Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 12-06-10, 12:31 PM   #1
TechKnowGN
Senior Member
Thread Starter
 
Join Date: Sep 2008
Location: Boston, MA
Bikes: 2009 Fuji Newest 1.0, 2011 Trek 3900 Disc MTB
Posts: 1,266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Bottom Bracket help, and yes; I've been to Sheldons

I think it's just a basic comprehension problem.

I have a 2008 Fuji Newest 1.0. I'm pretty sure the sound and problems I'm experiencing are coming from the BB. looking to upgrade. It came with the FSA Mega Exo BB and the Omega Crank.

http://www.fullspeedahead.com/fly.as...layout=product

2 questions:

1. The BB, what BB size/style would I need to replace it with for it to fit on the bike?
2. Is the Omega a decent crank? It doesnt seem to be the problem currently. If i replace the BB, will I be forced to replace the crank?

Thanks
TechKnowGN is offline   Reply With Quote
Old 12-06-10, 09:56 PM   #2
surreal
Senior Member
 
surreal's Avatar
 
Join Date: Mar 2002
Location: NJ
Bikes:
Posts: 3,084
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
you'll want an external bottom bracket. There are really expensive (and nice) ones made by chris king and phil wood. there are FSA ones, and RaceFace ones that'd work. I recommend getting a shimano 105 or similar; they're compatible and cheap and have been very reliable for me (more so than the race face, and from what you're describing, the FSA version you got might not be all that, either.) SRAM/truvativ bottom brackets are NOT compatible, as the crank's axle (the 2-piece crank's analog to the spindle) is of a wider diameter.

http://www.treefortbikes.com/eurl.ax...22362937___116

I don't have any experience with the FSA omega, but you can probably find reviews if you're interested. If it has been a good crank thus far, i wouldn't change it out. You'll need to take it off to replace your BB (make sure you get the proper tool for the BB; hex wrenches are all you'll need for the crank), then put it back on. You can always swap out the crank later, and even run the same BB, even if you switch to a double.

hth
-rob
surreal is offline   Reply With Quote
Old 12-06-10, 09:58 PM   #3
M_S
Senior Member
 
Join Date: Dec 2006
Bikes:
Posts: 3,693
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Also if you get an FSA you need the MegaExo version, which is for their aluminum cranks. The carbon cranks use a different size.

I second the Shimano recommendation though.

The Omega is FSA's least expensive external bearing crank I think. I haven't heard good things about the bottom bracket and I can't imagine the rings are anything special, but probably the only thing you'd benefit from by replacing the arms themselves is weight. I wouldn't bother. An entry to mid range bike which would come with an Omega probably has other things on it where your money would be better spent upgrading.
M_S is offline   Reply With Quote
Old 12-06-10, 10:46 PM   #4
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm pretty sure you can use shimano bottom brackets with FSA mega exo cranks, as they're both the same axle size.
the only thing you have to change are the amount of spacers you use, as mega exo cranks are spaced out for 73mm shells. a 68mm BB shell will use 5mm of spacers with a mega exo BB to take up the slack.

The shimano system and bearing seals are far superior to mega exo, GXP and campy external cups, that's for sure.
campy and GXP are not fully interchangable with the cheaper GXP or shimano external BB cup systems.

sram/truvativ GXP right side cup is interchangable with shimano, but the left side is special and requires the GXP cup, and obviously needs spacers to correct length.

I think, right now, you can buy 105 cranks off of ebay for $75+S&H
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm

Last edited by AEO; 12-06-10 at 10:49 PM.
AEO is offline   Reply With Quote
Old 12-07-10, 12:37 PM   #5
peripatetic
Senior Member
 
peripatetic's Avatar
 
Join Date: Oct 2004
Location: NYC
Bikes: All 70s and 80s, only steel.
Posts: 2,124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If the cranks are fine, seems unnecessary and wasteful to replace them along with the bb. At the least, you can swap in a new bb and see if that's sufficient for you to feel the bike's ride-able and safe again.
peripatetic is offline   Reply With Quote
Old 12-08-10, 08:02 PM   #6
ZippyThePinhead
Slacker
 
ZippyThePinhead's Avatar
 
Join Date: May 2009
Location: North Orange County, in Southern California
Bikes: 1986 Peugeot Orient Express, 1987 Trek 560 Pro, 1983 SR Semi Pro, 2010 Motobecane Le Champion Titanium, 2011 Trek Fuel EX 8
Posts: 1,065
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Dunno what sort of noise you were experiencing, but I was getting a creaking sound from my FSA BB, and my bike only has 600 miles on it.

My mechanic friend took off the left crank and found the splines on the spindle were completely dry. Water had worked its way in, and there was a bit of mineral residue/corrosion on the splines. He greased the spindle, reassembled the crank, and the noise is gone.
ZippyThePinhead is offline   Reply With Quote
Old 12-08-10, 09:15 PM   #7
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by AEO View Post
I'm pretty sure you can use shimano bottom brackets with FSA mega exo cranks, as they're both the same axle size.
the only thing you have to change are the amount of spacers you use, as mega exo cranks are spaced out for 73mm shells. a 68mm BB shell will use 5mm of spacers with a mega exo BB to take up the slack.

The shimano system and bearing seals are far superior to mega exo, GXP and campy external cups, that's for sure.
campy and GXP are not fully interchangable with the cheaper GXP or shimano external BB cup systems.

sram/truvativ GXP right side cup is interchangable with shimano, but the left side is special and requires the GXP cup, and obviously needs spacers to correct length.

I think, right now, you can buy 105 cranks off of ebay for $75+S&H
Dude, stop posting wrong things on this forum.

Seriously

1) Shimano BB's will only work for a very small selection of FSA cranksets. There's a reason why FSA makes half a dozen BB's for all their different cranks - becuase they're different.
2) Omega uses the CK-C4000 FSA bb
operator is offline   Reply With Quote
Old 12-08-10, 09:17 PM   #8
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ZippyThePinhead View Post
Dunno what sort of noise you were experiencing, but I was getting a creaking sound from my FSA BB, and my bike only has 600 miles on it.

My mechanic friend took off the left crank and found the splines on the spindle were completely dry. Water had worked its way in, and there was a bit of mineral residue/corrosion on the splines. He greased the spindle, reassembled the crank, and the noise is gone.
Let's hope those weren't carbon crank splines. That requires loctite 641.
operator is offline   Reply With Quote
Old 12-08-10, 09:25 PM   #9
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by operator View Post
Dude, stop posting wrong things on this forum.

Seriously

1) Shimano BB's will only work for a very small selection of FSA cranksets. There's a reason why FSA makes half a dozen BB's for all their different cranks - becuase they're different.
2) Omega uses the CK-C4000 FSA bb
the FSA part? yeah, they do have more than one type of bottom bracket and spindle diameter.
But I'm correct on the GXP part, I measured it, tried it, and it does work with the correct amount of spacers.

Why FSA would make it complicated is beyond me. They pulled the same thing campy did with square taper for low and high end cranks.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline   Reply With Quote
Old 12-09-10, 12:58 PM   #10
ZippyThePinhead
Slacker
 
ZippyThePinhead's Avatar
 
Join Date: May 2009
Location: North Orange County, in Southern California
Bikes: 1986 Peugeot Orient Express, 1987 Trek 560 Pro, 1983 SR Semi Pro, 2010 Motobecane Le Champion Titanium, 2011 Trek Fuel EX 8
Posts: 1,065
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by operator View Post
Let's hope those weren't carbon crank splines. That requires loctite 641.
No, the spindle looks to be stainless steel.
ZippyThePinhead is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:12 AM.