Well your issue is the 190lbs. If you're running something like a 28 then yes, you should be fine around 90psi/6bar. I'm a tubular guy that kind of moved on from tubies, but what I loved about my tubies was the ability to not run ridiculous pressures to avoid pinch flats. Now, that phenomenon is much less a concern for someone of my size, but the fear was still there.

In terms of pressure we need to look at volume and the larger the tires obviously the lower the pressure, all things being equal. In my Time Trial setup, which runs latex tubes and 23mm corsa speeds, I'm around the 6bar mark. but bear in mind that my entire system weight is ~30lbs less than just your weight. I also run as high a pressure I can get away with for the pavement I ride. Most of the stuff I ride on is like glass. For some of the Time Trials I do that have a lot more broken pavement I adjust down.

Really you need to experiment. If you're into testing then find a stretch of road that matches what you ride and figure out what works best. Then you'll have to figure out if pinch flats will be a problem. FWIW, I would ride a slightly higher pressure than optimum if it meant I would finish the race instead of taking a wheel from neutral service.

For testing out what works I suggest http://cdacrr.blogspot.com/

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