Tuesday, July 13, 2010

Cassettes, Chains, Cables

This past Friday, the rear derailleur started to become uncooperative.  I thought it was likely a cable-stretch problem, or possibly a chain stretch problem.  By the end of the Friday ride, the rear derailleur cable had 4988 miles on it (having been newly installed immediately after my Sep-19-2009 crash).  By the end of the Friday ride, the chain had 1879 miles on it (having been newly installed on Apr-29-2010).

During my Saturday ride, the problem worsened considerably.  Gary and I thought it might be a sticky cable inside its housing issue -- although the cable had received relatively frequent cleaning and lubing to prevent cable stick issues.

Long story short, it turned out the problem was that the rear derailleur cable was fraying, essentially at the brifter.  About half the strands that made up the cable had already snapped. 

Solution:  new rear derailleur cable.  So, including the Saturday ride, I had gotten 5059 miles out of the cable.  I'm not sure if that is good or bad or normal type performance. 
Decided to also change the front derailleur cable.  The old one dated from Oct-22-2009 and had 4560 miles on it.
While looking over the drive system, it was obvious that my current cassette (dating from Nov-12-2008, with 10.322 miles on it) is beginning to show obvious signs of wear.  It is not skipping or anything, but teeth on the cogs most used are showing tell-tale signs.  (I'm on the fourth chain on this cassette.  I got 3168 miles from the first chain, 2594 from the second, 2609 from the third, and 1950 - as of Saturday- from this, the fourth, chain.) 

In looking at the current cassette, I learned that I had been improperly identifying it for the last year-and-a-half (and almost certainly mis-identifying the previous cassettes).  It is a 10-speed cassette.  I have been referring to it as a 12-25; but it is actually an 11-25 cassette.  I have slightly more "gear-inches" than I thought I had.  I guess I will have to completely rethink what my top-end speeds are. 
For kicks, I looked at the possibility of replacing the 11-25 cassette with an 11-28 next month.  Given the very few trips to the mountains that I make, the fact that I have plenty of gearing to handle north-central North Carolina (and even adequate gearing to handle the Uwharries with tired body and legs), and the price differential:  I'll stick with the 11-25. 
This post is made solely for the purpose of "tweeking" certain acquaintences / friends that think I am a numbers geek.  ;-)

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