Road Cycling - ISIS or Octalink

One better than the other? FSA Carbon cranks come in both styles, and I can't decide.

thanks,

-Tak

While you're at it, can you explain the difference? Until 2 months ago, I had never heard of ISIS.

While you're at it, can you explain the difference? Until 2 months ago, I had never heard of ISIS.It's a splined spindle system similar to but not compatible with octalink. Dreamed up as a standard by a group of other aftermarket suppliers. Seem to be alot of issues with premature bearing failures.

I likeee the ISIS... never used Octolink though... I like ISIS much better than the tapered what-have-you's.

octalink. its a lot easier and cheaper to get a shimano octalink bb then it is an ISIS. I know from experience here...

They must have the Octolink BB's at CVS then ;); because I haven't had a bit of trouble finding ISIS ones in all flavors... bikeman.com has good prices on'em for one and its a local shop (ok, in Maine, but its still a "local" shop with a physical location)...

I use both, and really like the FSA Isis. I think the old Dura Ace was a terrible design - too many parts, but I just bought a new one that is 2 piece like everyone elses. Some people complained that the DA needle bearing design created a lot of drag, but I don't know.
I'd give a slight preference to the FSA Platinum Pro over the DA.

I use both, and really like the FSA Isis. I think the old Dura Ace was a terrible design - too many parts, but I just bought a new one that is 2 piece like everyone elses. Some people complained that the DA needle bearing design created a lot of drag, but I don't know.
I'd give a slight preference to the FSA Platinum Pro over the DA.
All octalik is not DA.Nothing wrong with the DA bb,but one has to know how to install it and too many don't have a clue. DA is actually smoother,and with less deag.All in the installation and adjustment.The clueless should just quit griping and stick with ultegra.

I'm not disputing what you say, except your statement that DA has less drag. I don't know if that is true. I'm sure there is some website in Germany that has bench tested 20 BBs, but I have not seen it.
If the DA design is so good, why did the get rid of it? I've installed a dozen or so, and I think the old design stinks. Please don't tell me that it was just too complex for the average human.

I'm not disputing what you say, except your statement that DA has less drag. I don't know if that is true. I'm sure there is some website in Germany that has bench tested 20 BBs, but I have not seen it.
If the DA design is so good, why did the get rid of it? I've installed a dozen or so, and I think the old design stinks. Please don't tell me that it was just too complex for the average human.It's just not DA that shaimano has dumped. Octalink will be history. DA does get alot of bad press and it is from the average human that does not install it right.The average human should probably just stay away from it, but they can't becaues it's DA ,cost more and weights 49 grams less.

I've got an FSA ISIS on the new bike, with the Megatech OS BB. The bearings are standard industrial bearings which just sit in the BB, so easy to obtain in the unlikely event they ever wear out.

I like the "open-standard" with ISIS and the Megatech BB...encourages the aftermarket and small frame builders. Shimano doesn't need all my business.

Don't notice any drag with this set up either. Compared to the drag of the chain, BB drag should be insignificant.

I like the "open-standard" with ISIS and the Megatech BB...encourages the aftermarket and small frame builders. Shimano doesn't need all my business.

What does small frame builders have to do with it?

What does small frame builders have to do with it?


Good Question...

ISIS has had it's share of failures.

LINK (http://www.sheldonbrown.com/fsabb.html)

Due to the over-sized spindle, the bearings are smaller and may wear faster. In mountain biking applications, ISIS failures are quite common if you believe the reviews on MTBR.com. I'm not sure how long they'd last on a road bike but why even mess with it when Campy and Shimano make perfectly fine products.

As for stiffness, the new 04 DA should be far stiffer than either Octalink or ISIS. Also, I've raced for the last two seasons on Chorus BB & Cranks and it's been plenty stiff IMO and don't know if I'd even notice a small percentage difference.

As far as Octalink goes I love it. Have it on both my road and mtb. When it comes to Campy though I have yet to find a square taper BB that I don't end up having to re-tighten the crank arms every 2-3 rides. Octalink on the other hand never seems to loosen.

Is Yet Another standard, which solves the ISIS bearing problem by using an extra-fat bottom bracket shell. Apart from providing room for larger bearings, the BB shell also gives a larger area for welding fat Al frame tubes.

. When it comes to Campy though I have yet to find a square taper BB that I don't end up having to re-tighten the crank arms every 2-3 rides.
That's just because you never did it right, or you rode it while loose, and buggered the arms and then it never will stay tight.

What does small frame builders have to do with it?

Aren't Cannondale and others are going to their own proprietary oversize BBs, away from the cartridge style? ISIS/Megatech give independents a way to go to oversize BB's as well on frames they build. If this is incorrect, please enlighten me.

Aren't Cannondale and others are going to their own proprietary oversize BBs, away from the cartridge style? ISIS/Megatech give independents a way to go to oversize BB's as well on frames they build. If this is incorrect, please enlighten me. Not incorrect,but maybe a solution looking foa a real problem.

i have an octalink BB. and while i've had virtually no problems with it so far (aside from my left crank arm coming a bit loos every once in a while) i really hate it. mostly because i don't trust the tiny, 3mm of splines that the crankarm is grabbing onto. i'd prefer to have an ISIS BB, just because there is more contact between the crankarm and the spindle. the ISIS failure that sheldon brown mentions was due to a really crappy design flaw in the spindle design, not so much the splines...

having said all that, of the three major types of bottom bracket designs, i prefer square taper. campy has been doing it for decades, and why bother changing something that works pretty flawlessly to begin with?

Check http://www.truvativ.com.

You will find that TruVativ explains the ISIS BB very well.

As far as weight goes, the TruVativ Elita crankset is lighter than the comparable Ultegra crankset. So, if there's any weight advantage to the Octalink bottom bracket, it will be more than offset by the weight difference in the cranksets.

My last bike had a TruVativ Elita crankset and ISIS bottom bracket. Though I put thousands of miles on the bike, I never experienced a bit of problem.

According to TruVativ, the ISIS system is also more foolproof, so the local wrench, who may or may not know what he or she is doing, is less likely to muck up the installation or repair.

They are both very good. I haven't had a bike with ISIS, but it looks good, and people seem to like it. I have an Ultegra BB, and anything that survives my tender ministrations is pretty good.

i have an octalink BB. and while i've had virtually no problems with it so far (aside from my left crank arm coming a bit loos every once in a while) i really hate it. mostly because i don't trust the tiny, 3mm of splines that the crankarm is grabbing onto. i'd prefer to have an ISIS BB, just because there is more contact between the crankarm and the spindle. the ISIS failure that sheldon brown mentions was due to a really crappy design flaw in the spindle design, not so much the splines...

having said all that, of the three major types of bottom bracket designs, i prefer square taper. campy has been doing it for decades, and why bother changing something that works pretty flawlessly to begin with?

Shimano used the square taper for many years also with fine results. I think it's mostly about weight savings.....a hollow axle with some kind of splines should be lighter. Plus, I believe the crank arms can be designed lighter as well.

We could argue the value of saving a couple of ounces on a BB, but it seems that the quest for lighter weight has a great sales appeal.

but....octalink spindles are bigger than square taper spindles...

i think if anything, it's more about strength than weight. BMX cranks had been using splined bottom brackets for years before shimano started doing it.

a round spindle might be stronger, but i still don't trust the thin-ness of the splines on octalink...i have heard a number of reports that the 105 cranks "stripped out" because the aluminum was too soft or something...which was why i went with an FSA gossamer crank instead. i highly doubt that i'll ever have a problem with any of it...

but....octalink spindles are bigger than square taper spindles...

i think if anything, it's more about strength than weight. BMX cranks had been using splined bottom brackets for years before shimano started doing it.

a round spindle might be stronger, but i still don't trust the thin-ness of the splines on octalink...i have heard a number of reports that the 105 cranks "stripped out" because the aluminum was too soft or something...which was why i went with an FSA gossamer crank instead. i highly doubt that i'll ever have a problem with any of it...

But aren't octalink and isis spindles hollow, vs the solid square taper spindles? A bigger diameter, hollow spindle would be lighter and stiffer than a solid one.

Agree the ISIS splines look pretty strong. And I'm sure not expecting any problems with my new FSA Team triple crank coming loose either.

all of the square taper spindles i've ever seen have been hollow as well...i'm looking at an older campy cartridge BB with a hollow square taper spindle right now, and the suntour track spindle that i have is hollow, and the shimano UN52 BB that i have on another bike is also hollow.

are you thinking of the REALLY old crusty spindles that have the "male" threads sticking out of the spindle and use nuts to hold the crankarms on?

octalink and ISIS are both oversized, and therefore stronger than standard square taper spindles. i think there are definite advantages to them, but mostly i feel like they relate to the mountain bike world where the bikes have to take more of a beating.

I've been riding a square spindle Campy Chorus setup - put it on almost two years ago, tightened it once after two rides, and haven't touched it since.

A buddy has a RaceFace Next ISIS crankset on his MTB, while I have the same Next crankset with a square spindle axle on mine. I've ridden both, and the only substantial difference I could find was the price - square spindle crankset was $100 cheaper. Otherwise, they felt exactly the same.

I'm with OneTinSloth - square spindle works, has worked for decades. There are more cost effective ways to improve your cycle.

it was probably me just using not-so-great cranks with square spindles, but when I swapped'em for a truvativ crank and isis bb, WHEW! much stiffer.. much nicer.. but, hey, maybe its just a placebo effect ;)

all of the square taper spindles i've ever seen have been hollow as well...i'm looking at an older campy cartridge BB with a hollow square taper spindle right now, and the suntour track spindle that i have is hollow, and the shimano UN52 BB that i have on another bike is also hollow.

are you thinking of the REALLY old crusty spindles that have the "male" threads sticking out of the spindle and use nuts to hold the crankarms on?

octalink and ISIS are both oversized, and therefore stronger than standard square taper spindles. i think there are definite advantages to them, but mostly i feel like they relate to the mountain bike world where the bikes have to take more of a beating.

The Shimano 600 square taper one I took off my steel bike a couple of years ago was solid, dating from 1992. I thought the Ultegra replacement cartridge I got had a solid axle as well, but my memory may be wrong here.

Anyway, agree I wouldn't change out a square taper for the new stuff unless a replacement crankset is needed....they work fine. I don't see spending money to "upgrade" something that's not broken.

[jinx on] I have used the old shimano square BB in both MTB and road bikes for a LOT of years with no problems, then switched to the Shimano Octalink 3 years ago using the Dura Ace BB and had NO problems. Ran the BB into the ground with about 3.5k miles on it (summer and winter riding) & swapped it out for a Shimano Ultegra octalink BB recently and have had no problems. [/jinx off]

I find the Octalink to be stiffer and easier to work with than the old school square taper. They are as dependable as ever and the price to performance ration is quite high

Octalink Dura Ace BB:
Function: Designed as a race ready, lightweight performance part. (NOT a "put it in and forget it" part)
Weight: 173 gms
Duration: 3 seasons (and still alive)
Cost: $60
Cost per season: $20

Basically I am saying that I don't understand the gripes about Shimano BB's. They just work.

I spent 3 years in the cycling industry and I have seen lot's of other companies try to better what Shimano does with miserable results. (See also: Cranksets, BB's, V-Brakes etc.) so I stick with Shimano for these key components. Shimano has a HUGE R&D budget, so their products are typically quite well engineered (with the possible exception of the "Rapid Rise" rear MTB der. and the "Bio-Pace" chainrings).

The reason Shimano discontinues some of their design ideas is not b/c they do not work well, but rather that they need to keep their product line fresh and progressive. The trend in cycling is lighter, lighter, lighter. Sometimes they hit a wall with what they can mechanically do with an older design to make it lighter and have to go back to the drawing board. Their new BB design is to accomodate their new Crank design (which is LIGHTER), not b/c the old BB's were not good.

Not trying to be a shill for Shimano, but I have tried most everything else and keep coming back for a reason!