One of my bikes has the 52-39-30 triple. The 39 is perfect for flat to rolling rides, where I can stay in the 39 for most of the ride. On my local rides, with hills in the 200-300 foot high range, I rarely use the 52, only if it's a long shallow downhill that I want to pedal down. The 30-29 low is fine for even the 18% grades here, since those are short enough to stand up on.
My Campagnolo triple won't fit anything smaller than a 30, it's a "tripleizer" with the 30 bolted onto the 39. I've wished for lower gears than my lowest 30 front - 29 rear on some long climbs (and especially on gravel).
Triples
My preference is for
closer range cassettes with the
appropriate three chainrings. A small ring for the steeper climbs, and a middle ring to put my flat road cruising speeds just about at the top third of the cassette range. Then the big ring is for shallow downhills or big tailwinds. I like reasonably close shifts in the middle ring at my usual roads speeds. I wouldn't like a really wide range cassette to make up for a too-big chainring or rings.
I even have 12-25 cassette that I'll swap in for long rides without any steep climbs. It's really nice to have the exact cadence while cruising along.
Low enough?
I consider my gears low enough if I can stay seated and use quite light pedal pressure to keep moving. It might be a very low cadence, and I'm only going 3-4 mph, but I don't have to strain my leg muscles by mashing the low gear. My 30F-29R does this on at least a 10% grade, I'm not pressing very hard on the pedals at that fairly steep grade.
Your road bike's 34F-30R is
4.0 mph at 45 rpm.
Your triple's 30F-32R is
3.3 mph at the same 45 rpm. That's a big difference. A lot easier.
A 28F-32R is
3.1 mph at 45 rpm.
(I also like to compare what rpm will get me down to 3.0 mph. Much slower than that, and I'm really working hard to keep the bike upright.)
~~~
Try a
28 instead of a
30 chainring. An easy swap, and the derailleur "should" handle it. Your chain will be fine as-is.
Or the suggestion above for a new crankset 26-36-48. (But see the comment about mountain cranksets having slightly wider gaps between chainrings.) See how that 36 works for you, using the calculator.
For the Blue Ridge Parkway itself, you should be okay as-is. I don't think there's any grade steeper than 10% on the BRP. But since you live in the area, you may want to ride more of the side roads, and these can be way steeper.
Calculator
I like to try different combinations on
Mike Sherman's Gear Calculator. All the charts update on the fly as you change gears or cadences.
Here's a 11-32 9-speed and
28,
30 and
39 chain rings. (I changed the calculator's 52 big ring to a 28 to get a direct comparison between a 28 and a 30 small ring.)
Link to
this setup. The URL changes when you click "Bookmark this set" so you can save it and recall it later.
From the calculator:
I usually put "85-97" in the Speed Over RPM chart, to see flat road "spinning" speeds. But you are more concerned with long, steady climbing, which might be more in the 70-80 rpm range.
39 ring in blue, 30 ring in black, 28 ring in red.