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Question of the day...
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Though we will not ever see (probably) in the Tri bike genre.....

How many "styles" of Bottom Bracket are there? Does anyone know what sets one apart from the others?

I think to be fair I would exclude the Phil Wood BB as it will fit into any of the styles that are available (with the cutting tool).

There is one style of BB that was proven to be not very effective at keeping your BB in the frame. Why was this and what style was it?


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What if the Hokey Pokey is what it is all about?
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Re: Question of the day... [Record9ti] [ In reply to ]
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IMHO it's tough to beat the Shimano Ultegra sealed cartridge bottom bracket. Totally dependable and smooth running. Not very light, but good for most triathletes who don't maintain their own equipment.

Tom Demerly
The Tri Shop.com
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Re: Question of the day... [Tom Demerly] [ In reply to ]
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I second Tom's opinion in every way.

1st Place, 50-55 2018 USAT Duathlon Sprint Duathlon National Championships, National Champion; 2nd Place Overall, 2018 Virginia Duathlon; 3rd Place, 50-54, 9th overall, USAT Long Course Duathlon (Miamiman); 4th Place Masters, 10th overall, 2018 Kiawah Island 1/2 Marathon
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Re: Question of the day... [TriBriGuy] [ In reply to ]
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This was a "style" question - not a "brand model" question. For instance - the Ultrgra BB is made in Two Styles....Though there are more

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What if the Hokey Pokey is what it is all about?
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Re: Question of the day... [Record9ti] [ In reply to ]
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I'm no wrench-head but, I like to research stuff, so here goes. There's lots of information at Sheldon Brown's web site: http://www.sheldonbrown.com/

There are British, Iso, Italian, French, Swiss, Raleigh and OPC or Ashtabula style. They also come in different numbers of threads per inch. The problem lies with the French and Italian which have the right fixed cup threaded in the wrong direction so they tend to unscrew themselves during use.

Richard
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Re: Question of the day... [Record9ti] [ In reply to ]
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While there are a series of different bb types that have been used over the years, the only one in real widespread use is the British, or ISO (of course this makes sense because ISO stands for international standard). Because the right cup is left hand threaded and the left cup is right hand threaded, the force exerted by the bearings on the bb shell serves to slightly tighten rather than loosen the bb cups. A few hyper-traditional italian road frames may still have the italian style, bb both cups right hand thread. This is really not a problem because if a builder is foolish enough to still use an italian bb shell you probably don't want the frame anyway.

More interesting is the return of the perenial interest in press fit systems in mountain and road bikes. Cannondale is already using an oversized shell/press fit bearing combination in their high end road, tri and mountain bikes, while FSA is pushing a standard (ala ISIS) called mega tech www.oversizedbb.com. Of course press fit bb's are nothing new Klein tried it a while back and it is the method of choice for most BMX bikes. The big advantage is the use a larger diameter aluminum spindle to reduce weight and add stiffness. There is also the advantage of an increased weld area on the larger bb shell and larger more durable bearings. The big problem is istallation issues, special tools and a need to have a perfectly faced bb shell. Ironicly just as press fit systems are gaining popularity for road and mountain, the hard core BMX riders are abandoning them for the easier and more reliable ISO bb (or EURO as they call it in BMX).

Hopes this helps
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