Thursday, June 6, 2013

DiamondBack Sorrento: Shifters

Previously I posted about my wife finding a mid-90's DiamondBack Sorrento at a local charity thrift store for $20.  With some elbow grease I feel like this could be an excellent bike for the kids to ride, as well as a great learning project for me.  

At this point I'm working on the shifters.  During the original examination of the bike it appeared like they were broken, as shifting wasn't possible.

The first challenge would be in getting the shifters off of the handlebars.  It seems like someone had already attempted to get the right shifter removed, and had ended up stripping the hex head out.  I carefully removed the bolt from the left shifter, and measured the shaft.  I picked a drill bit that was slightly smaller than the shaft of the bolt, and started the work of drilling out the screw.  To my surprise, and luck, the bolt broke relatively early in the process, allowing me to get the shifter off of the handlebar.  With a little work I removed the nut that secures the shifter in place, and put it aside for my eventual trip to the Hardware Store.

After removing the cover, I thought I understood the issue pretty well:  The part of the pawls that keeps the tension on the shifter (and makes the "click" noise), wasn't locking into place.  My initial assessment was that there was a spring that had lost tension, and it really wasn't going to be worth attempting to repair it.  I had already sourced out replacement shifters online, and I didn't think that the $30 was worth attempting to fix the existing hardware.  I wanted to take a trip to Lucky Bike to see if they had them locally, but I didn't plan to trek out there until later in the week.

What I did in the meantime was do a little more reading, and I found out that the spring was a known issue, but the bigger known issue was the lubricant in these shifters.  For whatever reason the grease they used when these were manufactured ends up causing the mechanism to seize up over time, and that a good dose of WD-40 (or similar) will clear it up.  I happened to have some cleaning+lubricating chain spray at the house, and I gave it a try.  Lo and behold the pawl start moving a little more freely.  I gave it some more lube and put the housing back together to work through the gears.  It took a little bit to work through the whole system, but I started having shifting on the rear deraileur!  

when good lubricant goes bad...
I moved over to the left shifter, and I found the same situation.  A good dosing of the spray lubricant and some time, and it started to act better.  It's taking some time to work them out, but they are definitely shifting better.  

A quick trip to the hardware store for some new bolts, and I should be good to go on the shifting front.  I decided to go ahead and replace both bolts with new 1" stainless cap heads, just to be safe.  This way I wasn't going to be searching for 2 different allen wrenches every time that I had to adjust the shifter position.

Originally I had put into the budget $30 to repair/replace the shifters.  The total cost for the repair ended up being $1.80.  

This makes the total estimated cost of the bike:

Purchase of the bike:      $20
New saddle: $25
New Tubes: $14
New rim tape: $10
Shifters: $  1.80

Grand Total: $70.80

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