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 Post subject: bottom bracket
 Post Posted: Mon Apr 11, 2011 12:41 pm 
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After I hosed down my bike following last week's mud bath TT, I noticed that my BB was very tough to turn. Not gritty or feeling like bad bearings, just really tough pedaling. Made me wonder if this is why the whole TT felt uphill. But anyway, I left the bike in the sun to dry, came back hours later and there was no issue with the BB.

Anyone heard of this before? Almost like the seals swelled up in the wet or something.

It's one of those newer BBs that's hollow in the middle (see through).

thanks


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 Post subject: Re: bottom bracket
 Post Posted: Mon Apr 11, 2011 1:43 pm 
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The ones on the GF have been failing early, but didn't know of any that would come and go - just go.

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 Post subject: Re: bottom bracket
 Post Posted: Mon Apr 11, 2011 1:51 pm 
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I have not had what you described happen to me. I have had one of the bearings completely seize up, but still have the plastic sleeve (that fits in between bearing and the shaft and covers the outside of the bearing) still spin sort of freely. It wasn’t very noticeable with the crank on, but definitely noticeable if you had the crank off and tried to turn the BB by hand.

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 Post subject: Re: bottom bracket
 Post Posted: Thu Nov 07, 2013 7:00 pm 
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After 18 months the BB on the Superfly started sounding very rough. This is the latest in BB design with the press fit internal bearings, so I can't say this style is any more durable than the threaded external cup bearings. Replaced them with Enduro bearings. The cranks don't turn as smooth as the old cartridge bearings but hopefully the Enduro bearings last longer than the stock ones did.

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 Post subject: Re: bottom bracket
 Post Posted: Thu Nov 07, 2013 7:24 pm 
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Give them some time to break in and you should find they will drag less.

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 Post subject: Re: bottom bracket
 Post Posted: Sun Oct 04, 2015 6:01 pm 
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gofunburnman wrote:
I have not had what you described happen to me. I have had one of the bearings completely seize up, but still have the plastic sleeve (that fits in between bearing and the shaft and covers the outside of the bearing) still spin sort of freely. It wasn’t very noticeable with the crank on, but definitely noticeable if you had the crank off and tried to turn the BB by hand.


Resurrecting this old thread since I had the problem again that I described in the top post. When I was rebuilding the bike after the dust of Idaho I noticed that the crank was spinning stiffly again. It turns out to be the problem Steve described above...the sleeve was spinning freely but the bearing was completely seized.

It's a SM-BB70 and I have the tool to remove the outer collars, but just wanted to check in with folks here before I try to fix this because I'm not sure if a) just the bearing is replaceable or if I need to buy a new BB; and b) if I can remove it just by taking the collars off. From reading Shimano's crappy tech manual on this, it looks like the collars that you can put a tool on are threaded and the rest are press fit?


Last edited by icycle on Sun Oct 04, 2015 7:05 pm, edited 1 time in total.
had wrong model # of BB


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 Post subject: Re: bottom bracket
 Post Posted: Sun Oct 04, 2015 7:24 pm 
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The notches on the external of the BB cups indicate a threaded BB. Press fit BB doesn't really show outside the frame.
I have taken both of these apart at one time or another and replaced the bearing assembly with Enduro bearings, and they have lasted longer than the originals.

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 Post subject: Re: bottom bracket
 Post Posted: Sun Oct 04, 2015 7:41 pm 
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Thanks Laura. Looks like http://www.enduroforkseals.com/id198.html, I'm thinking the 440C stainless bearing option looks good. Of course, there's the top of the line http://www.enduroforkseals.com/id240.html for $200... :o


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 Post subject: Re: bottom bracket
 Post Posted: Mon Oct 05, 2015 6:06 pm 
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I ended up just getting the bearings rather than the whole assembly. These ones are for the press fit BB90. http://www.bikeman.com/BB4400.html
of course the nitrogen will make you even faster I'm sure. :lol:

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 Post subject: Re: bottom bracket
 Post Posted: Mon Oct 05, 2015 7:44 pm 
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icycle wrote:
Thanks Laura. Looks like http://www.enduroforkseals.com/id198.html, I'm thinking the 440C stainless bearing option looks good. Of course, there's the top of the line http://www.enduroforkseals.com/id240.html for $200... :o


These guys are top notch too:

http://wheelsmfg.com/products/bearings/ ... -kits.html

Replaced BB bearings for my PF BB90 in May and no complaints so far.


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