In my last post about fixing up an older CCM mountain bike, I thought I was done tinkering with the thing. I believe I said: “Leave well-enough alone.” Yep, I did say that. But I didn’t do it though; oh no, I had to go mess with it even more.
Last time I worked on fixing up The Beast, I knew that the crank bearings (Bottom Bracket, or BB for short) were really bad; the crank wouldn’t spin a full revolution with no chain on. Since I was both waiting for spring and waiting for a recent knee injury to heal, I had nowhere to ride with any of my good bikes and I was itching to just do something relating to a bike. So I delved into the bottom bracket issue with my CCM Riptide.
First off, I’m not buying any specialty tools for this old bike. None of our modern bikes would use the tools this bike needs. However, I did borrow a BB lockring spanner from a friend to complete this job. The adjustable BB cup also uses a special tool, but I found a 5/8″ wrench worked fine if I was careful to keep it flat. I also used a crank-puller tool that I borrowed.
Disassembly, Cleaning, and Inspection
As with all repair/overhaul jobs, I disassembled the bottom bracket, removed all parts, cleaned everything, then inspected for damage. First, I removed the cranks with the crank-puller tool. The lockring on the drive-side of the bottom bracket came off next. Then the adjustable cup came out, followed by the guts of the BB (the bearings and spindle). Lastly, the fixed cup was removed with a pipe-wrench (clockwise). Here is what all the parts looked like in their rust-encrusted glory! It’s no wonder I couldn’t get this bike up to speed and was working hard every ride. The spindle wouldn’t even turn by hand with the cranks removed!
After cleaning everything, I noticed two main things that would normally call for new parts:
- The bearing surfaces on the crank spindle were pitted and worn. This is cause for replacement of the spindle.
- The spindle itself was bent. Another reason to replace it.
The bearings were in OK condition, but a couple on each side were pitted. Normally, if any bearings look the least bit dull or pitted they would all be replaced. In this case, the expected value of the bike didn’t warrant putting any more money in (I wasn’t even going to do this job in the first place), so I just re-greased everything and put it back. One thing that wasn’t worn at all were each of the bearing cups that thread into the BB shell in the frame.
It was obvious that by locking the bike up to a railing for at least one but probably several Edmonton winters, the result was disastrous on my BB. The rust and wear were probably at the lowest point where water collected every year.
Since I had no more budget for replacement parts, I decided to re-grease everything and just install it as-is and adjust it as best I could. I really was only doing this job for fun and as a learning experience. A bike like this would not normally be worth the time or the price of replacement parts. If it was a special frame, like an aluminum or chrome-moly frame, or if any of the components were the least bit better, it might be worth putting in new parts.
The crank and BB parts looked much better after cleaning! I cleaned out the BB shell in the frame too. Once everything was clean, I re-packed the bearings with general automotive and bearing grease, greased the threads of the BB shell, and re-installed everything.
Adjustment of adjustable bottom brackets is a bit tricky, as you want to tighten the adjustable cup just enough to remove the play. With a slightly bent crank spindle, this fine adjustment is impossible, as the spindle will be tight at one point in rotation and loose in another. Find the tightest point and adjust at that point so the play is just gone. Mine wasn’t bent too badly, so after adjustment the crank assembly spun like nothing! Without the chain attached, I could now give the cranks a spin and they would just keep on going round and round, just like my newer bikes! Awesome! A quick trick I learned is to lay a piece of tape across the BB shell (the lower frame tube) with markings about every 1/8″. This way you can adjust the moveable cup by rotating slightly from one mark to the next.
I also overhauled the headset, using about the same steps as above. The headset bearings were fine and once cleaned, everything went back in very nicely. Now it was time for some test rides.
Wow, does this bike ever ride nicely now! The crankset overhaul, combined with all the other work I put into this bike over the winter has made this bike ride almost like new, even without replacing all the parts. Yesterday I went for an hour ride and had no problems at all. I even managed a top speed of 34.6km/h! And that’s with studded tires mounted. With the lower profile commuter tires on and a clean and lube, this bike will be perfect for a bike commuter who wants something cheap to start out on. Plus, I had put my bar ends inside my shift and brake levers, like aero bars, and they actually worked! I was long and lean in that position and wasn’t out of control. I think I’ll leave them there.
For more information on rebulding bottom brackets, see Sheldon Brown’s Articles or the Park Tool Repair Help Website. I wrote a detailed post on rebuilding a headset, although it was for the modern threadless type, but the principle is the same. Sheldon Brown and Park Tools also has good information on this.
Oh, and I cleaned the mirror.