Shots - Bottom Bracket Teardown

I decided to upgrade the bottom bracket on my green 3-speed. It was a three-hour job at Broadway Bicycle School.

Removing the Old Stuff

The crank arms on a Raleigh are held on with cotter pins, which sometimes are a bitch to remove. These must be removed before you can take out the crank spindle. In my case, the left (non-drive) side crank arm came off without much problem (it was already loose anyway), but the right side was more trouble: I had to saw off the end of the cotter, and then take the bike out to the sidewalk and, with an assistant holding the bike steady and a length of pipe under the crank arm, pound out the remains with a hammer and punch.

With both crank arms off, the crank spindle is the next to go. The non-drive-side cup must be removed, and the crank spindle and any loose ball bearings pulled out of the shell.

Loose ball bearings inside the hub shell...

...and the crank spindle freed from inside.

Removing the fixed cup is a two-person job. You thread two halves of a big steel tool together around the cup, tighten the hell out of it using two gigantic adjustable wrenches turned in opposite directions, then turn the two wrenches in the same direction to unscrew the cup from the bottom bracket shell.

Installing the New Stuff

Raleigh used non-standard threading in their bottom bracket shells, so if you want to use a new cartridge-style bottom bracket in an old Raleigh, you need to use special cups made by Phil Wood. These cost $30 (as much as the bottom bracket itself), and come in a little gift box with a little vial of thread locking compound.

I used a Shimano UN-72 (Deore XT) bottom bracket with the Phil cups, and an old Specialized road crank. Not pictured is the process of getting the right chainline, which involved some trial and error to get the new bottom bracket positioned correctly in the shell so that the front chainring was in line with the rear cog.

The Phil Wood cups.

The Specialized cranks. This is before prepping them for the 3-speed, which involves removing the outer and inner chainrings, and refastening the middle ring using BMX-style bolts.

The new crank installed. The knurled piece inside the bottom bracket shell is the drive-side cup.

The finished crank, installed on the bike.

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