Drive Train

We’re now about midway through September.  The first week of September featured weather similar to the inside of a gym locker room.  This past week, the weather has been beautiful.  We’ll see what the rest of the month holds.

I haven’t ridden my mountain bike since I broke my chain a few weeks back.  I put a new chain on, but then I decided I should also replace the drive train.  The cassette and chainrings were all mid-1990s vintage, and probably completely worn out.  I wouldn’t be surprised if they contributed to the chain’s demise.  So anyhow, replacement 7-speed MTB cassettes are pretty cheap online.  I bought a new SRAM cassette for around $17.  We’ll see how it holds up.  The gearing is a bit different from my old one; the small cog has 12T vs 13T on the old cassette, which will give me a slightly higher gear going down hills.  The largest cog is also larger, giving me a lower gear for climbs.  I don’t really need a lower gear on this bike with the kind of riding I do, but as you can imagine, there isn’t a terribly wide selection of gearing choices in 7-speed cassettes nowadays.  This was about the best I could find given how I’m going to ride it.

Buying new chainrings was an interesting lesson in economics.  It’s very hard to find replacement chainrings for old cranksets, and when you do, the cost of 3 new ones often adds up to more than the price of a brand new crankset (which includes the chainrings).  There was nothing wrong with my existing crank, but I ended up replacing it, because it was cheaper than buying 3 new chainrings separately.  The new crank is a Shimano Acera M361, with the same specs and gearing as the old one, and a chain guard to boot — I am a big fan of chain guards now that I’ve had one on my road bike for awhile.  One thing to be aware of, is that some of the cheaper cranksets have the chainrings permanently riveted on.  If you have any intention of replacing chainrings as they wear out (which is more likely if you do a lot of riding), you’ll want to stay away from these.  Of course, if you’re like me and wait 18 years to swap chainrings, it won’t matter, because you’ll be replacing the cranks anyhow.  🙂

I’ve got the parts installed on the bike, but still need to readjust the derailleurs and get it shifting smoothly.  Once I do, I’ll report back on how the bike rides.  I’m hoping it’ll be an improvement.

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One thought on “Drive Train

  1. Well.. turns out my old crankset was a 46-36-26, not 48-38-28. So by going to a 48-38-28, I’ll definitely get some higher gears for road riding. I didn’t realize my outer chainring was larger until I put it on and found that the derailleur cage no longer cleared it. I moved the derailleur up about 3/16″ to clear the chainring, and I may also need to add a link or two to the chain. I’ll find out when I work on it this evening.

    Reply

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