Early Aug Night Ride at SFA and New XT Shadow Rear Derailleur

Shimano M772 XT Shadow Rear Derailleur

After my ride in Indy and the mechanical I suffered (being the second time I had that particular problem recently), I decided I needed to replace some worn parts…particularly my 9 yr old XTR M952 rear derailleur.  It still “works”, but I’ve had to bend the cage twice recently.  It’s on its last legs, I believe.

The Bike Shop in Nac had a NOS XT Shadow M772 rear derailleur in stock.  Not sure how old, exactly, but it’s probably been on the shelf for 5yrs or so.  I negotiated a deal for it with the owner and went home to install it.

I’ve been using an Avid Rollamajig to eliminate the ugly housing loop on my old XTR for quite some time.  That worked in my favor when it came time to install the XT.  The goofy routing had been fixed by this time, so my existing housing fit perfectly.  The inner cable fit perfectly, too.  Since the Rollamajig had the inner cable looping around the wheel, there was a lot more than necessary, so I was able to simply clip off the worn end when I installed the new derailleur.

The install went smoothly until I got everything ready to start adjusting the b-screw, limit screws, and cable tension.  I was having some odd problems in the largest cog that I couldn’t tune out.  So I proceeded to keep my eye on the cog as I rotated my cranks to see if I could figure out what was going on.  I noticed that the skipping was happening at the same cog tooth.  I marked that tooth with a sharpie and watched more closely.  Yup, that tooth was the culprit.  I couldn’t see anything obviously wrong with it, though, so I checked it out from other angles.

Sure enough, that cog was ever so slightly bent.  I found it by shifting out of that cog, and looking down the chainline.  I had to use my finger as a stationary point to see it.  It was only bent 1 mm or so.  Very slight.  It probably happened one of the times my bike threw the chain and bent my derailleur.  It’s hard to say if throwing the chain bent the cog first or what.  I could see things happening either way.  I used a smooth-jawed pipe wrench to grab the problem tooth and the 2 next to it and bend them back into submission.  That did the trick.  If it was a more severe bend in the cog, I wouldn’t have been able to tweak it like this.

Shimano M952 XTR Rear Derailleur
This was a SRAM PG-990 cassette that’s only a handful or two of rides old.  I’ve never bent a cassette like this before and I’ve ridden much gnarlier terrain than I’ve been on lately.  I’m doubting whether I’ll buy one of these again.

After getting the XTR off, I think I might clean it up and put it on my commuter to convert it to a 1×9.  The long cage isn’t exactly ideal to a 1×9 setup, but it’s a commuter bike and shouldn’t be a problem.  When this one finally goes, I could easily replace it with a derailleur that has a proper shorter cage for the tighter gearing range of my commuter bike.

I had my light battery on the charger to top it off, so when I finished up, I tossed the bike on the rack to get a quick night ride in.  To my chagrin, I couldn’t find my Oregon GPS.  Curses, the last time I used it was in Indiana, but I didn’t want to spend so much time looking that I didn’t even ride.  So I grabbed my Forerunner 205, checked the battery (good to go!) and hit the trails anyway.

Initially, I had a bit of cable tension tuning to do before I was riding well.  Stuff like that doesn’t often show up until you start putting power to the pedals.  Gotta get it off the work stand and actually test ride it.  I know better.  I was also reminded why I don’t wear the Forerunner when riding.  When I get warm and sweaty, my wrists swell up and I don’t have much adjustment room on the Forerunner wrist strap.  I really should just put it on the handlebars.

I haven’t been on this trail in the dark in quite some time.  Forestry crews have been cutting a lot of trees that were killed in last year’s drought.  Plus, the spring rains washed away a bit of the sandy trail.  So the trail character is a little different.  I wasn’t really “on”.  It doesn’t help that this time of year, the sand gets really loose and traction can be tough to find.  This was not one of my fastest rides.  I like riding Labyrinth when I’m out here doing night rides, but one of the felled trees was blocking the top of Labyrinth today.  Where a trunk crosses the trail, the crews have been good about clearing a path.  But in this case, it was the tree’s whole canopy that was blocking the trail.  In daylight, I’d have searched for a way around.  In the middle of the night, no thanks.

The North Loop was in pretty good shape, but hitting the rock gardens on Rocky Road in the dark is tricky.  I got the last two, but was unsuccessful on the first, which I think is a little more difficult, anyway.  There is some work going on up here, though, and workers have cut a pretty wide path down the fall line.  There were some piles of material that looked like gravel at the top of the hill by the access point they’re using.  It’s hard to see in the dark what they’re doing with all of that.  They might be trying to shore up some eroded areas caused by runoff from the neighborhood at the top of the hill.  It could also be material intended for use in the skills course towards the bottom of the hill.  Either way, cutting a path straight down the fall line is a recipe for a trashed trail.

Creekside is riding pretty nicely right now.  It’s faster than it has been in quite some time.

All said, though, it wasn’t my best ride.  It was good to be out, but the heat and humidity were pretty high, and my control of the bike was a little shaky at times because I haven’t been on the trails at night for so long.

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