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 01-29-06, 06:21 AM   #1
snailspace
Newbie
Thread Starter
 
Join Date: Jan 2006
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BB's

Very simple and possibly dull question for you bike mechanics and enthusiasts out there.
Quite simply standard BB or the external? Which is better and why?
Many thanks for your time.
snailspace is offline   Reply With Quote
Old 01-29-06, 08:51 AM   #2
af895
Senior Member
 
af895's Avatar
 
Join Date: May 2005
Location: Montreal, Canada
Bikes: 2003 KHS F20-Westwood folding & enough parts to make several more bikes...
Posts: 853
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Better is a subjective term.
Some people would say external bearing bottom-brackets are a solution looking for a problem.
__________________
af895 is offline   Reply With Quote
Old 01-29-06, 09:38 AM   #3
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 28,917
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 94 Post(s)
The type of bottom bracket is really determined by the crank you choose. If you buy a 10-speed Shimano or some of the FSA or Truvative cranks, you have to use their specific bottom bracket and it will be an external bearing type. Buy an Octalink Shimano crank, an ISIS crank or any Campy crank and the bb will be an internal bearing type

The external bearing bb's are supposed to solve the "problem" of the small bearings needed to allow a large diameter hollow spindle to fit inside the standard bb shell. Maybe it is a problem and maybe it isn't. I have heard lots of complaints about ISIS bottom bracket failures but very few about Shimano Octalink bb's.
HillRider is offline   Reply With Quote
Old 01-29-06, 12:02 PM   #4
Bottomfeeder
Mr. cost-benefit analysis
 
Join Date: Dec 2005
Location: Agua Dulce, CA
Bikes: Surly Crosscheck Single Speed, Novara 9 speed commuter/runabout
Posts: 437
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I believe it's cheaper to purchase a new external bearing set than it is to purchase an entire new internal bearing BB. Of course there are internal bearing BB's that are said to be rebuildable. I owned a couple high end Race Face BB's, and they claimed they were rebuildable. But I had no luck ordering the special tool and bearing kit to rebuild the things. The shops kept telling me they simply throw them away and install a completely new unit. I guess that's the easy route when you're spending someone else's cash.

There are folks here on the forums who say that it shouldn't be a problem to buy the bearings and install them in high end, internal bearing BB's, and that they will be doing just that when the time comes. Then again, I've never read here of anyone actually doing it.

I've gone to buying mid-priced BB's for my current bikes. They seem to last as long as the more expensive ones. So all things being equal, they make for far more attractive 'throw-aways'. If and when I build another new bike, I'll probably go with the external bearing type BB.

DanO
Bottomfeeder is offline   Reply With Quote
Old 01-30-06, 01:08 PM   #5
Matt Gaunt
Senior Member
 
Matt Gaunt's Avatar
 
Join Date: Oct 2004
Location: London, UK
Bikes:
Posts: 2,245
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I only use external BBs now, and I have noticed a great improvement in stiffness. The problem with this is that I also changed the cranks at the same time so I'm not sure whether or not to attribute the stiffness to the BB or to the cranks or to both.

Put it this way, you won't regret outboard bearings if you get them because all the Shimano ones at least come with quality cranks in my experience. Don't shoot me down here, I just never tried ISIS versions of outboard BBs!
__________________
Matt
2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics
Matt Gaunt is offline   Reply With Quote
Old 02-08-06, 01:07 PM   #6
snailspace
Newbie
Thread Starter
 
Join Date: Jan 2006
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Many thanks for your time.

Basically this comes from the fact that I puchased a carbon fibre monocoque frame, supplied with external BB. However the cranks will not turn over due to a lack of clearance on the frame. The manufacturers have told me to replace the external BB with a the standard BB. This with new cranks will give me the clearance I need. Hence the question as to whether I am losing out on what I believe (perhaps wrongly) is a stiffer crank. And my concern(again perhaps unfounded) that standard BB will soon be phased out by manufacturers in favour of the externals...

Any reply to this?

Matt
snailspace is offline   Reply With Quote
Old 02-08-06, 04:06 PM   #7
CBolt
Senior Member
 
Join Date: Sep 2004
Location: Kalamazoo, MI
Bikes: Too many
Posts: 234
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i think the problems with internal bearings occur mostly on mtb's. i have isis on my road bike with no problems, but i've gone through 2 isis BB's on my mtb. this is also what i've seen in the shop. that being said, when I build my touring bike it will either have square taper or external.
CBolt is offline   Reply With Quote
Old 02-09-06, 10:27 PM   #8
Pete Hamer
Senior Member
 
Join Date: Dec 2005
Location: Minnesota
Bikes:
Posts: 415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I had an XT hollowtech 2 crankset. I sold it and put the old race face square taper crankset back on. I can't tell any difference. But then again I'm 190lbs and don't think SID forks are flexy. I guess I'm not sensitive to parts flexing.
Pete Hamer 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 07:08 AM.