Outfitting a Trek 7.5 FX for a full summer tour

[RussSeaton]

A local bike shop could make the changes in your gearing.  It would be extremely expensive because bike shops charge MSRP plus 20-30% or more.  To get lower gearing you have to stay with a double crankset.  Your current shifters are for a double crankset.  Going to a triple crankset means you would also have to change the front shifter.  Expensive.  If you look at my post above you will see links to Shimano double cranksets with very low gearing.  You could buy these mail order and pay a local shop to install them.  Probably the lowest cost way to do it because the local bike shop will charge an outrageous amount for the parts and then much more to install them.

Currently you have a low gear of about 27 gear inches.  34x34 low gear.  If you packed ultra light you might might might be able to make it over the mountains with this low gear.  Might not.  You would have to pack ultra ultra light.  You really need lower gears to do any loaded tour.  Even packing ultra light you need low gears near 20 gear inches.  Your problem is you don't know anything about bicycle touring.  To pack ultra light or try to climb the mountains with not low enough gearing, you need experience.  Your first attempt should be with extra low gearing.  Second or thrid attempt you will know if your gearing is low enough and know how to pack light.  Your first attempt won't be light.

BoB trailers are kind of heavy all by themselves.  You can't really pack light if you start with a heavy BoB trailer.  You need low low gearing to pull a heavy BoB trailer.

[Gif4445]

Since you have some time, (and I applaud you for asking questions and doing some research), you should read some travel journals.  Maybe you already have.   They should give you a good feel for what you are up against.  A good source is Crazyguyonabike.com .  My first real tour ( https://www.crazyguyonabike.com/doc/?o=1&doc_id=10146&v=7s ) was only 500 miles, but I did have issues with spokes and tires in a credit card touring situation.  My second tour was twice as far, but went much, much better with a bike meant for touring (Surly LHT).  Bottom line, I finished with both bikes.  And maybe the challenges of the first tour just made it more of an adventure.  But I credit the people helping you out on this forum.  They have been there and done that.  It gets very frustrating when your equipment lets you down. 

[stiker]

A local bike shop could make the changes in your gearing.  It would be extremely expensive because bike shops charge MSRP plus 20-30% or more.  To get lower gearing you have to stay with a double crankset.  Your current shifters are for a double crankset.  Going to a triple crankset means you would also have to change the front shifter.  Expensive.  If you look at my post above you will see links to Shimano double cranksets with very low gearing.  You could buy these mail order and pay a local shop to install them.  Probably the lowest cost way to do it because the local bike shop will charge an outrageous amount for the parts and then much more to install them.

Currently you have a low gear of about 27 gear inches.  34x34 low gear.  If you packed ultra light you might might might be able to make it over the mountains with this low gear.  Might not.  You would have to pack ultra ultra light.  You really need lower gears to do any loaded tour.  Even packing ultra light you need low gears near 20 gear inches.  Your problem is you don't know anything about bicycle touring.  To pack ultra light or try to climb the mountains with not low enough gearing, you need experience.  Your first attempt should be with extra low gearing.  Second or thrid attempt you will know if your gearing is low enough and know how to pack light.  Your first attempt won't be light.

BoB trailers are kind of heavy all by themselves.  You can't really pack light if you start with a heavy BoB trailer.  You need low low gearing to pull a heavy BoB trailer.

I think that website might be down atm because i cant click those links. I will try again later but just to clarify would something like a mountain bike have a lower gear inches?

[csykes]

A mountain bike will have lower gears in most cases. But mountain bikes also have shorter wheelbases, higher bottom brackets, and knobby tires, things that you generally don't want in a touring bike.  Do some exploring on this site, CGOAB, and some Google searches and you will learn a lot.

[MNRider]

The Sora FD on the 7.5 FX should handle a triple and the R440 shifters are listed on Amazon as 2/3 x 9 so your shifter may be OK as well. Your bike shop will be able to tell you for sure. I'm not sure what bottom bracket the 7.5 FX has but if an Alivio crankset will fit (square taper or Octalink versions available) you can get 48/36/26 or 44/34/24 versions for around $50. Worst case scenario is a swap of the Sora derailleur $35, the left shifter $35 and the crankset $50 comes out to about $125 + about $50 labor and gives you all the gearing you could ever want for touring. If the FD and shifter will work you could get by for half that. According to Sheldon Brown, the 44 x 11 combo would give you around 28 mph at a cadence of 90. If you spin out at a cadence of 120 you will be at nearly 40 mph, plenty fast for a controlled downhill. The 24 x 34 combo should climb like a mountain goat even pulling a lightly loaded trailer.

Wheels are still going to be an issue and could be the deal breaker. You can get into a decent set of 32-spoke wheels on Deore hubs with butted spokes and double-wall eyeletted rims for around $300. Another option would be to check with your LBS to see if they can get a wheelset for the 7.4 FX which comes with 3-cross 32-spoke wheels. Sometimes you can find good used higher spoke count wheels from an LBS when a customer "upgrades" to a lighter racing/road wheelset.

Side Note: I am all for supporting your LBSs. Some people get all up in arms when you mention Amazon but many of the sellers on Amazon are LBSs (including one of three that I frequent) and have both retail and online stores. It really doesn't matter to me as one of my LBSs is an Amazon seller and it and one other shop in the area price match Amazon, so I have no reason not to buy locally unless there is something the local shops can't get.