Mechanical Updates

Aside from running errands around town I didn’t feel motivated to ride at all this weekend. What I DID want to do was get a bunch of chores finished around the house to free up other days for more fun things and try to hash out a kernel of an idea I had for a light mount.

The Ixon was too heavy for the high computer mount on the Topeak bag and the bag was cropping the base of my beam too. I went into the lab, started designing and created a new mount at the fork crown for my lights. Most of the time I need something I say to myself “Why hasn’t someone made this yet?” For this I can honestly say I know why. Making a mount that is sturdy enough to hold a battery light while not dangerously interfering with the canti straddle wire, fender, or lower headset cup turned out to be more of a challenge than I thought. At this point clearances are tight enough that changing any part of the front setup, even putting new pads on the brakes might send me back to the drawing board.

Prototype: For my last project I used cardstock, which was too flimsy to hold shape while designing. Now I keep a handful of old gift cards around the shop for just such an occasion. (also good for spreading/stirring epoxy, light scraping, fabrication projects and many other things!). The plastic is stiff enough to give you a good working model while being pliable enough to trim out quickly with scissors and reposition multiple times.

Once you get positioning worked out, the plastic bends flat for tracing out the template shape.

Cutting: Used the sawzall for the rough stuff, metal coping saw for shaping and large flat file for finishing and corners.

Bending and Fabricating: The main frame is 16 gauge steel which bends easily. The tough part is not bending it too much. The light mount area is a chunk of an old carbon handlebar. There’s a piece of synthetic wine bottle cork pressed in the center with a hole drilled through to dampen the mounting position slightly and center the connecting bolt.

Alpha: The final puts the light just at the right height. Any lower and the light would not reach out enough to clear the brake cable either from behind or at the straddle wire. The tire is casting a shadow in my beam now as it is… There aren’t too many lateral forces at play here, so I’m not worried about it bending from side to side. Vertically, I’m hoping that there’s enough metal there to handle the stress of the light mount. If it survives a few weeks of hard use I’ll pull it off and trim the sides for a cleaner look and more clearance. I’m not wasting time on finishing work until after I figure out if it’s a successful prototype. Now the only problem is the wireless computer being mounted near the light again so we’ll see if I get interference like I had up on the handlebars. Hopefully not. I’d like to leave it where it is.

offset slightly to the right (drivers left) for additional cable clearance in back. The carbon bar nub is kind of slippy. Probably going to have to replace with an aluminum bar end scrap in ‘Beta testing’.

15 miles out and I’m not getting any rf interference in the computer from the light yet. A little bit of slippage in the mount is making the beam tilt up after a few miles. Trying to tighten down the mount, but I think the carbon is too slick.


This part is clerical, so zone out for a while…

Stuff I did @ 4700 miles…

  1. Broke the Hubs down, cleaned, regreased, adjusted.
  2. Light lube in freewheel (non-servicable)
  3. Thorough cleaning of entire drivetrain. Removed and soaked chain in degreaser. Lubed and measured for wear.
  4. Light Proofide for saddle.
  5. Clean whole bike and wax frame.
  6. Replace thrashed jockey wheels in derailleur with VO sealed bearing jockey wheels.
  7. Made new rack mount for rear blinky.

Stuff I need to do when I break out the winter commuter…

  1. Replace brake pads and cables – hoods if I can find Tektro replacements.
  2. Replace Chain – 80% gone.
  3. Replace shifter cables and poss. left shifter pod.
  4. Check/Overhaul everything else.

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