Originally Posted by
stuabit
hello, sepo
In the same boat, just wonder what did you end up and experiences?
Hawk ($109+tax) vs c-bear ($185).
c-bear seems a much better deal, ceramic bearings + alum., for less then $70 difference!
No sure if official specialized site, specialized people mentioned good experience with c-bear
http://specialized.desk.com/customer...v-pro-frameset
Reading the thread, is Hawk material therefore acetal copolymer. Quoting rpenmanparker " technical name for a Delrin-like plastic. Not exactly the same thing, but similar. Acetal copolymer should be a bit more flexible and is slightly less expensive. It may not be as tough as Delrin in resistance to impact. "
My question,if Delrin is tougher, already so much problem, will the Acetal copolymer material be even worse.
Praxis solution - if I understand correctly, it is to be pressed onto Specialized supplied Delrin cup, which MUST be loctite secured.
How many sets do we need to fit a shimano to the specialized frame????
C-bear solution - press in, one set, no loctite ("non invasive" definitely) , that is it.
Did I miss anything?
To clear up a few things. First Delrin is a Dupont trade name for Acetal. View them as the same thing. There are many grades of Acetal as well as Delrin.
It appears...C-bear is notoriously lousy about technical descriptions of their various BB's on their website...that their product has an aluminum body.
Their PF30 version for Specialized is 46mm ID and it is a press fit right to the virgin PF30 version of Spesh carbon frame. This IS invasive versus not. Pressing aluminum into carbon fiber isn't widely done in the industry and why PF30 has Delrin bushings.
It is unclear from Hawk's website if their product presses into Spesh 42mm ID PF30 Delrin bushings OR their BB is 46 OD and presses right into the carbon PF30 shell. You would need to contact them to ask them.
In summary you have many options. To me almost $200 for a BB is ridiculous. C-bear's prices are stupid high so they are ruled out.
Hawk for about 1/2 is a better solution. If you want the most solid approach...go Praxis even though they spec a standard BB30 for Spesh version of PF30 which requires Delrin bushings supplied by Specialized. Even if you epoxy the Delrin bushings to the PF30 narrow that Spesh has on its Sworks bike this is fine for a number of reasons. First, you aren't pressing anything with high press into the carbon BB. If you expoxy the Delrin bushings to the carbon frame which Specialized calls for in their spec....now you have very robust composite of carbon and Delrin what won't squeak and the carbon shell will be protected. Knocking out low shear epoxy bonded thin Delrin bushings will do no harm to the all carbon BB. Next, the Praxis BB is not only cheaper....but expands into position and is rock solid. There is no press. So if you want a good cost effective solution this is the way to go.
If you want to effectively mount say a DA crank to Spesh Sworks bike the cheapest approach is:
1. Epoxy Specialized supplied Delrin bushings to all carbon BB shell.
2. Press in good quality BB30 bearings.
3. mount Wheel Mfg adapters which reduces bearing ID from 30mm to 24mm.
4. mount DA crank normally.
The reason anybody has squeaks with the above approach is they don't epoxy the Delrin bushings to the all carbon shell. Above solution will not only give you thousands of miles of solid performance but high quality BB30 bearings are cheap and easy to change versus any integrated spendy solution from C-bear, Hawk or even Praxis.
A last note. Yes DA cranks are great. But me personally if I buy a $4K frameset with PF30, I am going to mount a BB30 crank on it. Design intent. No adapters.
HTH.