Afrockalypse

I’m building my first bike! I’m using a Carrera Virago frame, which claims to be « BB30 ready ». The shell has a diameter of 40mm, which seems to suit the DUB BB30 I bought.
when trying to install it, I find that it’s not easy to press into the frame. I’ve greased it well and I’m trying to keep it as level as possible, but I can only press it in a couple of mms. I feel like it will go in if I force it, but I’m reluctant to use heavy duty force.
my question is - how tight are these things supposed to be? Is it normal to be having real trouble pressing it in with my hand?
In pressuring the BB30, I’ve managed to crack the plastic sleeve. Is this a fatal flaw? Do I have to replace the part?
Thanks in advance, and sorry for the newbie questions!

02Giant 

I have one of these https://wheelsmfg.com/presses-tools/...ket-press.html I use on my BB30 install.

A homemade device could be assembled.

Afrockalypse

Ah, a purpose made tool. I might get one of those to do it properly. Thanks!

cpach

It would be impossible to install a BB30 BB in a correctly sized shell by hand.

coupster

Building your first bike is great, building it wrong is not. Get a genuine bearing press with the correct drifts. BB30's are prone to creaking if the fit is even a tiny bit out of tolerance. If you try to press the bearings without proper alignment in all directions, your BB will creak and your bearings will probably wear out prematurely. What's worse is you may not be able to eliminate either because of the DIY installation method.

davidad

The BB30 bearing is 42mm in dia. and a press fit. You can make a tool with a long bolt and washers that are the near the same diameter as the bearing. You can get a 1and 1/8" bolt that will be a close fit and help hold the alignment.

WizardOfBoz

cpach is right: you need a press. coupster's advice isn't bad, but I think you can make your own press out of a bolt (or all-thread, that is, threaded rod available at the hardware store). If you make your own, though, you have to be sure that you have washers large enough to press on the outer bearing race. You really, really want to avoid pressing the outer bearing race in by transmitting force via the inner race and the bearings.

Allthread and washers are cheaper. That said, I've followed coupster's advice and have the proper bearing press with appropriate drifts. And, to be frank, my BB90 is a bit more tolerant as the press fit requires less force (the bearing seat is CF composite and the bearing is slathered up in PTFE grease).

DOS

I have had success with the diy approach but @02Giant’s tool definitely works better.

As for creaking, I have had good luck just using grease on my CAAD10 but some folks swear by Loctite 641 or 609 retaining compound to eliminate BB30 creaks. I also saw recently that Praxis recommends using Loctite superflex silicone adhesive, rather than retaining compound, for carbon shells with some of its BB options.

redlude97

Get the cups for BB30 install and removal https://www.parktool.com/product/bot...-pf30-bbt-30-3
Then build the press out of a lag bolt and washers/bolts from the hardware store. Get some loctite 609 as suggest above, press the bearings in and leave the press in place while the loctite cures overnight

cpach

redlude's suggestion is a reasonable middle ground. I'd feel sketched out installing a PF BB in a carbon shell without a real, appropriate drift to help center the press, but there's nothing that magical about the press itself, so DIYing that part would be totally fine.

Bearing retaining compound can help, particularly for BBs that press a bearing directly into carbon without any kind of delrin cup, but really a lot of creak problems are mostly poor frame tolerances, which is really still too common in the bike industry.

sch

One other approach is to put the shell in the freezer for 30-60 minutes before install. It will shrink enough to
reduce the force needed. Helps to have everything ready to go when you take it out of the freezer.
The plastic shell is mostly weather protection from stuff coming down the seat/down tube and to deflect any
cable housing/electrics away from moving parts. If electric wires go through the area the crack is not a problem
but it would reduce the weather protection slightly. Not a real problem either way if you can put the crack
at the bottom.

Note: don't put the plastic part in the freezer, only the metal parts. FWIW I used this method to hand install
a 30mm crankset spindle into a 30mm BB which would not go in by hand at room temp but was a slip in fit
after the freezer treatment which suggestion I found on a boutique BB manufacturer site.

bikeme

I made my own press as described from a long bolt and washers and it worked fine 2x. However, on the third time I used it, the smaller washers I'd glued on as pilots for the ID of the BB shifted causing the spacer between the BB to misalign and it ended up shattering inside the BB shell. I then had to pound out that new BB, ruining it. After buying another new BB, I had the shop do it for $10. In summary, it's better to buy a proper press if you do a lot or just have your LBS do it for a few $ if you only do one now and then.

cpach

You're lucky you broke the BB and not the shell--which is the more typical failure mode if the shell is carbon.