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Please help, Shimanmo DA vs FSA ISIS BB for FSA crankset?(13 posts)

Please help, Shimanmo DA vs FSA ISIS BB for FSA crankset?jjdbike
Sep 6, 2003 3:34 AM
Hello, thanks for reading my post. I am getting a double FSA Team carbon crankset for my 2001 Giant TCR Team Once. I have been using Shimano Ultegra BB. I was going to go for Dura Ace BB to maximize weight savings. The rest of the components are Dura Ace. I have heard that Dura Ace BB are not very dependable and if they get wet that they go bad quickly due to their colse tolorances. This being said, I am considering going w/ FSA ISIS Platinum Ti BB. The big question I the FSA Platinum Ti worth the price vs (double that of the Dura Ace)? What do you think? Thanks for any input!
FSA wil not fit a Shimano spline. Need Isis. (nm)TFerguson
Sep 6, 2003 4:39 AM
Odd since my FSA's are mounted on a DA BB (nm)Vamoots
Sep 6, 2003 5:01 AM
Yeah...mine too...merckx56
Sep 6, 2003 5:03 AM
they are made both ways. Either ISIS or octalink.
My bad. Needs either one or the other. (nm)TFerguson
Sep 6, 2003 10:42 AM
Should I Buy FSA cranks to fit Shim.Octalink or FSA ISIS BB!?!?jjdbike
Sep 6, 2003 5:55 AM
Thanks. I know that the BB has to match the spline of the BB. FSA Team Carbon cranset is available for either ISIS or Shimano Octalink compatability. What I am asking is which one should I buy, shimano Octalink or ISIS compatable cranks to match up to the better BB. I am torn between the Shimano Dura Ace BB which is light & on sale for $49 or ISIS FSA Platinum Ti BB which is closer to $90. As I said I have heard the the Dura Ace BB isn't very dependable? Is the FSA so much better/durable/dependable to warrent paying twice the price of the Shimano Dura Ace?
Thanks again
the correct answer...C-40
Sep 6, 2003 6:01 AM
You have to use the BB with the correct spline for your crank. If you purchased a crank with a shimano octalink spline, then you must use a matching shimano BB. If you purchased the ISIS splined crank, then you must use an ISIS BB. The two types are entirely different.

Folks complain about the durability of both types of BB.

The question is, how long will shimano make the octalink, now that they have another spline pattern on the 2004 DA group?
I've got a FSA Platinum Pro Ti ISIS BB on my SS MTB and a DA...SS_MB-7
Sep 6, 2003 6:06 AM
I've got a FSA Platinum Pro Ti ISIS BB on my singlespeed MTB with a FSA Carbon Pro crankset and a Dura Ace BB/crankset on my singlespeed 'cross bike. Both BBs are still running smooth after a season's worth of racing -- lots of mud, water, etc.

Take note that the majority, if not all, ISIS BB manufacturers (FSA, RaceFace, TruVativ, etc.) have issues with their BBs. In particular, premature bearing failure. Just read the comments in the TechTalk forums and review sections at

I've been fortunate with my FSA ISIS BB...others have not been so lucky. FSA did address some early issues with their BBs by increasing the width of the driveside bearing (now double-sized) and adding better seals.

As mentioned, the main issue with ISIS BB failures is the bearings. Since the ISIS spindle is oversized and the BB shell diameter is the same, something has to give...and it is the bearing thicknes -- they are really thin. Unfortunately, this leads to failures.

RaceFace is now adopting the XTR/DA-style BB in which the bearings are outboard from the BB shell. This allows the bearing thickness to be increased since it is not limited by the BB shell diameter.

Take note that ISIS is not the same as Octalink. What ever BB you decide to go with, you will need to order the appropriate crankset.

Ride Hard,
Mike B.
re: Please help, Shimanmo DA vs FSA ISIS BB for FSA crankset?lithiapark
Sep 6, 2003 6:33 AM
I have FSA ISIS Platinum Pro Ti BB on Ellsworth MTB for 2+ years-stiff, mounts crankarms easily, runs smoothly, very pleased. Just bought another and mounted FSA Carbon Pro Compact Drive double crankset on a Serotta road bike because I liked the first one. I'm very happy with their current products. Had DA before, never had problems, but I'm not a big person. I think the FSA is lighter than the DA if that is at all important to you. I'm going to build a cross bike and will use the FSA BB so I can try different cranks from my other bikes.
re: Please help, Shimanmo DA vs FSA ISIS BB for FSA crankset?PMC
Sep 6, 2003 10:05 AM
Stick with the Shimano splined version. As Mike B stated, the bearings in the ISIS BBs are prone to fail. Due to the spindle size, the bearings have to be undersized which doesn't do much for the lifespan. On a road bike that gets lots of miles, I'd have huge issues with having to service the BB on a regular basis.
re: Please help, Shimanmo DA vs FSA ISIS BB for FSA crankset?russw19
Sep 6, 2003 7:21 PM
However, as all the companies that make ISIS splines have continuously stated... they are pushing for a larger diameter bottom bracket shell standard so they can use larger bearings to solve this. But, the spline pattern of the spindle will not be changed. It is a standard and they want to keep it that way. They may change the bottom bracket, but not the spindle. So if that is the case, you are better off with ISIS as your cranks will still fit on the new bottom bracket.

The other side of the coin has already been spelled out by Shimano (and as C-40 rightly pointed out) with the new Dura-Ace stuff, and XTR, XT, and Saint on the mountain side, they have already abandoned the Octalink spline pattern. So just like Shimano and square tapers, how long do you think they will still make high quality Octalink spindles? That's the whole point that of ISIS being a standard as it is designed to not change when Shimano feels like putting something new out every 5 years.

I know there are issues with ISIS, but with 5 different companies working on it, I am sure it will be fixed, but I am also sure that Shimano will see Octalink as a thing of the past very soon. I think this comes down to picking the lesser of two evils, and I see that as ISIS right now.

Just giving my opinion on this....

Same situation, I went ISIS....DaveLobster
Sep 8, 2003 10:45 AM
I had the same choice, and took the ISIS compatible FSA cranks over the Octalink (shimano). My old cranks were DA, and I used the DA BB at first, and changed over to the Ultegra BB like so many others.

The way I figured it, at least with the ISIS you have several manufacturers' BB's to choose from, but with Octalink you only have Shimano.

BTW, I got the FSA Platinum Pro BB (not the Ti version), and it weighed in around 190g, or just a little below halfway between the DA and Ultegra BB's. Should have the bike on the road this weekend, I'll let you know how it works. -dave
Sep 8, 2003 6:35 PM
The Ultegra BB is only something like 40g more than DA, costs half as much, is better sealed and has none of the very widely reported durability issues surrounding ISIS BBs.