Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Galleries NEW FAQ Contact About
It is currently Sat Apr 30, 2016 4:33 am

All times are UTC+01:00





Post new topic  Reply to topic  [ 15 posts ] 
Author Message
PostPosted: Thu May 03, 2012 3:59 pm 
Offline

Joined: Wed Dec 07, 2011 1:26 am
Posts: 414
Location: California's country side
I have heard both yes and no for this.

I have heard the 24mm spindle diameter is just slightly different and won't work quietly?

What's is your take on this?


Top
   
PostPosted: Thu May 03, 2012 4:30 pm 
Offline

Joined: Mon Jan 29, 2007 4:38 am
Posts: 345
Location: TN
Nope.


Top
   
PostPosted: Thu May 03, 2012 5:32 pm 
Offline

Joined: Tue Jun 07, 2011 4:28 am
Posts: 118
Location: Berkeley, CA
To add a yes to this argument, a friend of mine ran a MegaExo crankset for quite a while with a Dura Ace BB. He thought it worked much better than the MegaExo bb.


Top
   
PostPosted: Thu May 03, 2012 5:37 pm 
Offline

Joined: Mon Jan 29, 2007 4:38 am
Posts: 345
Location: TN
Heh. Well, I guess there's only one way to find out for sure... But QBP says:

"Due to varying dimensional tolerances between manufacturers, FSA MegaExo bottom brackets are not compatible with any other brand of crankset
Different models of MegaExo bottom brackets are designed to be specific to each model of FSA crankset"

http://www.qbp.com/diagrams/TechInfo/FS ... tchart.pdf


Top
   
PostPosted: Thu May 03, 2012 5:54 pm 
Offline
Shop Wrench

Joined: Thu Feb 26, 2009 1:18 am
Posts: 284
Location: Boston
Talked to FSA, Shimano, and Race Face about this last year. All three can use the same BB.

_________________
I'm so rubbish at this.


Top
   
PostPosted: Thu May 03, 2012 6:48 pm 
Offline

Joined: Mon May 30, 2005 7:13 am
Posts: 1536
Just to add one more experience to this equation, I couldn't fit my Mega Exo crank in a Race Face bottom bracket, but the race face crank fit in a Shimano BB.

It is true that they are supposed to be compatible but in my experiences the tolerances make it a close call.


Top
   
PostPosted: Thu May 03, 2012 7:05 pm 
Offline

Joined: Sat May 07, 2011 12:23 am
Posts: 180
I replaced my FSA BB with an ultegra unit which has performed infinitely better. No compatibility problems to report.


Top
   
PostPosted: Thu May 03, 2012 7:34 pm 
Offline

Joined: Thu Dec 09, 2004 1:57 pm
Posts: 244
Last summer I helped my friend install an Ultegra BB with a FSA crank. The fit was "very" tight. We got it in with the use of a mallet (at my friend's urging, I cringed while doing it) and it has worked fine but the fit is less than ideal. I think it is hit or miss really, sometimes they fit fine, sometimes they need help.


Top
   
PostPosted: Thu May 03, 2012 8:18 pm 
Offline

Joined: Mon Oct 12, 2009 6:36 pm
Posts: 246
rbrtwyn wrote:
Last summer I helped my friend install an Ultegra BB with a FSA crank. The fit was "very" tight.


Doesn't sound like a BB compatibility issue but rather like a bottom bracket that needs some good facing. Most cheap frames are not faced and will have paint on the outside of the bracket. This prevents the bearings from lining up neatly.

Properly faced bottom bracket (note how metal is showing for the full 360 degrees):
Image


Top
   
PostPosted: Thu May 03, 2012 8:20 pm 
Offline

Joined: Thu Dec 09, 2004 1:57 pm
Posts: 244
Nope, the frame was faced. The FSA spindle is slightly different than Shimano, making it a tight fit. Cheap frames or expensive frames, most don't get faced anymore. This was an expensive frame that was faced, at my urging, by a shop.


Top
   
PostPosted: Fri May 04, 2012 2:27 am 
Offline

Joined: Mon Jan 15, 2007 9:27 pm
Posts: 11
I use a Shimano BB with my FSA cranks with no problems and the Shimano BB has much better bearings.


Top
   
PostPosted: Fri May 04, 2012 6:57 am 
Offline

Joined: Tue Sep 28, 2010 5:13 pm
Posts: 44
Location: BC, Canada
rbrtwyn wrote:
Last summer I helped my friend install an Ultegra BB with a FSA crank. The fit was "very" tight. We got it in with the use of a mallet (at my friend's urging, I cringed while doing it) and it has worked fine but the fit is less than ideal. I think it is hit or miss really, sometimes they fit fine, sometimes they need help.

I had the same experience when installing a Dura Ace BB with a FSA Gossamer crank. I had to use the mallet to push the crank spindle through the right bottom bracket dust cover, but it did not take more than a couple of hits.


Top
   
PostPosted: Sat May 05, 2012 8:29 am 
Offline
Resident Pro

Joined: Sat Jan 10, 2009 12:22 pm
Posts: 114
alexalecu wrote:
rbrtwyn wrote:
Last summer I helped my friend install an Ultegra BB with a FSA crank. The fit was "very" tight. We got it in with the use of a mallet (at my friend's urging, I cringed while doing it) and it has worked fine but the fit is less than ideal. I think it is hit or miss really, sometimes they fit fine, sometimes they need help.

I had the same experience when installing a Dura Ace BB with a FSA Gossamer crank. I had to use the mallet to push the crank spindle through the right bottom bracket dust cover, but it did not take more than a couple of hits.


same here- altough in previus time it did work just fine


Top
   
PostPosted: Mon May 07, 2012 3:18 am 
Offline

Joined: Wed Dec 07, 2005 2:31 pm
Posts: 289
I used to be on an FSA SL-K compact (23mm spindle) with a Shimano Dura Ace bottom bracket... smooth as butter!

Dura Ace BBs, I think, can take the 23mm spindles, but not the 24mm (K-Force Light, etc.)

_________________
"Truth is a pathless land." - Jiddu Krishnamurti

6.29 kg and dropping...

http://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=89221


Top
   
PostPosted: Mon May 07, 2012 7:40 am 
Online

Joined: Wed Feb 09, 2005 4:51 am
Posts: 1825
There are TWO versions of the MegaExo cranksets. One will work with Shimano BB's , the other won't even though they all use the same 24mm axle.

The ones that will work are the lower range Gossamer and Omega cranksets that use the same pinch clamp design as Shimano.

The higher range K-force and SL-K designs use a tension screw to lock onto the spline on the spindle. This requires a metal sleeve that comes with the MegaExo BB's to support this 'compression' inwards behind the bearings. Else you won't get your lock screw tight enough or, you will get it so tight, the BB bearings will cease.

So, do differentiate between the TWO versions of the cranksets before you attempt to swap between Shimano BB's and MegaExo BB's.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 15 posts ] 

All times are UTC+01:00


Who is online

Users browsing this forum: Exabot [Bot], kai-ming, maxxevv, ms6073, Yahoo [Bot] and 18 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited