Get a bigger big ring to keep from running out of gear going downhill

a 7 speed freehub is not compatible with 10 or 11 speeds soyou would need a new wheelset ( technically just a new rear hub, but if you are upgrading the drivetrain, makes sense to get better wheels). Then you need crankset,bottom bracket, shifters , cassette. Unless this is a very special bicycle, itsnot worth it since your main complaint is running out of gear going downhill . Bigger chainring will get you there for 20 bucks- make sure to raise thefront derailleur a bitto clear it

swapping the cassette toa 12-34 is pretty easy too


you didnt provide information about the bike itself, but since 7 speeds have been outdated since 1992 on enthusiast level bicycles, i am guessing the bike is either older or a budget model. If that is thecase, you spending $500 on anew drivetrain is only going to expose more deficiencies in the machine, likethe brakes, cheap suspension if it has any, etc etc

its akin to getting your girlfriend a boob job, only to realize while that is nice to look at, she still has a amuffin top, cankles and yellow teeth