Wednesday, June 24, 2009

Wrenching is Fun!

It's been awhile since I've had a decent bike maintenance session, I haven't renovated a dumpster bike for a while (no time!) and luckily my stable of bikes has been running just fine so there really hasn't been a need.

If you've been in New England lately you are well aware that it has been WET. But I still gotta ride my bike and with Pat's Peak on the horizon I have to try and snag as many miles as I can to get myself ready. Monday night's group ride was a wet one indeed; rained hard at first but then let off and then poured at the end. 14 miles in the pouring rain and mud will take a nicely running bike and turn it into a pile of crap pretty fast.

What I thought was going to be a normal boring hour or so in the area, cleaning and dialing things back in got real interesting and ended with me having to take my X7 trigger shifter completely apart.

FYI if you need to get BB5 disc brakes lined up real nice this article is the easiest most succinct I have found. I have had my doubts about disc brakes lately because I could never get the feel I wanted. Part of this is probably due to me being so used to V and being semi resistant to change. I also think that I never really had the discs set up right. After getting the rotors properly aligned things feel a lot stronger...granted I haven't ridden it yet but I think I might start to like them better now.

Got the drivetrain cleaned up and I was ahead of schedule (I have to try and set a time that I am going to work in the manarea otherwise I end up in there for waaaay too long) so I decided I wanted to slide my rear wheel back a tad. My Kona has sliding dropouts so you can set it up as SS or geared. When I set the bike up geared I put the dropouts in the middle of its slide range figuring that made the most sense. I also ride a Redline Monocog and now that I have been riding both bikes for a while I have noticed that I really prefer the Redline's longer wheelbase. So might as well slide those dropouts back as far as they go to lengthen the Kona's wheelbase right? Easy enough, I had an extra derailleur cable and housing in case the distance of the slide was too much for the current cable (it was). So I slid things back, recabled and went to test the shifting. And all hell broke loose. Shifter was completely thrashed, made it half way through its range and then just locked up, levers froze, nothing.

This is getting wordy so I'll skip to the end...I had to completely take the shifter apart and get into the guts. I was pretty worried at this point that I was screwed. When I popped the casing off a spring flew out and I thought for sure that was it. Too many gear mechs, springs and moving parts for me to figure out. Then I remembered that I have two advanced degrees. Played with it for a bit got the ins and outs figured out and came to the conclusion that the thing that was screwed up was the little gear indicator that shows you which gear you are currently in. Weird huh?

All that thing is is a little piece of thin plastic that extendeds down into the ratcheting system in the body of the shifter. There are 'teeth' on the plastic of the indicator that also engage with the teeth of the shifter so that when you shift the teeth on the indicator move with the teeth of the shifter and the little orange piece of the indicator moves down a notch. Turns out that little piece of plastic was getting jammed up about halfway through for some reason and preventing it from actually shifting. Remove the indicator, problem solved (I never look at that thing anyway). And now I know how trigger shifters work (X7's at least, but I would imagine the principle is similar for all).

Not sure how it happened...whether it was caused by moisture in there somehow warping the plastic or if I screwed something up when I recabled it but it was a learning experience and fun in a way.

1 comment:

  1. Yeah those can be scary to take apart. The first time I tried it the spring shot across the room. Mine were caked in mud and grit - you should probably take them apart once a season and clean them out...