# removing and replacing crankset bearings



## Langdon2 (Nov 8, 2015)

So I purchased an old Trek 820 ( 2002 Trek 820 - New and Used Bike Value ) for cheap because I wanted to do some commuting in the winter and my road bike just wouldn't cut it in the snow filled Midwest city streets.

The only thing that needed immediate attention is the crankset. There is some play when you pedal so I wanted to replace the bearing rings and clean and re-grease everything. Where I got stuck is figuring out what tool i need to get access to the bearings.

I pulled the rubber gasket out on one side to get a view but otherwise this photo is what I am working with.

TIA


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## VeniVidiVici (Oct 10, 2015)

Looks like you need this tool

Cycling Bike Repair Tool SEALED Splined Bottom Bracket BB Remover for Shimano | eBay


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## TiGeo (Jul 31, 2008)

It's a cartridge BB and as such you simply replace the whole unit. I suggest getting a Shimano UN-52..cheap and durable. You will need the before mentioned tool to replace it. You will need to know the width of the frame's BB shell and the spindle width. If you have doubts a trip to your LBS is recommended. Keep in mind that the BB is reverse threaded on the non-drive side. These things can be very hard to get out. Good luck.

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## Slash5 (Nov 27, 2011)

Bottom Bracket Service: Cartridge Type - Park Tool


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## Langdon2 (Nov 8, 2015)

Thank you for the information guys. It looks like I'll be doing a little more spending than I thought for this project but its manageable.

One more question: Are all Shimano bearing sets that use that same splined pattern retention ring using sealed bearing cartridges? 
I checked out an older bike my brother uses while I was home for thanksgiving and his bottom bracket also had one of them. I'd be good to know for future reference.


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## TiGeo (Jul 31, 2008)

The Shimano cartridge BBs came in several qualities. As the cost went up, the sealing etc. got nicer and the weight dropped. They do however comes in a myriad of sizes (68 or 73mm shell, and for each shell, a variety of spindle widths). Not a standard piece, you need to remove it and measure it to know what to get.


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## Langdon2 (Nov 8, 2015)

TiGeo said:


> The Shimano cartridge BBs came in several qualities. As the cost went up, the sealing etc. got nicer and the weight dropped.....


I guess what I was asking is if I see one of those identical splined pattern retention rings (as in the pic above) on a bike's bottom bracket that what's under that is definitely some variation of a sealed Shimano bearing cartridge and not what I was previously accustomed to: removable bearing rings and cones...


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## TiGeo (Jul 31, 2008)

^^^Yes.


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## Bigb2000 (May 20, 2013)

Take the old one to LBS to get the correct width. You can also replace that style with an external bearing style crank and bottom bracket. A good external crankset with bearings can be had for under $100 and will last about forever.


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## Langdon2 (Nov 8, 2015)

Bigb2000 said:


> Take the old one to LBS to get the correct width. You can also replace that style with an external bearing style crank and bottom bracket. A good external crankset with bearings can be had for under $100 and will last about forever.


I do plan on taking the old bearing cartridge to Rapid Transit, my LBS, once I get the removal tool but I am just going to get whatever the most cost effective replacement is. Hopefully they'll have the Shimano TiGeo recommended.

I only paid $25 bucks for the Trek and its intended use will be for winter commuting so I can spare my road bike the abuse from the salt and cold temps so I am reluctant to get more financially invested into this project than I have to be. The external bearing/crank would be a nice upgrade but probably overkill for me on this old of a bike.


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## TiGeo (Jul 31, 2008)

Agree...no need for a crank upgrade..these older ST cart BBs are long lasting and cheap.

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