Double chain rings for touring?
 

I realize that most people touring use triples.
But, is it realistic & feasible to use a double? And if so, what would YOU choose for chain rings?
My 8 speed cassette is a 12-25

There are quite a few variables you need to take into account. Where are you touring? How heavy are you loaded? How good of shape are you in? How far do you want to go in a day? Lots of variables to consider.

Hmmm... OK. Things to consider, for sure. Thanks for pointing that out to me.

I am a newbie to touring, but not to cycling. I am relatively in shape (always could get better) and have gotten back into cycling at the end of last year, after a 15 year hiatus. Prior to that, I was a USCF Cat 3 Road Racer. So I WAS in great shape! I have owned a few mountain bikes, and never once put it into the small ring. But I was never loaded for touring, either. It was just me.

As for the touring I will be doing, I don't see myself embarking on an epic journey anytime soon. I'll probably start with 2 or 3 day light jaunts. I'm not sure how heavy of loads I will be carrying, but whilst I was taking a break from cycling, I did a lot of backpacking, so my backpacking gear is pretty light weight.

In one day, I'd estimate that I can do 75 miles, if it's flat. I live in the Phoenix area, so it is pretty flat here. IF I head North, it is uphill for sure.

I was thinking that a 48/38 would work. But I could be out of my mind!

Also...

Are you young or old?
Are you touring in Florida or tha Alps?
Are you using 26" or 700 wheels?

There's no doubt that a double is perfectly fine for some touring by some people in some locations. On the other hand, it would be nuts for other touring by other people in other locations.

Even when possible to do it on a double, I think a triple would be preferable in almost all cases. If I did have a double, I'd want something that would get me down to at least 20 gear inches. With a 25 cog and 700 wheels, that's be an 18 ring. But you surely can swap that 25 for a 27 and then you'd only need a 20 ring. You probably can't even get a 20 ring on your cranks. But maybe you can use a 22, which would be getting you close.

I am 49 years old.
700C wheels
I live in the Phoenix area, where it is flat. Unless I decide to tour exclusively through Southern AZ/NM/CA/TX, etc., I will be hitting some mountains.

It depends. For quick rides with little load I'm happy with a compact crank (46x36, long story) and a 13-26 cassette.

For bigger loads you really lower gears. You could take a triple and put a 46-26 double on it say (or use one of those fancy/classy TA cranks). With a 12-25 cassette you'd probably be ok for anything but massive hills and huge loads.

What's the range on the rear cluster? Get a triple if you'll be doing any hills with a load, in the west, there are hills everywhere. Unless you are specifically doing flat rides, I'd have a triple.

Given that info, I wouldn't want to do loaded touring with a double. Not that it's impossible, but it'll be hard on the knees and will really start to drag you down at the end of a long day of hills.

Knock yourself out with a double. Your own experience will be your best guide.

The worst that can happen is that you walk up some hills.

What I am really trying to do is not replace my double brifter.
If I'm going to have to go that route, then I'll end up replacing the whole drive train and go with a triple with brifters, change to a long cage rear derailleur, and go with a mega-spread cassette.

That said, I already have the triple crank (just have to get chain rings); cassette; and an XTR front derailleur (not sure if it is a bottom pull, or not...). Unless I scavenge an old mountain bike (which I might just do) for a rear derailleur. Then, all I have to buy is a left brifter that will accommodate a triple.

Run the various gear combinations through a gear calculator.

http://sheldonbrown.com/gears/

you could just get a friction bar-end shifter and just use the brifter for your brakes. Just a thought.

And a good thought, at that. :thumb:

For fully-loaded touring, 48/38 sounds pretty high to me even if you were to combine it with a wider-range cassette (e.g. 11-28). If you're planning to ride where there are hills and/or mountains, I suspect you'll want lower gearing. Even a 50/34 "compact" crank and 11-28 cassette might not be enough if you're planning to carry 40lbs of gear... unless you're in really good shape.

I know that when I added 15lbs of gear to my road bike and started trying to climb hills, I was wishing for something much lower than the 34-28 combo. I'm a terrible climber, though. Still, with 30-40lbs of gear and a heavy touring frame, I'd probably want a 28/38/48 trekking crank and 11-32 or 11-34 cassette.

Standard and compact doubles will not give you enough range to climb even short hills in otherwise flat regions. a 50t & 34t is a common compact double chainring combination. Unless you are younger, stronger and your bike/equipment/ rider combination is lighter than normal you will need better gearing.

Here are a few options for double cranksets that allow a "granny gear" on the small chainring: http://www.bikeforums.net/showthread.php?t=530743

None of these are low-cost.

Michael

One of the bikes I use for bike camping has a double (originally 52-39, but now 50-39 after I wore out the large chainring). I've found the gearing to be fine for pretty hilly terrain, but the cassette is a 13-32 instead of your 12-25.

Sounds like you're in pretty good shape, so I'd suggest trying your planned combination with the double up front on some tours that don't have any really extreme mountains. You can always switch to a wider range cassette later (you'll wear out the current one at some point anyway - and a longer cage derailleur isn't that big a deal either).

On my first tour close to forty years ago I used a 52/42 double and a 13/28 cluster and soon wished that I had a triple crank. From Mt. Shasta in N. Calif. over the coastal mountains to and down the coast home to Santa Barbara. I spent a lot of time standing up in my lowest gear straining to gain the summits at the expense of my knees. Once home I had a third chain ring bolt pattern drilled into my crank. What a difference that change made in the quality of touring. As did learning to mail excess equipment home.

Good discussion here. But, as I understand, you are planning a two or three day trip for starters. So, there are many things to figure out. It's sounds like it's entirely possible depending on your route to do the trip with your existing double chain ring. So, why not start that way and see if you are happy or want lower gears. That way you will find out what works best of you.

I'd simply buy a compact cyclocross crankset- a 50/34 or so, and see if that's low enough (a typical entry-level touring bike comes with a 53/42/30).

Or, buy said entry-level triple crankset, remove the 53 (and replace the outer bolts with singlespeed bolts) and just use the 42 and 50.

A 42 and a 50 as your only chainring options for fully-loaded touring? Ouch! :lol:

When I rode a triple I found myself feeling that the 48t ring was too big and the 36t ring too small. So a while back I took the outer ring off my triple and went with 42/26 on the middle and inner positions. I have an 11-32 cassette and just stay in the 42t ring 95% of the time only using the 26t ring for steep stuff. My gear ratios go from 105" to 21". One thing to watch out for is the derailleur to chain ring gap, as it has to be bigger than normal to clear the chainstay, but it works just fine

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http://www.wheelsofchance.org

I don't think my "existing double" will work. It's a 54/44... yes, 54. I can, however, easily swap that with a 53/39. I'm fairly certain that a 39x25 1st gear just won't work. That's why I'm asking the experts here for some alternatives, and to see if a double is even a viable alternative at all. What the smallest ring I can put on a 130mm BCD crank?

I have one of my bikes set up with a 52/38 and 11/32 9speed cassette that I use for a loaded touring riding and it does just fine. I've ridden 140 miles with few moderate climbs with 25lbs of gear and it was doable.

Glad you're back into cycling - me too. Double chainring should be fine. I plan on doing the Coronado Trail (Morenci-Alpine) "loaded" using just a 39x34 1st gear. I do believe you may have to get the longer cage rear deraileur to use a touring cassette; ie 11-34. I can't imagine using a road cassette for loaded touring but I'm sure some people do just fine with them. I do, however, use friction shifters which presents no problem regardless of setup. I'm old school and just prefer them. I'll let you know how the ride turns out.

Correction - I meant to say 34x34 1st gear, a 1:1 ratio which isn't too bad for climbing. If I had a smaller chainring up front I'm afraid I wouldn't be going fast enough to stay upright!! Besides, walking the bike uphill would probably be faster, wouldn't it? :)