issues that I'll point out.

    First, here is the finished (for now) product. E-bike posing in front of E-car, which the good people of Fiat/Chrysler did the electric conversion on.
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    8-speed SRAM twist shift, 11-28 cogset, cantilever brakes, 28mm Continental 4-season tires on 36 spoke 700c wheels, front wheel "borrowed" from tandem, new rear wheel, air horn bottle mounted under top tube.

    A couple of issues in the build -
    Not knowing how much wiring to keep on the battery leads. I kept it all and for now have it shoved into the bottom of the battery holder, but I'll go back before the winter and clean it up so t hat I can seal that area against the moist air. I had to drill new holes in the mount to line up with my water bottle mounts. First go around, I used a hand drill and did a sloppy job that I cleaned up on a drill press.
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    Most vexing issue was getting the spacers and bolts on the mounting bracket to work well together. I ended up drill out the spacers so that they could move off center to allow everything to fit better.
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    Second issue is the chainline. Which is more a matter of use than build. I had read complaints about the stock chainring and the value of using one of the replacement ring options. They are all right, the chainline on the stock ring sucks. So does the Q-factor of the right pedal. It is all made a bit worse by the geometry of this bikes chainstays, which bow out to accommodate big tires. After a few rides where I was dropping my chain a couple of times, I put my front derailleur back on to use the outside of its cage as a chain catcher. I can dial in the rub so that it just hits on the largest rear cog, and I can easily tolerate that grinding for a few seconds before we're back up to speed and I shift to a smaller cog. Now it works fine.
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    I'm hesitant to go to one of the replacement rings with a better chainline as they are smaller. I got the bike for my work commute - 15 miles each way with about 1000 ft of climb - and don't want to spin at 120 rpm at 30 mph on the flats. With this setup, I can sustain 36 mph on the flats, and 20mph on my biggest climb - which is a 6% hill for 1.5 miles.

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    So now the bike is working great. 200 miles on it so far. The battery is a 52V 11.5ah. I was dismayed on the first couple of rides that I needed a bit more, but I've learned how to modulate my own effort and battery draw, and after a few charging cycles it is broken in nicely and holding much more juice, supporting this ride just fine. I charge it up at work and at night at home.

    The e-bike stuff was all purchased online at Luna Cycles - the full BBSHD kit and the battery - around ~$1200. New rear wheel for $100. New air horn for $20. Everything else was laying around.
    Attached Files

    Nice and sounds like what I may be looking for. Did you happen to take weight before and after?


      That looks like a very old bike, but high end for it's time. I would add some thicker tires (Schwalbe make some E bike versions), and be sure you have high performance brake pads in there.
      Trek uses a 73mm bottom bracket. I have cut them down a little on the right to bring the chainline in. I think they make a 48T inset wide/narrow chainring.
      At 36mph I would look into a stronger offroad fork with disc brake mounts. But you're obviously an experienced rider of tandems so maybe you have a trick brake setup already?
      For discs I like BB7cable brakes with metallic pads at least 180mm.
      Does that have a 1 1/8" stem or is it the old 1" standard?