hello I am planning a 6 week self supported tour in june from montana to california. I purchased a near new GIANT EXCURSION bike built for touring with fenders and racks. I will weight 310 pounds bike me and gear when i leave. The bike is currently geared as follows 14 32 rear cassette and 48 39 28 front shimano 105 equipment. Currently I have 23.8 gear in low and inches 93 in high. I would like to get to 18 and 100.
I have looked for a mega range 11-34 cassette with no success and have no idea what to do for the front gear rings.
I am frugal/cheap in that I will buy good used re the bike when appropriate and new when its smart like new tires and chain.
So with that in mind how do I get to my goal of 18 and 100 gear inches with out spending too much and changing derailers etc.
I NEED HELP IDEAS BRANDS the more specific the better.
Most of what I have leaned is from reading on this forum so thanks for being here and sharing the wisdom.
JOHN

I would replace the 105 crankset with a Deore 38, 36 & 26 crankset.



This Deore crankset has 48, 36 & 26t chainrings stock: https://www.google.com/products/catal...d=0CFsQ8wIwAw#

Then add a a 22t Shimano small chainring: https://www.universalcycles.com/shopp...s.php?id=23798

dont you think he'd be able to put a 24 on that crank? (or is 26 the smallest it can take?)

that said, searching for a 34 cassette should turn up results somewhere (without knowing if it is 8 or 9 speed--I quickly did a search for a Giant Excursion, to no avail)

Just curious as to how you came up with those specific numbers; 18 and 100?

should have been tipped off by the 14-32, its probably a 6 or 7 speed (most likely 7) with freewheel.

finding a used crank that will fit the bottom bracket might be easiest, if a 24 tooth cant be put on it. My 7 speed from 90 or 91 was able to take a 24 tooth granny.

ps gearing aside, if this bike is in fact over 20 yrs old (or 15 or whatever) all the bearings should be repacked before doing any sort of trip.

He could install a 24, but the jump from the 39 middle chainring to 24 can become slow & sloppy. The 36 and 22 chainrings shift well and 22 provides a deeper climbing range for a bigger guy.

agreed, having spent years shifting from a 40 to the 24, it requires good timing and finger technique (downtube shifters, two finger technique, one for each shifter) but yes, slowish, but it works.

what do you all think of a mtn bike crank? I realize bottom bracket width might be a problem here,but if doeable, it would be a real easy way to get lower gearing.

The MTB crank works well. The chainline is offset to the outside, so the chainline on the big chainring & big cog is less than ideal. I don't need or use this combination anyway. Other combinations are very-good to perfect and I can use all 27 combinations without issues.

I'll use a Shimano Tiagra 4503 front derailleur for triple with either bar-end shifters or Tiagra STE brifters with good results.

Well a little more info about me and the bike.It is a 7 speed free wheel and it has a Shimano LX crankset and I think it is a mountain bike model. My only other experience touring was about 8 years ago on an AIDS Vaccine Ride across Montana. It was fully supported and even though I had trained a lot of miles I had to walk the bike most of the long hills which caused ankle swelling and lots of pain.I rode all but 6 of the 540 miles in 7 days but I do not want to walk any miles on this tour.I only missed the 6 miles because I ran out of tubes and patches and it was over 100 degrees and I was not thinking clearly at that point.
I choose the 18 gear inches cause I have struggled with this bike up steep hills on early training rides so far this spring. The 100 gear inches was just a number.I have had the whole bike apart and new bearings and grease as I have a new neighbor who is an expert bike mechanic and really likes to help out and relaxes by working on bikes. Thanks for the responses so far. Feel free to ask more questions.
Again thanks for the responses as the more discussion that happens the more I think and learn.
JOHN

https://www.warhawkindustries.com/custom-chainrings.html I have no idea if this outfit has on hand or can produce a custom chain ring for you but it doesn't cost to ask.

my old touring bike has a LX Mountain crankset on it, and that bike is from I think 1990. There are 5 bolts on the crank and I have the specs written down somewhere of the size of the crank (distance between bolts), and as mentioned, it took a 24 tooth granny (very cheap to buy, if this is still possible, but I would think you could with some research and asking at a good store)
With a 30 tooth freewheel, and the 24 granny, with 700 wheels and 28 tires, I got the gearing down from the original 25 gear inches or so (with the original 28 tooth granny) down to 21.5 or something like that, which for me was low enough for having 40 lbs or so on the bike and doing lots of hills.
Getting it lower, to somewhere near your 18 number, would be great, but as you say you had problems on hills on a fully supported trip (I assume then, no baggage on bike) you must realize that a crapload of stuff on a bike really ups the effort doing hills, so lower gearing will be a must.
Others may know of the availability of 7n speed freewheels, I dont. I would ask your neighbor to do some researching for you, and/or putting on a true mountain crank that could allow you a 22 tooth granny (a standard mtn bike crank often has 42/32/22 and would be a help to you.)

Since you are trying to do this on the cheap I would just order a 14-34 freewheel and be done, that gets you about 20 gear inches and only costs $15. If you really want lower still you can try to find a slightly smaller granny ring for your crank set and although shifting might be a little slower it will work. I would also not worry much about being geared higher, you have plenty of top end for a loaded touring bike to be happy on the descents. https://www.bikeman.com/FW8140.html?u...ign=GoogleBase

I have been using my LHT with a 52/42/24 since I built it up several years ago. (Cassette is a Sram 11/32 eight speed.) I was happy enough with it that that when I built up my Thorn a couple years ago, I set that up with the equipment.

The upshift from the 24 to 42 is a bit slow but I can almost always make that shift over a distance of 30 to 50 feet. Downshifting from the 42 to 24 is smooth, but you should have a chain catcher/watcher to avoid dropping the chain. Need friction shifter for the front. I use a vintage Suntour front derailleur.



Why do I like this setup? I like the 42 as a middle ring, it gives me a nice range for most riding. But for those steep hills you find on occasion, I need the 24t. I only use the 24 when I need it which is rare so I do not make that shift very often.

If you are happy with a 42, that is of course fine for you, but having used the 50-40-24 for so long, I would absolutely go with a 36 middle ring crank for my next touring bike, as I find it more flexible when you have stuff on the bike. Depends on the terrain you ride in (as you say, you rarely shift into the 24, around here I am on hills a lot, even unloaded a 42 would be too tall) and also what kind of cadences you prefer, my knees dont like mashing.

Your point about a chain catcher is a good one, they are available for $5 or something, easy to put on and very effective.

and OP, John, yes newer 8 and 9 speed bikes are nice in that the gears are a bit closer between each shift, but I did a lot of touring on my 7 speed and had a great time, so the important thing is to get your low gears lower. As you say, walking up hills sucks big time (even more so when the bike is loaded), been there/done that--get lower gearing with either the 34 freewheel and/or smaller granny and you will enjoy whatever travelling you do do so much more.
If you really like touring and want to do more, it is always possible in the future to find a more modern used touring bike.
cheers