Guy here.

I ride compact cranks and a 12-25 cog on the back. This is an ideal set up for my 2008 races:

IM 70.3 Kansas
IMLP
IMWI

All three of these are very hilly. The compact crank allows me to spin up the climbs in the saddle. I "run out of gears" only if I exceed about 45 mph on the down hills.

So, I love compact cranks. The ONLY time I could have used regular cranks was doing Spirit of Racine HIM last year. It is very flat and fast so I was maxed out on gearing a couple times. However, this is quite rare.

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When I did that November race in Nevada last year someone on this board whose name you would recognize and respect helped me set up my bike. The first thing that got put on was compact cranks. Its just not the lower gearing – it’s the closeness of the gears. You are in the gear you want to be in – not making a Hobson’s Choice between gears. I also run Q rings.

Do it.
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yeah IMW kicked my butt last September. Even taking it easy on the relentless hills.

Thanks for your advice!

yes exactly-- there is a weird limbo zone I find myself in periodically with current set up.
Thx

both me and my g/f ride compacts, there is really no reason to ride a 53/39 in my opinion, if you prefer to spin a 50/34 or, even better, a 48/34 (or even 46/34 if you want to be even closer) is all you need. I personally have a few cassettes and like especially the 13-23 for flats to slightly rolling terrain as with the close gearing you can find something you like quite easily. Having a 12-27 for steeper stuff is also a lifesaver definitely.

And seriously, I am not going to be pedalling above 30mph anyways downhill (as in pushing hard) so having a 53 in front seems totally pointless...

http://www.sheldonbrown.com/gears/

try some scenarios there and see what happens, a 13-23 in the back with a 48/34 in front can take you from 11mph to 27mph at 90rpm, or basically any sort of speed range I can see myself pedaling at (from basically 9mph at 75rpm to 30mph at 100rpm) and with a reasonable overlap.

And btw, are you sure you are in the 53-12 at 90rpm on flats? that would put you at 32mph, and if you can sustain 32mph on a flat at 128lbs maybe you ought to try turning pro? ;)

Woman here. I have a compact AND a 12-27 on my tri bike. I use that 27 all the time (like to get up the 18% climb back to my apartment in San Francisco). I am pretty big and tall and not a gifted climber, but most of the women I ride with have either a compact or a triple. My road bike has a triple and I'll switch it to a compact when I need to do an overhaul.

I go downhill fast and generally pedal in the flats at 95-100rpm but I have only rarely spun out with my compact setup.

I don't think you need to ride 300mpw to get better at climbing... you just need to do more climbing in the miles you do ride. :) Learn to love hill repeats! They have made me a much better climber.

I ride a 50/36 on my road bike with a 12/27 (I think - it might be a 12/25). I really didn't like the 34 small ring as it felt too "in between" for a lot of gears. Most people don't seem to have an issue with the 34 however, so that might just be me. If you find the drop from 50 to 34 to be too large and you don't tend to push big gears, you'd probably do well with a 48/34. Stick an 11/25 cassette on the back and you should be golden, but if you want you could even go with a 12/27 or a 13/29. 48/13 is still 97 inches (700 x 23) and there isn't a huge amount of terrain where you'd spin that out unless you were hauling ass down hill or riding with a significant tailwind. On the flip side, there's (almost) no such thing as having too small of a bailout gear.

I'm a former roadie who likes to power up steep grades and push a big gear - but all this long distance tri training has been sucking the power out of my legs so I need to compensate with smaller (more reasonable) gearing. For just about any "normal" (or sane) person, it just makes sense to run smaller gears and spin.

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if you're frequently in 53/12 on flat rides, i don't see why you should be considering getting a compact crank at all, assuming your rpm is anywhere above 80.

if it is, you're probably chugging along at 30mph and you should have no trouble going up a hill. in fact, you are probably riding the tour this year.

cadel, is that you? posting in the womens again? tsk tsk.

Assuming you live in a hilly or moderately hilly area, compacts are a better choice. The Shimano 12x27 10 speed cassette is great and will compliment compacts well. Maybe the top 2% of the triathlon bike riders should be on non-compact cranks. There is some good history on this in the main forum from a few years ago.

With that said, you have a ton of options already with your current setup, and what the big deal if you have to muscle up a hill every now and then? 39x27 is a generous gear and would be fine even in most mountains. Grinding at 60 RPM every now and then is great for your leg strength.

Here are a few other posts about compacts:

• http://forum.slowtwitch.com/gforum.cgi?post=659970
• http://forum.slowtwitch.com/gforum.cgi?post=1238671

My husband installed Compacts on my road and tri bike. Love them.

Woman here and I use compact cranks on all my bikes.
Tri - 50/34 with a 12/27 on the back
Road - 50/34 with an 11/26? on the back
I am far from gifted as a climber and prefer to spin rather than grind. I love the compacts.

I use compact cranks on mine, but I live in a very hilly area of LA in the mountains. Even when I am in the flats, I really do not miss big gears as mine seems to be fine (and I usually like riding in big gears on flats). Really helps with the climbs without getting my legs to tired, but then I do have some steep climbs (14% grade being the steepest).

Hi Marco in BC, et al:
I really misrepresented myself and my abilities... (sheepish grin, trying to throw around the vocab a little too earnestly. I do like reading bike mtnc books however!). I mean to say I use the big chain ring and smallest cog often and am comfortable but I doubt I spin 80+ for long in 53/12. I do max out downhill on it tho sometimes. That is , I get spinning way too fast sometimes down hill, and get all bobbly in the hips.

I just got back from a 65 miler this a.m. hoping to give some examples of cadence and which gears I was in but the dang Polar bike computer is not picking up speed (fork sensor), nor cadence (down tube sensor). Oh well. You get my gist--Compared to my local fast female triathlete cohorts, I feel like I am a weenie on hills, yet can go pretty long and strong on the flats, but likely lack muscular endurance overall.

I just wanna go faster (keep up) up the hills and not capsize when my cadence falls too low... (that only happened once I have to admit, on a really long bad ass climb at mile 70 of a century)

PLUS have more fun climbing! :-D

But thank you everyone for your input. I just needed to get my brain around it more before calling my LBS... and breaking the news to my spousal unit :-) (who is a triathtlete too, fortunately!)

EDIT: duh--- I am gonna check what chainrings said cohort group is riding! (lightbulb moment. Can't see forest for the trees somedays)

I suggest some trainer high cadence workouts, start at 30 sec on/30 sec off at 100rpm, then 110, 115, 120 etc. being able to spin smoothly at fast cadences is a good skill to have :)

Girl here. I ride a compact with 12/27 cassette. That setup was specifically for IMLP which is hilly and the ability to spin up the hills really helped save what small shreds of energy I had left for the run. My average cadence for most training rides and races is around 95 rpm. I just rode the same set up at Eagleman--utterly flat--and didn't run out of gears in the big chain ring. However, on long descents I've found that I run out of gears but then I just coast, get drink/eat/pee.

added a compact last year; Campo. it totally revolutionized my riding and i loved it!

I've been on compact 50/36 with Q rings for a few years now. Never going back to 53/39.

My wife runs 50/38, the smallest ring combo that you can put on a 130mm bolt pattern. The reason she didn't go to compacts is because she claims to like the look of her DuraAce crank too much.

Female here - I started out with a 53/39 - 12/25 on my road bike, but when I was getting a new one, I decided to have them put on a 50/34 - 12/27. I loved it so much that I put the same set-up on my tri bike. Spinning up hills, or at least staying seated on steep climbs is so much easier.

can someone explain to me, what are compact cranks?

<hides face in shame at not knowing any cycling-things>

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I'm just going to quote Slowman here:

The rational for use of Compact cranks follows.

The conventional solution to maintain high cadence on a climb is to increase the size (number of teeth) of the large cog on the rear wheel. The smallest production cassette (on a 9 speed) has 11 teeth on the smallest cog and 21 on the largest (an 11-21 set). The next size up is an 11-23 which spreads the gears apart, not a desirable change. To get a 25-tooth cog gear manufacturers configure the set 12-25 and the next size up is 12-27 (other cassette manufacturers offer addition options, such as SRAM's 12-26).

The problem with a 12-27 cassette is the gears are spread apart even more than the 11-23 and you have lost some top speed potential. However, if you need the big cog to get up a hill you have no other choice. That is, until the Compact Crankset came on the market.

Compact cranks have chainrings that are significantly smaller than conventional cranks and are the polar opposite of the big chainrings seen so often on Tri Bikes. Compact cranks typically have 50/34 (sometimes 36) teeth on the outer and inner ring vs. 53/39 teeth on road bikes and 54/42 or bigger on Tri bikes. The ability to use these smaller chainrings occurs because of the crank's smaller bolt pattern, 110mm instead of the usual 130mm or 135mm spacing. There have been several articles about compact cranks in the Tri and Bicycling press in the past year. The argument put forward in these articles has been:

• Higher RPM’s can be maintained on steep climbs because of a lower low gear.
• Closer spacing of the gears makes it easer to maintain the optimal cadence as wind gusts and or small changes in elevation cause small speed changes.
• Some maximal speed potential on down hills is lost, but unless you are sustaining speeds of over 33mph on the flats this should not be an issue.

• The combination of Compact cranks and appropriate cassettes has less rotating mass (lighter) than a conventional set up.


This is an excerpt from http://www.slowtwitch.com/...techctr/gearing.html
those archives sure are useful....
Margaret

Road bike: 700 wheels, compact cranks. Don't like them. Really hate them in crits. May just put the old stuff back on.

Tri bike: 650 wheels, no compact cranks. 12/27 Fine for Vineman.

Get better at climbing? Ride more hills.

clm

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clm
Nashville, TN
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50/34 with an 11/23. I ride in somewhat hilly areas and doing IMLP this year, but I chose compacts not for riding hills but because in general I 'spin' more and keep a higher cadence. I'm on the smallish side and lack a lot power on the bike.

I also train w/ a 12/25 in the back but prefer the 11/23 for racing as I get one more gear for top speed. One thing I dont like is that I dont get much out of the small ring. I almost exclusively use it for climbing and have no use for it in flats. If I could do it again I would get a 50/36.

"Woman here. I have a compact AND a 12-27 on my tri bike."

I have the compact, which is great but am going to add the 12-27. Sometimes you just need another gear or two on the steep climbs.

I agree. I live where its rolling hills, no mountains here, longest hills are .5-1 mile long, up averaging 5-8% grades. I don't have compact cranks. Of the girls I ride with the ones who are always first up the hills are those of us without compact cranks. I didn't have any trouble with this setup riding mountains in Chattanooga or Lake Placid. Hoping to do Silverman on this setup too. There are always times I wish for one more gear, but I think I'd still think that even if I had more gears!