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Sealed or non-sealed bottom bracket(18 posts)

Sealed or non-sealed bottom bracketcbruce
Apr 7, 2003 7:15 AM
I am looking at dura ace components and have heard that I should get an Ultegra bottom bracket because it is sealed and the Dura Ace is not. Is this true? Also I ride in Colorado is something I should be concerned about or does it not really make a difference?
not true...C-40
Apr 7, 2003 7:49 AM
The only BB that may not have some sort of seal would be a special type for track use. All others will have bearing seals.
While technically true,TJeanloz
Apr 7, 2003 9:42 AM
The Dura-Ace bottom bracket (BB-7700) does not use "sealed bearings" but it does have "some sort of seal". As I understand the term (and I believe it is generally understood), a "sealed bearing" is an integrated unit which includes bearings and races, and is generally not intended to be rebuilt (though rebuilding can be done). The Dura-Ace bottom bracket uses a combination of needle and ball bearings with a standard cone -- if you take it apart and shake, they'll all fall out in your hands. It would be innappropriate to say that the unit is not sealed, because it has a rubber gasket on the outboard side of the cups "sealing" the whole unit from grime. It would also not really be appropriate to say that BB-7700 uses sealed bearings. Confusing, but true.

If routine BB maintenance isn't something that you like, the Ultegra (BB-6500), or Dura-Ace Track (BB-7710) use sealed bearings, which require much less maintenance, and are much easier to install correctly. The Ultegra is the lighter unit, because it uses plastic and aluminum where the track model uses steel.
Apr 7, 2003 10:42 AM
The Dura Ace BB is a cup and cone bearing system, while every other Shimano BB has sealing bearing. The Dura Ace BB needs to be set so that there is no bearing play, while the other Shimano BBs are insatlled without needing to deal with bearing pre-load.

If you need to save the 90g (or whatever the difference is), the Dura Ace is the way to go. If you want a service-free easy to install BB go Ultegra.
Apr 7, 2003 1:40 PM
I know this will draw a flame or two, but.....
The seals on the Dura-Ace bearings are just as good as the seals on the cartrige bearing of the Ultegra BB. It's just that you can rebuild your Dura-Ace if you like. With the Ultegra, it's a one shot deal. When it passes on to the afterlife, you pull it out and toss it. With the Dura-Ace you can rebuild it if you like, or you can replace it...but to be fair, the seals are just as good as those on the Ultegra. Just don't submerge the bottom bracket under water or spray a high pressure hose directly at the seals. That will kill ANY bottom bracket.

The bearings on the Dura-Ace will NOT fall out if you shake it, they are in retainer rings and double sealed. You have to pull the cup out of the frame, pull out the inner seal, then pull out the bearing retainer to get to the bearings. (ask me how I know all that) but it's not going to just spill out on the floor unless you did something wrong when you put it in, like remove the seals.

The Dura-Ace bottom bracket is very light (near the weight of a good Titanium BB) and is very stiff (due to the addition of the needle bearings that the Ultegra doesn't have) and by high end bottom bracket standards, it's pretty cheap. However to be fair to the Ultegra BB, the ultegra is maintainence free (only because you can not fix it even if you wanted to) and it's cheaper than the Dura-Ace. I have a Dura-Ace BB that I have about 30,000 miles on and it's still as smooth and trouble free as the day I bought it.

I am not knocking the Ultegra BB, it's a fine bottom bracket. It's simple, it's strong, and it's fairly light. What I am knocking is this misconception that it is any better than the Dura-Ace bottom bracket. If you are unsure of how to adjust a bottom bracket, take it to a shop with mechanics you trust and have them set it up right. If it's done correctly, you will never have a problem with that bottom bracket.

I am of the opinion that somethings on a bike shouldn't be disposable. Cables and housing, yes. Bearings and frames, no. That's the same reason I am against Integrated bearings in headsets. Somethings should be adjusted to work correctly. Bar tape should be disposable, not bottom brackets.

You know, it's funny that the biggest complaint about the Dura-Ace bottom bracket is that it's servicable. The lack of Shimano parts being servicable is the biggest reason pro-Campy people tell you they hate Shimano, but it's the servicability on the Dura-Ace Bottom Bracket that draws out the biggest criticism.

or just install a D/A track BB...merckx56
Apr 7, 2003 4:46 PM
and forget it. It has the same ball and needle bearings as the regular "serviceable" D/A BB but it's all completely sealed. The non-drive CUP is removeable but the drive side does not come off. The drive side cup and the non drive lockring are steel. No more stripping the threads when removing to service...oh that's right, it's completely sealed, so you don't have to service it! They are about $5 more than a regular D/A BB. Ultegra only have one row of bearing per side.
Bottom brackets are cheap. If there's even a hint of a rough spot when it turns, it gets sh*t-canned. Screw taking the time to service it! I'd rather spend that hour out riding!
or just install a D/A track BB...russw19
Apr 7, 2003 9:03 PM
OK, now this I can buy... but I am getting sick of the BS that an Ultegra is just as good. Blah blah blah.... it's a load of crap the Dura-Ace is better, but some people don't want to do the work of rebuilding it... that's cool, I can understand that.. but to use that as an excuse for saying the Ultegra is better....

I'll defend the Ultegra...TJeanloz
Apr 8, 2003 7:53 AM
The Dura-Ace BB (7700) is probably the best pro-level bottom bracket on the market today. It is a phenomenal unit. Stiff, light, high quality bearings. It is great if you love to work on your bike or have a professional mechanic who has college-aged kids to support. It's also good for fair-weather riders who get out for 2000 miles in the summertime, and never in the rain or snow.

My experience at the shop has been that the vast majority of people who buy Dura-Ace bottom brackets would be better served with an Ultegra unit. Of all of the rough bottom brackets I have ever seen, at least 75% of them were DA7700. Some people aren't anal about their bike maintenance. They wash their bike at the car wash. For these people, the Ultegra is a better choice. I have a bike built up with Dura-Ace, and it has a 7700 bottom bracket. I built up a bike for a non-riding friend who wanted to get into the sport with all Dura-Ace except an Ultegra bottom bracket. What's the best for you isn't the best for everybody.
I won't...merckx56
Apr 8, 2003 9:47 AM
I used blow up an Ultegra BB about once a year. I had two in two different bikes and both have been replaced not long ago. For some, Ultegra is fine, but if you put in the miles and are a bit rougher on equipment, buy the D/A track unit. The single rows of bearings in the Ultegra unit just seem to break down more quickly. The Ultegra in my cross bike didn't last 2000 miles over the winter.
Apr 8, 2003 9:56 AM
That's interesting, it just goes to further the argument that different people have different equipment needs. I'm sure I have some Ultegra bottom brackets with more than 25,000 miles on them. But I'm a lightweight, and I'd guess that somebody with more weight/power would go through them faster.
Apr 8, 2003 11:23 AM
Hey TJeanloz, I have never, nor will I ever, argue what is best for you or anyone else. My arguement is that the Dura-Ace is better. Not better for you, not better in dry weather... not better under certain circumstances like you have a good mechanic, just better. It's a whole new arguement when you say the same thing I did about spraying it with water at the seals (you mentioned people who wash their bikes at the car wash... that's an extreme circumstance that will kill every bottom bracket and I mentioned that in my post)
I know some people out there don't want to do maintainence on their bottom bracket. For that point, it needs to be said that the Ultegra is a better OPTION, but you can not use that to say it is a better bottom bracket. You can arrgue that it has a better cost to value ratio if you like, but that's not saying it's better. That was my point originally. Too many people confuse these types of reasons for buying an Ultegra bottom bracket over the Dura-Ace and then mistakenly try to use that as a claim that the Ultegra is better. It's not. It's a use and forget BB, but that doesn't make it better. You don't have to adjust the Ultegra, but that doesn't make it better.... do you see my point?

I see yours. But better for you doesn't equate to a superior product. That's my arguement, not that it matters.

I see your point, but what is better?TJeanloz
Apr 9, 2003 10:30 AM
I think I also made it clear that the Dura-Ace bottom bracket is probably the best performing BB currently in production (though soon to be out of production). But I disagree that there are any superior products in the cycling industry. At the higher-end, different models serve different users better, and things like cost and maintenance can't be eliminated from consideration. I don't think there are any products that are universally the best; and the DA bottom bracket is not without certain drawbacks (which, for you, are insignificant).
Let's argue semantics..Niemand
Apr 8, 2003 5:02 AM
I have to disagree here, I have always understood the phrase 'Sealed bearing' to mean that the bearings are sealed in some way against water/crap etc. Thus the Dura BB is a 'sealed bearing' BB and may legitimately be described as such.

What you describe is what I understand to be a cartridge bearing, where the bearings are inserted as a sealed unit (as on the Ultegra BB.) I have also heard the term 'sealed bearing unit' used to describe cartridge bearings which just confuses matters further. Of course the bearings in the cartridge unit are simply 'sealed bearings', though the seals are a lot better average.

Other manufacturers of say, hubs or headsets, tend to make it clear whether bearings are cartridge units or sealed, so I don't know why such a distinction isn't more clearly made when it comes to BBs.
That is an excellent point,TJeanloz
Apr 8, 2003 7:44 AM
The "cartridge bearing" concept had slipped my mind when I wrote the previous post, but I would generally agree with your assessment. I concur that cartridge bearings are sometimes called "sealed cartridge" or "sealed bearing units".

As I pointed out in the above post though, the seals on the DA are relatively worthless, and the Ultegra is certainly more sealed than the DA.
Shielded Bearings?Niemand
Apr 9, 2003 12:25 AM
I can't comment on the worthiness of DA vs Ultegra BBs since I have no experience with either, but agree that a cartridge unit is almost always going to be more sealed than a 'sealed bearing'. Wandering off topic a little I have a pair of Mavic 501 hubs with cartridge bearings that are about 10 years old and still are super smooth with no attention.
Perhaps it would be better if 'sealed bearings' were referred to as 'shielded bearings' which is a more accurate description of the degree of 'sealing'.
While we are on the topic...koala
Apr 7, 2003 2:52 PM
Is there any advantage to a ti bottom bracket besides weight? Is there a stiffness disadvantage that matters to most riders? Thanks

While we are on the topic...laffeaux
Apr 7, 2003 3:42 PM
The only advantage is weight. The disadvantages are stiffness and price. I was going to buy a TI BB for my MTB until I found out that it was three times the cost of a tapered XTR BB (which is what I bought).
While we are on the topic...russw19
Apr 7, 2003 9:09 PM
There was a thread about this question about 2 or 3 days ago. You won't find a Ti spindle bottom bracket to fit the Shimano Octalink spline pattern. You can find a Ti BB in the ISIS pattern, but that won't fit your Shimano cranks. I ride ISIS cranks and BB. My bottom bracket is the FSA Platinum Pro Ti BB. It's the best thing they make. It's about 5 grams lighter than the Dura-Ace when you factor in the alloy crank bolts, otherwise it's 1 gram lighter. If you have english threads you can use an American Classic BB, which is about 30 grams lighter than the Dura-Ace. But the catch is you have to use an ISIS splined crank. The Dura-Ace BB is one of the nicest BB's on the market right now. It's stiff and smooth, lasts, and is rebuildable if that is a quality you are looking for.