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  1. #1
    Daniel the Dog
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    It may be time for a new bottom bracket standard

    Shimano and other drivetrain manufactures do what they can to improve the performance of the bottom bracket crankset interface; however, it is inherently flawed.

    I'm less than excited about the X design. The bearings outside the BB shell getting douched by water and widening the Q factor. Ugh! I can't fell a real world difference in stiffness in my XT outboard cranks over my old Octalink system. The wider Q factor doesn't bother me all that much.

    The Isis system sat inside the shell but the bearing were too small and fragile to last. The old square BB was durable but did flex a bit. The Octalink system is probably the most succesful thus far but fell out of favor for some uknown reason.

    It is time for different standard. Why not a bigger bottom bracket shell. Keep it at 73mm and 68mm but make the shell larger, so the bearings fit inside the shell where they are protected from the elements and keep the Q factor narrow.

    They can make the head tube bigger. Why not the bottom bracket shell?

    Your thoughts?

    Jaybo

  2. #2
    Elitest thrill junkie
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    Quote Originally Posted by Jaybo
    I'm less than excited about the X design. The bearings outside the BB shell getting douched by water and widening the Q factor.

    What the heck did you think happened to the bearings on regular BBs? There's no such thing as a "sealed bearing". At least this way they can be be cleaned and serviced relatively easily.

    I feel a HUGE difference in stiffness with the hollowtech 2 cranks. Definitely makes for a solid ride when the rest of your bike is built solidly. If you can't feel any stiffness increase with that huge axle, then you'd be just as well served with old sugino cranks on a square taper. Those UN72 BBs always lasted a long time for me anyway.

    We might need a new standard, but the hollowtech 2 system is a huge step forward. Octalink just didn't get as long a life, and it was a good system, but hollowtech 2 is better. I can take off my crankset (for cleaning) by loosening a couple pinch bolts, instead of having to get some sort of crank-remover that presses the cranks out.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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  3. #3
    Daniel the Dog
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    That is your opinion! I COMPLETELY disagree....

    Quote Originally Posted by Jayem
    What the heck did you think happened to the bearings on regular BBs? There's no such thing as a "sealed bearing". At least this way they can be be cleaned and serviced relatively easily.

    I feel a HUGE difference in stiffness with the hollowtech 2 cranks. Definitely makes for a solid ride when the rest of your bike is built solidly. If you can't feel any stiffness increase with that huge axle, then you'd be just as well served with old sugino cranks on a square taper. Those UN72 BBs always lasted a long time for me anyway.

    We might need a new standard, but the hollowtech 2 system is a huge step forward. Octalink just didn't get as long a life, and it was a good system, but hollowtech 2 is better. I can take off my crankset (for cleaning) by loosening a couple pinch bolts, instead of having to get some sort of crank-remover that presses the cranks out.
    However, you have a right to your opinion. The Octalink system was easy to take apart and had an outstanding reliability record with a lower Q factor. The stiffness factor is complete placebo effect. I have outboard bearings, XT and Ultegra, on both my road and mountain bike and cannot feel a difference over Octalink. I regret buying both now after riding 'em. Hollowtech system is a only being used because we need a new BB standard. The Hollowtech 2 system has had plenty of mechanical problems too. It is deeply flawed system.

    Jaybo

    PS by the way, the XT crank was self extracting. Simple! Oh, yes, you have to face the BB shell on many frames for the HT 2 system. How ridiculous is that!
    Last edited by Jaybo; 02-04-2006 at 09:01 PM.

  4. #4
    Ebo
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    I've continued to use square taper cranks. They work well enough for me and the bb's last longer than a lot of the ISIS crap out there. Oh yeah. No experience with the outboard bearing cranks. They too have had some problems, but the potential is good.

  5. #5
    Meh.
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    Quote Originally Posted by Jayem
    What the heck did you think happened to the bearings on regular BBs? There's no such thing as a "sealed bearing". At least this way they can be be cleaned and serviced relatively easily.

    I feel a HUGE difference in stiffness with the hollowtech 2 cranks. Definitely makes for a solid ride when the rest of your bike is built solidly. If you can't feel any stiffness increase with that huge axle, then you'd be just as well served with old sugino cranks on a square taper. Those UN72 BBs always lasted a long time for me anyway.

    We might need a new standard, but the hollowtech 2 system is a huge step forward. Octalink just didn't get as long a life, and it was a good system, but hollowtech 2 is better. I can take off my crankset (for cleaning) by loosening a couple pinch bolts, instead of having to get some sort of crank-remover that presses the cranks out.
    Self-extracting crank bolts. But removing and replacing the cranks too often wears out the interface between the crank and bottombracket splines.

  6. #6
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    Drainage

    The tubes drain thru the BB.Why? I use scotch over the head hole. and the seat tube will drain to the BB too. A proper fender should protect the crank and the front tranny. There is no such design.
    Isis is the lightest.They`re all the same except weight?
    Q seems irrivelent on a MTB? The inconsistant nuture of it.
    Weight is what I bet on this year with an Am. Classic BB{replacable bearing} and FSA carbon crank.
    Expensive and high maintanenance. custom fender and the scotch tape for sure.
    130gram over octilink.It was good but I did`nt want to buy another. For my $350,XTR?

  7. #7
    Gimme my MOJO!
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    Quote Originally Posted by consumerbydesign
    The tubes drain thru the BB.Why? I use scotch over the head hole. and the seat tube will drain to the BB too. A proper fender should protect the crank and the front tranny. There is no such design.
    Isis is the lightest.They`re all the same except weight?
    Q seems irrivelent on a MTB? The inconsistant nuture of it.
    Weight is what I bet on this year with an Am. Classic BB{replacable bearing} and FSA carbon crank.
    Expensive and high maintanenance. custom fender and the scotch tape for sure.
    130gram over octilink.It was good but I did`nt want to buy another. For my $350,XTR?
    This has got to be one of the most confusing posts I have ever read!

  8. #8
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    Quote Originally Posted by leleklegrunt
    This has got to be one of the most confusing posts I have ever read!
    Yeah, I have no idea what the point he's trying to make is.

  9. #9
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    I think I like my '00 lx hollowtech cranks and xt bb. I also think you're over thinking this. It's a bike not the space shuttle and the parts work amazingly well. Lastly I think that it's probably your riding style that needs the work, not the bb.

  10. #10
    Neg reppers r my biatches
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    my standard is a Phil Wood bottom bracket....bomb proof.

  11. #11
    Elitest thrill junkie
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    Quote Originally Posted by Jaybo
    It is deeply flawed system.

    Jaybo

    PS by the way, the XT crank was self extracting.
    How is it deeply flawed?

    And as mentioned above, not only does it require much more force to remove the octalink cranks, but it wears the interface everytime you remove and install em.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  12. #12
    Daniel the Dog
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    That is a good point

    Quote Originally Posted by Jayem
    How is it deeply flawed?

    And as mentioned above, not only does it require much more force to remove the octalink cranks, but it wears the interface everytime you remove and install em.
    However, I had a pretty old Octalink XT 752 that never wore out the interface despite repeated removals and installs. I think I've written about why I think the external bottom bracket technology is flawed.

    All I'm saying is make the bottom bracket shell a half inch bigger. Give the shell a bit more room, so manufactures can use bigger bearings and subsequently have stronger bottom brackets. Easy.

    I understand internals bottom brackets are not completely sealed but doesn't it make more sense to you to have them inside? Are you denying that external bottom brackets have had less than stellar durability records? You understand that Q factors are widened as a result of external bottom brackets.

    Heck! Cannondale has used a different BB technology on their road bike frames.

    It is just a thought but I understand people are slow to adapt new technology. It is one of the reason that outdated technologies continue to exist on bikes.

    By the way, I"m not trying to be argumentative but just think a bit...outside the box.

    Jaybo

  13. #13
    Elitest thrill junkie
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    Quote Originally Posted by Jaybo
    Are you denying that external bottom brackets have had less than stellar durability records?

    Yes. By and large, I think they've had excellent durability records.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  14. #14
    Daniel the Dog
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    Use the search function on this site

    Quote Originally Posted by Jayem
    Yes. By and large, I think they've had excellent durability records.
    I think you may find a different opinion.

    Jaybo

  15. #15
    ballbuster
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    Quote Originally Posted by Jayem
    Yes. By and large, I think they've had excellent durability records.
    I gotta second this. I ride with lots of folks with external bearing cranks, and nobody seems to be having problems. Add to that, I live in Northern California, and we ride all year round through crazy mud.

  16. #16
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    Mass Confusion

    So I cleaned my BB. whats up with all that dirt and water in there?
    It seems to be coming in thru the tubes man.
    I gotta new bb and want to stop the infiltration.
    Are you still confused?

  17. #17
    Elitest thrill junkie
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    Quote Originally Posted by Jaybo
    I think you may find a different opinion.

    Jaybo
    I monitor the formums pretty frequently. I don't see a lot of "problems" with the external bearings. I'm still waiting for you to tell me what the "flaw" is.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  18. #18
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    Quote Originally Posted by consumerbydesign
    So I cleaned my BB. whats up with all that dirt and water in there?
    It seems to be coming in thru the tubes man.
    I gotta new bb and want to stop the infiltration.
    Are you still confused?
    Drill a hole in the bb shell to let it drain out. SpeedNate posted some excellent dirx on how to do this.

  19. #19
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    More Holes? No Thanks

    Quote Originally Posted by Shawn595
    Drill a hole in the bb shell to let it drain out. SpeedNate posted some excellent dirx on how to do this.
    If I went that route,I would glue on the cable thingy on the bottom of the shell and remove the bolt that currently holds the cable thingy on. Got that? Utilize the existing hole.
    But,a big but. I dont want holes. the water is trashing my BB bearings.
    The hollow tubes leading to the shell need to be sealed.
    The shell is not "sealed".
    Everyone says my Isis Am.Classic replaceable bearings will not last very long.
    Ok, so the bike needs to drain. But thru my bearings?
    I`ll be covering up the holes of unused water cages, Under the fork the big hole gets scotch tape. To keep out water and the 100s of grams of dirt .
    The seatpost on mt HT has a hole thats perfectly in line to collect water and send it directly to the BB.
    People look at me funny for scotch taping over my hollow cranks.
    I want a fender that protects the direct assult on the drive train. For a lot of funny looks.
    Who cares ? I do long endurance rides away from the "park" anyways.

  20. #20
    Daniel the Dog
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    Use the search function

    Quote Originally Posted by Jayem
    I monitor the formums pretty frequently. I don't see a lot of "problems" with the external bearings. I'm still waiting for you to tell me what the "flaw" is.
    1) I don't like the wider Q factor. Too wide
    2) Problems with bearings blowing up (use the search function). LBS also said they have seen this in many bikes

    Use your mind and try and lose your typical argumentative approach. Think about it! How much sense does it make to have the bearings outside the BB shell. None!

  21. #21
    Formerly DMR For Life
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    the problem that i see with a new standard is that sales of the new bb's will be not be high enough to offset the R&D costs...ie you have to get a new bike to upgrade and can't just upgrade your existing bike (which we all like to do)
    DMR

  22. #22
    Live 2 Ride
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    consumerbydesign - quit using tape and get a front fender.

    I have 3 bikes that use sqare taper. Two of them is the sealed kind and the other one can be serviced. I've never had a problem with any of the bikes. Keep in mind every one of these bikes has seen ugly nasty conditions and lots of water and mud yet the square tapers hold up fine.

    IMHO Hollowtech 2 was just another Shimano "Lets create a product to fix a problem that dosen't exist" much like Dual Control.
    My Bike: '03 Specialized HardRock FrankenBike
    My Blog: http://http://kona0197.wordpress.com/

  23. #23
    Elitest thrill junkie
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    Quote Originally Posted by Jaybo
    1) I don't like the wider Q factor. Too wide
    2) Problems with bearings blowing up (use the search function). LBS also said they have seen this in many bikes

    Use your mind and try and lose your typical argumentative approach. Think about it! How much sense does it make to have the bearings outside the BB shell. None!
    And you still havent told me what the "flaw" is.

    A flaw is an improperly designed part, or void in metal/casting. This is what might cause something to fail, but when you just say that the bearings have "problems", it's vague and is not pointing out an actual "flaw".

    I don't see many people having problems with the bearings. I see lots of people complaining about certain products from time to time, but I also know that for particular products there are just lots of them out there on peoples bikes, and a few stories doesn't mean it's a bad product or has a "flaw". Original XTR hollowtech 2 cranks had some intial bearing problems, but that was a while ago and doesn't apply today. XT, LX, and XTR bearings are solid.
    Last edited by Jayem; 02-05-2006 at 07:31 PM.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  24. #24
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    Quote Originally Posted by Kona0197
    consumerbydesign - quit using tape and get a front fender.
    Or a rear fender.. whatever. Still a funny post!

  25. #25
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    I have to agree with Jayem that the accusation of flaws sounds vague. I never got more than a year out of my octalink EN72 BB but I have a year and a half on my XT External bearings with no major issues yet. I would hardly say I can feel a stiffness issue at all but the only complaint I have about the external bearings is chainline. Q factor is a non issue for me.

    All of that said the arguement for maintenance is a valid one for me as well even though I have all the tools. I much prefer to work on an external bearing system.

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