Oh my bottom bracket...
 

Hey guys,

I need some help. I've posted a couple of times today. I need suggestions on a problem. Please read my op on what happened here:

http://www.bikeforums.net/showthread...for-a-new-bike

I don't know what else to do. I doubt a shop can do anything more. I mean if I wasn't able to get it out with an impact gun, I think the frame might be dead. :(

Suggestions?

Happy Riding!

Oh, here's another thread on a new bike I'm thinking of getting. I'd appreciate some feedback.

http://www.bikeforums.net/showthread...012-Giant-Roam

You know the drive side is left threaded, right?

Which means the impact (holy hell) gun needs to be set to "tighten" to get the BB out.

And the non drive side is normal threaded.

Yes, I am aware. Good to check, though. Thanks.

Pictures? Are you stripping the tool or is the cam of the impact rolling over? Have you tried a big breaker bar?

What tool are you using?

depends how good your impact gun is and compressor setup. the air lines and compressor at work are kind of crappy, so the impact gun wont always get it. breaker bar usually takes care of it. sometimes i enlist a coworker for help

Do you have any pics of the bike in question? neither side of the BB came out?

It's not slipping. I tried a breaker bar, but the splines are too shallow to get some decent torque on it, that's why I used an impact gun. I thought my crappy two thank compressor would get it out even though it barely puts out 110 psi, since last time I took out my bottom bracket, I only hand tightened it. But it didn't, so I went to my friend's house. He has a ten gallon tank and a nice gun. We had that thing on 400 psi. Neither cup would budge. I just don't get it because last time I took it out, I only hand tightened the thing since I knew it was coming out "soon". I'll try to post some pictures. Any other ideas?

FYI, I can't use a quick release to hold the tool because the axle isn't hollow, which is another reason I used the impact gun.

Did you grease the threads when you installed it? If not, you may have some luck using a penetrating oil (PB Blaster) if you can get it in there. Keep soaking it for a day or two before trying to remove it again.

Get a bolt that matches the crank bolt thread to hold the tool on tight?

Or this-

http://www.treefortbikes.com/cat/0/1...22343539___283

That's a good idea IthaDan. I'll look into that.

Just ordered the holder. Hopefully I can get it out with brute force. I did try earlier, but obviously had to put force into keeping the notches in the splines, so hopefully with the holder and I can just torque it and get it out of there. Although, I'm still worried that if I couldn't get it out an impact gun, how I'll be able to get it out. I'll keep you guys posted.

One thing about that holder and cartridge BBs- One side (USUALLY the drive side) with that bolt you can crank down and forget about it, the other side (NDS most of the time) you'll need to loosen incrementally because, as the cup comes out, the bolt gets even tighter. But you probably knew that already.

I was having the same issue with my 15 yo road bike. My neighbor loaned me an electric heat gun. That did the trick. I didn't have a pneumatic setup, so I used a rubber mallet to tap the breaker bar and I think that helped, too.

Try the heat suggestion. Not sure what tool you're using to interface with the BB on the right side, I have a spline tool with 10" handle. Also a separate socket for impact-gun. Then I use one of these:

http://ecx.images-amazon.com/images/...V60660574_.jpg
http://ecx.images-amazon.com/images/...V60660574_.jpg

1000 lb*ft torque is more than enough. I use it to install centerloc lug-nuts on my racecar. On one particularly difficult bottom-bracket fixed-cup, the threads were corroded and it spun the threads off the BB-shell. The fixed-cup came out with a spiral of threads from the bottom-bracket !!!

The trick to keeping everything together to get all the torque into the BB-cup is to lay the bike down on its side with the right side facing up. Then lay the spline-tool into the BB-cup. Then impact-gun. Hold down the gun with all your weight, then push the button. Or if that causes you to wiggle too much, have an assistant push the button while you keep the gun and all your weight on it steady.

Tell me more about this race car with centerlock wheels. Do you ever make it over to the glen? (Do you need a capable pit crew member?)

Always good to be reminded of little things like that. Thanks IthaDan.

It's not about the air pressure when it comes to impact gun power. It's all about the air VOLUME at a given pressure, and most air tools should NEVER have more than 90 psi put through them. I have an Ingersoll-Rand 650 ft-lb impact that requires a compressor that supplies at least 5 cubic feet of air per minute at 90 psi. My big upright 26-gallon compressor just barely manages to put out this much, and only in short bursts. Most small tanks 10 gallons and under only put out 2 to 3 CFM at 90 psi.

That IR Ti gun pictured above consumes 24 CFM at maximum load, which would require a HUGE 80-100 gallon commercial/industrial air compressor. Anything less and it's not going to produce 1000 ft-lb of torque.

most impact gun at load needs ~25 cfm and 90psi to get full power. a tank can supply that for a short period of time until the pump kicks on. the pump cant keep up if it wired for 120v(about 1 hp). a nice hose and regulator helps too. most compressors come with regulators that cant keep up so plug the hose in directly to the tank

I think you're on to something there Patrick. The thing I don't get though is why I can't get it out now. When I took it out last, I hand tightened it back in, since I knew I'd be replacing in the "near" future.

Are you saying it takes consuming all 24-CFM in 60-seconds for the gun to reach maximum-torque? Except that no one in their right mind uses an impact-gun for 60-seconds straight (100% duty-cycle). The gun does 1250 BPM and requires 5-6 blows to reach its rated torque, or 0.3 seconds or 0.12 cubic-feet of air.

To remove a wheel that's locked on at 350 lb*ft requires no more than 5-seconds or 2 cubic-feet of air. Actually less because once the nut is free, the gun's freewheeling it off with very little power needed. This is usually done between run-groups on the track, so we're taking our time. All four wheels requires 4x 10-seconds = 40 seconds of air or 16-CF total. Taking a leisurely 3 minutes to do this, that gun's operating at 22% duty-cycle. So any compressor that can do 5.33 CFM @ 90psi can keep up.

I have yet to see any bottom-bracket that requires more than 4-5 blows to remove. The one that ripped out the threads may have required 6 blows. Or 0.29 seconds or just 0.12 CF out of that first 24-CFM.

If you didn't tighten it down to spec the 1st time, the loose threads may have allowed wiggling & fretting. This will have distorted the threads and now they are locked or even welded together. This is why it's usually a good idea to use some teflon tape or anti-seize compound on the threads when installing.

If you can somehow position and hold the tools firmly enough to develop sufficient torque without slipping, you may very well strip the threads out of the BB. Well, nothing to lose at this point.

If you've got a splined socket for the BB, you can try using a 1/2"-drive breaker-bar with a 5-ft extension pipe. Clamp the downtube near the BB-shell with V-blocks in a vice and apply more and more torque with the breaker-bar + extension combo. Something will give at some point.

Heh, heh... Search for "Open Track Challenge" on YouTube. Sorry West coast only, although I'd love to run the Glen in the future. However, that would make it difficult to include in the 7-tracks in 7-days format...

I'm guessing I'm thinking of the wrong saratoga based on your location there.