Dissecting a Raleigh Bicycle Chaincase

My 1952 Raleigh Sport came with the fully enclosed chaincase, as seen in the photo above. It was one of the reasons I wanted the bike. I think it's a really cool look, and it's certainly practical. I do understand why all bikes don't have these. They do make things more difficult when you're dealing with maintenance issues. And they add weight.

I was a bit intimidated by this chaincase. Things I had read on the web led me to believe that these chaincases wildly complicate such everyday jobs as removing the rear wheel. As I read through Sheldon Brown and others, I learned that you would have to remove the pedal and the drive-side crank in order to remove the chaincase.

That is true. But the belief that you have to remove the chaincase to do anything to the bike is wrong, and it's what I inferred from various bike forum comments. Once I cracked into the chaincase myself, I found out that it's really not difficult to deal with. First off, you can remove the wheel quite easily with only minor effort.

Understanding the anatomy of the chaincase is the key, I think. Here's a breakdown of the entire chaincase, as it comes apart into separate pieces:

The part labelled "A - Main Chaincase Body" in the photo is actually bolted onto the bike frame from behind the crank and pedal. So it is true that you have to remove the crank in order to get the chaincase body off. But for most purposes, you never need to take it off. The only reason I did so was to give it a thorough cleaning. Otherwise you could leave it on the bike to remove the wheel, change or maintain the chain, or even remove the pedal and crank for that matter.

To remove the rear wheel, you only need to remove the part called "B - Bottom Piece." It is attached to "A" with two small screws. Only a screwdriver is required to remove it. Once you pull it off, you can easily access the cog, axle nuts and chain area.

Keep in mind that in order to remove the rear wheel, you also must disconnect the gear cable from the end of the axle. But as long as you tighten the small knurled nut on the indicator chain up snug against the gear cable's screw-on when you have the gears properly adjusted, you'll always know just where the screw-on needs to go when you put it back on.

Another tip is to put a wire or something through the chain when you remove the wheel, so that it can't slip out of view. As long as the chain is not unlinked, it won't go far.

I seriously wonder how often the back wheel was removed from my 1952 Sport. I'm guessing only a handful of times. The back tire was not original, and there were patches on the tube. So at some point it had to be accessed. But probably not often.

When I pulled the chain out of mine, it was covered in gunk. But I soaked it in vinegar for a day, then wiped it down with some oily rags. I then used a bit of solvent on it, then cleaned it some more. And it looked like new! So these chaincases really protect that chain, no doubt about it. There is a small oil port at the top of the chaincase, so you drip oil directly on your chain without removing any part of the chaincase.




To get into the crank and bottom bracket, you'll need to remove "C - Crank Cover," that round part. There is a small piece marked "D Lip" in the photo which slides into two grooves. There's a small lip sticking out that you can grab, then pull it down, sliding it out of the grooves.

To remove the crank cover you will need to remove the pedal. The pedals on the older Raleighs are not the same size as more modern bikes. So a correct sized pedal wrench is a must. The old Raleigh multi-tools that came with their bikes has the right wrench head on it, though you might need a large diameter piece of pipe to use as a persuader bar. It also seems that a 5/8" wrench is the right size, but it is to wide. Some people have ground them down thin enough to work as a pedal wrench.

The Crank Cover is simply fitted into the hole. You can pry it off carefully with a small screwdriver. Try working in several places around the hole. It's a bit like carefully prying a lid off of a paint can.

At this point you should see the chaincase looking something like the photo below (it's not a Raleigh, but shows what the crank looks like when it's exposed):

To service the bottom bracket you can just leave the "Main Chaincase Body" in place. But to remove the entire chaincase from the frame, for whatever reason you might have, such as cleaning or painting, you will need to remove the crank.

Removing the crank will mean removing the cotter pin and just pulling the crank arm straight out. Removing the cotter pin can be an entire project all by itself, depending upon what issues you encounter. Sheldon Brown's website addresses the cotter pin issue here. I also discussed the use of a cotter press in my posting on restoring the 1961 Raleigh Sport.

Once the crank is off there is a bolt behind the crank that attaches the case to the frame. Then you'll need to squeeze the chaincase off. If you look at the photo above of the "A - Main Chaincase Body" you'll see that at the back of the chaincase there is a narrow separation between the upper chamber and lower chamber, right near the rear axle area. It takes a bit of squeezing, but you can just maneuver that split through the frame dropout on the right (drive) side and pull it through.