Upon further investigation, there appears to be two different Quarq BB spindle lengths. I had no idea. That doesn't appear obvious on the ones that came with my meter, or ones for sale separately.

Seems to me I need the longer spindle one and the wider BB width? The Shimano crank I had with that BB, the BB was physically a bit wider when done threading in.

I feel I could fix this if I could shim the right BB when screwed in but there isn't enough extra "crank shaft" to account for this. It seems it would tighten down but probably wobble or start overloading the pre-load.

Here is exactly what I have:

-2008 or 09 Felt DA
-Quarq dfour with 165mm crankarms included. The box came with the little preload plastic threaded shim, alloy crankarms.........it appears the shaft is permanently attached to the left crankarm, BB30
-Rotor 1x 54T round chainring
-A BB30 threaded bracket

Yes, you need the BB386 version

Meaning, the shaft on the carbon crankset "BB386 version" is longer than the crankset I have now? Thus allowing the use of the spacers on the drive side of the bike?

I apologize if it sounds like a dumb question, I just want to be sure I get this right.

This is what it sounds like I need: sorry for long link
https://www.backcountry.com/...WEAQYASABEgI5wvD_BwE

Edit: think I found a photo of the carbon Dub crankset showing 100mm of exposed shaft length versus 87 I think on the alloy ones. 13mm would more than do it.


Update: bought the carbon Dub ones. They are longer by a good bit allowing use of the proper spacers per the user manual for that part. They work with what I have and can be spaced on the drive side.