My bike has lower end components, so I'm not really sure what's normal as far as performance goes. I'm wondering if things need to be adjusted or if what I'm experiencing is to be expected.

Here's what going on...

My crank is a 52/42/30 and my cassette is an SRAM 850 12-26 8 speed...front derailleur is a Shimano 2203 and the rear is Tiagra.

Biggest chain ring - all gears are fine, no chain rub. Unfortunately I rarely use this ring because it's really hilly here and there's no way I could get up a hill in this ring!

Middle ring - out of the 8 gears, can functionally use all of them, but the 2 "hardest to pedal" gears have pretty good chain rub going on. I try not to use them.

Small ring - out of the 8 gears, only use about 4 or 5. Easy pedalling gears work fine, but as I shift into harder-to-pedal gears, I start getting major chain rub. By the time I'm up to the 5th gear, it's making so much noise I'm afraid something is going to break.

I hope this is just something that needs adjusting. My difficulty is that I need my granny gears to get up most of the hills around here. But then I'll have a flat or a downhill and I want to be able to pedal, but I don't want to be switching rings every 1/8 mile. It would be nice to be able to use all 8 on the middle and small rings. Any advice would be appreciated