Touring - Upgrading a road triple chainrings?

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rmwun54
01-25-06, 10:51 PM
Where can I find on the net a company that carries smaller rings for the granny gear and the middle ring on a Shimano road triple. I looking to alter my triple from a 52-42-30 to a 52-38-24 in black. Has anyone done something like this? Looking for the parts on the net. Thanks to those who respond.


Camel
01-26-06, 12:14 AM
Black may be a problem (may not be?).

Check Harris Cyclery online (Google).

vosyer
01-26-06, 12:30 AM
TA rings - look on line for Peter White, another option are OR campy rings if you can find them


seeker333
01-26-06, 12:47 AM
can you do that? most shimano f der for triples have 22t capacity.

MichaelW
01-26-06, 02:24 AM
With a 52 ring you may find that the mid-granny shift is poor with occasional de-chaining onto the bottom bracket shell. As the chain is moved down by the mech it is also moved inboard.
The solution is a smaller big ring and a lowered front mech.

TA make some of the best rings for touring, very hardwearing and the shift is OK. If you really insist on black chainrings then Egg rings (http://www.highpath.co.uk/cycles/products/eggs/01.html) are pretty similar to TA.

velonomad
01-26-06, 06:35 AM
I don't think you will get the 24 tooth to work very well. A friend tried it and the chain wouldn't clear the cage brace. he managed to get a 28T to work however

lillypad
01-26-06, 12:10 PM
Yeah, unless you have a touring set-up to begin with with front and rear derailleurs designed for such large teeth ranges you will probably not be able to get it to work.

24T is really small - usually reserved only for mountain bikes where the rider is leaning on the handlebars trying to keep the front wheel on the ground. I did a transcontinental bike ride coming through the cascades and the appalachians and made it just fine with my 30-42-50 combination. Your cadence may be a little slower with the 30T but there probably isn't any paved road that you cannot traverse with it.

challengea2z
01-26-06, 03:32 PM
TA rings are the way to go and by the way Campag don't fit Shimano you spread of rings is to big make your 52 a 50 and get a casette with a 11t as you'll need to change that and you chain if your rings are worn out.

wagathon
01-26-06, 04:54 PM
You might consider putting on a XT/XTR triple, e.g., 22/32/46 or 24/34/48 and going with a smallish cluster--depending on how low a gear you want--such as 12-25 or 12-27, etc.

All you'd be giving up is a gear that is higher than a 46x12 or 48x12 but maybe you need that. For me, I have seldom had the need for the big 52 or 53T ring on any of the road bikes that I've ridden, except maybe to peddle like crazy down a big downhill just because I could. I once had an 11T sprocket on a cluster and that is nuts.

Something to consider; otherwise, teaming up a 12-32 cluster with your current triple provides a 30x32 low gea. That provides a gear that is less that 1-to-1 but you give up having closely-spaced gears. Still, it's been my experience that the spacing is not bad if you have, e.g., a 9-spd cluster.

rmwun54
01-26-06, 08:05 PM
Well here is the deal I have a FSA road triple with 53-39-26 set up with a 12-34 cassette and it works excellent and without any glitch. Of course I am using XT shiftres and derraileurs too. My friend who I am doing this for wants a similar set up as mine but needs a 24 granny for the uphill. Yeah this sounds a bit much to do, but the reason why we have our bike set up like this is because it was my dream to have a all around bike that could be ridden quite fast on various conditions on the street and bike path, and then also at the same time have the capability to be ridden up on a fire road like a mountain bike. So I came up with this bike where I took a Giant OCR touring frame and placed a 29'er shock fork on it, a converted road triple, full XT components, a Rock Shox seatpost, and 700x32c WTB Cross wolf tires. And this bike rocks, whether riding on the road or fire roads this bike can do it all. So my friend like's this set up as much as I do, but hew needs just a little more grearing to make it up the hill. So I am just looking to see if anyone has ever done a 24 chainring before on a road triple, that's all.

wagathon
01-26-06, 08:43 PM
. . .So I am just looking to see if anyone has ever done a 24 chainring before on a road triple, that's all.

Yup, I have 22-32-46 rings on a road bike but with a 12-27 10-spd freewheel. Your setup gives you a ~0.76 low gear ratio compared to my 0.81. It is fun having a goat in the stable. As a all-around road bike, I generally never leave the middle ring but I did have an opportunity to use the low gear on a pedestrian path that was steep enough to be doing stairs and it worked great.

Michel Gagnon
01-26-06, 08:49 PM
As one said, "24 is small", but my single has a 22 on a mountain crankset and I use it. It may be slower than standing on the pedals, but I get up steep hills without problems.

With bar-end shifters (i.e. front is in friction), I use 44-34-22 on the touring bike. On the tandem, I had 48-38-24, and the derailleur covers a wide enough range to easily shift through 52-40-24 or 52-38-24. The tandem now uses a 48-38-28-18 quad, and again, no problems with the 105 derailleur.

With STI or any other indexed front shifter, I heard of a fair number of people using a wide range triple more or less like what you suggest. The only problem they have is that they strongly recommend using a gizmo like the Jump stop (http://n-gear.com/) to keep the chain on the small ring.

Another problem is that with a 12-34 cassette and 52-38-24 rings, you may be beyond the capacity of your rear derailleur. That would result in a loose chain in the small-small combo; however, since one never uses it, it's not a real problem.

P.S. I often read that Shimano road derailleurs are optimised for 10 to 12 teeth between middle and large ring, and that too large a gap would make shifting more difficult. Is it a real issue or not in a touring environment? Is it a problem with STI?

rmwun54
01-26-06, 09:04 PM
Thank you Michael for the input, I like the idea of the jump stop gizmo, didn't know it exist before. That will work and will be insuring at that.