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  1. #1
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    Caution;  Merge;  Workers Ahead! Square taper or ISIS BB ???

    What’s the verdict on this issue??

    ISIS- no durability!!!??… square- taper... flex ???
    (Have an ISIS now – Changed BB three times in one year )

    Hello - aren’t all the road bikes square taper!!!???

    Going for a new crankset…can use some opinions about the BB type - Actually it'll determine the crankset.




    Thanks

    Rares
    The magnitude is in the Details...

  2. #2
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    Go for X-drive. Big bearings, and stiff too.

  3. #3
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    There's not much choice in square taper cranksets

    these days, many places don't sell even one model anymore. If you can afford the hollowtech/Shimano or x-type/RaceFace you might want to check for threads on durability issues too. I have a fleet of square tapers and will probably use 'em until even the next technology comes out (hopefully a different bottom bracket standard from the manufacturer's first which would be the best solution). I also have the first XTR with splines; never noticed that set being noticeably stiffer than square tapers. I believe Campagnolo is still square taper, but they're too pretty for mountain bikes.
    "...the people get the government they deserve..."
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  4. #4
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    Quote Originally Posted by RARES
    What?s the verdict on this issue??

    ISIS- no durability!!!??? square- taper... flex ???
    (Have an ISIS now ? Changed BB three times in one year )

    Hello - aren?t all the road bikes square taper!!!???

    Going for a new crankset?can use some opinions about the BB type - Actually it'll determine the crankset.




    Thanks

    Rares
    Try having your BB shell properly faced and chased and THEN fit a good quality ISIS BB. There is no reason why you should have these problems with ISIS, the system does work, installation and good quality are key though.

    Chris.

  5. #5
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    They work but dont last

    Quote Originally Posted by Ye Olde Balde One
    Try having your BB shell properly faced and chased and THEN fit a good quality ISIS BB. There is no reason why you should have these problems with ISIS, the system does work, installation and good quality are key though.

    Chris.

    Apparently the bearings on the ISIS standard seem to much smaller. Holding the BB ,you can actually see how small\ thin they are. The ISIS works alright but has no durability, coming from my experience and from a quick research here about the experience other people have had with the ISIS.


    Rares
    The magnitude is in the Details...

  6. #6
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    Any ideas on where and what Squar tapper should i get ?? stong (very) &light....


    Rares
    The magnitude is in the Details...

  7. #7
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    Quote Originally Posted by RARES
    What’s the verdict on this issue??

    ISIS- no durability!!!??… square- taper... flex ???
    (Have an ISIS now – Changed BB three times in one year )

    Hello - aren’t all the road bikes square taper!!!???

    Going for a new crankset…can use some opinions about the BB type - Actually it'll determine the crankset.




    Thanks

    Rares
    As for flex, there is a definite measurable difference in stiffness between large hollow tube spindles and smaller diam solid ones. But I don't think this has any practical value in a mtn bike BB app. On a suspension bike,by the time enough force is applied to deflect the spindle (a lot), frame flex and suspension bob from mashing the pedals will completely overshadow any of the power loss from spindle deflection. Splines are a better attachment system from crank to BB. But, the mfgs like Shimano are using their proprietary spline patterns more as tool to keep you buying their consumable BB's and not somebody elses, as you've probably noticed.

    Shimano's current road BB's are splined hollow types, Campy's are still square taper.

    As has been mentioned, the bigger spindles of ISIS and Octalink BB's force the mfg's to use smaller bearings to fit into the same size shell space, so bearing life is less. The new bigger outboard bearing integrated cranks like Deus and XTR/XT havn't had a glowing track record. Seems to me, the mfg's ought to be able to optimize these systems in a year or two, to the point where they're pretty bulletproof. Until then, it's square taper for me. Again, limited availability of square taper cranks is a bummer. I'm bucking the trend and running a square taper Phil SS spindle BB and RF Next LP cranks after running Octalink for a few years with less than stellar performance.

  8. #8
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    Thanks !
    The magnitude is in the Details...

  9. #9
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    Quote Originally Posted by RARES
    Apparently the bearings on the ISIS standard seem to much smaller. Holding the BB ,you can actually see how small\ thin they are. The ISIS works alright but has no durability, coming from my experience and from a quick research here about the experience other people have had with the ISIS.


    Rares
    I think if you asked how many of those people had proper prep work done on their frames before BB installation, the number that have is far smaller than those complaining about ISIS.

  10. #10
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    Quote Originally Posted by RARES
    What�s the verdict on this issue??

    ISIS- no durability!!!??� square- taper... flex ???
    (Have an ISIS now � Changed BB three times in one year )

    Hello - aren�t all the road bikes square taper!!!???
    Its called OCTALINK...ya know...shimano splined BBs that had proper R&D into bearings done before releasing them to the public (unlike ISIS), and thus, are reliable and dependable.

    Shimano road cranks from dura ace thru 105SC are splined and square-taper below that and Campy uses square-taper still on all their cranks.

    As to flex of square-taper... yeah maybe for freeriders landing big jumps there's flex.

  11. #11
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    I'm on my 3rd bike with ISIS, and have had ZERO problems with it.

    Square-taper sucks. Both of the bikes in my house with Square-Taper have crank-loosening issues, and it's because the square eventually wears out on the edges, and the cranks start chewing em' up.


    -Matt
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  12. #12
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    Quote Originally Posted by DeeEight
    Its called OCTALINK...ya know...shimano splined BBs that had proper R&D into bearings done before releasing them to the public (unlike ISIS), and thus, are reliable and dependable.
    I wouldn't argue Octalink is better than ISIS for durability and dependability, but still not as durable as the old sq taper UN72 BB's. My exp with the Octalink (571 LX Hollowtech/ES71 BB) was that the BB would go (loose smoothness, develop play and noises) after about 1yr/1000mi of xc/trail riding, where as sq tpr UN72's would last 2-3 yrs.

  13. #13
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    Quote Originally Posted by Ye Olde Balde One
    Try having your BB shell properly faced and chased and THEN fit a good quality ISIS BB. There is no reason why you should have these problems with ISIS, the system does work, installation and good quality are key though.

    Chris.
    ISIS was flawed from the start. Its a well known fact and pretty basic piece of the design that an oversided spindle cuts down on the size of bearings you can run inside the BB cups as the BB shell of the frame is a fixed size. ISIS proponents tried using off the shelf cartridge bearings with tiny ball bearings inside, that wear out quickly. Truvativ at least tried designing their own bearings but haven't had any better luck. The ISIS makers rushed the concept to the market to try and compete with shimano's head start on splined BBs, and in doing so, rushed a flawed concept to market, and people ate up the ISIS concept like mad until they began to find out about the short BB lifespans. I know people who've worn out the most expensive / top model ISIS BBs in under a month.

    Shimano had the right idea for the bearings from the start though, and as such, have never had bearing durability issues. When XTR went to Octalink splined in 1996, it had both caged roller bearings (about a half inch long) and cage ball bearings in each cup, to cover lateral and vertical loads in an excellent fashion. And that is the same bearing setup they've used ever since and in all the follow-on groups until their latest move to external bearing setups with the spindle fixed to the right crankarm.

  14. #14
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    Quote Originally Posted by sweetdaddy
    I wouldn't argue Octalink is better than ISIS for durability and dependability, but still not as durable as the old sq taper UN72 BB's. My exp with the Octalink (571 LX Hollowtech/ES71 BB) was that the BB would go (loose smoothness, develop play and noises) after about 1yr/1000mi of xc/trail riding, where as sq tpr UN72's would last 2-3 yrs.
    That's more to do with the small size of the seals used in the Octalink shimano cartridge style BBs than the square-taper ones have. The smaller seals are more vulnerable to debris/damage and allow moisture and dirt to get inside the bearing assembly, wearing them out faster. The M950 XTR BBs had a 2 stage outer cup seal setup. A rubber lip seal covered the outermost bearings (the small ball bearings used for lateral support), and a hard plastic cover went in place over that rubber lip seal, to protect it from debris/damage.

  15. #15
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    Quote Originally Posted by DeeEight
    That's more to do with the small size of the seals used in the Octalink shimano cartridge style BBs than the square-taper ones have. The smaller seals are more vulnerable to debris/damage and allow moisture and dirt to get inside the bearing assembly, wearing them out faster. The M950 XTR BBs had a 2 stage outer cup seal setup. A rubber lip seal covered the outermost bearings (the small ball bearings used for lateral support), and a hard plastic cover went in place over that rubber lip seal, to protect it from debris/damage.
    I wouldn't doubt that the seals in the LX Octalink BB are weak compared to the XTR, but this just brings up another bone of contention against Shimano's Octalink: I can't upgrade to an XTR BB because it has yet another spline configuration. The newer LX and XT Octalink BB's arent even compatible! This pidgeonholing of components fu cking pisses me off. I can and have run XTR deraileurs with LX shifters, but when it comes to consumables like BB's I have to upgrade cranksets and deal with yet again shimano's proprietary chain ring pattern. I used to be a shimano fan before Octalink, now I'm lukewarm at best.

  16. #16
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    Thanks !! think square tap. ll be it

    maby a Race Face Turbine (square) if i can find any and a plain old Shim BB....

    Thanks alot

    Eyal
    The magnitude is in the Details...

  17. #17
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    Is ISIS really an inherently flawed system? I mean, what's to prevent Truvativ, Raceface and co. from going and manufacturing an ISIS bb with roller bearings themselves?
    That aside, I think the idea of a two-piece setup with external bearings is marginally better than the current Octalink with a quality roller bearing bottom bracket.
    I know this has been said a zillion times before in different ways, but the most annoying thing about this whole crank/ bottom bracket debacle is that all of this technology has existed for decades, and that Shimano pushes things forward in the smallest increments possible to maximize sales.
    Prime example: cantilevers, then V-Brakes, then discs. Cantis were fine, especially the ones with the medium profile arms that made a nice, solid 90-degree angle with the straddle cable. But Shimano had to move from those nice, efficient medium profile cantis and retrogress to the low profile ones, which in fact offered less power unless paired with SLR Plus levers. All this in the name of heel clearance! So what was the solution to the low-profile canti's problems? V-Brakes, with new levers, to boot. We all know Shimano could easily have designed a feasible disc, but they'd rather make everyone buy new stuff three times than just once.
    The same thing is going on with cranks here, and Raceface and the ISIS bandwagon are just as much to blame as anyone. Spline technology and two-piece setups are old as dirt- Profile and Bullseye cranks have been around forever, and Sweetwings made two-piece splined cranks with an external bb almost ten years ago. I am living in what used to be East Berlin, and two of my friends here remember seeing two-piece setups on bikes in the early 80's.
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  18. #18
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    Quote Originally Posted by BigHit-Maniac
    I'm on my 3rd bike with ISIS, and have had ZERO problems with it.

    Square-taper sucks. Both of the bikes in my house with Square-Taper have crank-loosening issues, and it's because the square eventually wears out on the edges, and the cranks start chewing em' up.


    -Matt
    I have a square taper shimano crank from 2000, with 2000-3000miles on it, with NO loosening problems, crank is still as square as ever.

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