Since I bought my 2010 Marin Muirwoods 29er from Craigslist in the beginning of January of this year (2012), it has been my daily commuter ever since, and sometimes my weekend recreational ride. As a side note, many considered this type of bike not exactly 29er due to the stock tire width of 1.6 in. versus 2.0+ in. on a regular 29er. Some say the chromoly frame of this bike is too heavy, but it's just about right to me. The settle matte black is stylish and low-profile at the same time, just how I like it. True, the components are entry-level: Alivio 3/8-spd shifters, Truvativ X-Flow 3.0 (triple) crank, Deore rear derailleur, Alivio front derailleur, Hayes MX-4 FR brakes, etc. This is the right setup for this type of bike. Everything had been problem-free and silent during the first month, but as time passed, it started to get louder, and components began to fail one by one. Shifting is inaccurate, gear skips, chain refuses to move down to the smallest cog, chain won't shift to the largest chainring, and rear disc brake squeals. I hope I am not overworking the bike. As I am writing this entry, the Muirwoods is taking a short break in the ICU department.
Although I bought the Marin used, but it wasn't messed up like it is now when I first got it. Apparently, during the heavy rainy season from February to April, parking outdoor and biking in the rain makes it the progressively worse. Initially, the front derailleur doesn't move to the correct position, then the rear gradually became a problem. When a bicycle transmission went wrong, there could be many variables involved those could be causing the problem. It could be the derailleurs, the chain, the cable, cable tension, derailleur adjustment, shifter, inadequate lubrication, worn-out gear(s), incorrect chainline, etc.
Because the chain won't go down to the smallest cog, I went with the conventional wisdom that adjusting the high limit screw of the rear derailleur and aligning pulley with the smallest cog would solve the problem, but I was wrong. The position of the pulley did changed a bit, but it still starts from and align with the second smallest cog, (second highest gear), no matter which way I turn it won't go down to the highest gear. Then I thought, the poor shifting might be the result of cable stretch, so I increased the tension by adjusting the barrel, but I still got the same result meaning attempt failed. Then I decided to be spontaneous and started loosening the tension by turning the barrel the other way. It works! Well sorta. The chain did move to the lowest cog, but it makes this really annoying rubbing noise, and when I was shift to third it skips to the four gear. Upon inspecting the shifting, I noticed there's a stiff chain. The stiff chain could be caused by inaccurate shifting making chain stuck either between the wheel and the cassette or the frame and the cassette. I tried loosening the stiffness by bending it sideway, but it didn't seem to work. I haven't try to further lubing it, but if that doesn't work, I might have to replace the chain. Fingers crossed.
I did tried to look for further solutions as well as find answer to the disc brake squeals. Aside bikeforum.net, I came across videos from Park Tool's Blog, which I find very helpful. Usually, an instructional video clip provides a what-it-seems-to-be-the-most-effective method to troubleshoot a particular problem. Not that I find anything wrong with that, but Park Tool's blog is different. The video shows you multiple trial and error approaches to resolve a problem. Those approaches may not give you a total relieve, but I find them quite realistic. Of course, being working for Park Tool would mean you get endless of bicycle tools and other accessories/components to test and see if something works or not; for instance, one of the demonstrators use different chains to test if it's the cogs or the chains' problem. However, most of the stuff shown is really practical, and they can be done by someone like you and me.
If you have the curiosity and patience to watch and learn, please see the links below:
Calvin's Corner, Reconditioning Older Bikes: http://www.parktool.com/blog/calvins-corner/reconditioning-older-bikes
Calvin's Corner, Disc Brake Squeal, Case Study: http://www.parktool.com/blog/calvins-corner/disc-brake-squeal
Park Tool Company Channel on Youtube: http://www.youtube.com/user/parktoolcompany
There's actually more blogs, tutorials, and videos on Park Tool's official website. Enjoy!
