Nemesis8

Hello. First of all I am a new to the site, and to building mountain bikes from scratch. I have a question pertaining to the new DUB pressfit bottom bracket (MTB). This is my first pressfit BB install. What should the DUB BB inner diameter measure? I have a genuine Sram DUB SX crankset, but I bought an after market bottom bracket with ceramic bearings. The genuine spindle diameter measures 28.99mm just as it should, but the inner diameter of the aftermarket BB measures 28.97mm, and the spindle will not fit through completely, just the tip goes in. Note this is before installing into the frame. I also have a genuine Sram threaded BB, and the crank fits perfectly through it before installation. I contacted the seller, from China by the way, and they said it needs to be installed first, then it will fit. This seems absurd that the inner diameter will change after installation, but again I'm new to this so I may be wrong. I don't want to install the BB, and risk damage if I know it will not fit. Any suggestions? And yes lesson learned about buying parts from China. Thanks in advance.

Anyone maybe have a loose DUB Pressfit BB they can measure to confirm this?

cxwrench

Return the Chinese bb if you can. Get the genuine SRAM bb. Do not bother w/ ceramic bearings.

Barry2 

Uninstalled, it might be returnable.
Installed, you get to keep it.

Sounds like the seller is banking on you falling for it & installing.


I'm sure it will "ride up with wear"

Barry

Nemesis8

Thank for the input guys

Troul 

The SRAM bb pf30 I've bought is initially a tight fit for the crank shaft. After it's been exercised a few miles, the removal & install is less tight.
ymmv