BMX Cranks Bearings- Mtbr.com
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  1. #1
    Retro Grouch
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    BMX Cranks Bearings

    Anybody know anything about these? I installed a euro bottom bracket and BMX cranks on my Bianchi SASS and six months later the outer bearings seized (there are 2 stacked cartridge bearings on each side). I hoped to find some better bearings (at least better sealed) but they are an odd size; 31x19x7(3/4). I was hoping Phil Wood had some submersible pump quality, but they don't make them in the right size. The BMX web sites sell the replacement bearings ala Redline for about $6 @. I also figured out I could pretty much buy a whole new bottom bracket kit for the same price as 4 new bearings. So what I did was look for a higher priced kit, hoping they would have better bearings.

    Shadow Conspiracy, DK and Profile have a $36 kit; DK has blue/orange colored seals as opposed to black, so I went with the blue. Anyway, anybody use euro BMX cranks and figured out who makes the good bearings? THX
    Just one more rep and I get the toaster!

  2. #2
    @adelorenzo
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    Euro bearings suck, they are the one downfall of using BMX cranks.

    Profile Racing is now making an outboard kit with much bigger bearings, I would go for that option. I'm gonna get a set myself, but right I'm running Spanish bearings pressed into a set of old Race Face cups and a home-made tube spacer:


  3. #3
    All 26.5" all the time!
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    Quote Originally Posted by aka brad
    Anybody know anything about these? I installed a euro bottom bracket and BMX cranks on my Bianchi SASS and six months later the outer bearings seized (there are 2 stacked cartridge bearings on each side).

    Check the length of the tube spacer between the bearings. It's probably too short.

    The most interesting thing to me about Profile's new external bearing BB is the fact they include two shims with the spacer to compensate for slight variations in BB width. They should have done this from the beginning.

    I've got a Profile euro BB that is approching ten years of trouble free use (with regular maintenance). They can last if you pay close attention to setup.

  4. #4
    Retro Grouch
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    Quote Originally Posted by anthony.delorenzo
    Euro bearings suck, they are the one downfall of using BMX cranks.
    Now you tell me..

    Quote Originally Posted by Zanetti
    Check the length of the tube spacer between the bearings. It's probably too short.

    I've got a Profile euro BB that is approching ten years of trouble free use (with regular maintenance). They can last if you pay close attention to setup.
    Nope, I mic'd the tube spacer with cups and bearings before installation. I now have some extra cartridge bearings so I will be replacing them until I run out. What kind of maintenance does one do on a cartridge bearing?
    Just one more rep and I get the toaster!

  5. #5
    All 26.5" all the time!
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    The seals on each side can be removed for cleaning and repacking. . Whatever grease is in there from the factory is pretty thin and there's not much of it.

  6. #6
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    Wow, you guys really dislike euro bmx bearings that much? I ride an old Standard STA bmx frame that has euro bb, i have some no-name bearings in there (by the look of the color i'm thinking demolitions) and my 220lb ass hasn't broken them yet...

    -Connor

  7. #7
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    Quote Originally Posted by conbon
    Wow, you guys really dislike euro bmx bearings that much? I ride an old Standard STA bmx frame that has euro bb, i have some no-name bearings in there (by the look of the color i'm thinking demolitions) and my 220lb ass hasn't broken them yet...

    -Connor
    I bet you don't ride your bike in the mud and water ether.

    Tim

  8. #8
    one chain, two sprockets
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    This is were the American BB shell rules! Funny how the BB30 standard could bring it all back...

    Tom P.

  9. #9
    All 26.5" all the time!
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    The newer external bearing bottom brackets suffer from the very same problem - a lack of grease from the factory.

    http://forums.mtbr.com/showthread.php?t=497220

    BB bearing maintenance is just a fact of life. Some of us choose to do it and have no problems.

  10. #10
    AUGER-N
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    If you repack the sealed bearings be carefull not to over grease them. This is one of the biggest causes of bearing failure. This can cause overheating of the bearing and excessive drag. Granted this is at much higher rpm. Just dont over pack them. they need room to move.

  11. #11
    one chain, two sprockets
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    Quote Originally Posted by Superbike373
    ...Granted this is at much higher rpm.
    ...and not applicable to bicycles in general...

    Tom P.

  12. #12
    AUGER-N
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    Yes it is. Just not as critical. Hydraulic forces come into play. Just at our rpm's it really is not doing damage. There is no point in packing a bearing 100% full of grease is my point. You just are not gaining anything and just adding drag. Maybe not alot but it would negate any loss in friction gained by using a high end bearing Most bearings that come with "hardly any grease" are greased exactly the way they were engineered. Lubricants today are amazing. Quality bearing manufactures know what they are doing.

  13. #13
    mtbr member
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    The problem with repacking bike bearings isn't overheating, but the risk the extra grease can push the seals out when the balls roll around. It can also bleed out past the seals and make a big mess.
    Owner of www.shockcraft.co.nz, Mech Engineer, Tuner, Manitou, Motorex, Vorsprung EPTC, SKF, Enduro
    www.dougal.co.nz

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