Although it has to be said I ran out of gears on virtually every downhill. It does feel a bit under geared at the top end.
Pedal faster! 😉
Seriously though, I found investing in a Cadence sensor (to go with my Garmin Edge 500) was worth the while to help me improve my cadence. I wasn’t exactly a grinder before, but was tending to average 78-80rpm over a ride. A few months on and in regularly in the 88-90rpm average over the length of a ride now, and am faster and feel better for it.
I’d say if it hasn’t got one already, fit an 11-28 cassette. You only get wide(ish) gaps right at the very bottom end of the gear ratio where it’s not important, but having a 34/28 bottom gear is much nicer for most newbies than the typical 34/25, and having an 11T on the back helps you keep pedalling over 40mph… Ok, I can spin quite well, but there’s a local descent near me I’ve done a few times that’s not steep enough to be faster tucking, so you’ve got to pedal, and I’ve done over 45mph on it a few times pushing 50/11.