Campag4life

Robert..
Lets say the OP is big and strong which he is. He puts more stress on the BB.
Let's say he is crappy at maintenance which he likely is and joins 80% of the 41 in this regard.
Let's say he rides in all kind of wet weather wicking water and dirt into the BB.

I don't think him wanting to change to a steel frame bike with BSA BB is out of line. I tend to agree with him. Yes, he could make carbon work with more vigilance, but he isn't vigilant. I would say many struggle with maintaining their pressfit BB on this forum as reported. Not the guys that know how to maintain it...but there is a large subset who don't.

To me, an external bearing BSA BB is probably more trouble free than press fit. A DA or Campy UT crank with external bearings...both are highly reliable.

Nothing wrong with a nice high end steel bike build spec'ed for a stronger cyclist. Yes it will weigh a bit more than carbon and perhaps even flex a bit more in torsion but it should last a very long time and a bit extra weight is not an issue for a very strong rider. I ride with guys on all kinds of materials including fast guys on steel. Most are on carbon but not all...Al and Ti as well. All good and people have difference preferences. BTW, my personal favorite is a carbon frame with BSA BB...what I ride.

PS: Here's a pretty cool vintage flashback. Scott is built very different than the OP but still a cool look back:
https://velonews.competitor.com/2015/...serotta_368495

rpenmanparker 

^^^

I was just trying to lighten this up a little bit. And I agree that the BSA BB with external bearings is the best plan. Right now that is all I ride. But his record of frame destruction as related here goes beyond BB maintenance. I wonder if any of those frames had BSA BBs like yours. That would be interesting to know.

rpenmanparker 

Nice video.

Campag4life

Scott is a cool guy and a nice look back in time. I totally get his nostalgic fondness for his first pro bike...a reminder of many happy times I am sure. Bet he rides carbon today however and no doubt he is still fast...he looks fit.
Also his comments about his talent resonated with me. He said he was a middle of the pack crit rider but shined climbing with his slow twitch...

Other thing the OP could do is buy a BB30 or PF30 bike, insert a collet BSA sleeve aka Praxis and regress it to BSA and run a DA or Campy crank. The problem with Cervelo and Trek 86/90mm BB shell widths is you can't regress them to a threaded BB and run the bearings outside the shell...so you are stuck with pressfit and if unattended to, in harsh conditions, it ain't gonna be a happy ending. By contrast a BB30 frame turned into BSA via Praxis would likely be robust and offer the stiffness the OP needs. Both DA BB's and Campy bearings run inside threaded cups are very robust. But the OP may indeed be done with carbon. Since carbon is more pressfit than BSA by a long shot, likely the OP has struggled more with the BB type than frame material. Technically carbon is stronger than steel...and lighter.

rpenmanparker 

I have asked this before, but don't think it has been answered. Can you comment on why the bearings pressed into the threaded cup are more robust than pressed into a metal BB shell liner? It seems so superficially similar. Is it the higher precision of the fit and "squareness" of the cast, forged or machined, threaded cups?

Campag4life

Number of reasons and by virtue of you asking, shows you are ahead of the curve in thinking about the difference.

Essentially 3 reasons and lets compare an Ultegra/DA threaded BB to say BB30 bearings pressed into alloy bores insert molded into a carbon shell.

1. DA BB bearings are captured in 3D. They are enclosed/encompassed by cup casing. This difference from BB30 in that bearings simply are retained circumferentially by interference (and/or Loctite) along their outboard edge and against circlips as a locating shoulder. This is significant. DA bearings aren't going to move within their cups. Nowhere to go. With BB30, if the press is less than decent and/or Loctite isn't used, the bearing can cock. Likely part of the problem with the OP is he is so strong/weighs so much out of the saddle if his bearings aren't installed properly, i.e. low press, insufficiently seated,no Loctite, too little preload, the bearings will cock and fail prematurely.

2. Second reason relates to 1. What is the biggest detriment to pressfit? It isn't the design. Its the guy installing it and/or not maintaining it. This isn't relevant with a captured bearing threaded cup BSA BB like DA. Bearings are machine pressed then captured at the factory. Translation? Better retention of the bearings and much better control. Human error with pressfit with only the edge of the bearing outer race retained is the opposite.

3. Sensitivity to contamination. DA BB's are sealed better than just about any press fit BB out there...narrow or wide shell. Btw, Campy Record and below UT cranks do a good job also in sealing provided they are greased sufficiently. SuperRecord does not use internal seals to minimize drag at some detriment to sealing. Thought there is, guys who ride SR, can afford to have their BB properly serviced.

HTH

rpenmanparker 

So based on what you say about the machine pressed cartridges in a new set of BSA external BB cups I am thinking you don't recommend punching out the bearings to replace them. You would suggest buying the whole new cups and all? I can't remember looking, but I'm assuming there is enough of the cartridge exposed at the back of the cup to push it out.

colnago62

The problems I have with cycling equipment is not uncommon to large track sprinters. Many of my friends have had similar issues. I have ridden steel for years. In between the Kestrel and the Trek was a steel Colnago that really liked.
My track bike is made of steel. It uses a rear triangle designed for a tandem. I ride with steel handlebars. I am at the far end of the spectrum in terms of build needs.The top sprinters of today all ride carbon frames. Those frames are much heavier than the same sized road frames made of carbon.

colnago62

C4life is correct. The only durability issue I have had with this frame has been the BB bearings. I do ride in all conditions. The tech. guy for Trek mentioned that there might be something on the inside of the BB area out of line. If it does turn out to be a manufacturing issue, I would keep the frame. Pressing in bearings once every 1,000 miles I wouldn't have a problem with.

Campag4life

Bearings in BSA external BB cups are not designed to be replaced. Cups are disposed of when bearings are spent. This adds a bit to the cost of maintenance versus replacing BB30 bearings at 7 bucks a pop. But...lets call it a reliability cost. For all intents there is virtually no difference between an Ultegra and DA BB threaded cups with integrated bearings. Replacing Ultegra BB cups is not expensive and likely bearings will last longer than BB30 because of better sealing. So for the average guy who doesn't want to mess with Loctite, an external bearing BB is probably easier.

Campag4life

To me, your 'tech guy' is out to lunch. For a big high watt rider like you colnago, its all in the set up. The frame and BB bores can become ruined by improperly installed bearings and lack of maintenance when under the stress of high pedal forces. The frame probably started life out ok and it could be argued it wasn't the frame's fault for what happened. Up to Trek to decide if they are going to replace it. You mentioned oversize bearings in a previous post. If proper inference was exceeded by using over sized bearings, this will spoil the alloy bores in the BB shell of the frame for example. Devil is always in the details.

rpenmanparker 

That's good to know. Thanks. I'm riding all FSA cranks and external cup BBs. The oversize BB386 Mega EVO cups that I am using on two bikes are a little more pricey than the 24 mm Mega EXO ones, but you are right. It is worth it. Besides, I am not sensing any replacement need at present. Thanks again for the information.

Stucky

OP, just curious: Have you had bikes with square-taper BB's? If so, howe did they work out for you?

RogueRadio

inb4 OP is drunk

colnago62

Square taper bottom brackets have worked well. I bent a Dura Ace one once, other than that, never a problem.

colnago62

And you are stupid. In the morning, I will be sober and you will still be stupid.

colnago62

He is not my tech. guy, he works for Trek. I think he is in charge of the west coast. The oversized bearing is the fix that Trek came up with for shell wear issue.Up till now Trek hasn't seen the frame. We will see what their final conclusion is. I am pretty sure he is more knowledgeable about this Frame than anybody on the forum. He will also have the added advantage of actually see the damage, which no one here can do.

Campag4life

I know what the oversize bearings are for. The point is, they can be used abusively and spoil the frame. Did your Trek BB expert install the oversize bearings? No. So who did? Some bike shop jockey that thought this may be the best approach?...which leads back to the point. People with limited understanding of physics tend to think in binary terms...good versus bad. This isn't reality. Physics is made up of many elements. There isn't good versus bad press or interference fit. What is the line of demarcation between proper use of oversize bearings? .001" interference? Slip fit? .00001"?
How about bore eccentricity? How about bore cylindricity? Your bike shop tech probably doesn't even know the difference any more than 99% on this forum don't. If I were to pose a basic design question like, which plane is more prone to bore wear due to your high pedal forces, most here wouldn't know. Oversize bearings can be problematic if improperly assessed. Using standard size bearing with Loctite for example will provide more longevity. Oversize bearings with too high a press will fail prematurely. Lack of bore cylindricity will make oversize bearings prone to cock and spit out and fail...especially with insufficient crank preload under high pedal forces. Basic physics that goes well over the head of most undertrained techs.

Many times bikes and throw cars in the mix are ruined by people and not the flaws in their design. Designs are tested under extreme conditions.
Good luck with your replacement.

I will help you look into the future a bit for example. Lets say you get a frame replacement and stick with your current shop. History is going to repeat itself. By contrast, lets say you lived near me and I looked after your BB maintenance. You wouldn't have any problem. Why is that? Same bike. Its because of how the bearings and BB is installed and maintained. For a guy like you, Loctite is pretty essential. Without it, the bearings are going to cock over time, you will get bore wear (lack of cyclindricity) and use of oversize bearings to bandaid worn bores will only make matters worse because of bore taper induced by the rocking of insufficiently seated bearings due to your high pedal forces. Unless your BB has the correct support, best to move on with a bit less demanding BB like BSA with threaded cups and captured and better sealed bearings. Hope that makes sense.

Stucky

Ah, thanks. Just what I figured. All the plethora of modern BB's, and they're all a "solution" to a problem which didn't exist. I could see if they had wanted to play with that design, and just make them a little stiffer without adding weight [or maybe just have heavy-duty ones available- even if they were to weigh a few ounces more, I'd guess guys like you wouldn't sweat it]- Heck, at least even if you'd bend an occasional square-taper.....at least it didn't ruin the frame.

colnago62

The over size bearings came directly from Trek USA. Bearing installation was looked at originally as a possible problem and dismissed. More than one Trek dealer has installed bearings in the bike. It hasnt been the same person every time. The individual at Trek dealing with this is the technical director for shops on the West Coast. I know this because that is what the bottom of his email states. I am sure whatever the problem actually is, Trek will figure it out. If it sounds like an issue that might reoccur, I will start looking at going to a custom frame.

I took another look at the email. My contact person at Trek is In charge of the whole division for Trek. He has done a good on trying to make this right. He had the frame expedited to Trek. I get the feeling there is a process of least expensive to most expensive fixes for this issue. Step 1 is oversize bearing. Step 2 is resurfacing the bottom bracket. Step 3 Is replacement. That also makes the most businesses sense.

RoadTire 

There, I learned something.

BoSoxYacht

IIf you are thinking about getting a custom frame built, be prepared for Campag4Life to tell you about how inferior they are to high quality carbon frames from the mass producers.

rpenmanparker 

Me too. I'll join in that conversation. Anything to warn the masses about cyclings many pitfalls.

BoSoxYacht

I wish my builder would get off his ass and build my frame, but for the price($0.) I can't complain. His wife has had brain tumors removed, and chemotherapy, so I understand why things are getting a bit backed up.

rpenmanparker 

Thst's too bad. I know you are anxious. Hopefully it will come through soon.