Double to Triple conversion
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Double to Triple conversion
Considering converting from a compact double to a triple, partially for slightly wider gearing (though my current gearing is pretty wide at 30-101 gear inches), but mostly because I find that my sweet spot on flattish terrain is in the high 50s to mid 70s, so I am constantly switching chainrings (because my gearing is so wide, the large ring can't be used with the largest cogs). I figure with a 39t or 42t middle ring, I can stay in that ring for most flats/rollers. Also, I'd get the benefit of more closely spaced gearing, so I can maintain a steady cadence.
Am I nuts? I suppose I could use some of the larger cogs with the large ring on the compact double if I used a long-cage RD, but I'd still be cross-chained. And I figure the shifting on the triple will be at least as good as the compact double because the jumps between rings are smaller. The conversion probably won't cost much money because I'll buy used components and sell my compact double components, and I figure I can do all the wrenching myself.
If I want to use an Ultegra 6603 crank, do I just need to get a Shimano 6600 bottom bracket with the right threading for my frame (not sure if it uses English or Italian - it's an Orbea)? Or does the Ultegra crank come in English/Italian varieties (guessing this isn't the case, but want to confirm)?
Am I nuts? I suppose I could use some of the larger cogs with the large ring on the compact double if I used a long-cage RD, but I'd still be cross-chained. And I figure the shifting on the triple will be at least as good as the compact double because the jumps between rings are smaller. The conversion probably won't cost much money because I'll buy used components and sell my compact double components, and I figure I can do all the wrenching myself.
If I want to use an Ultegra 6603 crank, do I just need to get a Shimano 6600 bottom bracket with the right threading for my frame (not sure if it uses English or Italian - it's an Orbea)? Or does the Ultegra crank come in English/Italian varieties (guessing this isn't the case, but want to confirm)?
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No you're not nuts.
The cage length has nothing to do with max. cog size.
Before you start asking specific questions about how to do it, first provide more info about the components on your bike. Otherwise the only answer is, "It depends".
I suppose I could use some of the larger cogs with the large ring on the compact double if I used a long-cage RD,
Before you start asking specific questions about how to do it, first provide more info about the components on your bike. Otherwise the only answer is, "It depends".
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If I want to use an Ultegra 6603 crank, do I just need to get a Shimano 6600 bottom bracket with the right threading for my frame (not sure if it uses English or Italian - it's an Orbea)? Or does the Ultegra crank come in English/Italian varieties (guessing this isn't the case, but want to confirm)?
Bottom bracket is where you make the English/Italian threading determination. Make sure the bottom bracket also has the correct spindle length for a triple crank arm.
Bottom bracket is where you make the English/Italian threading determination. Make sure the bottom bracket also has the correct spindle length for a triple crank arm.
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Originally Posted by DMF
The cage length has nothing to do with max. cog size.
Before you start asking specific questions about how to do it, first provide more info about the components on your bike. Otherwise the only answer is, "It depends".
Before you start asking specific questions about how to do it, first provide more info about the components on your bike. Otherwise the only answer is, "It depends".
Currently, I have Ultegra 6600 double components, and an FSA SLK compact crank (with MegaEXO bottom bracket). Looking to swap brifters, crank, bb, front and rear derailleurs to Ultegra 6603.
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Originally Posted by oilman_15106
Bottom bracket is where you make the English/Italian threading determination. Make sure the bottom bracket also has the correct spindle length for a triple crank arm.
Last edited by Proximo; 06-14-07 at 01:50 PM.
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Originally Posted by serpico7
Yes, I know. But the cage length does have something to do with whether or not you can use big-big or small-small combos (or how close to those combos you can get).
Currently, I have Ultegra 6600 double components, and an FSA SLK compact crank (with MegaEXO bottom bracket). Looking to swap brifters, crank, bb, front and rear derailleurs to Ultegra 6603.
6600 is a Hollowtech II design where the axle is of one piece with the drive-side crank. There is no bottom bracket per se - just external bearings. The bearings are the same for double and triple. Just install what comes with your new crank. Threading is probably English, but do some research.
Dérailleurs FD-6603 (-B or -F as appropriate), RD-6600-GS.
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Last edited by DMF; 06-14-07 at 11:34 AM.
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Originally Posted by DMF
No it doesn't. The length of the cage affects *only* how much slack the tension arm can take up. What you're talking about is the affect of chainline variance - nothing to do with the dérailleurs.
Note that in my first post I mentioned my gearing range - though it's not explicit, that gearing range on a compact double means I have a very wide cassette (in this case, 13-30). Wide cassettes present a chain wrap issue, hence my mention that simply switching to a long cage RD might address part of the reasons I am considering converting to a triple.
Of course one of the problems with simply using a long-cage RD is that even if I could stay in one ring for the flats, I'd be cross-chaining a lot. With the middle ring on a triple, I'd have my "flat land" gears on one ring and a straighter chainline.
Thanks for the bb info - that's all new to me.
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Originally Posted by serpico7
... the longer cage can take up more slack. That means you can use a longer chain,
N.b. that the standard method of determining chain length doesn't take the dérailleurs into account at all. You wrap the chain big-big (without going through the RD) and add two. When changing from double (53/25) to triple (52/25) one can use the exact same chain, even though the max. amount of slack increases (27T to 33T) and RD changes from short to long cage.
Of course one of the problems with simply using a long-cage RD is that even if I could stay in one ring for the flats, I'd be cross-chaining a lot.
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Last edited by DMF; 06-14-07 at 12:03 PM.
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Originally Posted by DMF
Nope. Think about it.
N.b. that the standard method of determining chain length doesn't take the dérailleurs into account at all. You wrap the chain big-big (without going through the RD) and add two. When changing from double (53/25) to triple (52/25) one can use the exact same chain, even though the max. amount of slack increases (27T to 33T) and RD changes from short to long cage.
N.b. that the standard method of determining chain length doesn't take the dérailleurs into account at all. You wrap the chain big-big (without going through the RD) and add two. When changing from double (53/25) to triple (52/25) one can use the exact same chain, even though the max. amount of slack increases (27T to 33T) and RD changes from short to long cage.
Originally Posted by DMF
Cross-chaining is simply a function of the physical relationship of the rings. The configuration of the RD does not affect it.
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chain wrap
For a Shimano road double (53-39) the delta ∆ is 14T. The short cage RD can handle the widest road cassette that they sell, 12-27 or ∆13T. Your compact (50-34?) is ∆16T, and your cassette is ∆17T. That's out of spec for the short cage, assuming you use it all (i.e. crosschain).
So you should be running a long cage, but doing so won't solve the problems you have with your compact. If you go to the triple, think in terms of a 12-25 or even 11-23 cassette. You'll thank yourself.
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Originally Posted by DMF
So you should be running a long cage, but doing so won't solve the problems you have with your compact. If you go to the triple, think in terms of a 12-25 or even 11-23 cassette. You'll thank yourself.
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For steep climbing I use a 12-27, but 11-23 for more reasonable stuff. It's also possible to customize Shimano cassettes.
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I wonder, then, why Campagnolo recommends medium RD's with cassettes with 29 tooth gears but not those with 25 or 26 tooth gears?
For the OP, I prefer triples to compact doubles personally but I think doing this conversion may be an expense that doesn't really net you much. I ride a triple and a couple of compact doubles and do fine with either setup. The triple is a little more efficient for me and more flexible but the compact double works just fine. Personally, I wouldn't worry about it. I think you will get used to what you have.
I'm not a fast rider. One thing I do, however, is change out the small chain ring on the doubles from 34 to 36 tooth. That lets me spend more time on the small ring at higher speeds and that improves efficiency a little for me. That with a 25 or 26 tooth cassette works out almost as well as a triple for my kind of riding.
For the OP, I prefer triples to compact doubles personally but I think doing this conversion may be an expense that doesn't really net you much. I ride a triple and a couple of compact doubles and do fine with either setup. The triple is a little more efficient for me and more flexible but the compact double works just fine. Personally, I wouldn't worry about it. I think you will get used to what you have.
I'm not a fast rider. One thing I do, however, is change out the small chain ring on the doubles from 34 to 36 tooth. That lets me spend more time on the small ring at higher speeds and that improves efficiency a little for me. That with a 25 or 26 tooth cassette works out almost as well as a triple for my kind of riding.
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Originally Posted by fmw
I wonder, then, why Campagnolo recommends medium RD's with cassettes with 29 tooth gears but not those with 25 or 26 tooth gears?
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Originally Posted by fmw
I'm not a fast rider. One thing I do, however, is change out the small chain ring on the doubles from 34 to 36 tooth. That lets me spend more time on the small ring at higher speeds and that improves efficiency a little for me. That with a 25 or 26 tooth cassette works out almost as well as a triple for my kind of riding.
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Originally Posted by Al1943
I like that idea too but the OP says he needs a 30" gearor lower and he can't get there with a 36t chainring. A 36/30 combination is 32.4 gear inches.