In this article you’re going to learn how to overhaul an old style bottom bracket. Or rather, in this case, an adjustable cup-and-cone bottom bracket.
You can find these typ of bottom brackets on bicycles up to the early nineties. Already during the eighties, sealed-cup bottom brackets, became popular. But we’re usually only on more premium bicycles.
These old style bottom brackets consists of a spindle held in place with two bottom bracket cups. In between the spindle and the cups are the bearings. By tightening the cup on the non-drive side play in between the cups, the bearings and the spindle is removed.
Step 1. How to detect play in your old style bottom bracket
I had been noticing movement while pedalling in my Scott Town XC bike for a couple of rides. At first I thought that maybe the Biopace crank chainring could be worn out. But it quickly turned out it wasn’t a worn chainring but play in the bottom bracket.
Detecting whether or not your bottom bracket has play is very easy. Just take one of the crank arms and try to pull it away from the frame. If you feel the crank arm move you’ve got play and the extension in the crank arm makes this more noticeable. Especially where the pedal goes in. So you feel rather than see it.
Step 2. Removing the crank arm
So now you’ve noticed play in your bottom bracket you need to get to it. Remove the crank arm with the help of a crank puller and adjustable wrench.
If you have a dust cap covering your crank bolt, remove it.
Then use a crank bolt removal tool to loosen the crank bolt. I use a the Park Tool Crank Bolt Wrench CCW-5C.
With the help of a crank puller and adjustable wrench you can get the crank arm loose. I use the Park Tool Compact Crank Universal Puller CWP-7 and Park Tool 12-Inch Adjustable Wrench PAW-12 for this.
Step 3. Removing the adjustable cup-and-cone bottom bracket
When I was fixing the play in the old style bottom bracket and tested the spindle it just didn’t feel right. When I rotated the spindle in its cups it didn’t feel smooth at all. So I decided there and then to do a complete overhaul of the bottom bracket.
The adjustable cup of the bottom bracket is kept in place with a lockring. This prevents the cup from moving when in the correct place. This ring needs to be removed with the help of a special lockring wrench. I use the Park Tool Bottom Bracket Lockring Wrench HCW-5 for this.
It has a hook which slides in one of the gaps of the ring so you can exert force. Be careful not to damage the lockring, which is done easily since you only have a minimal hold on it with the lockring wrench.
The adjustable cup needs a specific bottom bracket wrench to loosen. I use the Park Tool Crank & Bottom Bracket Wrench HCW-4.
The bottom bracket wrench has two pins that go into any of the 6 holes in the adjustable cup. Make sure to rotate towards the direction the bike is facing, meaning counterclockwise to loosen the cup
With the adjustable cup removing, you can simply pull out the spindle.
Next up is the fixed cup of the drive side (where the crank with the chainrings goes). You’ll need the same bottom bracket tool, only the other side. The cup has to flattened sides where your bottom bracket tool slides over. Be sure to rotate clockwise to remove the cup! Again towards the direction your bike would be moving if you actually pedalled.
Step 4. Cleaning your old style bottom bracket
After I’ve removed all the parts of the bottom bracket I put them in a small salad bowl and douse them in mineral spirits. This easily takes away all the old dirt, grease and grime.
I use this stuff to for general cleaning purposes and always put it back into the bottle afterwards. Nothing goes to waste!
Step 5. Checking bottom bracket parts for damage
Now is a great time to check your bottom bracket for any signs of damage.
Check the spindle to see if the bearing race has pits on them. The bearing race is the silver circle just besides the shoulder of the spindle. If it has extensive pits (caused by corrosion), you’ll need to replace the spindle.
Also check your ball bearings for the same type of damage. You can clearly see in the picture below that water had seaped into my bottom bracket and caused the right bearing ring to rust. So I went to my LBS and picked up a set of fresh ones.
Step 6. Putting your old style bottom bracket back in the frame
Before you can put your bottom bracket back in the frame it’s also a wise thing to clean the frame and threads.
Also put some grease in there. My ball bearings where rusted and grease might not prevent this from happening, but it at least slows it down and minimizes it. One of the worst things for any bike restorer is a seized bottom bracket.
Also put in a copious amount of grease in the bottom bracket cups. Make sure you place the ball bearing cages in the right way. That is with the ring of the ball bearing cage facing outwards and the balls making contact with the bearing race.
Putting the bottom bracket back is basically a reverse from removing it. Keep in mind that when you put the spindle back (after you’ve greased it), place it in such a way that when sitting on the bike and looking down you could read the engraved text on the spindle. Spindles might not be symmetric, with the non-drive side being shorter. If you’re unsure about this process simply mark the right- and left side of the spindle directly after you’ve pulled it out.
When replacing the non-drive side, tighten the cup in such a way that it’s loose enough for the spindle to move freely, but tight enough to remove any play. This is the same process as with removing play in a wheel hub. Detecting play is easiest with the right-hand crank arm already on the bottom bracket.
If you feel confident the play is gone, the final step is to put both crank arms in place (or the non-drive side).
And that’s how you overhaul an old style bottom bracket!