I have ordered this Truativ AKA chainset from merlin cycles as it seamed a bargain and I was hoping to run a bling ring with it.

I wanted to put it in my trek superfly which has a press fit (BB91) bottom bracket.

I have now realised that I ordered a BB30 option (not arrived yet). Would this still fit if I used something like this?

No. that is a gxp bb adapter for Sram gxp cranks.

Your bottom bracket (BB91) uses 24mm spindles.

A BB30 crank will not work with it. They only fit BB30 frames.

Cancel your order or return it.

I think rotor do a BB that will take a 30mm axle in a 24mm pressfit shell. (I’m presuming that BB91 is similar to bb89.5 and bb92, i.e. 41mm inner shell diameter)

According to the below the 4124 should do the trick.
rotor BB compatibility chart

Never used one though, so not sure how long the bearings will last etc…

Interesting… The 4130 bearings look like they would do the trick. yeah the width (W) across the shell is 98.5 which I guess makes it a bb98.5

It doesn’t appear to come with a inner cover though?

I suppose I’ll have to check the spindle length as well.

Any idea how these bearing will do with a truvativ gxp crank with regards to the load on the non drive side?