Removing a BB
 

While this is a Lemond Revmaster (Sport) spinner bike, I believe that the basic structure is the same as a conventional road bike.

I am trying to remove the BB assembly (to be replaced) and have the cranks removed and have the right BB remover tool. I've never done this before. The tool is this multi-toothed thing where the teeth slide into 'their mates' in the BB cups. According to the instructions the right side is reverse threaded so I have been careful here.

But with my not that big 1/4" socket drive (that fits into the BB cup remover tool) I really can't confidently hold the tool in place while I put about about a billion foot pounds of torque into this thing. I'm afraid that I am either going to ultimately tear up tooth things as I can't securely hold this tool in place and the tool has a tendency to kind of twist/pop out under heavy (one-sided) applied force.

Is there some technique here? It seems like I need some kind of socket drive where I can apply torque from two sides so the thing doesn't have this tendency to slide out.

Also the left side did budge a little bit. But it felt like I was tightening it (I was going counter clockwise). After just a hint of turn that same force will no longer do anything. So I am proceeding very cautiously here for fear of really messing something up.

Thanks.

dave

One trick you can try if the BB spindle is hollow is to get a long bolt with the right thread, and a washer use it to hold the tool in. It might take a bit of finagling, but isn't hard (the hardest part is sourcing the screw). With the tool securely held into the cup you should be able to torque it more without it camming out.

Otherwise, you can try fitting a block under the "hub" of the tool or wrench, so you can apply torque without the tool moving down.

Lastly, if you can improvise something, take a hint from people who have to remove tight lug nuts on cars and trucks and find a T handle or 4-way tool, so the torques are applied up and down and don't push the center across.

All the above is for extremely tight cups. In most cases I do fine simply holding the center against the sideways force with one hand, while torquing with the other.

This is a common challenge at work, keeping the splined (or other) BB cup tool secured on the cup while also reefing on it. I've used the stock arm retaining bolt with washers to hold the tool in the cup. QR skewers, long thin bolts (think AllThread), a Stein tool, a Trek made tool all do this in various situations. All require the BB cup splined tool to also have wrench flats on it's outer surface, not a square drive in the center. Andy.

You already have the "long bolt" FBinNY said you need to pass through a hollow BB spindle. The rear quick release skewer will fit. (The front skewer is too short.) All you'd need is a big enough washer to fit over the end of the tool.

Edit: Andrew beat me to it. You will need to use a large adjustable wrench as he wrote, but that's better anyway. A 1/4" socket drive may not be able to handle the recommended tightening torque.

I put a bar clamp across the whole assembly; BB, tool and torque wrench/breaker bar, to keep the tool engaged with the BB. Then I can concentrate on loosening/torquing the BB without needing three hands to hold everything.

Thanks for the suggestions/information.

Next step is to see what I can do by bolting the removal tool to the threaded ends of the BB. I can't pass a long bolt through the BB assembly, but if I can find a longer "crank bolt" that would just hold the thing in place, that should be helpful. My tool does have flat sides so a conventional wrench will work.

dave

I leave the drive axle in, put the stud on with a washer to hold removal tool from slipping. When removing bb from my '92 Trek 970 I used a 24" adjustable wrench, placed front fork on plank and proceeded to stomp on wrench. I had spent a lot of time trying other methods to no avail. The large wrench worked, you need a lot of leverage!
I happen to have the wrench, first time I needed it!

Go to any company that sells fasteners. Any M8 fine thread bolt will work.

The length of bolt you need depends on the length of your BB removal tool AND the length of your spindle.
Since I work on bikes, I have a couple different length bolts and a stack of washers.
I got the 8mm bolts at car Quest.
They are NOT the common 8mm thread size.
Take a bolt with you and check it with a nut when you are there.

http://bikeforums.net/attachment.php...hmentid=399835

Pedro's sells a specific tool to do this job of holding the BB cartridge tool snugly against the splines. The threading on the BB bolts is a finer thread than most hardware stores generally stock in their Metric bolts bins. The Pedro's version has a knurled collar that can be threaded down to meet the top of the tool. You won't need a stack of washers and you can back off the tension as the BB cartridge begins to turn and back out. Most of the time, you wouldn't need this but if the BB is rusty or has some tenacious thread sealant, then this feature is useful.

http://pedros.com/products/tools/ped...socket-holder/

I use a 1/2" impact wrench when they are tight.




Jon

As I wrote before, ask for M8 fine thread. Any company that specializes in fasteners (not a home center) will immediately know what that means. Any decent-size city will have such a company.

Easy to make with M8 fine all thread and a matching nut, but the Pedro's is cheap enough that you don't have to. There's one now on eBay with a Buy It Now price of $9.27 shipped.

common thread size for square taper bolts is m8x1. the common hardware store size is m8x1.25

It's not the company, but the competency of the employee-

Or spend $2 for a couple bolts and a pack of washers.

FWIW, I cobbled together with washers and a 5/16"-24 bolt something that will hold the tool in place. That was all that was available on a Sunday and was the best fit even among the metric stuff at Lowe's. It will go in a couple of threads and it doesn't really doesn't take much force - mostly functions as another set of hands.

With a 12" wrench I still can't get the darn thing off. I could probably force it with a sledge hammer but given the cobbled up contraption holding the tool in place, I'm not comfortable with that. And I don't have a breaker bar that I can fit over the wrench. And I don't live in a 'decent sized city'. So I'm off tomorrow to (probably) get a breaker bar and the right bolt (about 45 miles away).

Thanks again for the great help (even though I have failed so far). And this has gone a LONG way toward dampening my (possibly ill-advised) intent to get good at real bicycle mechanics :-)

dave

Oh yeah - and just to show how things are going these days. I was out on a 2 hour ride this morning. My front brake caliper fell off (whatever nut thingey that holds it to the frame is gone). And my local LBS is closed on Mondays. So I've got a dead bike and a dead trainer bike - I would think that this is easily fixable with some generic nut, but I'm no longer assuming anything is doable. Most irritating and somebody with real power up there want me walking for some reason :-)

dave

Sometimes they're corroded in and don't want to come out. It's sounding like yours may be this way. If you haven't yet, try your luck on the opposite side. Also if you can't find a decent M8x1 bolt to do the job, pass a 1/4" threaded rod through the hollow spindle and use a nut and washers at each end.

Now, the best way to get high, and even torque is to out the tool into a vise and turn the frame. ***** if using this technique be very careful to track the direction of turn -- for a LH thread, turn the frame as if making a right turn.

In any case, do not let this discourage. If it turns out that corrosion is binding the cup, you're in good company and even the best mechanics struggle (and often fail) at getting the cups out in one piece.

FB, thanks. Unfortunately there is no hole in the BB assembly for whatever reason. Your suggestion of mounting in a vice and turning the frame is most interesting. But this damn thing weighs on the order of 100 pounds. Screwed at every turn (or lack thereof) :-)

dave

You don't really need a breaker bar. Just get a piece of long pipe that will fit over the handle of your wrench. Go to a plumber with your wrench and he might be willing to sell you a two or three foot scrap of iron pipe for just a few bucks. And like I said, the Pedro's tool on eBay is so cheap, you're better off buying that instead of wasting money trying all sorts of makeshift setups that may or may not work. You've already blown a few bucks on the bolt and washers and it didn't work. Here's the tool:

Pedro's New in Package BB Socket Holder 6460210 Free US SHIP | eBay

Use Buy It Now on Monday and it'll probably reach you by Thursday or Friday.

i just went through this today. I couldn't find a way to apply enough torque to the tool without it slipping sideways and falling out. I did have the fortune of having a Pnumatic impact wrench, but still no joy in getting it to budge.

I applied a bit of penetrating oil to outside and it let loose very quickly on the next try.

Try the easy stuff first, it may be that simple. I hope it works out soon for you.

Dan

SUCCESS (for now, anyway).

Our area does have an 'old fashioned' hardware store. While they had a place for a 8mmx1 set of bolts, that area was empty. OTOH, I was able to buy a 3 foot steel breaker bar that would fit over the 1 1/8" end of my wrench, and got that for $4.50.

And Home Depot (a 40 mile drive away) surprisingly had some 8mmx1 bolts so I bought one of the proper length. Given those two items (8mm bolt holding the extractor tool in place plus a 3' steel breaker bar) I was able to break loose the BB on the drive side. Surprisingly it stayed SUPER TIGHT until it was more than halfway out. I had to use the breaker bar for at least half of the extraction.

And once the entire BB assembly was out the non-drive side cup was only marginally easier to remove. Actually, since I could not hold the tool in place (I didn't have a washer big enough to use to clamp the tool in place), that piece actually took more time/effort than the drive side piece.

But the damned things are now outta there. I'm done for the evening and re-assembly starts tomorrow. I assume that this will be equally frustrating.

dave

Installation is the easy part. Clean the threads and use plenty of grease.

Well, let me just observe that if you absolutely INSIST on turning the right side BB assembly clockwise to install, it isn't as easy as it might first appear :crash:

But once I got over that the BB assembly went in without much trouble. So that is major progress which would have taken much longer (or never) without the great help from folks on this forum :thumb: But I can tell that putting on the belt is going to be an issue. Regardless this is progress. Thanks!

dave

Well, it is all back together. Re-assembly was honestly 10x easier than taking things apart. After 3 minutes of pedaling things are all quiet, but previously it took as much as 15 minutes before the squeal showed up. But I think that this really is a solved problem and will verify with a workout later today. I would guess that I could do this again with about 15x less time/effort than it took the first time. And it will probably be 15 years before I have to do it again. Such is the life of the occasional bicycle mechanic.

For the record the proper 8mmx1 bolt to clamp the tool to the BB assembly plus a 3 foot steel breaker bar was the key to this endeavor. Could not have done this without that or a similar kind of approach.

dave