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Discussion Starter · #1 ·
Need opinions and logic behind selecting chainrings on new triple.

I'm converting from a standard double (53/39) to a triple. Two chainring choices are 52/42/30 and 52/39/30. Cassette is 9 sp 12/25, which I don't intend to change. I'm light framed (6'0 @ 155 lbs) and climb relatively well. My pedaling style is a spinner (even when climbing). Out of saddle only to stretch or on particularly tough/short climbs. This conversion will be for a bike that I'll use predominately when I'm in Colorado to ride multiple, consecutive days in the mountains.

My LBS recommends (strongly) I go with the 52/42/30 for cleaner shifting, but a 39 middle ring makes more sense to me from a gearing standpoint. My other two bikes are both standard 53/39 doubles. I need more lower end range than a compact provides.

Opinions? Logic? Makes little difference?

TIA

Bill
 

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I'm with you. I'd say make the decision based on gearing choices. Make charts of the gear layout with the two systems, and pick the one that gives you the gear choices (including shift patterns) that work for you. If you like the patterns you get with your 53/39 doubles, and you're getting the triple mainly to give yourself 2 or 3 bailout gears for long climbs (that's what it sounds like), then 52/39 probably makes sense.

"Cleaner shifting" is a red herring, IMO. You don't have any trouble shifting your current 53/39. Shifting a triple always introduces a bit more complexity and possibility of minor problems, but a 3-tooth change in the middle ring isn't going to affect that one way or the other.
 

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I third that with suggestion

I'd be more concerned about getting more usable gearing variations.

The "cleaner" shifting statement is based on someone who doesn't understand the best method of using a road triple. Unfortunately I'm forced to use it all the time at work. I try to educate people once or twice them fall back to the standard position.

What I'm describing is to never shift to the small 'ring while in your innermost cog in back. If you're coming to a grade that you know you need the small ring shift down while in the third from the innermost cog. If your FD is properly set up you shouldn't ever "drop" your chain. If you find yourself needing the granny in the middle of a hill, double shift - shift to the second from the innermost cog before shifting to the small 'ring. With experimentation, you'll find that there are some very usable gears in the small 'ring/larger cog region. Also, using the double shift will give you smaller drops/jumps in gearing so you don't suddenly spin out on a too small gear. I'm always surprised how many people don't know about double shifts, even for standard doubles...

Obviously practice this stuff on training rides where there is a safe margin of error/frustration.

Good luck,
Bob
 

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double shifts

I'm always surprised how many people don't know about double shifts, even for standard doubles...
Yeah, and they're easier to do than in the old days, too. With Campy Ergo I can punch both thumb buttons simultaneously, dropping to the small ring and one or two smaller cog in the back, and be in the perfect gear without missing a pedal stroke, ready to make further shifts as necessary.
 

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I have an Ultegra 30-39-52 on one of my bikes - with a 9-spd cassette of equal gearing as yours. It shifts smooth and precise. I went with Shimano Ultegra as I wanted to try the Hollowtech II components. I was tired of "churning ice-cream" with Octalink. The Hollowtech II is a delight - easy to install and smooth as silk. The only difficult part of the transition was choosing a FD. As the bicycle is a Trek FX 7.5 (or was before I fully customized it), it requires a top-pull FD. Choices were limited. I went with a Shimano XTR FD-M961 - even though the specs say it has a MAX of 48T chainring. Ignore that - it works perfectly.

Sounds to me like the bike-shop was trying to sell you what they had on hand. Such games are why I try never to darken their doorsteps. And being a trained bike-mechanic doesn't hurt! LOL.

So as for your plans I can say this with some authority: If it's an Ultegra you're looking at, it will work very nicely indeed. But check your chainline to make sure you have enough distance for the triple's small ring to clear.

Happy Trails!
 

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get the 39..

The 42 middle ring is old school and will force you to use the little ring more often since you really shouldn't use the middle ring and largest cog, except briefly. The middle ring on a double is nearly as far to the right as the big ring on a double, so I treat it as such.

The a 39 ring makes perfect sense with modern indexed shifting that can easily shift 2-3 cogs quickly.

I used a 53/39/28 with a 12-25 for several years, riding in the Colorado mountains. Worked great.
 

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I agree, get the 39.

Don't get the Dura-Ace triple. It uses a unique BCD for the small ring, so you are locked into one size. And they are not cheap.
 
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Discussion Starter · #9 · (Edited)
Thanks for the replys........................

The LBS is a terrific shop, I've been a customer for 20 some years. I've dealt with the owner since he was in short pants and to my knowledge, he's always treated me well. I'm sure I've put at least one of his kids through school, possibly his son (the MD). I defer to his knowledge when in doubt. This is the first "head scratcher" I can recall related to his work or knowledge.

I'm suppying the replacement parts (left STI lever, front and rear derailures, crank and bottom bracket), so he has no financial upside to recommend something he has on hand. Even if this were the case, the guy's record and integrity with me is stellar. I recommend him often and with no hesitation. That's why I asked for "logic" to go along with folk's suggestions.

Thanks to those with the "double shift" advice. I rarely do this on my doubles anymore.

Bill
 

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Triple options

I have both a 42 and 39 middle ring on different bikes and find the 39 more versatile in that I can stay in the middle ring for most hills and only need to go to the inner ring for the steep sustained climbs. As far as shifting goes, when I found a good mechanic the shifting became as good as a double.
 

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I agree about the mechanic

orthobiker said:
As far as shifting goes, when I found a good mechanic the shifting became as good as a double.
At the shop I work at, it's a matter of the right mechanic. The two primary (technically I'm no longer a primary) wrenches will get it right. It's when a triple-equipped bike with front shifting problems gets handed off to one of the college racer guys that I cringe. They usually don't take the time to look at every detail of the derailleur set-up. In their minds it's purely a "training" issue..."nobody should ride a triple..."

Bob
 

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I will suggest the 39T for yet another reason. If you want to use a 26T granny ( I expect I would like one in CO) the downshift from 39 will be smoother. My personal experience is that the 39 to 26 works fine but the 42 to 26 would often derail.
 

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ericm979 said:
I agree, get the 39.

Don't get the Dura-Ace triple. It uses a unique BCD for the small ring, so you are locked into one size. And they are not cheap.
A DURA-ACE triple won't do a 26T? Not a 74???
 

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With the LBS around here, I might let the owner take a crack at installing a triple. But the Three Stooges he has working for him - I wouldn't let them install a set of pedals on a bright, sunny day.

Triples can be finicky to set-up just right. Especially the front-derailleur. You need to know what you are doing. Then it's just mildly aggravating. But when you get a "kid-with-pliers" - the chances are good they don't know how to properly install the cable. Seriously. Many people do not if it's an index-system.
 
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