BBDUB

I'm building my first bike and could use a little help on the BB I need to purchase. The frame is the CAAD13 requiring a BB30
The BB shell measures 73mm. I'm building with SRAM and plan to use the DUB BB.
When looking I see what I think are two choices.
SRAM DUB BB30A 73mm
or the
SRAM DUB BB 42mm x 68/73mm
Which one is correct to use?

Thanks in advance for any advice/help

Crankycrank

Contact SRAM & Cannondale. They can give you an accurate answer. Cannondale has been known to make some of their BB shells with special fitting needs for different BB's.

bitpuddle

CAAD13 has a BB30A bottom bracket shell; you’d need the BB30A bottom bracket.

smashndash

Bingo. BB30A is asymmetrical. Not the same as 73mm MTB BBs.

BBDUB

The Cannondale site specs just BB30.
After reaching out to them they came back with this BB, SRAM DUB BB 42mm x 68/73mm

smashndash

Frame
All-New, SmartForm C1 Premium Alloy, direct mount rim brake, integrated cable routing w/ Switchplate, SAVE, BB30a, 142x12 Speed Release thru-axle, Di2 Ready

https://www.cannondale.com/en/bikes/...ku=c13250m1044

your crank will be a few mm off if you get a standard BB30 BB. it’ll install fine. You’ll probably get crank strike on the chainstays though.

BBDUB

Well horse crap if that’s how it works out. I ordered the SRAM DUB BB 42mm x 68/73mm based on Cannondale’s support answer. Oh well, live and learn.

DOS

You should be fine. The 68/73 indicates the BB will work in both 68 (BB30) and 73mm (BB30A) shells, using different spacer combinations to accommodate BB30 and BB30A crank spindles. The difference is actually more important if you were trying to use a BB30A crank in a 68mm shell because you would need more spacers to accommodate the longer spindle. But assuming your crankset spindle is BB30A length and DUB diameter, the BB you ordered is correct.

smashndash

My bad. It looks like the “BB30A” DUB BBs out there aren’t actually specific to BB30A. They’re just marketed as such. There’s just one BB30 DUB BB and as DOS says, they use a spindle spacer.

BBDUB

Thanks, Guys! The parts arrive Tuesday and then the fun begins.

smashndash

I assume radio silence means everything worked out?

BBDUB

The solution was the BB30A, and not the BB30.

dukeiii

Hi a question on the DUB spacer，does the drive side 4.5mm outer spacer fit into the bearing cover tight？It did on GCN setup video. Mine didn't, i'm concerned about friction and wear between the spacer and bearing seal over time.

BBDUB

I can't say. I installed the 3mm spacer and It was a pretty song fit in the grove. I never tried the 4.5mm. I would imagine should it be loose to start with, you should be okay once the pre-loader is set.

dukeiii

Thanks, I'll check with the dealer.