Component question
 

I currently am running SRAM Apex (11-32 cassette, bar end shifters) on my rig for commuting, brisk rides and light touring. A friend and I are planning a loaded tour over the mountains in Montana and I don't think the double crankset will pull the trailer up a mountain. I'm wondering if the SRAM Apex 10sp is compatible with the mtb components. I would like to get away with purchasing a triple crankset and front derailleur if possible.

Barring that, any other recommendations?

what about compact chainset.

Worst case you have to get a new front crankset say a Shimano LX (pretty cheap on jensonusa.com) and a mountain FD, just switch your front bar end shifter to friction and you're good to go. I actually made the switch to a compact crankset up front for a light tourer and it gives me enough range but I have never pulled a trailer.

to give you an idea of costs if you do need to go the new crank route, there are good quality Shimano mtn cranksets like Alvio (42/32/22) that are quite cheap new ($45 here in Can) and a mid level derailleur can be had new for probably $25, so conceivably, you could put a whole new set of nice low touring gears on your bike for well under $100, probably less than $75 in the states. (crank mentioned is a square tapered crankset)

I've ridden northern Montana a few times: Lolo Pass to Missoula, up to Glacier N. P. (though I stopped short of the Going-To-The-Sun Road) and last summer I rode the Great Divide MBR from Eureka to Helena. For the roads in the mountains, get a triple with at least a 24 inch granny. For the Great Divide, get mountain components - as low as possible - and you'll still probably end up walking up some of the steeper climbs.

It's beautiful country!

Blue, my wife and I drove our car up the Going to the Sun road on our honeymoon, damn pretty landscape. As you say, one sure as heck would want at least 24 inch low, I would personally want 21 or so.
I am a big fan of using a mtn crank and a tighter cassette (11-28 sort of thing) that would work great for this sort of terrain.

on a major touring track down the coast, 50/34 doubles are pretty common this summer.

but steep trails ,, looong climbs with a lot of gear..
maybe an MTB crank would be a worthy change ..

Definitely, I should say. My own bottom gear on the tourer is about 19 inches. I very rarely use it but there have been times, on very serious hills, when it has made the difference between riding and walking. And I hate to walk...

I find that 26 teeth on the front and 11 teeth (Surly LHT supplied setup) on the back are low enough for me to ride all the way up long steep climbs, even at altitude, when fully loaded. I still spin at a reasonable cadence at 5 kmph.

z

wut? The 11-tooth sprocket is the highest gear, not the lowest...

I think 20-24 inches is a good range. I'll be on the lookout for a triple crank, front d. and probably a long cage d. Thanks for the recommendations.

Pulling a trailer and carrying a light rack, I'm wondering what size tire to use.

I kept my 11-32 cassette and replaced my 34/48 Apex cranks with an X7 28/42. This netted me somewhere around a 24" low. At some point I'll probably get the 11-36 cassette and a long cage RD, but for now this crankset got me a lower low for the same money.

all this online analysis of what is low enough in gear inches is so dependant on the amount of weight on bike (I used to have about 40lbs) and how steep and how long the hills are.
KD, only you and you alone can try some "steep" hills with teh weight you will actually be carrying/pulling and see if 24 gear inches is low enough--I personally would find that a minimum for really hilly areas, and 21-22 is more realistic for steep steep sections and or when you are bagged, or at teh end of the day and you've added 5-10lbs more of food on your bike etc etc.

but the only way is for you to try it. Remember though, beating the heck outta your knees will show up later in life (if you are young)