bottom bracket question

[FarmerBEN]

I need to clean and lube my bottom bracket, I got the cranks of but now I can't get it out the frame, My general mechanical philosiphy is "get a bigger hammer" but I'm trying to be careful not to wreck anything, is there a trick to getting it appart. it is on a gary fischer big sur, if all else fails I'll just take it in and have them do it, but self-sufficiency is the goal,.

[Homebrew]

If you don't have the proper tools for the job, I'd bring it in. You'll just end up with a mess without them...

[bigwheel]

The Right Side BB is reverse-threaded. Left side is normal.
(Note: Pedals are the opposite.)

Don't ask me why. IMO, it is an evil conspiracy by the LBSs, who do not want to see the public capable of working on their own bikes.

At least Race Face was courteous enough to print directions on their brackets.

[rideharder]

you need a special scoket to get it out. if you dont have one you will realyl F up the BB

[steef]

Don't most modern bikes have sealed bottom brackets? I'm not sure ho old the Big Sur is, though. Even with sealed BBs I'd remove them every once in a while just to make sure they don't get stuck into the frame in case you ever have to upgrade. Buy yourself the proper tools and you're starting onto a lifetime of happy wrenching.

[FarmerBEN]

you need a special scoket to get it out. if you dont have one you will realyl F up the BB


that was my concern thanks for all the help guys, I think I'm going to just take it in, as not to screw anything up.

[bigwheel]

that was my concern thanks for all the help guys, I think I'm going to just take it in, as not to screw anything up.

Ben, I suggest buying one of the well-stocked toolboxes that most places sell. Nashbar has one for about 100 bucks. They have a lot of the "wierd" tools that you will need. (such as a bottom bracket tool). You may also need to buy a few other tools, but they are always a good investment.

However, you are still going to make mistakes (and F things up) now and then, while learning the secret tricks. If you are only going to do it once, you are best to take it to the shop. However IMO, if you plan to do this a lot, you may as well take your lumps learning to do it yourself.

If it is not obvious, you can usually look it up on the web. The Park Tool website is a lot of help. Also, the Sheldon Brown site has tons of good info on how things work and how to fix or build stuff.

[FarmerBEN]

Ben, I suggest buying one of the well-stocked toolboxes that most places sell. Nashbar has one for about 100 bucks. They have a lot of the "wierd" tools that you will need. (such as a bottom bracket tool). You may also need to buy a few other tools, but they are always a good investment.

However, you are still going to make mistakes (and F things up) now and then, while learning the secret tricks. If you are only going to do it once, you are best to take it to the shop. However IMO, if you plan to do this a lot, you may as well take your lumps learning to do it yourself.

If it is not obvious, you can usually look it up on the web. The Park Tool website is a lot of help. Also, the Sheldon Brown site has tons of good info on how things work and how to fix or build stuff.

I plan on getting tools, but with a day like today and hopefully more to come, I just wanted it going and taken care of. I took it in got it done and got a nice leisurely rail-trial ride in this evening. thanks for all the advice and additional resources I am sure they will come in handy in the future.

[Trevize1138]

Bottom bracket removal can be a major PITA! I bought an aluminum Trek frame from GeneO's basement last year for $25 and it came with a shot BB. Just had to remove the BB and the frame would be worth building up.

It wouldn't budge right away, so I dumped a bunch of Liquid Wrench down the seat tube and let it soak for a few days. Still nothing. Finally took it to my LBS (Sunrise Cyclery on 2nd Ave S 1/2 a block south of Lake) and Jamie tried his hand at it. Nothing. He put a 1' cheater pipe on the wrench while I hung my weight on the rear dropouts and all we got was a cloud of profanity.

Next we took it outside with his portable repair stand and a propane torch. That made the plastic cup on the left side brittle but even that didn't want to come out completely! That's when I just left it with him.

A week later he finally got the thing loose. I believe he submerged the BB in Liquid Wrench for that week with a 1 gallon ice cream bucket cut out to fit the downtube on one side and two chainstays on the other.

Moral of the story: if you can't get the BB removed yourself and you HAVE the BB socket, take it in ;).

[steef]

My friend and I have gotten one out by welding an old socket to the BB cup, then using the socket wrench and a big pipe. I think the heat did a lot of the work for us, but it still wasn't easy. This technique like will not work on the newer splined BBs. That's why I remove the sealed ones every so often just to make sure they're still removable.

[bigwheel]

Speaking of bottom bracket screw-ups, a few weeks ago, I decided tor rebuild my wife's road bike. Her crankset was turning really rough. It had probably been at least 12 years since we rebuilt the crank, as we don't ride as much as we used to. It has the old square-taper crank, on a 25 year old (original) crankset. I have all the necessary tools and know how. But...

I first pulled off the drive side. No problem.

Non-drive side:
1: Removed the cap. No problem.
2: Removed the bolt using my crank bolt taker-outer. No problem.
3: Spun on the crank puller. No probllem
4: Started turning the extractor arm. Not working. This sucker was tight.
5: Slipped on my handy piece of conduit and cranked like hell
6: Watched the puller pop out, stripping the crank arm threads. Aw Sh**
7: Cleaned out the stripped threads, and found the washer that I forgot to take out. DOH!!!

I was just pushing the arm against itself. :confused:

Anyway, I was able to get the crank out without taking the arm off. So, I cleaned and greased it up, then put it all back together. It's running fine now, but it's still maimed for life. Maybe I should buy her a sealed crankset for her birthday. (I'm such a nice guy)

[Crash]

The Right Side BB is reverse-threaded. Left side is normal.
(Note: Pedals are the opposite.)

Don't ask me why. IMO, it is an evil conspiracy by the LBSs, who do not want to see the public capable of working on their own bikes.

At least Race Face was courteous enough to print directions on their brackets.

Isn't that so they don't back out while pedaling?

[funky-funky-chicken]

Isn't that so they don't back out while pedaling?

Misconception: Think about what would happen if your BB spindle suddenly seized and somehow with your Herculean strength you were able to continue to move your pedals around. Which way would the cups of the BB turn...That's right, they would un-thread.

[Crash]

thanks for clearing that up for me Ken!
How about pedals? Is it at least true for them?

[berrywise]

Simple way to remember for me is to remove pedals sping wrench towards the back of the bike. To remove bottom bracket spin wrench towards the front of the bike.

[steef]

7: Cleaned out the stripped threads, and found the washer that I forgot to take out. DOH!!!

I'll admit to doing that same thing.:hit:

[Kosk]

Misconception: Think about what would happen if your BB spindle suddenly seized and somehow with your Herculean strength you were able to continue to move your pedals around. Which way would the cups of the BB turn...That's right, they would un-thread.
But think about this;

As viewed from the right side, pedaling forward,

the BB spindle rotates clockwise. As a result,
the ball-bearings between the spindle and the BB case
all spin in a counter-clockwise direction.

There is a slight amount of friction induced at the inner surface of
the BB case by the counter-clockwise rotating ballbearings, causing the
BB case to want to rotate counter-clockwise too. This is why the
right-side BB shell is reverse threaded, so the BB case does not slowly
unthread itself.

Everything is reversed for the Left side, so that is why that side is threaded righty-tighty. Draw a picture and you will see what I mean.

It works out the same for pedals too.
- The left-side pedal rotates clockwise with respect to the pedal spindle,
- this causes the bearings to rotate counter-clockwise which induces a,
- counter-clockwise friction force at the pedal's spindle, causing it to want to rotate counter-clockwise too,
- hence the reverse threaded-ness of the left pedal in the crank-arm.

[tedsti]

Pedal threads - I have heard people question why they are the way they are. It you hold the pedal spindle and spin the crank forwards they will unthread. This is true, but it is not the largest rotational force acting on the pedal.

Here is the deal, take a piece of pipe or a sturdy tube of some kind about 1/2" in diameter and hold it in your hand. Now with your other hand, move the end that is sticking out in a clockwise circular motion. As the tube wiggles in your hand it will actually spin counterclockwise. There is a technical term for this that presently escapes me. This is the force that keeps your pedals tight.

[dopey048]

There is a technical term for this that presently escapes me. This is the force that keeps your pedals tight.


Its called: Magic.
:D

[funky-funky-chicken]

Hat firmly held in hand. You're right. The physical phenomenon is called precession. I was not thinking about the force that the bearings exert on the spindles while in motion, which is oposite the direction of travel.

[mhester]

OK. I have a campy drive side cup that is stripped in my road bike. Looks like the Shimano splines have a larger diameter. What about hand cutting a shimano spline into what's left of the cup? I'd gladly lose a socket by welding it in like the previous post mentioned. The cup is made of steel? So a steel/steel weld should be easy enough?

[mhester]

My friend and I have gotten one out by welding an old socket to the BB cup, then using the socket wrench and a big pipe. I think the heat did a lot of the work for us, but it still wasn't easy. This technique like will not work on the newer splined BBs. That's why I remove the sealed ones every so often just to make sure they're still removable.

OK. I have a campy drive side cup that is stripped in my road bike. Looks like the Shimano splines have a larger diameter. What about hand cutting a shimano spline into what's left of the cup? I'd gladly lose a socket by welding it in like the previous post mentioned. The cup is made of steel? So a steel/steel weld should be easy enough?

[steef]

Yup, steel to steel is a pretty easy weld.

[nord0306]

Pedal threads - I have heard people question why they are the way they are. It you hold the pedal spindle and spin the crank forwards they will unthread. This is true, but it is not the largest rotational force acting on the pedal.

Here is the deal, take a piece of pipe or a sturdy tube of some kind about 1/2" in diameter and hold it in your hand. Now with your other hand, move the end that is sticking out in a clockwise circular motion. As the tube wiggles in your hand it will actually spin counterclockwise. There is a technical term for this that presently escapes me. This is the force that keeps your pedals tight.

Also, if the bearings for some reason seized all together, the pedal would unscrew instead of ripping your foot off. Both reasons sound good enough to me.

[crux]

Back from working on old vintage bike we have seen some really weird stuff not to mention a few rusty threads. Our solution was to start of with spraying the bolt down with some WD-40 or Liquid wrench and let it sit for a while and hoped that some of the solution penetrated the threads to lube thing up a bit (Feel free to insert joke here). Then if needed a second application followed by locating the correct tool along with a second person to help out or just laugh at the pathetic attempt to move an old bolt. If all goes well you should be able to move the bolt now and inspect the BB. If not here is where your buddy comes into play, lay the frame down on the floor and with the correct tool along with a short breaker bar attempt to crank on the stuck BB while not allowing the frame to rotate with yor feet. Second guy places one hand on top of the wrench pushing directly downward not allowing the tool to pop out of the interface or torque over stripping the head. Other hand goes towards supporting the frame as your wrench on the BB. (You must know which direction you need to go to get to bolt out.) This has worked almost every time withthe exception of one old frame which we actualy broke the paws in the socket wrench (Snap-on replaced it very quick and was shocked when we told them we were just working on a bicycle).

Best of luck.

[soupboy]

OK. I have a campy drive side cup that is stripped in my road bike. Looks like the Shimano splines have a larger diameter. What about hand cutting a shimano spline into what's left of the cup? I'd gladly lose a socket by welding it in like the previous post mentioned. The cup is made of steel? So a steel/steel weld should be easy enough?

If your bike is that important to you you may want to consider having the BB removed and replaced with a new unit. I don't recall ever seeing steel cups but then again most of my bike parts knowledge is post 1988.

Check with some of the local builders to see what they think the remedy might be.