Tuesday, August 7, 2007

The Crank

I finally went to the hardware store and bought a big enough wrench to take off the crank. For future reference, I needed the 10" adjustable wrench for the 1 1/8" inch nut.

The photo on top is the "before" picture of the crank assembly. In this photo, the bike is upside down and we're looking at the left side crank.

The second photo shows the "exploded" assembly after I took it apart, with the bearings exposed. The bearings come out, too, but were left in for the picture. One note here: everything I've read on removing the crank says that a spanner wrench is needed to remove the bearing race (a.k.a., adjusting cone), but mine came off just by turning with my fingers. Is this bad? I don't know.

In the third and fourth photos, I've circled the groove in the threads and the little tooth on the crank plate and washer than fits into it. These should be lined up for reassembly.

The fifth photo shows how dirty and grimy the inside of the crank assembly was. Shown here are the bearings for the right side. The old bearing grease has dried up and gotten gummy and dirty, which was probably dramatically affecting the ride of the bicycle. The last photo shows what fell out of the inside of the crank assembly--one very greasy, very dead insect.

Once I clean things up, I'll post some new pictures, just for contrast. I also have some thoughts on painting to post soon.


  1. Are you going to insert another insect? I've had the same experience with the adjustable cones on bottom brackets, that is, they are adjustable by fingers.

  2. No, I think I'll leave the bugs out altogether! :-)

    Since I wrote this post, I've learned that with this one-piece crank style, bottom bracket cones are definitely finger-adjustable, but with three-piece cottered cranks, the cones are held on with a lock ring that definitely requires the spanner wrench. Actually, the cone itself is still adjustable with fingers, however, once the lock ring is off.