Pedal adjustment mechanism

Tonight I went to work on the mechanism that allows the pedal to be adjusted. The main part of the locking mechanism consists of six thin aluminum spacers, two steel lift levers, and a center aluminum piece to which the adjustment cable attaches to. All these parts had to be deburred, drilled to final size, and finally riveted together. Then the lock pin was fabricated from a 1/4” clevis pine; here, you just cut off the tang of the pin, smooth and chamfer the end, and insert a long roll pin into the cotter pin hole. The roll pin is engaged by the lift levers to pull the lock pin out and allow the pedal assembly to move.

With the lock pin complete, the lock assembly went into place. Pretty simple here, the mechanism pivots on another 1/4” clevis pin, with a stiff spring to keep the locking pin in place unless the release cable is being pulled. I installed the pin, bent the cotter pin, and…the pedals wouldn’t move. Apparently I made the locking pin a bit too long. So I removed the mechanism again (that cotter pin had a really short lifetime) and trimmed the lock pin a bit. That was kind of obnoxious with the roll pin installed; the first time around, I just chucked the pin into a drill and spun it against the bench grinder to get the length right and add the chamfer. This time, I tweaked the length by just filing away at the thing, and then rotating it against the bench grinder by hand to add the chamfer. It didn’t look nearly as nice as last time, but it won’t be visible anyway.

This time, with the mechanism in place (which I tested before bending a second cotter pin), the pedals moved and locked correctly. Here’s a close-up of the mechanism:

IMG 6822

That only left one more task: cutting the release cable to length and attaching the handle (just a 2” piece of tubing with a hole drilled in the middle). And this was where things went awry. The instructions are to cut the cable to “the desired length, leaving 5/8” for a knot at the end of the cable.” For some reason, I decided the best course of action was to just cut the cable 1” longer than it needed to be to clear the guide with the pedals full forward. After running the cut cable through the handle and beginning to tie the knot, I was thinking that it looked too short, and sure enough:

IMG 6823

At the current length, the two forward most positions are unusable. The main issue with fixing this problem is that the cable was preassembled, with the loop already crimped in the end and through the locking mechanism. So a replacement part from Van’s would require replacing the entire locking mechanism. I suppose I could make a new cable myself, but I’m not sure if I need special tools to crimp the loop in the cable properly. Something fun to investigate, I guess…

UPDATE: It didn’t take much research to discover that the proper tool for crimping Nicopress sleeves is…quite expensive. On the other hand, the necessary replacement parts from Van’s are about $25. It’s not really imperative that I get these parts in anytime soon, so I think I’ll add them to a parts order backlog, something I’ve been thinking of doing for a while.

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