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View Full Version : Stuck Campy AC-H bottom bracket


bw77
08-26-2007, 06:09 AM
I want to replace my Campy AC-H bottom bracket, because I noticed some play in it, but I cannot get the old one out. It's in a steel frame, and has been there since I bought the bike 7 years ago. I have the Park BBT-4 tool, but it seems useless due to slipping off the cup. So I am going to buy a Tacx tool that screws on. Is there a better way to use the BBT-4? Any other tricks to getting it out? I have put Liquid Wrench on it, too. Also, a few years ago the drive side cup was loose, so I put some blue thread locker on it, and it never loosened again. Was that a mistake?

Thanks.

Bill

regularguy412
08-26-2007, 08:28 AM
I've never used Locktite to set the cups on a bb. I was always afraid of having the very issue that you describe.

I've had a similar, though not exactly the same, situation with a barrel adjuster on two different rear brake calipers. I had sweated so much, that the adjuster was frozen in the caliper arm and would not screw in or out. I tried several different liquid penetrating lubricants with no success. Finally, I put one in the freezer overnight and then applied heat from a soldering iron to the exposed tip of the adjuster. The contraction and rapid expansion of the metal allowed the lubricant to finally work and I was able to gradually work the adjuster free.

You might try some variation of this method. Maybe lay the frame out in the sun and allow it to heat up thoroughly. Then apply somthing very cold, possibly in the form of a frozen ice pack to the inner part of the BB and its lockring. The good thing about this method is that there's no torquing involved and it lets the parts move in very small increments -- just to get them 'broken loose'.

For BBs that work loose in the future, you might try teflon tape on the threaded part of the lockring. The tape takes up any extra space, but does not 'freeze' the lockring to the frame. I had to use the tape method on my old C'dale beater. The BB came loose on two occasions. Evidently, the BB is not perfectly round or it may not be properly faced, and therefore allowed the BB to not stay put. I've _NEVER_ had this problem on either of my Serottas and I've never used Locktite or teflon tape on them. The tolerances on a Serotta when it leaves the factory are very good.

MIke in AR

rePhil
08-26-2007, 08:49 AM
I think it's still a mystery as to what is causing the stuck. I agree with going with the Tacx tool.
The antidote for Loctite is heat. With the steel frame you want to be careful of the paint. A heat gun carefully applied will release the Loctite, if thats what's holding it rather than corrosion. The heat would help if it's corrosion too.

Dekonick
08-26-2007, 09:51 AM
The tacx tool works. Makes a huge difference.

In future install BB's with antisieze and teflon tape.

jbl
08-26-2007, 10:10 AM
With the AC-H BB, I have heard of people using a quick release skewer to help keep the tool from slipping, similar to what one would do with a recalcitrant cassette lockring.

Dude
08-26-2007, 05:41 PM
use a breaker bar to get good leverage, assuming the tool is locked on. If that doesn't work, try a longer breaker bar. If that doesn't work, try torching the bb cup with a torch. If that doesn't work, by a new frame.

Louis
08-26-2007, 10:49 PM
Bill,

Is your BBT-4 the old style or the new style?

The new one has welded "fingers" that make it easier to keep the tool in place. The old style can be pushed inboard until it slips off inboard of the BB scalloped area, and was a PITA to use. The fingers prevent the new style from doing this.

If you have the old style you may want to try a new one. If you are already using the new style, then good luck...

A stupid question: Are you 100% sure that you are turning the BB in the correct direction?

Louis

bw77
08-27-2007, 05:27 AM
I have the old style BBT-4, it's good to know that Park realized it was a poor design. Thanks for that bit of info. Yup, I'm turning the right way. My plan is to get the Tacx tool and use a long breaker bar.

guyintense
08-27-2007, 09:18 AM
Clamp the bb tool in a large vise, hold the frame in position on the tool with a large c-clamp and turn the frame.

Dekonick
08-27-2007, 10:24 AM
Clamp the bb tool in a large vise, hold the frame in position on the tool with a large c-clamp and turn the frame.

Ahhhh!


work smarter, not harder!

David Kirk
08-27-2007, 10:34 AM
I'll reiterate or combine what a few others have said.

Use a QR or a piece of threaded rod through the BB to hold the tool on and then, with the tool securely in place, put the tool into a vice and spin the frame off the BB. Spin it the right way!

Works every time.

Dave

bw77
08-27-2007, 01:33 PM
I'll reiterate or combine what a few others have said.

Use a QR or a piece of threaded rod through the BB to hold the tool on and then, with the tool securely in place, put the tool into a vice and spin the frame off the BB. Spin it the right way!

Works every time.

Dave

Thanks for the ad-vice. I have several vices, but, not a single vise among them.

Bill

guyintense
08-27-2007, 03:10 PM
Thanks for the ad-vice. I have several vices, but, not a single vise among them.

Bill
It's a poor workman who blames his tools.

cmg
08-27-2007, 03:24 PM
put the tool in place then place large washers and use the crank bolt to hold them there. Keeps the tool from slipping. as others have said make sure your turning in the correct direction.

bw77
08-28-2007, 05:27 PM
I got the Tacx tool, and it worked like a champ, just needed a big wrench, no breaker bar, no vise. I would like to put in a plug for Harris Cyclery for their fast service, I ordered the tool on their website on Monday morning, it was shipped standard UPS that afternoon, and arrived at my house noon on Tuesday.

As for the Park BBT-4, it is truly a useless tool, and there is no way I can see that a quick release and washers could help. Maybe with a bottom bracket that's more like a cassette lock ring, but not with the AC-H which has a scalloped kind of shell.

Louis
08-28-2007, 09:25 PM
As for the Park BBT-4, it is truly a useless tool, and there is no way I can see that a quick release and washers could help. Maybe with a bottom bracket that's more like a cassette lock ring, but not with the AC-H which has a scalloped kind of shell.

BW,

I'm guessing that the folks who recommended this approach aren't familiar with the AC-H and the old-style BBT-4. If you had a very big washer that would help with the new-style BBT-4. (I have one of each...)

Glad the new tool worked for you.

Louis

Orin
08-28-2007, 10:34 PM
My solution...

I had time at the end of machining class, so I machined a cup to hold the original style BBT4 in place. Works wonderfully.

Orin.

jbl
08-29-2007, 01:13 AM
I'm guessing that the folks who recommended this approach aren't familiar with the AC-H and the old-style BBT-4. If you had a very big washer that would help with the new-style BBT-4. (I have one of each...)

Out of curiosity, what does the old BBT-4 look like? I use the BBT-5 on my 2006 Centaur AC-H BB, and that seems to work. Park doesn't list a BBT-4 in its current catalogue.

jbl
08-29-2007, 01:15 AM
Nevermind. I found a picture.

I was thinking of a completely different BB anyways. :crap: The 2006 Centaur ACH has the Chorus/Record style splines and uses the same tool.