smoothness 

I recently acquired a Univega Gran Turismo of questionable crash status. Being the foolhardy person that I am, I decided I must ride it, slightly crashed frame and all. Unfortunately, my attempts at removing the bottom bracket have been met with fierce resistance. Such refusal has included two broken pins on the giant Park bottom bracket wrench, smashed fists, and spitting ammonia at me (granted, I tipped the frame the wrong way). I'm at a loss as to how to get enough grip or leverage to remove these cups. The threads have been slightly damaged due to my hammering zeal.

Both cups had lockrings on them (now lost), and I've tried unscrewing in both directions, just for good measure. The cups are very much seized, as there is a slight amount of corrosion creeping outward onto the threads. The cups are aluminum. Also: anyone know why they stuck the letters on the bottom of the frame? I've seen two Univegas with those stickers so far, and I don't think they came from the same bike shop.

Anyone have any homemade tool suggestions?





I'm at wits end; my next idea is to just throw some dry ice down the seat tube to see if i can cause some shrinkage. If that doesn't work...out comes the blowtorch!

Any suggestions are appreciated.

FlatTop

I've had good luck using PB Blaster on aluminum-steel threadings. The stuff wicks in there and has a bit of lubricity.

IthaDan 

Are you planning on saving the cups? Can you get a bite on it with vice grips?

Be careful, that "G" side is left threaded.

smoothness 

FlatTop - You just reminded me that I started out with PB blaster, squirting a fair amount and letting it sit for a week; didn't break, and didn't visibly reduce any of the corrosion.

IthaDan - I first tried a non-destructive removal with a regular pin spanner; however, after i determined that it was not going to come out with such a paltry amount of torque, I put a set of vice grips on it and wrenched pretty hard on it. The vice grips came loose . I tried turning it left first, but it wouldn't move at all. My next action was to turn right, logic being that if I could tighten it a bit more, it might break the corrosive bond. No luck with that either.

noglider 

Try the Sheldon method using a big bolt. Clamp the bolt in a vise, and use the frame as the lever.

Jeff Wills

A blowtorch would expand the aluminum more than the steel, seizing things more thoroughly. It might break the corrosion, though.

Umm... destructive removal? File flats in what's left of the cups and then grab and turn them with a bench vice?

mainstreetexile 

It sounds like you've been using all the right methods, ammonia is supposed to be the best for dissolving the chemical bonds between aluminum parts in a steel frame (but I've never had much luck with it).

As others mentioned, heat will make the aluminum parts expand faster so it's better for steel parts stuck inside aluminum (I recently had a bike trailer axle that it worked well with) but who knows, it may break something loose. I used a heat gun, which may be better than a blowtorch for saving the paint. Cold may also help, especially if you alternate hot and cold.

No one knows what those bb stickers are for (someone prove me wrong!). I've seen them on a few Univegas, mainly from the first few years of the 80s. Looks like this one is an 81.

jebensch

+1. Done this a couple of times.

JReade

If both cups are jammed in there, where does the bolt go?

JohnDThompson 

Spot-weld a metal rod or bar onto the cup to use as a handle to turn it out.

acoffin 

Just brainstorming here. What about drilling two holes in the cup, then put two bolts in a vice to act like a very large spanner wrench?

squirtdad

you need to get the spindle out first for that......can't do that unless at least one cup is out

squirtdad

My theory on the A and C letters on the BB shell. My mother in law's gran turismo (circa about 78) had these. I think these were during a boom period and shops may have not had as much experienced help. The letters probably matched a diagram that said put part that looks like this in the BB on the A side. Just a theory, but makes sense.

smoothness 

i was thinking of trying to cut some ridges into the cups...but i wanted to make sure that i was not going to be cutting into a nice bottom bracket, or a sealed one for that matter. it still spins well...i'm just uneasy with the fact that there are no lockrings on there, and i have no clue on the condition of the inside of the bottom bracket shell.

JReade

I would go with the "drill some holes" method, and try to twist something inserted.

cooperryder

What tools have you tried on the fixed cup?
I have had success with this tool for many fixed cups.

Park HCW-4 Bottom Bracket Fixed/Adjustable Cup Wrench*

https://m.parktool.com/product/crank-...t-wrench-HCW-4

However I have broken pins b4 on the adjustable cup side as well.

If at an impasse is there a bike shop or Co-Op
*in area with experienced guys who may have the more expensive*BB removal *tools?

Found this YouTube *vid on BB removal humorous.

https://www.youtube.com/watch?v=dYlEG...e_gdata_player

abarth

I seen letters like those on early 80's Miyata too.

mainstreetexile 

Since both of these are adjustable cups (with lockrings), I wonder if someone jammed a cup in the fixed cup side, trashing the threads and getting it stuck in the process?

mparker326

Whenever I run out of my homemade options to get something stubborn like this off, I take it to my trusty LBS. My LBS has been around for a long time and is used to dealing with stuff like this. I wind up spending $3 and saving about 3 hours of my own time.

goatalope

There's better ideas already posted but...

I've had some luck heating up parts with heat gun, then pouring cold water on it/putting it in ice water. Had to repeat the cycle a couple times, but seemed to work sometimes.

Trakhak

(1) File or grind flats into the back of a pin spanner.

(2) Reinstall the crank arm (use the left crank arm on both the left and right sides to give you room to work) so that the pin spanner is held firmly in place (i.e., so that it can't slip).

(3) Use a large-diameter pipe (e.g., the steerer tube of a fork) for leverage and remove the cup by turning clockwise for the right cup and counterclockwise for the left cup.

If one of the cups still won't budge, grind down another pin spanner, hold both pin spanners in place with the crank arm, and use two pipes (one for each spanner, of course).

smoothness 

I love the alternative suggestions, especially Trakhack's idea of monstrous leverage. Unfortunately, I do not feel like breaking any more pin spanners. I think I might take it to the shop for laughs later on today. Hopefully they'll be game. I'll report back with results.