And so it came to pass that I had noticed a grinding noise from the bottom bracket (that’s where the spindle that holds the crank arms sit) of my folding bicycle(*). I recognized the familiar noise from my inline skates as being that of a broken bearing assembly.

(*) I use it to increase my cycling handicap. I can only got about 14mph or 17mph if I really spin, perfect for “recreational rides” with friends and family 🙂 .

Since I got the bike for free(**) I decided to use this as an opportunity to increase my repair skills. So I have been watching videos on— I’m an visual kind of guy—until I felt confident enough to get dirty.

I put in an order for a pin spanner crank wrench, a crank puller, and a lock ring spanner and then spent the next week being very excited (why anyone would pay extra for fast shipping is beyond me), this being the first amazon (where I buy most things) order for more than 6 months.

(**) I traded it for a couple of books with a guy who was very impressed with one of my previous/other websites. Funny story. I was looking for a folding bike on craigslist, contacted the guy, and he goes “Are you the Jacob, that … and if so you can have it for free”. Turns out I was.

I borrowed a 14mm socket wrench from DW’s set (she’s well-equipped 😀 ), to get the bolt of the crank arms. I then used the crank puller. In the process of getting the second crank arm off I ruined a couple of threads, since I only got it finger tight and didn’t realize that it wasn’t sufficiently far in; ah, the cost of incompetence. It’s still usable though.

In general my greatest worry is not having the right tools, so I was amazed that the lock ring spanner fit! I got the lock ring right off. Next, I had to get the bearing cup on the lock ring side off. I was very dismayed to find that the pin spanner crank wrench didn’t fit! That is, until I realized I could unscrew one of the black nuts and lever it off. It is very helpful to know whether something unscrews clockwise or counterclockwise. It is also very helpful to not weaken yourself by doing kettlebell exercises simultaneously(***).

(***) I was utilizing the 20-40 second breaks to work on the bike.

Once I got the bearing cup off, my suspicion of a wrecked bearing race was confirmed.

A replacement costs $1-$2 in materials. I went to LBS#1 worried that they wouldn’t know what I was talking about, but he went right on it. Unfortunately, they didn’t have any, so now I’ll try LBS#2.

Total estimated cost:

  • Tools: $60
  • Parts: $1
  • Fun and satisfaction of doing it yourself: Priceless

Any idea of what it would cost to have it done professionally?

Stay tuned for part II, where I put everything back together, pending the acquisition of the bearings, and grease+grease gun which I did not think of getting the first time around.

Update: I went to LBS#2 (by bicycle of course) and they sold me 22 loose bearings. I suspect those will be fun to put in. Now I just need some waterproof grease. It is quite likely that I will not need the grease gun.