Tuesday, October 27, 2009

Murderer's Remorse

I stare blankly at the floor.
What had just happened?
The implements were all there.
The 4.5" cutoff wheel. The long chisel. the 5 pound sledge.
My feet are wet.
Where was the bike anyways?
My hand is numb.
Looking around the room, I start to piece it back together.
Another small hammer, a vise, two long wood clamps, two blades from a hand plane..
And in the middle of the floor, my headset wrench.
Picking it up, I focus in on the new indentations in the 34mm flats.
I touch the new distorted metal and it all comes flooding back to me.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The wrench slipped off the drive side BB cup!
I double checked I was turning it the right way. Drive side reverse thread, check.
I put the wrench back on, and held it in place while I carefully leaned into the bike.
The wrench slipped again. My hand hit the chainstay.

Inspecting the BB cup revealed that the two wrench flats were not flat.
I sprayed liquid wrench around it's circumference, and inside the bb in the hopes of loosening it up. Giving it some time, I thought about my options.

How long had that cup been in there?
I thought I had it out when I replaced the ball bearings a few months ago.
No! I didn't. Now I remember, I couldn't get it out back then either.

The balls had been crushed and were being eaten. The cranks were hard to turn. I had to remove them, wipe the whole thing out and replace the balls through the non drive side. Even after that, the bottom bracket would develop play after one ride for some reason.

This time all of the new balls were in tact. The grease wasn't even that dirty from the last rebuild. I just wanted to put a slightly shorter UN53 cartridge unit in it to stop this constant loosening. I was determined to get the drive side cup out.

After doing some other household chores I came back to look at the bike. The BB cup hadn't moved in the time I was away. As if it was just going to unscrew itself while I was gone. Sigh. There was a small pool of liquid wrench in the BB threads closest to the cup. Sure. I wiped it up, and cleaned off the outside of the BB area with a rag.

I opened the large bench vise up to bottom bracket size and dropped the frame in. After double checking that I was rotating the frame the right way, I gave it a push. Of course, it just jumped right out of the vise. twice. thrice. Clearly this was not the answer.

Some wood clamps, and flat steel. Hand plane blades, clamped on both sides of the BB should hold the wrench on. Bike upside down I strike the wrench with the five pound sledge. Thankfully the wrench doesn't shoot off the contraption I have just assembled. I check for movement and strike again. I adjust the clamps tighter. I am getting nervous, fearing for my fingers. After many strikes, I observe movement. One more good hit should do it!

Finally the wrench has turned... but upon removing the flat steel stock and clamps, I find that my 34mm wrench has rotated around the cup, without the cup moving. Picking it up, I focused in on the new indentations in the 34mm flats. I drop it on the ground and pick up the frame.

I throw the frame outside onto the lawn. In the rain.
I put on my safety glasses.
I grab my disc grinder and an extension cord.

Before I even know what is going on, I am attacking the BB cup.
First I grind a slot straight across its face.
I then angle the cuts to have a sloped surface in which I can fit the next implement of destruction. My legs and arms are sprayed with chrome and steel dust.

I march back inside with my grinder.
I trade it for a long dull angled chisel and my favorite sledge. The five pound.

I look over my prey. Everything is tinted red.
I straddle the tubes so they contact my ankles.
If this is going to hurt you, I want to feel it.
I jam the chisel into the fresh steel slot, and hold it there.
I pause to calculate. I wouldn't want to miss my shot in this position.

I strike.
The frame sings.
My ears ring.
I strike again and again.
I move the chisel to the second slot and continue to strike.
I work this fucking cup for an eternity.
The metal begins to peel, but the slot holds the blade.
My right shoulder burns, my left hand is numb.
The frame didn't ring out crying in that last strike.
I have detected movement.

I'm not as happy as I thought I would be.

I work the cup around, and it is still quite difficult to turn. Finally, after getting about 3 revolutions around, it spins freely. Out it comes.

I walk inside and drop my tools.
Suddenly I am dizzy.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I stare blankly at the floor.
What had just happened?
The implements were all there.
The 4.5" cutoff wheel. The long chisel. the 5 pound sledge.
My feet are wet.
Where was the bike anyways?
My hand is numb.
Looking around the room, I start to piece it back together...

After collecting myself, I go outside and pick up the frame off the lawn. It is cold and wet. I cradle it in my arms and inspect the face of the bottom bracket shell. Some slight marring. You'll be okay. We'll file that down. The threads appear to be in perfect condition.

I bring the bike inside and hang it up. I close my eyes. I don't want to think about what I've just done.



Epilogue: The cup was not rusty, as I orginally assumed. Instead, it had developed a crack along the outermost thread. This essentially changed the thread pitch around half the circumference, locking the cup into place. I attribute this to the original problem of the steel balls detroying themselves. Cranking in this condition may have lead to exccessive pressure on the outer cup. This would also explain why the the bottom bracket spindle would work itself loose every ride. The UN53 bottom bracket went in without issue.

3 comments:

Bato said...

Just been hammering away at a bb on a nice old khe streetbeater, gave up for now but will resume tomorrow. Excellent post, fucking wonderful.

tenspeed said...

wonderful tale.

dfs said...

i find heating up the shell with a tourch helps, come out like butter