Sam,
Sorry I’m not familiar with the bike models but this is where I’d start:
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Do you experience brake rub (if the calipers are on the seat-stay). If yes, then I’d start with upping the rear wheel spoke count (There’s an article on slowtwitch somewhere that explains this idea. Maybe 2014). If you didn’t know, there’s no aero penalty for added spokes just a 4-6g weight penalty per spoke. If you don’t have SS caliper brakes then maybe you could fab something with zip ties (and a paint marker?) to see if you’re getting wheel flex there.
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If you don’t have brake rub then check the spacing in the CS with your wheel and tire set-up. As others suggest you might not have enough room. When I’m designing a bike I spec at least 5mm space for the client’s specified tire width. So if a client says they use x-rim and y-tire @ 80PSI I take calipers and measure the tire width (as you know tire mfgs aren’t the most honest with their labeling and internal rim width has an impact). Then I’ll adjust the spacing, bend, dent, whatever to make sure there’s enough space (hard to do that with stock CF bikes)
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Out of saddle technique: At your weight and power if you’re really plowing out of the saddle (especially if you’re tired) you might be pushing the pedals (and bb) left and right instead of up and down. I only mention this because I’ve ridden with some beastly guys on whippet-like bikes (e.g. Vitus 979 bonded aluminum) that never experienced rubbing issues. Necessarily, they were some of the smoothest riders I’ve ever seen. I don’t want to bag on you or your riding skills, it’s just something to think about. And, yes, there’s always going to be some lateral movement when you’re “jammin”