I purchased a Specialized Expedition 08 three years ago. (LINK = https://www.specialized.com/us/en/bc/...008&spid=32563 )

I have ridden it off and on (during warmer months) as a commuter to save gas and mainly lose weight (I started at 371 and I am 325lbs now and 5'11") The bike has served me well for this ride. 6.3 miles both ways.

I think I would like to move to a little more road-like bike or just something with thin tires. I still My main question is (and with VERY limited finances) what would get me the best bang for buck from my LBS?

How much different would a Trek FX 7.1, 7.2, 7.3, and doubtfully a 7.5 be in comparison to my current ride now? Would even the low end 7.1 seem like night and day to me, or would it be only slightly better? One of my main frustrations with my Specialized Expedition is that I there are times I could go faster on down hills but I am limited by the gearing (sorry i am not very versed in bike terminology) however I have some rather tall hills to climb and I use some of the very lowest gears too. I wouldn't want to lose that ability or I might end up pushing my bike up the hills

I hope this is understandable.... thank you for any input.

I would expect an FX to be pretty different. Your current bike is a 'comfort ATB', and you'd be moving to basically a road bike with flat bars. You'll be on bigger wheels with narrower tires and be riding with a much less upright posture. I'd be surprised if you didn't feel a significant difference between the two. However, I think you should just go test ride one and see. Just go see what you think when you're on the bike.

As for 7.1 vs 7.5 etc., the differences are not nearly as large as the differences between the FX and your bike. The higher end bikes have better components, but the basic feel is the same. I have a 7.3, and I bought it over the 7.1 and 7.2 for the better shifters, derailleurs, and so on. (Oh, and the better tires.) It felt pretty similar, though, perhaps smoother shifting. The 7.5 I felt actually rode better, presumably due to the carbon fork and rear dampener, but it wasn't a night and day difference (and it wasn't enough for me to justify the upgrade).

Any of those FX have better gearing than your bike, i would recommend the 7.2 this one have better components than the 7.1,better value for your money as well,you can air up the bike u have now and try slick of u just want more speed,you have a comfort bike with suspensions and upright riding position,the FX is more of a fitness bike,u have to learn to ride in a new position with the FX set up.
Here is the comparison of the 3.https://www.trekbikes.com/us/en/bikes/compare

Get the 7.2, I have a 7.1 and I instentaly upgraded most of the compents to that of a 7.2 or 7.3. If you go any higher, you comming from the bike you have you wont notice much of a diffrence. Basic diffrences bettween the 7.2 and 7.1, that I noticed are, better grips, better tires, metal pedals not the rubbery plastic stuff, the seat is diffrent but steats are persanal perfrence and I think the shifters are better but I am not sure.

To me, the 7.2 seemed like it was a better value than most other bike's in its price range by a large margin. The 7.3, not as much. I've been riding a 7.2 pretty hard for the last several months without major issue - some of the 7.1's parts, as mentioned above, arn't as durable and/or comfortable over long distances.

As of last winter when I was shopping, it seemed like alot of Bikeforum posters preferred the 7.3, but if you are coming off of an Expidition I'd say save the money ($100 or so, right?) and customize specifically what you want to improve as you become used to the new style of riding.

7.2 is the sweet spot for price/performance. 7.1 is a little heavier and the ride is a bit less refined. The 7.3 is lighter with a smoother ride and smoother controls. Can't go wrong with any of them, though.

any bike w/ 23 mm tires will feel like a rocket ship compared to your current ride!
tire pressure will be almost double so they will feel rock hard. your rolling resistance will be at least halfed.
your big chainring on your current bike will only have 3 or 4 more teeth than the small one on a road bike, so your gearing will be made for speed not climbing.
a roadbike will be atleast 10 pounds lighter than your expedition and your body position will put less pressure directly on your tailbone and more on your wrists, plus you'll be more aerodynamic so no more wind blasting you in the chest.
I recommend you make the switch asap.

#1 - congrats on the weight loss. i went from 280 to 180 myself and know how good you must feel!

#2 - i have had the 7.2, the 7.3 and the 7.7 within the last 3 years. between the 7.2 and the 7.3, i'd go with the 7.3. as others have said, it's lighter and it's perfect for working out! it's more expensive but you do get better components too. it's a good trade off instead of going crazy and getting a 7.5+

cheers,
-sh00k

I purchased a 7.3 a week ago and have 70+ mikes on it and love the ride - i went in with the plan of getting a 7.2 but the upgrades on the 7.3 caught my attention. My ride today was 10 miles and very easy ride - bike is light, fast and responsive.

I have a 7.3 and a 7.5. I bought the 7.3 in Korea last year for transportation and to keep in shape. It is a great value and I would recommend it. The 11-32 cassette was kind of wide for me though. I like tighter gearing. I bought the 7.5 in 2006. I have since converted the 7.5 to drop bars with bar end shifters and added a 9 speed 12-26 cassette. I love this bike. The stock seat is garbage though.

Agree on the 7.2 being a good compromise. Main difference going up to the 7.3 is the grips and the fork is aluminum instead of steel. I like the steel fork just fine. And I'm upgrading the grips to Ergon. So I feel like I will have a pretty good bike and not be missing anything.

I picked the 7.3 for my most recent bike because it's lighter and because the components feel much better over the 7.2 that i bought a couple of years back.

another reason why the 7.3 might make more sense is because you can find it for way below msrp if you go to the right bike shops. the 2011 7.3 is $679 MSRP - I paid less than $550 for mine, brand spanking new. the 7.2 is in the upper $500s (i havent checked) so for almost the same price, you get a "better bike" - better components, lighter frame, etc. i will say that either the 7.2 or 7.3 is an awesome ride. you'd be happy with either one

i think you're going to become addicted when you ride one of these things...

This.

I changed my bike's handlebar to a drop bar and I've been seeing a lot of people get the bar end shifters prolly cause they don't wanna spend for the road bike brake/shifter levers plus there may be incompatability issues unless you change out your whole drivetrain. I just kept my exisiting trigger shifters, you can either dremel the clamp to make a wider clamp to fit on the top of the drops or not worry about dremeling it and make about a 8 inch bar right under the dropbar to put your shifters like I did. it's almost the same as them being actually on the top and I can reach them perfectly while riding on the top too. You can attach a peice of copper tube to the stem either by a U bolt or a couple hose clamps. It doesn't add much weight and it looks good when you wrap it in the same color as your handlebar wrap but use colored electral tape and you can plug some end plugs like on your drop bar too. I have pics of mine somewhere in diff spots on here if you wanna look.

Thanks to everyone who replied. It looks like 7.2 or 7.3 is the way to go and that choice will probably come down to finances more than which one feels better. MY LBS carries both so I will test ride both.