jfmckenna

Didn't read the whole thread but just a few words. I have a triple on my touring bike with friction DT shifters and it works like a charm. However I have found shifting often times cumbersome and faulty on STI triples. A compact will give you very closely every gear you want and still have that smooth double shifting. I know people will chime in here and say that if your triple is set up properly then blah blah blah but I never have a problem with a double and always have a problem with a triple. So FWIW there is my 2 cents.

exRunner

I was thinking the same thing. IMHO you can not figure out what you need without a reference frame. Buy something, ride it, and if it doesn't do it for you change the crank. If you buy a 105 bike then you won't even have to change the left STI (until you break it, but that is a different thread).

If I was in this position I would buy the triple, then if I decided I needed a compact douple, change the crank and sell the old one on ebay (or keep it in case I changed my mind). They aren't that expensive, and if you can't change a crank yourself it isn't that much at the LBS to let them do it.

Yes, I ride a standard double and a compact double, and the compact is about to be changed to standard. It is quickly becoming a failed experiment. I also have a triple that was given to me, but it has not been out of the garage in 5 years. Besides being a triple, it is somewhat of a "lead sled" and not much fun to ride.

bretgross

I'm old, slow, weak, stiff, and clumsy. I don't care about style points, I want what works for me.

That said, I have a triple on my 20+ year old MTB and I use it on days when I'll be doing a lot of hills.
Other days, I use my 53/39 road bike, or I did before the road bike got destroyed by a pickup.

The new bike will have a compact crank (50/34) with 11-26 cog. Compared to the old road bike setup, I'll have higher high and lower low.
Might start leaving the MTB at home... we'll see.

Herbie53

Brief hijack, but I had a double/triple compatible left 105 brifter die (as many have) and was able to send it back to Shimano using their online return form (I did call them first). I got a new double only one in about 2 weeks for nothing but postage to send them the old one. Issue is related to how you set up the triple one. If it is set so you're on the big ring in the "middle ring" position you can over tension things by trying to go the the bigger ring position. You want it set up to use the top two. They were cool about replacing in any case.

Hijack over.

Carry on.

guy2600

I think you should get the triple. The weight saving of a double is minimal if you get a quality triple crankset and that's the only drawback from my point of view. You'll have extra gearing available to you which is never a bad thing...

cyccommute 

No, it's not. Most compacts are 50/34. If you look at a traditional road crank, they are 52/42, 52/40, or 52/39. The difference between the rings are 10, 12 and 13 respectively. A 48/36 has a 12 tooth difference...right in the middle the other cranks. A compact crank has a 16 tooth difference. That 16 tooth difference causes a huge shift in the gear ratios with the cassette. If you run the numbers, it's almost like you have 2 separate cranks on the bike. You end up with lots of gear combinations but you'd have to make shifts on the front and several shifts on the rear to get all of them. It's just a bad combination. Your 50/36 or a 50/38 gives a much better gear selection but negates the low end 'advantage' of the compact.

pacificaslim

FWIW, the reason I want to go to a compact instead of the 48-36 is that I want the 34 so I can run smaller cassettes in the back. I'm currently running 9 speed and have big mtb cassettes available to me. There are occasions off road when I'm glad I could shift into 36 -34.

But if I go to compact cranks and 10 speed, then I'll run normal 10 speed cassettes and have either a 27 or 28 as my largest cog (or 29 with campy). So I'd like a smaller chainring so I still have something low enough for dirt climbing. The advantage of having the 50 instead of 48 would be mainly if I go to campy because their large cassette is 13-29, and with that 13 I'd rather have a 50 chainring than 48.

If I go with SRAM, and get to keep the 11t cog, then heck, I'd be tempted to try something weird like 46-32 if those chainrings are available, with an 11-23 or 11-25 cassette. I'll have to go run the gear calculator and see how bad that'd be.

clutchy

I'd agree w/ that, i did 3 climbing centuries on standard gearing and wished for a compact most of the time.

Randochap

I prefer a triple for 2 reasons: Lower granny. Closer spacing (so less need for double-shifting) I heroically open and examine this can of killer worms here.

NaBlade

For racers, this "bad" gear combination is important, although most serious racers would have standards anyway. For most recreational and fitness cyclists, having to double shift in the back after shifting on the front is not such a big deal at all. I'm not a strong rider at all and I live in a very hilly city. But I've been thriving on a compact for 2 years now. If I toured regularly with loaded packs, I'd get a triple, but I don't.

cyccommute 

Personally, I just don't see the appeal of the compact. Looking at the gear ratios, the number of shifts on the back are more than a couple. For example a 50/17 is 77 gear iches. The next gear, on a 10 speed 12-27 cassette, is 69 gear inches. There are two combinations that can be used for that 50/19 or 34/13. The 34/13 combination would require a shift to the rear and then upshifting 6 times. If you just wanted to shift from the 50/17 to the 34/13, it's still 5 rear shifts and a front shift. I don't see how you do the shift either. Drop to the low ring in the front and then spin like crazy until while you hunt and peck for the proper gear or shift the rear first to a much higher gear and then dump to the lower ring. Either way, you are going to be spending some time in combinations that just don't work that well.

The traditional ratios with a 10 or 12 tooth difference between the chainwheels gives a much smoother transition without all the futzing.

RichinPeoria

nice..that acticle is current

Barrettscv 

If I want style points, I ride my classic bike with a 52 & 49t chainrings and a 14-26 freewheel.





When I want to ride a double metric and not fear any hill, I use a 50, 39 & 30t triple.



Ask yourself what your riding goals are.

Michael

NaBlade

The math of gear ratios on paper is all well and good, but you're doing the shifting on paper what I probably won't do on the road. In practice, or at least in my experience when front-shifting, all I really need is 2 rear shifts. That's because I only shift the front gear when there's a big change in road gradient. By the time I get to my "sweet spot" as far as cadence or pedal power is concerned, the gradient has changed dramatically that it really only takes 2 shifts in the rear plus the 1 up front. Been riding this compact for 2 years, I don't EVER remember shifting the rear 5 positions, right after shifting the front just to get my rhythm back.

SMH707

Boy-no offense intended-but you're making it way too complicated in practice, imho! I just went out and rode 40 miles today and basically did the entire ride on my small ring (36). As I stated earlier, the 36 is good for the long steep climbs all the way up to fairly fast flat or mild descents at 26+ mph. No double shifting, no hassles, no gigantic gear-inch steps to fight through--I guess I just don't see the problems that you are raising when riding a compact crank during actual use. Now, I'm not going to argue with you that there are combinations on the big ring (whatever size you've chosen for the compact-anywhere in the low 40's to 52) that will fall in between the combinations you get on your small ring. But honestly if looking at the gear-inch layout on Sheldon's site is what is causing you concern, then you should really just ride one for a while-with the appropriate chainring combos selected for the type of riding you're planning to do-and I think you'll see that all this '5' and '6' shifting on the rear *never* happens (do you *really* need *that* small of steps in gear-inch changes with each shift?). When you look at other charts, based on speed and cadence, you'll see that most shifting (while staying in the small ring only and just shifting the rear) results in a loss of 10 rpm from your largest cog down to the 17, and 5 rpm from 17 down to 12--keeping the speed roughly constant across the shift. With this arrangement, your cadence will stay between 90 and 80, or 90 and 85 worst case scenario--hardly a 'horrendous' scenario in reality.

I think you missed my point regarding the flexibility of a compact crank: the 110 bcd allows the flexibility to run whatever pairing of chainrings you want from 34 on up. BTW: my Rival 16 tooth delta between front rings shifts much better than my previous FSA triple did--so the 16 tooth diff really isn't an issue in practice--it shifts very smoothly. I can't speak for other manufacturer's cranks/chainrings since I've not ridden them. Also, a traditional 'standard' 53/39 or 52/38 is a 14 tooth difference--not far off the 14-16 tooth difference of a traditional compact (50/36 or 50/34, now they are starting to come in 52/36 and 52/38 combos as well).

Anyway my point is: regardless of what the charts tell you, the compact really isn't as bad as you're making it out to be in real life use. I prefer compacts because the 110 'compact' bcd gives me all the chainring combinations that I need, and the ability to custom select the pair I need for the ride I'm embarking on (it gives flexibility you don't have with a standard)--including giving me 'standard' ratios without having to take off the crank (though large changes in the big ring does still require the front derailleur height to be adjusted for optimum shifting). I've looked at the charts, and also ride it in reality and am telling you from first hand experience that compacts really aren't as bad as you're making them out to be...

SMH707

+1, well said! Plus when you finish climbing a hill in the small ring, as you crest and begin to descend, a shift to the big ring gets you a very nice shift to a 'faster' gear (like a double rear shift). From there you only have to work the rear derailleur on the rest of the descent. Likewise if you're riding rolling hills: after descending in the big ring and starting the next climb (still in the big ring) a simple shift down gets you set up nicely for climbing (in the small ring, and on the smaller half of the cassette--ready to shift to several easier gears as the climb goes on or gets steeper). Of course this same strategy can be used for a standard crank-but it just seems to work nicer (for me) with a compact rather than a standard.

logdrum

What's with this you shift too much on front derailleur of a compact. You need to give attention to the front cable/shifter with the rear. Otherwise one party may get jealous.

Having said that and now riding a compact, the small guy 34T has thought me to spin faster and the B.I.G. taught me to mash harder

Retro Grouch 

That's a point that I've often posted about. I think that the key to how well you'll like a compact crankset is the dead flat road gear ratio. If your favorite flat road ratio falls in the middle of the cassette, compact cranksets work great. You only use the little chainring for climbing hills. If your flat road ratio is near the end of the cassette, you'll find yourself making a lot of front shifts - along with some compensating rear shifts.

For me, the conversion from a 53/39 to a 50/34 might be the best equipment change that I've ever made. I gave up some fast riding gears that I never used and picked up a couple of hill climb gears that I desperately needed. YMMV

cyccommute 

Look at speeds at 90 rpm for the combinations. For example going from the 50/17 to the 34/17, the speed goes from 21 to 14 mph. To keep the same speed, you'd have to increase rpm to over 120 rpm without making a shift on the rear. 120 rpm is a huge jump from 90. I ride a 'compact crank' just not the one that is currently in favor, i.e. the one with the 16 tooth jump. I also happen to have triples on all my bikes. I don't use them that much but if I have a need for one, it's there.

I'm didn't say anything about the flexibility of the compact. That flexibility is available on just about any crank set system when paired with the proper rear cassette. However, most of the compacts sold are sold as 50/34. The gear combinations that those cranks give with the rear cassettes available aren't ones that I'd ever consider because of the giant holes in the gear combinations. I have enough cycling experience to know what works for me...as I prefaced in my post... and having to jump to 120 rpms on downshifts aren't something that I like to do.

Personal preference. I just like a more progressive shift pattern. My riding is more mountainous and hill than a lot of areas and on climbs I end up making more shifts from large chainring to low chainring.