Sunday, 11 July 2010

Renovating a Raleigh Twenty: Part 4 - Bottom Bracket

I was intending to service the bottom bracket and change the chain today, but was stumped by the fact that the old chain had 93 links. That's possible because of this half link with cranked plates - photo of the old chain above. I don't have a replacement, so had to order one. Anyway...on with the bottom bracket for now.

Above is a photo of the bottom bracket with the retaining ring removed. The cotter pins came out with no difficulties, thankfully, but I'll need new pins when I re-assemble.

Here's the axle cleaned up, with shiny new 1/4" balls, 11 each side. Cups were in reasonable condition and although the axle has bearing wear, it's good to go for a while yet.

I forgot to take a photo of what was inside the bottom bracket shell when I opened it. It was dry, balls were all present, but there were flakes of rust scattered around, mainly over the middle of the axle inside the shell. The photo above is after I'd cleaned it and packed the chainwheel side cup with ball bearings and grease. (The chain wheel side cup is welded in place). Looking inside, you can see that the shell itself is absolutely fine, the steel is in great condition actually. So, the flakes of rust must have fallen through from the seat tube opening - at the top of the cylinder. So, the frame saver that I squirted down the seat tube was needed! I decided to make a sleeve, in the good old fashioned way from a washing up liquid bottle.

Thing is, that nowadays, washing up liquid is not sold in cylindrical bottles any more! So, here's some transparent plastic taken from a bottle of some potion, nabbed from da boss's toiletries collection.

After a bit of snipping with scissors, in goes the sleeve. It butts conveniently against the lip of the chain wheel side cup. The ends overlap at the bottom, in case any water gets in there, it has a way out.

Here you can see the sleeve after being trimmed to size and in position. The outer edge is just inside the thread on the shell.

After screwing in the cup, I gave all the stay tubes a few squirts of frame saver. I've been doing that as I work round the frame, and the only tube that still needs some frame saver is the big chunky down tube.

On eBay, you can buy these cheepo plastic pipettes for pennies. These are great for all sorts of uses round the house, including squirting engine oil into the Sturmey Archer AW hub!

Next time I'll assemble the cottered cranks and fit the new chain. By the way, on close inspection, the chain wheel was not totally straight. Clearly it had been knocked from the side at some point in history. Actually, I had not noticed until now. A couple of whacks with a hammer, and the chain wheel was much straighter! That's the beauty of steel...


  1. I love the writeup. The visuals are really helpful vs. blind.

  2. Hi,

    I have a same bottom bracket, what kind of tool did you use to disasseble it?

  3. Hi Andres, I used a standard steel punch and a hammer to carefully loosen the lock ring, then unscrewed it by hand.