There have been a couple posts on compacts cranks the past few days and it brings up a questions…if more MOP and even FOP athletes could benefit from them, why don’t more people use them? Also, why do thiose who build bikes not put them on as standard equipment and make a larger crank set an upgrade?
They allow a much lower gear, when paired with a 12-27. Maybe equal to a 30 tooth rear.
Most people don’t feel they need a gear that big.
There are other reasons to have one, but that’s the big one for most people, I think.
If you live in moderately hilly terrain they are great for climbing as they allow you to spin and not pound of the climbs. However, and this is from personal experience, there is a certain point where you simply run out of gears on a descent or on the flats.
In addition, to use a compact crank, the braze-on (Providing its a carbon frame) needs to be able to have the FD sit lower for the jump down to the 34. This is a minor issue mind you, with the larger being the one I mentioned above.
Bob
Also, why do thiose who build bikes not put them on as standard equipment and make a larger crank set an upgrade?
Industries like standards, not having to customize half the products they sell. The bike industry is no different.
Really, everyone should pick their own gearing based on terrain, riding style, and abilities.
But no shop wants to have to change rings on every bike they sell.
Any given bike could be optimally spec’d with:
54/42
53/42
53/39
52/38
52/36
50/36
50/34
48/36
48/34
48/33
46/34
46/33
depending on the rider, riding style, and terrain. And that’s without even considering cassettes.
No shop wants to open this bag of worms.
“Compact” (52/36; 50/34) is an attempt at standardization, but I think the Pandora’s Box of gearing is now open and standards will fall by the wayside.
I have a road bike with compacts. 50/34 11-21. I typically use it for all my group rides. I know I can pull it out and have gearing for pretty much any terrain. I don’t sprint, I will bridge on fast paced training rides and have never had a problem. At 90RPM your still at 31 and some change as opposed to 33 and some change. It’s never held me back and benefits me greatly when we get in the hills.
I wouldn’t use it for any crits, but for road racing I think it definately has it’s benefits. easier gear for climbing, less cadence deviation in winds, and I’m not competing with Cat1/2’s most people stop pedalling on the decents in part on long road races especially when those descents have turns, yet your constantly pedaling uphill despite turns and it certainly helps to have closer gear ratios for slope changes. I always figure if your always one of the first people at the top of the climb you don’t have to pedal as hard on the descent. Must easier going down when your at the FOP.
I agree with you. In fact, the better question for most people would be “why not CC’s?”. Depending on the terrain in your area, buying a new bike with a std 53/39 up front and a 11-23 on the back is crazy for mere mortals like myself. I think most bike shops must do a lot of swapping out to either a CC set-up or at least to a 12-25 cassette. I doubt that I will ever go back to a std crank, although I live in a pretty hilly region.
robert
So, essentially you’re agreeing with me. I did not knock CC"s, but rather said there are two limitations, both of which you pointed out.
I’d eb interested in seein the gear combinations for a 50/34 11-21 as I think it would be very similar to a 53/39 12-27. If so, I’d take the 53-39 for the extra gears in the big ring.
Bob
50/34 11-21 compact is actually closer to a 53/39 12-25 (actually, almost bang on equivalent to a 12-24)
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I thing it all comes down to the type of rider you tend to be. I’m not a great climber per se, but on the flats I am doing the big pulls. This is where I need the gears.
To my knowledge, no pro-team runs a compact on the flats or non-mountain stages.
Bob
Yeah, I mean like anything else gear the bike depending upon what your doing. I like have a bike that I can train on week in and week out without having to mess with it.
Racing is a different story. I don’t race compact, I prefer to pick my rear cogs based on the course I am riding. I do agree with the statement though that most people are probably over geared and a compact would suite them just as much if not more then a traditional setup.
There is a comparison at
http://www.slowtwitch.com/mainheadings/techctr/gearing.html
I guess an 11-21 compact would be most similiar to a 12-25, but giving a better edge to the high speed versus the low speed.
You’re asking a logical question to an emotional issue. Compact cranks are less popular than normal cranks for the same reason a tripple is less popular than a compact crank. People don’t ride tripples because, next to having childrens training wheels on your bike, they are seen as indicative of weakness and lack of cycling prowess.
Functionally, a tripple is great. The Q factor is different than a double, but I think that is a plus, as the narrower the stance the more biomechanical issues create. (Unless you are small woman, a tripple likely fits your anatomy better.) The weight difference is only about 60 grams, which is insignificant.
I ride a tripple. I ride HIM bike splits of about 2:2x, and always under an hour in an olympic distance race. I use a 11x23 cassette, which is good for pretty much any hill and/or wind I ride in. Note that I only need the low gears on easy days where I still choose to ride in the hills, but in Colorado the hills are sometimes hard to avoid. (There are some extremely windy days in winter and springs where I also need the low gears even on relatively flat rides.) Also, I put on a 12x32 and ride the mountain single track, which is a great way to avoid hassles with cars, as is a frequent topic on ST.
But everyone should keep their normal cranks, and hammer into the wind and hills when you race. Please blow up, it makes the run that much easier for me 
Paul
"To my knowledge, no pro-team runs a compact on the flats or non-mountain stages. "
I don’t think that’s a fair statement though. We don’t push near the watts they do.
Tyler Hamilton BTW used compact gearing. Perhaps this was before he decided to get doped 
"they are seen as indicative of weakness and lack of cycling prowess. "
Compacts have made good inroads into general acceptance. I converted four or five years ago when they first came out and the comments on ST back then were quite negative and along the lines that CC’s were for wussies or weaklings. Even after Tyler won his TDF stage on them, there were still a number of sceptical holdouts. That’s changed - one LBS owner told me he’s now selling almost as many compacts as regular cranks.
I’m on 50/36 with Q rings. Couldn’t see myself riding any thing else.
Tyler used a compact on the Mountain Stage he won in, I think 2003. Other than that he used a normal 53-39.
Bob
A couple of thoughts on compact cranks…
One is that some bike companies are putting compact cranks in the specs of some of their bikes.
Two is flexibility. With a 50/36 setup with an 11-23 cassette, you have a good road racing setup with a high gear that is higher than a 53x12. Then, if you need to climb the steep mountains on a different ride, you can swap out the cassette and use a 12-25 or a 12-27 and have a great low gear for climbing. More flexibility than a 53/39 crank would allow, and it is easier to swap out cassettes than it is to swap out the cranks.
Last thought is that depending on how strong a rider you are, you may be able to ride “more completely” in the low to middle cogs on the cassette with out cross chaining or double shifting with a compact setup than with a 53 in front.
He also broke his collarbone three days prior and had to remain seated…
My mini rant on compacts has always been the same. It’s all about gearing, not about product. Quite honestly, many folks who are riding compacts should really be riding a triple…but want to save the weight.
Funny story is that a riding buddy has a triple b/c he’s too cheap to buy a new bike. On each climb, he’s just dying…b/c he doesn’t want to “lower” himself to the granny gear, so he rides his 42x25. It’s hilarious. I tell him to go double-standard to drop to 39x25 and he claims he needs the granny, but yet never uses it!
Regardless…to the original post, it’s all about gearing.
You would be surprised how many people actually think that “compact” means they have shorter crank arms…
Anyway, I ride compacts on my road and tri bikes. Love 'em. 50/34 with an 11-25 in the rear for most rides, but I’ve been known to throw a 26 or 29 back there when the roads are really steep (for example, the 29 may be on there for the Death Ride). I have no real need for a triple, since I can always put “triple gears” on just by changing the cassette.
I must say I somewhat disagree. It is frequently said that the compact gives you triple gearing but with less weight. But I think the real benefits are different from that. Yes, you get sufficient gearing with compacts to cover most needs so you don’t need triple gearing. For example, a 50x34 compact with a 12-25 cassette gives you a lot of versatility for most riding situations (granted there are types of races where the top gear just isn’t big enough for some). I started with a triple and switched to a compact double, and the thing I noticed most was that I was not double shifting nearly as much. Also, with a triple, the cross chaining happens early as you go up the cassette and at least on my ultegra triple setup started rubbing the front derailleur. With the compact, this problem was solved, and I have more and better use of the gears I frequently use on the compact setup than I did with the triple. It is all about gearing, but not just what gears show up on a paper chart. How accessible each gear is while riding is also important, and this is part of the benefit of compact cranks.
So my opinion is that many people who are riding triples should be riding compacts, not the other way around.
“Also, why do thiose who build bikes not put them on as standard equipment and make a larger crank set an upgrade?”
i’ve been asking that for 3 years now. i scratch my head and just can’t figure out what product managers are thinking.
why “standard” cranks?
For me I would only use a compact crank unless I was doing flat road races.