I just picked up a Tarmac BB30 framset but I have a 6mo old 9150 threaded crankset. What are my options here? Do I replace the BB with a adaptor for threaded crank and give up the Ceramic Speed bearings or replace the crank? Any other options?

Check out Praxis. I have one on my Tarmac so I could use my Quarq. It's been perfect.

https://praxiscycles.com/product/shi...f30-68mm-road/

So you have a Dura Ace Crank that you have been using on a bike with a threaded ceramic speed bottom bracket? If that is the case, I would keep the crank and get a new BB. You could go cheap with an adaptor or drop a lot of money, if you like ceramicspeed, on a ceramic speed BB designed for use with shimano cranks in a BB30 shell.

If by “threaded crank” you mean Hollowtech II, you have the following options:

- Put 24mm adapters in your BB30 bearings (I think Wheels mfg makes something like this). This is the least preferable but also the cheapest option. It lets you use your current bearings, probably.
- use a thread-together BB from Ceramicspeed, Token, Wheels mfg, Praxis etc. This is the most common option
- the best option, in my opinion, is to get a one piece aluminum bottom bracket from BBinfinite or Hambini. The bearings spin way better, last longer, and creak less. Hambini sells a BB for around $100, which is a lot, but it should last you a very long time and I think it’s a worthwhile upgrade.

I went for the Wheels mfg adapter for the time being. I will probably end up with a screw in adapter in the long term. Big thanks for all the options everyone. I really want to ride that bike today and was successful.

Wow.... So often I read posts of others that obsess over things like this for weeks to months with seemingly no end. It's refreshing to find someone that does whatever it takes at the moment to get their bike in the condition to ride without worrying whether it's the perfect choice.

I have C’dale BB30 and have been tempted to get a bbinfinite, https://www.bbinfinite.com/products/...nt=44403002702

but my bearings just haven’t creaked enough to warrant the $150 cost. I hadn’t heard of hambini, how does it compare (do they even make a sleeve for bb30 shells or do the just do conversions to use 24mm spindles in bb30 shells?)

For BB30, you can do either. Reducers in direct bearings, or a sleeve with appropriately sized bearings. I prefer hambini because he uses standard 25mm bore bearings and a 1mm reducer, which opens up your bearing options a lot. You can get really nice or really economical bearings rather than Shimano specific ones. (EDIT: This is the case for BBInfinite as well.) He claims his BBs are significantly stiffer, which may help with feel, but is mostly for bearing alignment. I’m indifferent to that since I’m quite light. But overall I’d recommend the Hambini one. Those NTN contactless seal bearings spin real fast.

of note: I’m currently using a BB30 to Shimano hambini racing BB. I can definitely feel some extra “eagerness” when out of the saddle, compared to my praxis thread together, which has questionable bearings.

I am intrigued by the smoother bearing and less creaking. But to clarify, I don’t need reducers. I am using a bb30 crank in a bb30 shell. I am just wondering what Hambini and BBInfinite offer for that set up so that I might improve upon the bearing I have pressed directly into the shell. BBinfinite seems to have a sleeve.

Incredible. How did BBInfinite manage to fit a sleeve around a 42mm bearing in a 42mm shell? My only guess is that they’re using nonstandard bearings, or have modified the standard 6806 30 x 42 x 7 bearings. Maybe there’s some gap in my understanding of bottom brackets, but it’s quite telling that Hambini doesn’t have any BB30 sleeves. Only a “bearing kit”.

I would ask BBInfinite what dark magic they employed to achieve this.

EDIT: After 10 seconds of googling: “They took a standard BB30 6806 bearing, which has a 42mm outside diameter, and reengineered the outer race to have a 40.5mm OD, which lets it fit inside their sleeve. That lets them bring their creak-free, perfectly aligned design to a frame design that’s plagued with reliability and tolerance issues. But it keeps the 30mm inside diameter, so you can still run your BB30 cranks.” And this is why BB30 is a mess.

Pick your poison I suppose. Understand that the bearings are probably significantly compromised after you machine away 1.5mm of hardened steel and press it into aluminum. The biggest effect is usually the bearing’s inability to resist deformation in the press-fit housing, thus crushing the balls in the bearing. Also, replacement bearings will be a pain to find - BBInfinite has you by the jewels.

Edit again: I’d recommend going with some quality, fully sealed bearings like these: https://www.hambini.com/bearings/ful...e-bearing.html

I had an email exchange with them a while ago (they were very responsive), wondering if they us smaller balls. Here is what they said..

“We use a custom made 40x30x7 bearing. The balls are ř.125”, actually the same size as the cycling industry 6806 bearing. Some industrial 6806 bearings use an ř11/64” ball.”


Wes

Indeed. I assume this confirms my hypothesis that they simply machined the outer ring to meet their specifications. I can’t imagine how else they’d reach those dimensions while holding ball size constant.

EDIT: They may also have “shaved” material off both the inner race and outer race, which is a much better, and much more expensive solution. However, my point still stands.

This seems consistent with what this industry does when a square block meets a round hole. Or more specifically, when a large OD bearing meets a small OD shell. People try to fit the same 6806 30mmx42mm bearings into 41mm holes for BB86. BBInfinite also makes a BB86 BB for 30mm spindles, which I assume uses a similar strategy.

The following is a novice speculating based on crude internet research: The reason why machining the outer race down causes balls to get crushed is because there is a minimum amount of “retention force” required to keep the bearings from popping out of the aluminum sleeve that BBInfinite makes. This retention force is proportional to the stiffness of the shell, the stiffness of the bearing and the amount of interference between the two. If the stiffness of the bearings goes down, then the interference must increase (slightly) to achieve the same retention force. Also, when you put your body weight on one of these machined bearings, the ball at the bottom will get crushed a lot harder relative to the others in the bearing. This is magnified when the outer race loses stiffness.

However, the biggest reasons for bearings getting shot are misalignment and contamination. Contamination is unaffected by this approach and misalignment is reduced. Like I said, pick your poison.

The specific question I asked was “How does your sleeve solution work with 42mm shells without requiring reducing internal diameter of the bearing cartridge to the point of being too small for 30mm spindles? Are the balls you use smaller than those used in standard 6806 bb30 cartridges?” I couldn't fathom that machining the races down would be a good idea, but, as you say, pick your poison. Hambini’s solution for BB30 shells, near as I can tell based on limited googling, is ensuring bearing cartridges meet very strict tolerances and then installing them correctly (retaining compound, the correct snap rings).

Yep, sounds right. I'd stick to regular BB30 bearings for now. If you ever have the opportunity to get a new bike or frame, stay away from BB30 (PF30 is better, allows for sleeves), BB86 (not compatible with 30mm spindles) and BB90 (not compatible with 30mm spindles or sleeves).
PF30 and BB386EVO (which is just a wider PF30) are the most broadly compatible press-fit shells. PF30 is more compatible than BB386EVO because it allows for narrow BB30-only cranks. However, you sacrifice a little bit of stiffness - especially with longer spindles where the journals (ie, where the bearings load the spindle) sit outside the frame shell. /rant

I have the BB30 frame, Cannondale CAAD10, because my 12 year old C’dale with good ole fashioned threaded BB shell suffered a cracked dropout.To my surprise, C’dale, replaced it under warranty.I went with BB30 crankset...Sram Red..because I didn’t want to mess with adaptors and such, which seemed to cause more problems than they solved. I considered praxis with Shimano cranks at the time...praxis did seem a good design, but decided to go with the lighter option.

In the 3 years and many miles since getting the bike, I have had one bearing seize (almost immediately, I think the LBS that built the frame damaged it when they pressed it in) and very occasional (twice in 3 years) minor creak that so far has been easily cured by taking cranks out and cleaning everything, which is no different than life was with a threaded shell.I keep waiting for the dreaded incurable BB30 creak but it hasn’t happened, and I didn’t even use retaining compound when I replaced the aforementioned seized bearing (ignorance). In fact,I researched BBInfinite last year because I was having a creak that I thought was BB related, but it turned out to be a cracked saddle rail.New saddle, no more creak... although I was drawn to the bbinfinite super spinny bearings, I opted against changing anything. Just about everyone I know with the various BB designs you mention creak a whole lot more than my frame — particularly guys with PF30 shells — so I guess I will keep things as they are until creaks set in or the bike industry decides threaded BB shells were actually a pretty good idea.