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Discussion Starter · #1 ·
I'm thinking double, but I don't think I'd like the shifting annoyance of the 50/34. Will I always be spinning out of the 46?
 

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saddle tramp said:
Will I always be spinning out of the 46?
Depends on where and with what kind of people you ride and how well you've learned to spin. I have a 48T big ring on my Surly Pacer and actually came off the back of a training group hammering down a slight (perhaps 3% or so) incline because I "spun out" my Pacer. Keep in mind that's what I keep telling myself. The truth might be something else altogether. :)
 

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simple math...

A 46/11 is the same as 50/12 and just a little higher than a 53/13. If you have a 53T big ring now, can you live without the 12?

As for the shifting annoyance of a 50/34, it's a no-brainer. All you have to do is shift 3-cogs after every chainring shift instead of two. How tough is that? Most shifters, except the new DA7900 can shift 3-cog larger with one sweep of a lever. Shifting 3-cogs smaller is 3 quick taps, unless you have Campy. Then it's one push of the thumb button.
 

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Discussion Starter · #4 ·
For the relatively flat terrain around here I'm thinking 50/38 or maybe 36 would be my preferred but I'm not seeing it out there.
 

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50/36 is a good combo. shifts better then 34 and the gap is less, makes for less changing in the back, maybe 1-2 cogs when changing between the chain rings.
 

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saddle tramp said:
For the relatively flat terrain around here I'm thinking 50/38 or maybe 36 would be my preferred but I'm not seeing it out there.
If you live in relatively flat terrain, I suggest 53/42 or 53/44 ring combo with bigger cogset ratio. I never like a big spread between the big/small ring.....
 

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I tried a 50/34 compact crank for one season and switched back to a 53/39. It seemed that I was always shifting the front back and forth between the rings. The comment about how hard is it to shift 3 cogs instead of 2 is from someone who must have never ridden with a compact crank. The normal Shimano and Campy shifters shift 3 cogs with a full stroke and you need to shift 4 cogs. That is a double stroke with the right when shifting to the big ring and the opposite is true too when you have to keep punching the lever way too many times.
 

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saddle tramp said:
Is it uncommon to buy a new crankset and then rework the dang thing?
Used to be done all the time in the days of 5, 6 and 7-speed rears. Racers would pick rings depending on the course. It wasn't uncommon to see someone ride a 52/50 in front on a flat course on Saturday, then put on a 52/42 or 53/39 for a hilly race on Sunday. For many years, 52/42 was the all-around standard setup. With 10 or 11 speeds in the rear now, picking rings for a race or ride isn't really needed any more.

Still, you might benefit fom some experimentation. As cpark said, some people (myself included) find a big spread between large and small ring annoying. On my go-fast bike, I use a 52/42 and like the way I can just shift down and find myself with good resistance on the pedal and a sane cadence. Watch people with 53/39s or 50/34s run up to a hill in the big ring and shift the front: one second they're turning the pedals nicely, the next second they're stepping into thin air, trying to turn an impossibly high cadence. I know, it can all be staightened out with some simultaneous quick rear shifting, but I prefer not to have to do that. :D
 

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JimP said:
I tried a 50/34 compact crank for one season and switched back to a 53/39. It seemed that I was always shifting the front back and forth between the rings. The comment about how hard is it to shift 3 cogs instead of 2 is from someone who must have never ridden with a compact crank. The normal Shimano and Campy shifters shift 3 cogs with a full stroke and you need to shift 4 cogs. That is a double stroke with the right when shifting to the big ring and the opposite is true too when you have to keep punching the lever way too many times.
Curiously, if you found yourself switching back and forth between the front rings on the 50/34, what do you do with the 53/39?

I have a compact and I find myself either crosschaining a lot in the 50 or switching back and forth between the front rings. I also find that I never use the 34x25 and I spin out in the 50x12. I'm thinking of trying a 53/39 setup.
 

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vortechcoupe said:
50/36 is a good combo. shifts better then 34 and the gap is less, makes for less changing in the back, maybe 1-2 cogs when changing between the chain rings.
I also have a 36/50 with a 11-23 cassette (Sram Red) and find this ideal for flatish rides mainly using the 50 ring, this does involve 'cross chaining' a bit but not often and only 1-2 changes on the cassette when changing 'rings.
For any serious climbing I can swap to a 34/50 & 11-26 cassette, note that I don't race and I'm a relatively poor (slow) climber :wink5:
 

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saddle tramp: lots of people mess around with the chain rings on their cranks. Even pro racers; for paris-roubaix plenty of guys run a 53-48 for the relatively flat conditions. The only problem with swapping chainrings is that most higher end cranksets have paired rings. That means that the rings are made to be used only in certain combo's. For example, many 130bcd cranks only have paired rings of 53/39 and for compact (110bcd) its hard to find anything other than 50/34 or 50/36 combos. These ring combos are set up with special pins and ramps to smooth out the shifts and catch the chain better when dropping to the smaller ring.

If you change to a non standard ring it probably won't have the ramps and pins. This might lead to slightly slower shifting and a need to let up just a little more on the chain when shifting.

That being said I've used plenty of non-standard ring set ups. I like rings from TA Specialites. I currently run a 38/46 on my cross bike, the the 46 is from TA and works quite well.

As far as compact cranks go, I use them for climbing very short steep hills and maintaining a high cadence. I have never had any problem shifting with them, neither have the man pro riders who use them when the situation calls for it. (ever heard of Fabian Cancellara?) But for flat terrain I don't think they are necessary. A 39x25 combo is pretty fast spin on flat ground. A 53 might seem big but its nice with a tailwind or when drafting, or when standing when paired with the smaller teeth of the cassette.

My opinion is that there is no such thing as cross chaining on a double set-up. I think with a double that the whole cassette should be usable with either front ring. And most decent set-ups can be done so that there is little to no rub on the front derailleur in any of these combos. Cross chaining is more of an issue with triples, although there are reasons to do it, especially while racing off-road in the big ring.
 

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pbayne said:
My opinion is that there is no such thing as cross chaining on a double set-up. I think with a double that the whole cassette should be usable with either front ring. And most decent set-ups can be done so that there is little to no rub on the front derailleur in any of these combos. Cross chaining is more of an issue with triples, although there are reasons to do it, especially while racing off-road in the big ring.
I agree, but I just went through a Dura Ace chain in about 1000 miles. I thought there was no way it could be the chain since it had so few miles on it. My mechanic said that it was so stretched out that it was off the chart on the chain measuring tool. I'd probably spend 90% of my time in the 50 ring if it weren't for the scolding I got about "No crosschaining!" :p
 

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My road bike has a 39/53 with a 12-27 (campy 11). It does everything I need to go fast. My commuter has a 38/48 with a 13-26 and it sees most of the miles. My commute has two 35+ mph descents which reach the limit of spinning out. The 48 with the 13-26 prevents cross chaining and the 38/48 is a good shift. If I have been riding the road bike and then get on the commuter, I often look down to make sure I have shifted onto the big ring since the change is so subtle.
 

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Discussion Starter · #16 ·
"My opinion is that there is no such thing as cross chaining on a double set-up. I think with a double that the whole cassette should be usable with either front ring. And most decent set-ups can be done so that there is little to no rub on the front derailleur in any of these combos."

Man, this is just what I'm looking for. All the bikes I've ever had in the "modern era" have been triples and I've never used the smallest ring. And I'm always hunting around trying to get the most without any rub, I find any odd noise very annoying. (kind of kooky)

I'm thinking if I keep it to a 14 tooth difference and the cassette 12-26 there should not be any rub?
 

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saddletramp- I think you'll like going from triple to compact, you get a similar range of gears with a little less shifting hassle. A 14 tooth difference is easy, many FD's can handle a 16 tooth difference no problem. Shimano FD's are great for that, especially when the front shifter has a trim position or two to get rid of that annoying rub. My older 105 shifters do this, so do my ultegra sl levers. Cassette spacing shouldn't matter, they are all the same width nowadays (not sure about the new 11 speed cassettes). I switch between cassettes from an 11-23 to 12-27 depending on what I want with no issues whatsoever. I set my chain length with an 11-25 and have never had issues.

Be aware as Tyro mentioned above that if you "cross chain" with a double it may wear your equipment a little faster. If you're on a tight budget and don't race this may be an issue. If you want performance just do it anyway, functionally its fine.
 

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thoughts...

saddle tramp said:
For the relatively flat terrain around here I'm thinking 50/38 or maybe 36 would be my preferred but I'm not seeing it out there.

A 50/36 is not common because it rarely makes much sense. All it does is drop both the top gear and low gear down by one ratio. You can do the same thing by using a 12-27 casssette instead of an 11-25.

On flatter terrain, a 53/39 should be perfectly adequate. I rode the rolling terrain aroudn the Kansas City area and rarely used a gear lower than a 39/21, until 10 speed came out. Then a 23 or 25 low was easier to get without big jumps between the cogs.

These days, I use a 50/34 with an 11-25 11 speed drivetrain for the Colorado mountains. I can handle everything with one setup.
 

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I am using Ultegra 50/34 12-27. I have steep hills and rolling flats, so I find it ideal to eat them all. My builder and I had a long, long "discussion" over this (he prefers 53/39 in front) and I insisted for the compact set up. I'm glad I stuck to my guns. I did a 65 mile mountain ride with 7 climbs and the 34 ring was just right. On my way home I had a nice long flat section with occasional lights. I passed some guy on a Giant road bike and he started to draft me all the way down the road (wouldn't even say hello at the lights). The 50-12 was plenty fine to sprint ahead and lose him. As far as the hills... man I either know i can take it in the big ring, or prepare with the small one in time so I don't need to screw with it on the climb (my climbs are steep and abrupt, so maybe a different case.)
 
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