PhotoJoe 

In all of my reading here, one of the reasons people say they prefer the double over triple is that it shifts so much better. If I were to convert a triple to a double (say, bonktown Ultegra double compact), leaving the shifter as a triple but adjusting whatever needs to be adjusted so it thinks it's a double, would it still shift as well as a real double setup. I keep seeing all these triples on CL and it got me wondering. What part of the system makes a double shift so much better? Or, is it the entire system as a whole?

Daytrip

A standard double will shift better than a compact. I'm not sure if a compact will shift better than a triple. What kind of shifter do you have? If it's a 105 (5600) then it should work for either. Probably not as good as a dedicated double STI, but still pretty decent.

shatdow

I converted my triple to a double by only changing the crankset and BB and it works for me. I can't speak to whether a true double front der would be much better, I still have the triple on there. It would make sense to me that the double derailleur could perform slightly better as it doesn't need as long of a cage for the capacity.

The most difficult part is getting the indexing right after the switch. I believe most recent Shimano groups have a universal front shifter, it's just a matter of setting it so the stops are in the right place for a double. In my experience, the double doesn't actually shift any better, it's just that there is less fiddling needed to get the indexing correct, and you can use a wider range of rear cogs for on a given chainring resulting in less shifting.

I say go for it, if it doesn't work well enough for your taste you can change more parts as needed. If it does work, you have a very easy switch back to a triple in case you need it for a particular ride.

EDIT: Just noticed from the post above that you're talking about a compact. I changed to a standard; I haven't ridden or set up a compact so I don't know if my advice still holds.

PhotoJoe 

I currently ride a mtb with slicks. I'm shopping for my first road bike in 20+ years. Was hoping to do something nicer, however, a ton of stuff has made it wiser to buy a used bike now and upgrade in a couple of years. Was looking at a 2007 Allez with a triple (tiagra shifters/front and 105 rear) and it just got me thinking.

Jumpinj98

I changed my previous bike over from a Triple to compact double. It was a full ultegra bike, and only had to change the cranks and rear derailleur. The triple rear derailluer was a long cage and could never get it adjusted right. Bought a short cage rear derrailuer and adjusted it and it was perfect. I had to adjust the front derailleur a couple times to find the "sweet spot" for making the large jump from small to large ring, but it shifts incredible. And if you need a short cage rear derailleur, I have a extra ultegra one with less than 20 miles on it I was keeping for a spare but am switching to sram.

Al1943

Actually it's just the opposite. Shimano 10-speed Ultegra and 105 are now double or triple specific. The 105 10-speed shifters started out double/triple compatible but there has been problems with using the earlier shifters with a double crankset and more recently 105 has become double or triple specific.
The 9-speed Ultegra and 105 shifters went both ways. Dura-Ace is now double only.

Drew Eckhardt 

My triple had better rear shifting than the double which preceded it with the same overall range (50-40-30x13-21 versus 52-42x14-28, with the one tooth jumps being a lot smoother (I realized that I could have a straight block for flat terrain plus climbing gears without changing cassettes or wheels; the setup rocked).

My triple front shifting was better than the double which followed it (50-34) but that was probably as much a function of the better pins and ramps on the Campagnolo triple rings versus the FSA double rings as the smaller difference between chain rings (I switched because I wore out my chain rings, 34x23 is the same low gear as 30x21, and I believed the hype about doubles being better).

The triple was quieter too since I could cruise in cogs closer to the middle of the cassette instead of the ends. With 50-34x13-14-15-16-17-18-19-21-23 I spend a lot of time cruising around 17-19 MPH in 50x21 and 34x14 one in from each end of the cassette while the 40 middle ring on the triple let me use the 16 or 17 cog which is right in the middle.

I wouldn't choose a double unless I could have a low enough gear while still running one tooth jumps up to the 19 cog and had a small ring big enough to cruise in.

shatdow

Ah thank you for clearing that up. I have 9 speed 105 so that explains my experience.

Paul Y.

You'll never know whats best unless you go all the way Dura Ace Double

roadwarrior

Having thousands of miles on both, I have an issue with this. I had Hollowgram with FSA rings with Dura Ace, later Red, and switched to a 50-34 set (the nice part about Hollowgram is that the crank and spider are two separate parts and easily switched) and it shifted no differently than the 53-39 I had previously. Not a single issue. You have to adjust the front derailleur and I took a couple of links out of the chain, but that's it.
I've since switched back, mostly because I ordered two new bikes and that's what was available.

I usually recommend the compact setup to people that are coming off a triple.

icyclist 

"one of the reasons people say they prefer the double over triple is that it shifts so much better."

Not true for me. On a typical triple, it's fairly easy to stay in the middle ring most of the time. Cross-chaining? It's not an issue.

On the other hand, switching from the big ring to the little ring, or the reverse, on a compact, means moving up and down about four cogs in the back to reach the next nearest gear. On the triple, its about three jumps.

So, for me, on a triple, it's less changes of chainrings, no cross chaining, and less jumping around on the back.

Each kind of bike has it's purpose, though, so in the end, none of this matters.

sced

I still don't understand why a 105 triple 10spd shifter and triple FD can't be set up for a double. It sounds simple enough, what's the catch?

travkat

FTW...SRAM Apex and your set!

Phil85207

I thought I needed a compact too and wound up buying a new bike instead of changing what i had. Now I want to change back to a triple. I am old and just need more low gears. My old bike had 105s and I had zero problems with it. I haven't noticed any improvement in shifting with the compact even though its a Ultegra. Good luck.

Carbon Unit

I converted my Campy double to a triple and see no difference in shifting on the cassette and if there is a difference in shifting on the front dr. it isn't very much. However, I have plans to replace my triple with a compact but for a different reason than shifting performance.

My triple is a 53/42/30 with a 13-26 on the back. I probably only use the 30 chain ring once or twice a year, but it is great to have it when I need it. I do go between the 53 and the 42 a lot though. Going to a 50/34 with a 12-29 Campy 11 speed would give almost the exact same range as the triple and the 53/42 has just about the same range as the big chain ring on the compact. So 98% of time I wouldn't need to shift the front dr. It would also reduce a pound or more from the bike.

Drew Eckhardt 

Sounds great if you're in the bike business (fewer SKUs mean higher profits), if you don't care about performance (a double is easier to adjust and perhaps less confusing to people), or if you have "friends" who'd laugh at a triple but let pie-plate sized cogs pass.

Looks lousy if you're riding a road bike and want to be faster to burn more calories in less time or keep up with a group (racing is a theoretical consideration, although to be competitive you'd have the weight and fitness to run 53-39 x 12-13-14-15-16-17-18-19-21-23 in most terrain and wouldn't be thinking about a such a configuration).

The Apex wide-range gearing is 50-34x11-12-13-15-17-19-21-24-28-32.

The same range in a triple can be had with 53-39-28 x 12-13-14-15-16-17-19-21-23-26.

The later makes it easier to ride just a bit harder without running out of RPMs on the high end when you're already fatigued or keeping your power up by mashing the pedals hard enough that your ride tomorrow sucks.

I can go out, have a nice 45 minute tempo ride in the morning and a hard 45 minutes in the evening averaging 200W pedaling 80-90 RPM, try the same thing tomorrow but struggle to make 180W in the evening, and still be slow after a rest day.

Or I can keep my cadence over 90, ride 3x10 at 205-235W on today's evening ride, average 200W tomorrow evening, take a rest day, and do about as well the next two days. While 100-110 RPM works great for shorter intervals or one 10 minute effort I'm not going to do it for any great length of time.

With the big gaps in gearing either I'm going to push for the power and have weak work-outs the rest of the week or compromise by taking it easy every day.

To do a little bench racing as internet denizens do, at nice cruising speeds the wide range double can call for a 50% power increase to maintain the same cadence in the next gear (aerodynamic drag increases with the square of velocity and distance increases linearly making power required to overcome it proportional to the cube of speed) moving from the 15 to 13 cog.

Allowing cadence to drop from 100 to 90 means the power increase required would be only 12% which looks OK until you consider that blood lactate levels are approximately proportional to power raised to the fourth level, or 57% higher with the big gear jump. Over 10 minutes that's the difference between a little uncomfortable and painful counting down minutes remaining.

It's a straw man but might go farther than saying "I rode a triple with the same high and low as the preceding wide range double for a decade, and it was way better"

travkat

I only mentioned Apex because the OP was considering a double. Apex gives the OP pretty much the same spread of gears witha double. I ride a standard RED 53-39 with a 12-26 so none of this triple vs compact makes any sense to me anyway