# Bottom bracket maintenance



## SFTifoso (Aug 17, 2011)

My BB is a JIS squared tapered type. How often should that bottom bracket be serviced? Can it be serviced, or is it a throw away and replace type of deal? 

I have 2500 miles on my BB, should I replace it? The pedals still spin very smoothly and quietly when the chain is off. 

Should I periodically re-torque the crank arm bolts? I heard square tapered BB can strip if the crank arm bolts are loose.


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## wim (Feb 28, 2005)

There is no service. You replace the BB when it gets rough. If you want to make the eventual replacement easier, you can remove the crank, pull the BB, clean and regrease BB and frame threads and re-install it all once a year or so. Some consider this overkill. But if you like to work on bikes, why not.

Other than one time after the first few rides on the newly-installed crank, you shouldn't re-torque the crank bolts to specs. You do want to keep the crank bolts snugged up, but that's done with much less torque than you used at installation. As you will notice, a loose crank bolt does not necessarily mean a loose crank if the installation was done right.

If a crank arm did come loose and you ride on it even for just a few miles, the square hole will "wallow" out. This means the crank is ruined. (Keep in mind that in a contest between steel and aluminum, steel always wins.) The number one cause for a crank arm to come loose is insufficient installation torque.

/w


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## Akirasho (Jan 27, 2004)

... square taper indicates an older/cheaper design which may be user servicable depending on it's make. 

Check over a Park Tools for more info. 

Under "normal" conditions, a BB could last for decades and 10 times the milage you've reported without being touched (most new designs are sealed anyway).

Retorquing bolts only adds stress after a point and would be... inaccurate from a measured torque POV. If installed correctly, they rarely loosen of their own accord. If you notice issues.. retorque but not as a matter of course.


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## wim (Feb 28, 2005)

Akirasho said:


> ... square taper indicates an older/cheaper design which may be user servicable depending on it's make.


Right, square taper could possibly be serviceable. My post above assumes a sealed cartridge bottom bracket.


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## tlg (May 11, 2011)

SFTifoso said:


> I have 2500 miles on my BB, should I replace it? The pedals still spin very smoothly and quietly when the chain is off.


You're over thinking it. 2,500mi is nothing in the life of the bearings. As mentioned... as long as the pedals spin smooth, you're fine. It's best to do with the chain off the chain rings. You'll feel roughness easily. 


> Should I periodically re-torque the crank arm bolts?


No. If they were properly torqued, there's no reason to re-torque them. Do you periodically re-torque the lug nuts on your car?

I still run a square taper BB on my MTB. Gosh it's around 10yrs old and functions fine. It see way more abuse than a road bike does. I haven't touched it in years. 
The only thing you really need to worry about is if you get water in your BB. Then you might want to pull it apart. I always use marine grade waterproof grease in my BB's in case some water gets in there.

(everything above is assuming you have a sealed cartridge BB)


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## PJ352 (Dec 5, 2007)

SFTifoso said:


> My BB is a JIS squared tapered type.


OP, as has been stated, your BB is most likely fine. But as you can probably tell from the posts, some confusion exists on the exact type of square taper BB you have.

Some are cup/ cone, loose ball bearing assemblies while others are cartridge. The type you have would dictate how it's maintained, (or IF).

That given, why not post specifics... year/ make/ model of your bike along with the OE specs, if available/ known, then you'll have a definitive answer.


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## SFTifoso (Aug 17, 2011)

My bike is a 2011 trek 1.2. It comes with FSA Vero cranks.


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## laffeaux (Dec 12, 2001)

SFTifoso said:


> My bike is a 2011 trek 1.2. It comes with FSA Vero cranks.


Being that new the BB is definitely a sealed unit. Once the BB goes bad you'll need to replace the whole unit. As others have said it should last a long long time. When it does go bad, when you turn the cranks buy hand it will feel like there is sand inside the bearings. It's very noticeable.

I still run square taper cranks on my Campy equipped bike. Works great.


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## PJ352 (Dec 5, 2007)

As laffeaux states, it's a sealed (cartridge) BB, so not serviceable. FWIW, FSA calls it Powerdrive.

The link below brings you to a pic of the ISIS version. If you click on the first link under *Inside Tech/ Manual*, it'll bring you to the installation instructions and warranty info.
POWERDRIVE STEEL


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## SFTifoso (Aug 17, 2011)

Cool, thanks for all the help fellas.


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## wim (Feb 28, 2005)

PJ352 said:


> FWIW, FSA calls it Powerdrive.


While there is a FSA Vero PowerDrive crank, I think the OP has the JIS square taper version of the Vero. PowerDrive is a proprietry 10-spline design not compatible with ISIS.


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## PJ352 (Dec 5, 2007)

wim said:


> While there is a FSA Vero PowerDrive crank, I think the OP has the JIS square taper version of the Vero. PowerDrive is a proprietry 10-spline design not compatible with ISIS.


You're correct, wim. And as the 'manual' states, the BB can be JIS (square taper), ISIS and PD (Powerdrive).

Agree that the OP's crankset/ BB are JIS (square taper).


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## SFTifoso (Aug 17, 2011)

Just a few days after I started this thread my BB started making some grinding and clicking noises (annoying as hell). I've decided to replace it. I guess I could buy a better BB/crankset, but I rather continue saving for a better bike than upgrade a cheap bike. Anybody got any recommendations on square taper BBs? Are the Shimano square taper BBs any good?


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## wim (Feb 28, 2005)

Nothing wrong with Shimano square taper BBs, especially considering the price.


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## PJ352 (Dec 5, 2007)

wim said:


> Nothing wrong with Shimano square taper BBs, especially considering the price.


... and a second vote for replacing your OE BB with Shimano... :thumbsup:


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## wim (Feb 28, 2005)

PJ352 said:


> ... and a second vote for replacing your OE BB with Shimano... :thumbsup:



It occured to me that the OP might not have the needed special tools. Just for his information: if he doesn't, he needs to figure on spending $35 or so for the minimum set (crank puller and BB tool).


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## PJ352 (Dec 5, 2007)

wim said:


> It occured to me that the OP might not have the needed special tools. Just for his information: if he doesn't, he needs to figure on spending $35 or so for the minimum set (crank puller and BB tool).


Good point, wim. For these types of (possibly one time) replacements it might be better to have the LBS perform the work.


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## SFTifoso (Aug 17, 2011)

Well I like working on my bike, gives me piece of mind I guess. I already have various torque wrenches and other tools for my car that I can also use on the bike, so I just ordered BB tool (the one with the 20 splines) and a Park Tool Universal Crank Puller. Got both for about $20 on Ebay. I'm gonna have to take out the BB first to see the size anyways.

Once I know what size it is I will be ordering a Shimano BB-UN55. Total, looking at around $41. About what the LBS wanted to charge me to change it.

Thanks again fells.


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## SFTifoso (Aug 17, 2011)

Ok I ran into a bit of a problem trying to find the right size BB for my crankset. It uses 103mm spindle length, and the smallest shimano BB I could find is 107. The other brands come out a bit expensive in that size. So I decided to just buy a take-off Tiagra crankset that I found on ebay for $45. I plan to keep this bike as a commuter anyways, so upgrading to a better crankset made sense to me. 

However, I made a mistake, and didn't read if the crankset came with an English or Italian BB. The listing didn't specify, and the seller doesn't know as it has already been shipped. No big deal, Tiagra BB are cheap anyways. However, I don't know if you need and Italian crankset to go with an Italian BB, and an English crankset to go with an English BB, or if the cranksets are universal and will fit both types of BB.


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## PJ352 (Dec 5, 2007)

SFTifoso said:


> Ok I ran into a bit of a problem trying to find the right size BB for my crankset. It uses 103mm spindle length, and the smallest shimano BB I could find is 107. The other brands come out a bit expensive in that size. So I decided to just buy a take-off Tiagra crankset that I found on ebay for $45. I plan to keep this bike as a commuter anyways, so upgrading to a better crankset made sense to me.
> 
> However, I made a mistake, and didn't read if the crankset came with an English or Italian BB. The listing didn't specify, and the seller doesn't know as it has already been shipped. No big deal, Tiagra BB are cheap anyways. However, I don't know if you need and Italian crankset to go with an Italian BB, and an English crankset to go with an English BB, or if the cranksets are universal and will fit both types of BB.


There's no guarantee, but odds are you'll get an English threaded BB, which your Trek accepts. _However_, make sure of this before installing it, or you'll ruin the BB shell threads. If it's Italian, the drive side BB won't thread on, because it's right hand threaded and your BB shell accepts left hand (reverse) threaded. But... don't try.  

Some info here:
Bottom bracket - Wikipedia, the free encyclopedia

Cranksets have to match BB _design_, but there are no Italian/ English cranksets, so your new (to you) Tiagra crankset will fit both English and Italian BB thread types.


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## wim (Feb 28, 2005)

SFTifoso said:


> So I decided to just buy a take-off Tiagra crankset that I found on ebay for $45.


No problem here. But just in case you got the newer external bottom bracket Tiagra crank, the tools I listed in one of my previous posts would not work with this. You would need the Park BBT-9 tool to install the BB cups. FWIW, Tiagra cranks came in square taper and Octalink and now come in the external bottom bracket design.

/w


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## SFTifoso (Aug 17, 2011)

Cool, thanks again for the info. I got this tool for $10 from universal cycles. 

Universal Cycles -- IceToolz External BB installation tool

One side is for removing the cups, and you flip it over to remove the cap on the left crank arm.


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## wim (Feb 28, 2005)

SFTifoso said:


> One side is for removing the cups, and you flip it over to remove the cap on the left crank arm.


Sounds good. Keep in mind that you set the bearing pre-load with that cap before you tighten the two pinch bolts. So easy does it when tightening that cap.


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