Turbofrog

So at some point this summer (a long way away, I know) I'm planning on doing a 1500+ km tour in Eastern Canada, and while I'll likely try and travel reasonably light, I'm a bit concerned that the gearing on my bike (a Jamis Coda Sport) will probably be a bit too high. The crankset's 50/39/30, and the cassette is 11-32.

Basically, I'm hoping I can get away with using one of Shimano's new 12-36 tooth cassettes, which would give me just under 23 gear inches in my lowest gear, compared to about 26 now. That's significantly cheaper than getting a new crankset (48/36/26) and BB (pretty sure the current one is proprietary to the cranks), especially since I'd probably need to get a new front derailleur, since the current one I've got has a 20T capacity. Both of those options would give me a similar low-low and high-high (a few more gear inches with 48x11 than 50x12, but I almost never max out, anyway).

Anyone see any fatal flaw in taking the cheap cassette-swap route?

10 Wheels

Just change the 30t chain ring to a 24T and your good to go.

Turbofrog

I wish it was that simple. That would put the difference between my chainrings at 26T, and my derailleur's max is 20T (probably could stretch that to 22-23, but doubt 26). On top of that, most MTB triple-front derailleurs have a maximum front tooth capacity of 48T. So it's almost a matter of cassette vs. crankset AND derailleur, which gets pricey quick if I want to use decent parts.

...especially since I already feel like I should get a beefier 36H wheelset instead of the 32H wheels I've been running, so that's probably $200 right there.

Barrettscv 

I would get a touring crankset with a 48/36/26t chainring set. The 12-36 cassette wil have huge spacing between gears.

Michael

10 Wheels

I completed a 3700 mi tour last August on touring bike with a 50-39-30 crank set and a 11-32 cassette.
I made it OK.

Wished the small chain ring had been changed to a 24T and it would have been perfect ride.

So you are saying you cannot change out the small chain ring?

Turbofrog

I'm afraid so. Not easily, anyway. Could probably swap to 28T, and might be able to get away with a 26T chainring if I also managed to find a front derailleur that works. Otherwise, it's all or nothing.

But it's good to know that you were able to do your tour just fine with the same gearing.

CCrew

What's your current rear derailer? It may or may not have the capacity to go that big.

Turbofrog

It's a long-cage Deore (MY2008, so I believe that's an RD-M510).

Apparently Shimano is recommending the cassette for any of the new Shadow-type RDs, but harriscyclery says regular Deores do just fine with the B-tension screw in.

BengeBoy 

I'd do the cassette swap first, to an 11/34 or 12/36, if your derailleur can handle it.

If that's not low enough, I'd change the inner chainring to a 28t. Not lower.

After lots and lots of consideration, I just built a new bike with 50-39-30 in front and 11/34 in back, and I think it will do fine for lightly loaded touring. But on my next cassette I think I'll go to 12/36 just to have a bit more of a safety net on the low end.

Doug64

If you don't need a new chain, you could swap your whole drive train out for about $150. A Sugino DX-500 mtb 44/32/22 (Universal cycles), new bottom bracket (If you are running a 110mm on your road cranks it will take about 103mm spindle length to get correct chainline, Harris cycles) These two components will cost in the neighbor hood of $115. With that combination you may not have to change cassettes. I've set up several bikes that way, and am happy with the results. The Trek (my rain bike and everyday ride now, but used for light touring in the past) has a 46/36/26, and the Bianchi has a 44/32/22. Both have 11-34,s on the rear. The gearing on the Bianchi is a good match for even the hilliest tours. I used it for the first time this summer on the Oreon Coast, and was glad that I'd made the change. I did the same thing to my wife's Cannondale T800, and she really appreciated it.

Doug64

PS. I just did something that I should have done before I shot my mouth off-- look at the specs of the Jamis closer! You may only have to go to a 110mm bottom bracket to maintain chainline.

Weasel9

I'll bet your derailleur can handle 22. That number is really only for indicating a range in which it will shift well in. It'll still shift, it just might hesitate a bit. Don't completely rule out a new granny ring.

Ok, here come some numbers:

With a 12-36 in the rear, your lowest gear is about 22.5 gear inches. That's pretty damn low. I've got a 26t granny ring on my rig, with a 11-34 cassette in the back. This gives me a lowest gear of 20.8 GI, and frankly I think it's too low to ride for any substantial period of time in. I rarely shift lower than the 3rd lowest gear in back (26t) which comes out to about 27.2 GI. Any lower than that, and it feels like I'm using more energy spinning away.

My experience has been that I only use the absolute lowest gear sparingly. For a minute or two to get over a particularly nasty rise. 22 GI should get you past almost anything, and if it doesn't, I doubt 20 GI would have.

BigBlueToe

I'd recommend at least a 24-tooth granny for touring. Before you decide your derailleur won't work, give it a try. If it doesn't, derailleurs aren't too expensive. I have a 105 triple in front and an LX in back on my LHT. My chainring is a Sugino 46-36-24 (I replaced the original 26 with a 25) and my cassette is a Cyclotouriste from Harris - the one with the widest range. I've never had shifting issues.

acantor

It is not possible to generalize for everybody about what is an appropriate lowest gear. There are many factors at play: fitness level, cardiovascular conditioning, age, injuries, length and slope of hills to be climbed, total weight, and more.

I run a 22T chain ring with a 11-34 cassette, and I use it frequently when climbing. On really long, steep hills, I am working hard, even in my lowest gear. I have never, ever had the impression that I waste energy by spinning; in fact, on the nastiest hills, I am spinning more slowly than is comfortable, and wish I had lower gears. Before I switched to 22T, I had a 24T, and rode my lightly loaded touring bike up a mountain pass in the Swiss Alps. It was exhausting, and after a day of all-day climbing, I lost the ability to deliver power to my legs. I needed almost a week of rest before I was ready to continue. Smaller gears would have made it easier for me to get up that mountain.

Some mountain bike aficionados manage to set up their rigs with substantially lower gears, e.g., chain rings with 18 or 20 teeth with an 11-34 or 12-34 cassette. One of my riding companions has a 20T chain ring, and I have seen him climb extremely steep dirt paths. He waits for me at the top while I walk up. For some people, extremely low gearing is appropriate.

Saintly Loser

I've got a Sugino 48-36-24 crank, and it's shifting reasonably well with a very ordinary Sora front derailleur.

cyccommute 

Not really. Looking at the teeth count , there isn't any difference between in the spacing between gears: 12 - 14 - 16 - 18 - 21 - 24 - 28 - 32 - 36 and an 11 - 13 - 15 - 17 - 20 - 23 - 26 - 30 - 34. Each one has 2 teeth difference in the highest gears, 3 in the middle and 4 on the low end. Should shift pretty similarly.

LeeG

how cheap?

Not so much a fatal flaw but I'd suggest saving yourself some money and loading the bike up and riding it to see before the trip. When I did my big trip when I was young and traveling light the front chainrings were 44/48 with a 14-36 Suntour five speed. If I was to go about changing your stock setup I'd go for a more useful set of high gears because you're not going to be using a 50/11 or 50/13 where it'll actually be useful for getting from point A to point B, very few non-racers ride a non-stop pace at 25mph-30mph and I would guess the number of loaded touring cyclists who would go that fast pedaling over coasting is nil. If you don't really need a 23" gear over a 25.5" gear you will have a new set up with the same useless big gears .

nun

Your crankset is a 130/74 BCD square taper, so the simplest solution would be to just get a Sugino XD triple
46-36-24. You can pick one up for around $100. Your FD will probably work ok and all you have to do is adjust it down a bit. You could also just change your chain rings and go with 46-38-24

Turbofrog

$35?

At the moment, I don't have the cash for multiple nice bikes, so this is sort of my do-all beast, for commuting, weekend rides, and (soon to be) touring, so if it's possible for me to keep my regular gearing mostly intact, I'm happier with that. It is rare that I top out at the 50/11, but 50/14 and 50/12 definitely gets used when I'm feeling vigorous.

Even if I go with the cassette swap and swap out my 28T granny chainring for $20, I'm still spending half what I would on a new crankset, so I suspect that's the route I'll take.

As far as cassette spacing on the 12-36, it's actually exactly the same as my 11-32, except that I'm trading the 11T for a 36T. No worries there.

BengeBoy 

I posted about the new 12/36 cassette a couple of weeks ago. My post was greeted by a big yawn (not new for me, for sure).

In any case, though, there are lots of 50-39-30 'road triples' out there, and the kind of request you have seems common to me - what's the cheapest way to go from "sorta low" gearing to "low enough for touring" gearing on a 50/39/30 triple. With a 28T inner chainring, and a 12/36 cassette, it seems to me you would be set, with a minimum of swapping stuff out.

I hope you come back and post on how it works, as I would potentially be interested in something similar down the road (I currently have a 50/39/30 triple with an 11/34 cassette, but the cassette is due for a replacement soon).

rodar y rodar

XD 600 for a hundred (Bens), or a set of rings for about 90. It kills me! I need a set of 74/110 mtb rings for my road triple and I think I`m just gonna shell out the extra couple bucks for shiny new arms while I`m at it.

Weasel9

Yep, that's why I said "In my experience..."

I agree it's very different for everyone. For some, trying to control a loaded bike at 2 Mph in the low gear is worse than simply pedaling harder. Others prefer the super-granny gear. I was just stating what I'd found in my riding.

I'll second the Sugino XD suggestion. Excellent cranks, they've been exactly what I've wanted out of a touring crankset.

davidad

We put a 24 on all of my friends bikes. It works. The only problem is that the up-shift requires a little more consentratiom
to get it done. shimano went to the "racing triple" 30 because they couldn't engineer the shifter to index the shift.

staehpj1

We went the Sugino XD600 route and are pretty happy with them. I thought the range was perfect everywhere we went in the Cascades and Rockies, but in the Appalachians I would have liked a 24T. My two companions put a 24T on it early on. Oh, btw that was with an 11-32 cassette.

I have since swapped my 26T for a 24T.

Erick L

Where are you going in eastern Canada? If that includes Charlevoix, you might want a MTB crank!