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I need some help removing this bottom bracket. I am obviously no mechanic, and watching several videos on youtube I found nothing that could help in this specific case. Basically after removing both crank arms, I take off a plastic cup like dirt protection, and then I see this:

enter image description here

So after turning, looking, sniffing, pushing and tugging - I remove the strange black ring (comes of easily) and I see the bearing cage, however still cannot pull anything out..

Here is a pic:

enter image description here

Anybody recognize this type of bracket? I must get it off because it desperately need cleaning and regreasing.

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2 Answers 2

This type of bearing is not serviceable. The plastic piece is the seal that retains the grease and keeps water and dirt out. The crank needs to be pressed out to remove the bearings. Try to tap the crank with a soft faced hammer. the bearing on the opposite side should be pushed out by the crank. Installing the new bearings will require some care. I have had good success using standard and deep sockets to drive in the new bearings.

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Yeah, that appears to be an early "sealed" cartridge bearing. You've only removed the grease seal. You'll likely have to drive it out, and finding a replacement will be problematic (though the bearings may turn out to be standard-sized industrial bearings that your local electric motor rebuilder can find for you). (Be careful not to bung up the crank end, since you'll need to save the crank.) –  Daniel R Hicks Jun 21 '13 at 11:04
If you bring the number on the seal (6003 RSR?) to a bearing supplier like Bearing Specialty, Eastern Bearing etc they can easily cross reference it and they sell retail. –  mikes Jun 21 '13 at 11:40
Thanks for the many tips! @mikes I must be doing it wrong, nothing budges at all.. I tried hitting a bid harder too. –  anaheim Jun 21 '13 at 12:09
Spray it with some penetrating oil Liquid wrench, PB Blaster etc. Place a wooden block on the crank and hit it with a heavier hammer. –  mikes Jun 21 '13 at 12:13
@anaheim Good work on this. Would you mind writing up your comment as an answer? That way whenever this question is queued up it will have the correct procedure in the answers and not at the bottom of the comments. Be sure to include the details! –  WTHarper Jun 21 '13 at 17:17
up vote 2 down vote accepted

Like Mikes pointed out in his this bearing is not serviceable. You just replace it. In this particular case the bearings are of type: 6003 RSR. find on ebay

After you removed the crank arms and find yourselves looking at something like what you see in the images I posted above, you just hammer out the crank. It will take some force. Make sure you don't damage the crank - for example by protecting it with a block of wood.

Putting back in is more difficult: you either have professional hydraulic press, or you use a guiding tube. Put one new bearing on each side of the BB - the guide tube is passing throught he middle. On one side you screw on a cap, on the other there is a two sided handle, and by turning it you pressure both bearing inside the BB. Without the guide tube and this lever you will most likely damage the frame permanently. I went to my LBS to do this, mainly because I was missing the pressing tool but also because if the frame gets minimally damaged at the edges of the BB the bearings will not fit properly. Better not to this alone and with improvised tools.

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Do you have the pic of the spindle, I'm a bit curious how it looks and whether it's a standard one? –  Mladen Jablanović Jun 24 '13 at 13:54
no unfortunately I made no photos. I was quite excited and concerned about the frame while we were working. Not a very valuable frame, but somehow remarkably precious. I can describe it though: it's a very simple cylinder in the middle, quite slim. No cover or so. Basically if you'd look down the seat tube you'd see it spinning there. I was surprised it was in such good shape after more than 30 years. At either ends the was a inwardly thickening section around which the bearings will settle (substantial pressure applied), followed eventually by the visible part in the photos. hope that helps –  anaheim Jun 24 '13 at 14:10
Oh I found the whole process in pictures: forums.mtbr.com/vintage-retro-classic/… :) –  Mladen Jablanović Jun 24 '13 at 18:10

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