|What Titanium BB can I use with Dura ace Octalink Cranks||Jeffatan|
Mar 31, 2003 5:31 PM
|I have had problems finding a lightweight titanium BB that is compatible with the Octalink crankset of a shimano Durace. Anyone know where I can Find one?|
Mar 31, 2003 6:34 PM
|you've had problems because no one else has, to my knowledge, made one. Shimano is the only manufacturer of Octalink BBs right now.|
Mar 31, 2003 7:48 PM
|None is correct. Either you need to get an ISIS crank if you really want to use a Ti BB, or you have to stick to the Dura-Ace BB. It's still pretty darn light. If it makes you feel better, you aren't going to find a BB that is much lighter. The Dura-Ace is 173 grams, for comparison, the FSA Ultimax Ti is 172 grams. The only real difference becomes the 4 grams you will save because the FSA uses lighter crank bolts. So over all, you are looking at 5 grams or so. The lightest ISIS BB I can find is the American Classic, it's 140 grams, but is only available in English threads, so if you ride an Italian frame, you can't use it.
Anyways, point is that the Dura-Ace is about as good a BB as you can possibly get.
|Helpful vision: 5 grams is a teaspoon of water. nm||Spunout|
Apr 1, 2003 6:55 AM
|re: What Titanium BB can I use with Dura ace Octalink Cranks||jocallaghan|
Apr 1, 2003 3:16 AM
|given the stiffness of a dura ace crank, going to a ti bb would not be the wisest thing to do since they have a tendancy to flex. to save weight on the drive train, replace the fixing bolt which hold the crank to the BB with Ti SRP bolts. Replace your pedals with lighter ones.
On top of it..... no one really makes a Octalink BB that is Ti basically for the reasons above.
|re: What Titanium BB can I use with Dura ace Octalink Cranks||russw19|
Apr 1, 2003 10:58 AM
|Sort of true...nobody makes an Octalink Ti BB because Shimano makes companies pay for the license to use their patented stuff (Octalink is a Shimano Patented Design) but there are plenty of companies that make a Ti Spindle in the ISIS standard (free design to use as long as you don't try to modify it without permission.)
And most of the stiffness from a Dura-Ace BB Crank combo is more the BB than the crank. The crank is stiff, but the BB is the key. The use of the oversized pipe spindle and needle and ball bearings on the drive side is what makes the difference. I haven't run the tests, so I don't have the numbers, but I would bet if you tested the combos of D-A crank on Ultegra BB, and Ultegra BB on Ultegra crank, they would be very simaler. As if you did D-A BB/crank to D-A BB/Ultegra crank... I would still bet they are simaler, but higher than the first tests because of the Dura-Ace BB.
The Dura-Ace BB is designed a bit different from the Ultegra and is said to be one of the stiffest on the market.