Ok, I'll keep it brief.. I've been riding my bike as much as I can (typically 2-3 times per week after work) on a route out of town that's about 30 miles (I'm still a newbie here...). At first it was tough to keep a decent pace (which is expected) but I got better.. Last week I had a schedule change at work so I've been cross training, and I hopped back on this week but things have been WAY harder lately..

Which of these factors do you guys/ladies think would influence my riding difficulties the most?

1. It seems to be easiest to ride with a tire pressure around 80psi. Any higher or lower and I feel like I'm dogging it.
2. Upon further inspection, I've realized that one rear brake pad is rubbing on the rim a little.. Not much, it still spins freely, but a little.
3. I've recently added two brackets and two full water bottles to my frame (ever since a bad dehydration experience out in the country).
4. Is it all in my head? Do I just need to be more consistent with my workouts?

I'm not racing by any means, just keeping my pace ideally around 19mph average and keeping the weight off.. But this has been disheartening.


Thanks!