# Removing and replacing bottom bracket out of older bike



## MB_rider (Mar 19, 2016)

Have a older bike that needs a new bottom bracket and need some tips on replacing the bottom bracket. 
The shell size is 68 mm and the spindle length is 118 mm 
Wondering the best way to remove the old one(seems on there pretty good and a adjustable wrench doesn't seem to work that well) and where i can buy a new one that will work.
Thanks.
Hope the pictures help
Sorry the last picture isn't that good it shows that one end is threaded that had a ring on it at one point


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## Uncle Grumpy (Oct 20, 2005)

Poor old bottom brackets. They collect crud and moisture and end up gluing themselves in place pretty good sometimes.

Start with a good penetrating lube, even pulling out the seatpost and flooding it from above.

What sort of bike is it? I'm going to assume it's a British threading and not Italian, French, Swiss or something obscure.

In that case, the drive side cup is left hand thread, the BB unscrews clockwise. The left hand side is the usual right hand threading.

A big adjustable wrench is probably the better option for the home mechanic (save for an expensive one-off specialist tool or spanner that fits). Hold the head of the wrench on there nice and firm and hit the handle with a mallet to shock it loose. Or if you can, clamp the flats of the BB cup in a vice and turn the frame. 

I had one that was stuck, I drilled a couple of holes in the cup, tapped a thread in each hole, installed a bolt in each threaded hole, which gave me better purchase with the adjustable wrench.

Any decent bike shop should be able to get you a sealed Shimano BB to suit. Not period correct, but far less hassle to install, just bung it in and not need to adjust the bearings.

I've also seen a good method of welding a length of bar to the BB cup, not pretty but bloody effective!

Grumps


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## mik_git (Feb 4, 2004)

Is that an old Diamondback?


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## MendonCycleSmith (Feb 10, 2005)

I can't imagine any other brand than DB with that paint!

Speaking as a shop, OP, if your efforts with a wrench don't bear fruit, and you don't plan to get as involved as Grumpy, stop while there are still decent wrench flats to work with, as once they are gone, someone is going to have get pretty medieval on it, and the number of shops with mechanics willing to do so, are getting fewer and farther between. Most have high school kids as wrenches, whose managers really want them to just be sales portals, so when a bike comes in that presents a challenge "sorry sir, you need to just buy a new bike". 

The flats are thin, and get bunged up pretty quickly if you don't have the tools to keep the wrench flat, and in place....


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## sbsbiker (Dec 1, 2007)

"The flats are thin, and get bunged up pretty quickly if you don't have the tools to keep the wrench flat, and in place...."

I have used a BB tool that screws into the spindle and fixes a BB tool onto the flats for removal without the fear of the tool slipping off the flats.You would place a BB tool onto the flats, screw this tool onto the BB spindle to keep the BB wrench fixed onto the flats, and then when you hit it with a hammer, it wouldn't slip off sideways and round off the flats. I looked on Park tools website and did not see it, but it was effective at backstopping a BB tool onto the flats for serious removal problems. Anyone know of what I speak of, and can post a pic? 

You could "rube goldberg" a similar tool by getting a socket that's big enough to fix onto the outside of the HCW-4, and using a washer and crank bolt to hold the tool onto the flats. I would first flood the BB with penetrating oil just to help things off.


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## sbsbiker (Dec 1, 2007)

Stein Fixed cup wrench clamp!

Tools_for_Cranks


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## MB_rider (Mar 19, 2016)

Its an old diamondback that is from the mid-90s.
Anyone see a problem with applying some heat to help loosen it up?
Bottom Bracket is totally shot and new paint will be applied so not worried about it just dont want to damage BB housing.
Tried an adjustable wrench and didn't have much luck trying to be careful not to strip anything. Will probley try the bench vice idea next.


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## sbsbiker (Dec 1, 2007)

(trying) to Remove fixed cup

This forum has a pic of this tool in action.


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## MendonCycleSmith (Feb 10, 2005)

Was thinking VAR, but yup, Stein it was. I loved that tool.

Dammit, off to eBay to scratch the old tool itch....


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## girlonbike (Apr 24, 2008)

That's nice that Stein also makes a TA crank extractor. Thanks for the link!

TA_Extractor


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## apat13 (Jun 19, 2006)

If the cup with flats is really stuck, I have had great success clamping the cups in a (good and square) vise, and essentially using the frame as the breaker bar. Usually breaks free with minimal effort, and there are no tools to slip or bang your knuckles on.


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## mik_git (Feb 4, 2004)

Change the paint!?!?!?!

Also just in case you don't know, are you unscrewing the right way, BB's are all backwards, topsy tervey


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## sryanak (Aug 9, 2008)

You will need a pin spanner or something for the non drive side. I'd try find a shop that has been around for a long time or maybe a bike collective or co-op group that has the right tools and knowledge about what it takes to remove old style bb's.


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## NYrr496 (Sep 10, 2008)

A long time ago, an old guy that owned the LBS I frequented as a kid asked me to help him out removing exactly that same kind of BB. It was FROZEN. We were unable to get it out with anything we had in his store or my van. I was a diesel generator service tech at the time. 
I asked if I could take the frame to my shop. He trusted me so I did. 
I mig welded a big 1" nut to the face of the BB and turned it out with a big wrench. The heat from welding it on helped immensely because I remember really having to work getting it apart. I sincerely believe it wouldn't have come out any other way.


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## Shane5001 (Dec 18, 2013)

Uncle Grumpy said:


> Poor old bottom brackets. They collect crud and moisture and end up gluing themselves in place pretty good sometimes.
> 
> Start with a good penetrating lube, even pulling out the seatpost and flooding it from above.
> 
> ...


Drilling the holes is genius, thank you.


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## Shane5001 (Dec 18, 2013)

sbsbiker said:


> Stein Fixed cup wrench clamp!
> 
> Tools_for_Cranks


Also very ingenius


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## Shane5001 (Dec 18, 2013)

MB_rider said:


> Its an old diamondback that is from the mid-90s.
> Anyone see a problem with applying some heat to help loosen it up?
> Bottom Bracket is totally shot and new paint will be applied so not worried about it just dont want to damage BB housing.
> Tried an adjustable wrench and didn't have much luck trying to be careful not to strip anything. Will probley try the bench vice idea next.


I have ran into this many times because most old bike purchased on craigslist have never had the bb removed and serviced since the bike was built. It helps if you take the non-drive side with bearings and axle out first. Now you can really soak the threads with penetrating oil. I've put heat with a little plumbing torch on multiple frames and haven't had any issues yet, seems to help. You can buy an old school headset wrench on amazon for <$20 that has the right size for that bb, nice and thin and flat like cone wrench. I have cursed and bled from using adjustable wrenches.


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## Uncle Grumpy (Oct 20, 2005)

Shane5001 said:


> Drilling the holes is genius, thank you.


Thanks. I was thinking of another method, and that was if you drilled holes big enough to take the thread of a bolt, tight, but not screwed in to a thread, then make a tool comprising a long length of flat bar, drill two holes the same distance apart, put a bolt through each hole and put a nut on each bolt, you'd have a long handled pin spanner, effectively.

The long threads of the bolts wont slip out like a spanner can slip off, and provided you used a long enough bar, you'd get a lot of leverage.

Just a thought, and good if you don't have a thread tap.

Grumps


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