The bike I use on organized rides is equipped with DA 9 speed stuff (Cannondale). I use my Lemond as a beater and trainer bike (195 and Ultegra mix). I've put about 600 miles this year on my Cannondale and 3800 on the Lemond. Lemond is till running very well. But although I don't use the Canni as much, it was making a knocking noise in the rear. So I check the wheel, the skewers, derailleur adjustment and everything is fine. But dark knocking is till there. SO I ride the Canni on the last couple of short rides to see if the knock gets louder. It does!
So I remebe somewhere tha a bike makes a knocking noise if the cassette is not properly tightened.. SO I ge out my $10 chainwhip and the $5 Park Tool key for the cassette. I place the key on the cassette and it practically turns itself. Great, now I know where the problem stands.
I take the cassette apart piece by piece from the wheel. I clean the hub body and the cogs. As I'm removing the caked on greas and grit, I begin to wonderhow much this stuff weighs. It's caked on between cogs where it can only be removed if the cassette is removed. No way if it's on the bike! I scrape out quite a bit eventhough it appears very clean form the outside.
I lube everything then reassemble. Everything is nice and tight. I put it on the trainer, spin the crank and SMOOOOOTH as butter again!
I think back to threads about weight savings on the bike. Some riders don't replace the plastic cap over the valve stems of the tubes in order to save rotational weight! I'm not a wieght weenie but could not wonder how much weight I saved by removing the gunk!..The bike runs better and is ligther, therefore it must be faster too!
Really the purpose of this post isn't only about the weight, that's just kinda kidding around. But remember if your bike is knocking in the rear, doesn't mean the derailleur is out of adjustment, you need a new wheel, chain, or even a crankset like some may tell you. Could be something as simple as tightening the cassette with a $5 tool!
I'm happy, bike is clean, light and cheap!