What do you have against Dura Ace and 105?
105 was fine. the DA ones supposedly had poorer seals but if you were diligent about regularly servicing the bearings i.e. every 3 months or something like that then they were great.
It’s hard to beat the old Shimano Ultegra bottom bracket (pre-outboard bearings).
Yeah…too bad they don’t make them anymore. 
But, Al knows how to rebuild them. He got the instructions from the guy who “upgraded” one of his old Ultegra BBs to ceramic. You can always just rebuild it with regular balls, no?
Besides, you can still get both the BB-5500 (105) and BB-7700 (DA) bottom brackets…I actually prefer the 7700 due to it’s more “logical” design. Yeah, I know, you actually have to “adjust” it…but when it’s adjusted correctly it’s pretty sweet.
What do you have against Dura Ace and 105?
Dura-Ace: not (as well) sealed, thus requiring periodic maintenance (for which I don’t have time).
105: haven’t tried one, but I’ve alway assumed that the black spindle was more susceptible to rust (although reading just now, it claims to be chrome-moly).
I’m with on you on DA, that was pretty much junk from the get go. (Or, I suppose, to be fair, very high maintenance).
The rust issue with 105 never occurred to me. It was never a problem I saw as a mechanic, that’s for sure.
Really though, the outboard bearing cranks are so much eas to deal with and the BBs so much cheaper, I really don’t miss them.
You guys might want to consider an outboard bottom bracket with Phil Wood’s new “Carbonyte” bearings. They are steel bearings and won’t crack like the ceramics. Phil Wood has been working on this project for 25 years. It’s all about optimizing the tolerances between the balls, races, and seals. And of course, a very special lubricant.
Without a chain on the cranks, they actually pendulum back and forth until they lose momentum and settle straight up and down. Even the Campy Super Record cranks/bottom bracket won’t do this.
They are available for Shimano/FSA (black anodized) or SRAM cranks (red anodized).
105 was fine. the DA ones supposedly had poorer seals but if you were diligent about regularly servicing the bearings i.e. every 3 months or something like that then they were great.
Puh-leeze…every 3 months? Hardly.
I had my one on my road bike for over 2 years before it ended up needing any service…and that was most likely because I had re-installed it at one time and didn’t get the preload set exactly right (dumb mistake on my part) which ended up damaging the races. The good news is though, the races for the ball portion (the BB is a mix of needle bearings for the radial loads and smaller than normal balls for the axial loads) are replaceable and available as spares. 
You guys might want to consider an outboard bottom bracket with Phil Wood’s new “Carbonyte” bearings. They are steel bearings and won’t crack like the ceramics. Phil Wood has been working on this project for 25 years. It’s all about optimizing the tolerances between the balls, races, and seals. And of course, a very special lubricant.
Without a chain on the cranks, they actually pendulum back and forth until they lose momentum and settle straight up and down. Even the Campy Super Record cranks/bottom bracket won’t do this.
They are available for Shimano/FSA (black anodized) or SRAM cranks (red anodized).
Sigh…all that to save another milliwatt…literally.
As others have mentioned before, it’s more about knowing that you have done everything possible to make yourself faster.
As others have mentioned before, it’s more about knowing that you have done everything possible to make yourself faster.
I prefer to concentrate on the things that actually matter…but, maybe that’s just the engineer in me 
.
When I put together a new race bike for Harriet Anderson to ride in Kona this year, it will have Carbonyte bearings without seals installed in the bottom bracket and hubs.
Why?
So she will push a little harder when she is trying to beat the age group record.
I’m with on you on DA, that was pretty much junk from the get go. (Or, I suppose, to be fair, very high maintenance).
Junk? I don’t think so…it’s actually one of the most logically designed BBs produced.
I think it got a bum rap, especially from mechanics, due to two things: First, as I mentioned before, you have to set it up properly…which after mechanics had been spoiled by years of installing the the “crank it in and go” cartridge BBs was something not likely to happen correctly. Second, about that same time pressure washers were introduced to the pro mechanic’s “tool kit”. Why do you think the first generation of outboard BBs had such heavy seals? I find it humorous that this development most likely spawned the whole “ceramic bearing” hype…too funny.
When I put together a new race bike for Harriet Anderson to ride in Kona this year, it will have Carbonyte bearings without seals installed in the bottom bracket and hubs.
Why?
So she will push a little harder when she is trying to beat the age group record.
Just out of curiosity, but what tires and tubes will that bike be sporting?
In the December 4, 2006 issue of *Velo-News *there is a very nice article on page 40 by their technical editor Lennard Zinn. In the article Zinn compiles a chart of test data that compares the rotational resistance of, among others, an FSA Mega EXO steel ball bearing bottom bracket as compared to the same bottom bracket equipped with ceramic bearings.
His test results reveal an end result of **.09 **(nine one-hundredths) of a watt difference in rotational resistance. For the remaining results see the chart and test protocols on pages 41 and 42 of that issue.
I believe that article also showed that the square taper bottom brackets took less power to spin than the external cup BBs. But again, we are talking 1/10ths of watts here. At most.
Another way of looking at it: if total drivetrain losses are something like 10 watts, and assuming generously that the BB accounts for half of that, the 4% saved with ceramic bearings is 0.2 watts.
Rik
External cups allowed for larger bearing and wider axle support. The larger diameter bearing adds a lot of durability, and the outboard design reduces flex, and the overall weight reduction for the BB/Crank is fairly large. All-in-all it’s a better design, but it doesn’t reduce wattage needed to spin the cranks when the bike is on a workstand.
Someone can easily improve the smoothness of any bearing set (in ideal conditions) by removing the seals…but I wouldn’t recommend it.
Just out of curiosity, but what tires and tubes will that bike be sporting?
**
**
We haven’t decided if she will be using clincher or tubular rims yet, and consequently haven’t decided which tires would be fastest.
Do you have any recommendations?
Just out of curiosity, but what tires and tubes will that bike be sporting?
**
**
We haven’t decided if she will be using clincher or tubular rims yet, and consequently haven’t decided which tires would be fastest.
Do you have any recommendations?
Yeah…I recommend you guys spend more time on those selections than removing seals from bearings 
I understand that tire and tube selection is a hundred times more important than bearings, that’s why I asked for your advice.
I understand that tire and tube selection is a hundred times more important than bearings, that’s why I asked for your advice.
Probably more like 1000X more important…literally.
- Clinchers. Triathletes can’t “weld” their tubular tires on like a road racer or TT’er can get away with since they need to be able to “field change” in case of a flat.
- Latex tubes in tires, butyl for spares (with CO2 inflator…oh yeah, practice beforehand
- If 19mm wide rims, Bontrager AeroWing TT 19c. If 23mm wide rims, Bontrager RXLPro23 or Specialized S-Works Mondo “Open Tubular”.
External cups allowed for larger bearing and wider axle support. The larger diameter bearing adds a lot of durability, and the outboard design reduces flex, and the overall weight reduction for the BB/Crank is fairly large. All-in-all it’s a better design, but it doesn’t reduce wattage needed to spin the cranks when the bike is on a workstand.
Someone can easily improve the smoothness of any bearing set (in ideal conditions) by removing the seals…but I wouldn’t recommend it.
DA went from 770g to 740ish, Record from low 700s to just under 700. Hardly large reductions in weight
REcord UT bearings durability no where near as good as old bbs. Have seen no evidence of SHimano external bbs being more durable than octalink - if anything I’d say they’re less so. Certainly FSA MegaEXO far less durable than octalink or campy taper.
No performance advantage from the increase in stiffness. Measurable performance detriment in terms of bearing drag. Plus many of the ext designs have much wider q-factor which is a pain for some. I’m not seeing many advantages to external bbs.
Just for argument’s sake, let’s pretend that Harriet isn’t concerned about flatting and changing a properly glued tubular tire.
Is there a tubular tire that would be as fast as the Bontrager or Specialized clinchers?