Saturday, February 11, 2012

Know Your Drivetrain pt. II

What does a family man do when the family goes away for a week?

a) Works loads of overtime
b) Drinks loads of beer
c) Listens to loads of heavy metal very loud on the stereo
d) Eats nothing but loads of hamburgers, while standing over the sink (in order to avoid having to wash the dishes)
e) Goes to loads of sauna (every night)
f) Sets up a bicycle repair shop in the living room
g) All of the above.

Of course, the correct answer is g). A week home alone can truly be a bicycling nerd paradise.

Of course, when you set up a repair shop in the living room, you've got to be careful with the appliance of solvents and grease, as well as with cleaning parts with compressed air. Better do that outside, even though it's cold there.

So, the drivetrain of my MTB requires some attention. I lately got a new chain, as the old one was too short and worn, but should have changed the cassette and chainrings at the same time. A couple of weeks ago, when the snow situation was the worst it's been this winter, I suffered from a bad case of chain suck when using the middle chainring. Can't figure out exactly why though, the chainring seems ok to me, but maybe it's just too worn.

First, the specs:
  • the gruppo is Shimano XT, except for the front derailleur, which is XTR
  • the toothing of the cassette is 11-32 (9 speed)
  • the chainrings are 22-32-44
  • the length of the cranks is 175 mm
  • the bottom bracket/crankset system is Shimano Hollowtech II.
 Here's the crankset and the new parts:

Yes, no new big chainring. It would have cost as much as the cassette, and I'm cheap, and I figured that the old one will work ok for some time. After all, who really uses the big chainring on a MTB? 

Here's the old cassette. It might not seem worn, but yes, it's worn.

BTW, the new wheels I speculated of purchasing some time ago I indeed did purchase, and they're fine: 

Wow. Admire the thing the front derailleur is attached to - it's crabon fribé:

Or at least it looks like it with the fishy kind of patterns. There's some damage from a skipped chain. Hope it doesn't fail completely. It might be difficult to get a spare one.

BTW, I see that my repair stand has been designed by a person who knows what bicycle repair is all about: there's a beer holder in the tray!

Now, to dismantle the crankset. Some months ago, I solved an annoying clicking issue in the drivetrain by tightening the bolts of the chainrings as tight as I could (that is white-hot-shit tight, scientifically speaking). But opening them is a mother*ucker, if you don't own a special three-pronged tool for holding the counterparts in place - they just spin through. I finally managed to open them with the aid of a vise and a steel square. (I just looked it up - the special tool is called a nut wrench. Gotta order one of those.) 

Here's the crankset with the new rings:

And the new cassette. Installing a cassette has always gone without problems for me, and I've installed at least two. Actually, that's amazing. They've managed to design one part of the bicycle that's ham-fisted-idiot-proof.  

Ok. I managed to replace the cassette and the chainrings, and for once I'm not in an insane hurry to wrap the thing up and go to sleep. In fact, I think I'll leave the bicycle in the living room and overhaul the jockey wheels tomorrow. If I were a bachelor, I'd always have at least one bicycle disassembled in the living room.

Ah. Sweet, peaceful solitude. Just blissful, calm silence, except for the heavy metal blasting at deafening volume. And, of course, myself belching at deafening volume every now and then. I think I'll go to the sauna now.

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