Bicycle Mechanics - Triple Crank vs Compact Double

The triple would have like 50-39-32, the double is 50/36

Thoughts? I'm hoping that a double would 1) have cleaner shifting and not as much rattling around the front derailleur and 2) be a bit less unwieldy than the triple.

Where do you ride? Discribe why you ride, please.

It's a matter of having the right tool for the job.

Michael

mostly commuting, fairly flat, but I have at times used my "granny gear"

I'm mostly concerned with mechanical advantages besdides weight

A compact double will have about 90%, or more, of the gear range of a road triple. The double is simpler, has a thinner Q factor (the width between pedals) and shifts better in many cases.

Most compact doubles tend to cross chain at normal riding speeds of around 18 to 21 mph. To avoid using the big chainring with the bigger cogs on the cassette, the rider needs to shift the front chainrings while slowing. In the same situation, the middle chainring on a triple will not need to be down shifted.

I like having a triple, however a double should work well for you. You will be shifting the front chainrings as you speed up to 20 mph speeds. You may also need to shift the chainrings again as you slow down to 10 mph speeds.

Michael

Double crank

Seriously triple cranks are rediculous for all but the most extreme riders. The nominal difference in gear ratios that you get from a triple vs a double is not noticeable to the average rider. In some cases you can even end up with redundant gear ratios. All it generally does is add weight. It is just as stupid as bikes having more than about 7 rear cogs.

Think about this- how many gears do you actually use on your bike. For most people its really only 3-4 different gears. Unless you are doing high grade(7%+) massive hills or steep technical riding there is no need for anything less than a 2:1.5 and no greater than 3.5:1 these are easily attainable with a 12-14 speed setup.

Do you really think you would feel the difference between a 2.61:1 and a 2.54:1, I don't think so.

Who really needs 21-30 speed setups, c'mon

:P Sorry for the rant!

Double crank

Seriously triple cranks are rediculous for all but the most extreme riders. The nominal difference in gear ratios that you get from a triple vs a double is not noticeable to the average rider. In some cases you can even end up with redundant gear ratios. All it generally does is add weight. It is just as stupid as bikes having more than about 7 rear cogs.

Think about this- how many gears do you actually use on your bike. For most people its really only 3-4 different gears. Unless you are doing high grade(7%+) massive hills or steep technical riding there is no need for anything less than a 2:1.5 and no greater than 3.5:1 these are easily attainable with a 12-14 speed setup.

Do you really think you would feel the difference between a 2.61:1 and a 2.54:1, I don't think so.

Who really needs 21-30 speed setups, c'mon

:P Sorry for the rant!

A good triple crankset is not significantly heavier than a double at the same pricepoint. A double provides two speed ranges: faster for flats or slower for climbing. A triple provides three speed ranges, very slow for steep climbs, moderate speed for normal riding and third range for higher speed travel.

See this thread for more info: http://www.bikeforums.net/showthread.php?t=719

Michael

Double crank

Seriously triple cranks are rediculous for all but the most extreme riders. The nominal difference in gear ratios that you get from a triple vs a double is not noticeable to the average rider. In some cases you can even end up with redundant gear ratios. All it generally does is add weight. It is just as stupid as bikes having more than about 7 rear cogs.

Think about this- how many gears do you actually use on your bike. For most people its really only 3-4 different gears. Unless you are doing high grade(7%+) massive hills or steep technical riding there is no need for anything less than a 2:1.5 and no greater than 3.5:1 these are easily attainable with a 12-14 speed setup.
Do you really think you would feel the difference between a 2.61:1 and a 2.54:1, I don't think so.
Who really needs 21-30 speed setups, c'mon


I ride standard doubles myself, no offense but I really don't agree with some of your reasoning. In my experience flat land riders tend to use all of the cogs in the rear and benefit more from closer ratio spacings. My riding is mostly flat with some rolling hills and a few short steep grades. I prefer my 10-speed cassette to my 9-speed cassette because the extra cog in the middle helps keep my cadence in the 95 - 105 rpm range. This really helps when riding in a pack and when trying to match speeds with others and with fighting gusty headwinds. If I had a triple 10-speed I would have the same advantage but a heavier bike. I use every gear on my bikes on every ride and would use more if I had them.
If I switch to a compact double I'll probably go with a 50-36, I don't like the bigger ratio jump of a 50-34.
Would I feel the difference in a 2.61:1 and a 2.54:1? Absolutely.

like the other poster said, get thr right tool so YOU can do the job. so understand the job, and understand YOU.

some folks HAVE to have a triple out here in the west. Hills can go on for 25+ miles, can get steep. others can manage with a compact double.

i have three bikes. touring bike with a mtb triple (as LOW as you can go). two road bikes, one standard road gearing, one compact. which one i use depends on that job i want to do.

i had a road triple, but discovered i am strong enough to use a compact on most hille out here so I wasn't using that bike a lot. so I sold it.. if its too steep for the compact double, i use my touring bike.

not hilly and want to go faster, i use the regular geared double.

bikes in a quiver, use the right arrow for the job.

Seriously triple cranks are rediculous for all but the most extreme riders. The nominal difference in gear ratios that you get from a triple vs a double is not noticeable to the average rider. In some cases you can even end up with redundant gear ratios. All it generally does is add weight.
Tell you what. I don't know where you live or what terrain you have to deal at home with but come to SW PA or West Virginia and go riding with me. After we get back from Walker Mill Road, Sycamore St. and Potomac Ave. we'll discuss how ridiculous a triple is for ordinary riding.

Sure a triple has several redundant gear ratios. That's a feature, not a bug. Also, the weight difference is very small except for the most committed weight weenie and the availability of lower gears can be invaluable at times. Don't knock it if you haven't needed it.

Double crank

Seriously triple cranks are rediculous for all but the most extreme riders. The nominal difference in gear ratios that you get from a triple vs a double is not noticeable to the average rider. In some cases you can even end up with redundant gear ratios. All it generally does is add weight. It is just as stupid as bikes having more than about 7 rear cogs.

Think about this- how many gears do you actually use on your bike. For most people its really only 3-4 different gears. Unless you are doing high grade(7%+) massive hills or steep technical riding there is no need for anything less than a 2:1.5 and no greater than 3.5:1 these are easily attainable with a 12-14 speed setup.

Do you really think you would feel the difference between a 2.61:1 and a 2.54:1, I don't think so.

Who really needs 21-30 speed setups, c'mon

:P Sorry for the rant!

no disrespect, but..

selection of triple, double, or regular gearing depends on terrain and strength of rider. right tool for the job.

and:

I use all of my gears (non cross chained) gears every time i ride.

difference between 2.61:1 and a 2.54: IS detectable

having more than 7 cogs is not stupid - for everyone. might be stupid for you, given the tool YOU need for the job.

The nominal difference in gear ratios that you get from a triple vs a double is definately noticeable. depending on strength of rider and steepness of terrain, you might not need the nominal difference of the triple.

Guys,
I didn't say triples were totally useless, but for most people they really are. Kudos for you if you use every gear on your 30 speed bike, I'll race you any day on a 12 speed and probably only use 6 gears of that.

As to the guy from PA or WV, dont talk about the apalacians as if they are real mountains, I'm from VA and I know those hills well. You still don't need more than 14 speeds for those provided you have a high enough top end and low enough low end.

To the westcoast riders, I feel you, I'm on the west coast now. I didn't say that 3 speed front is never a good idea, in fact I specified that they are good for somone ride long steep inclines. like we have out here. Jeez.

My argument is that most riders dont need the rediculously small differences in gear ratios you get from these mega-geared bikes, 12-14 speeds is more than enough for most riders. I know some of you want to justify having spend bucks on more gears than you need, but get real folks. Man up and use your legs, technology doesn't improve the skill of a rider.

BTW I ride single now if that says anything to you about my bias towards lower gear numbers

Pick up your cadence if you want to go fast, muscle up if you want to climb, that is my motto.

BTW I ride single now if that says anything to you about my bias towards lower gear numbers

Pick up your cadence if you want to go fast, muscle up if you want to climb, that is my motto.

It's all about you.

My 1 gear is 34:16, and it worked in VA for almost everything(not the apps of course) and it works in SoCal fine too.

Of course

eh, 52:16 feels similar to 42:13. With a compact, you're mainly giving up the middle ring, which I think I could live with, especially if it gives me a smoother mechanical shifting in hte front.

I don't think a *properly adjusted* triple shifts any worse than a *properly adjusted* double or compact. Therefore, I don't think you will get improved shifting moving to a compact, all other things equal. My triple shifted like butter, and my current compact double shifts like butter.

Other than that . . . choose the gearing you like, and don't tell somebody else how ridiculous their gearing is.

52:16=3.25 ratio
42:13=3.23 ratio

are you seriously going to feel the difference between 2 tenths of a rotation per pedal stroke when you are above 3 rotations. Not a chance. This is what I am talking about.

my bad 2 100ths of a rotation per pedal stroke. even more rediculous

Like I was saying find out what you need on the low end and what you need on the high end. Gear your bike for these two cogs, and i guess decide how many increments you want in between

You have more options than those two (triple vs. compact double).

I've run a 53/39 with a 12-23 cassete (stock gearing on my first road bike). Not fun for a fatso like me.

Then I went to a 110bcd compact 50/34, switching cassetes between a 12-26 and an 11-32 if the bike was loaded on the rear rack or not, and in respect to how fit I was or how hilly the route was.

Now I've gone back to the original 130bcd crank and fitted a 42t middle tripleizer chainring that holds a 24t on the inside, giving me 53/42/24 x 11-32 or whatever I feel like using as a cassete for the given ride.
With a 11-32 cassete there's no overlap in the 53/42 chainrings giving me a "half step plus granny" option and I use the 24t chainring for only the steepest climbs. The search for my perfect road riding/loaded commuting gearing has ended. I feel like I'm married for life with this setup.

apalacians

What's that?

Oh, and for some serious enlightenment on gear options don't forget to read from The Gospel of Sheldon (http://sheldonbrown.com/gear-theory.html)

Why can't Shimano and Campagnolo market a serious half step plus granny system, instead of, say, the stupid and overpriced electronic shifting and 11 cog cassettes? Why? WHY?

I never claimed to be a spelling bee champ. Cant find a legitimate thing to say so you attack my spelling. good on you bro.

Like I was saying find out what you need on the low end and what you need on the high end. Gear your bike for these two cogs, and i guess decide how many increments you want in between
True but limiting the cog numbers and using a double crank, while still able to get both extremes, does leave big holes in the middle. Now a straight block from 11 to 19 isn't essential but smaller steps can be very comfortable. One advantage to most 10-speed and some 9-speed cassettes is that they have the VERY useful 16T cog.

I'd do the compact double. I had a 42-52 on my hybrid, with a 13-21 7-speed. Never used the highest two or three gears, and always seemed to be "bringing up the rear" of the pack while riding. Considered a triple for a short time, but then realized I have to change the rear derailler to a long cage. That made the change too expensive. So, I just swapped out the chainrings to 38-46. It really helped alot. I can run the top gear without pulling my knee sockets out, I have a lower couple of gears for hills, and I can keep up with the spring chickens. Plus, the rings were good condition used @ $4 each! Best $8 upgrade I ever made!

Why can't Shimano and Campagnolo market a serious half step plus granny system, instead of, say, the stupid and overpriced electronic shifting and 11 cog cassettes? Why? WHY?

What do you like so much about a half step plus granny setup? I've used them, and much prefer a modern triple with the bulk of the shifting done with the rear derailleur.

What do you like so much about a half step plus granny setup? I've used them, and much prefer a modern triple with the bulk of the shifting done with the rear derailleur.

I think the 53/42 ratio is better suited for small hills than the 53/39 that always makes me shift in the back (which I don't like much).
On flat terrain, since there's half stepping, I can always keep about the same cadence, despite the fact that I'm using a widely spaced mountain/touring cassette.
Finally, there's the everpresent bailout chainring that contributes to my peace of mind, if nothing else.

So, the shifting strategy is:
a) small hills: adjust the cog in the back to the steepness of the hill, and keep the chain there. When you go over the hill, just shift from the 42 to the 53. The downgrade on one side of the hill is almost always the same as the upgrade on the other side of the hill, so the cog remains the same. The next hill is probably has steep as the last one, so you just have to keep shifting in the front. Flat terrain is the only occasion where I don't mind having to shift both in the front and in the back.
b) flat terrain: there are non overlaping combinations to keep you entertained in finding just the right confortable cadence. Lenghty flat terrain can be boring, so I get to fiddle with the shifters.
c) hard climbs: when the cassette runs out of cogs, you still have options with the granny.

I realize a light to medium build fit rider will find happiness in a classic double or compact double, and the touring cyclist and lesser-fit cyclist will do so with a classic triple, but the half step plus granny setup is the perfect compromise between:
a) using a widely spaced mountain/touring cassette; but
b) still keeping small jumps between chainring/cog combinations; and
c) having a "climb everything" chainring. The 30t chainring that comes on most triples is not enough in some circunstances, so not really a "granny".

I also realize that half step chainrings where originally meant to be combined with a freewheel of 13-15-17-20-24 or whatever to solve the problem of widely spaced cogs, but the thing is: they still work fine for my purposes, when put together with lesser spaced 8-9 speed cassetes.

What do you like so much about a half step plus granny setup? I've used them, and much prefer a modern triple with the bulk of the shifting done with the rear derailleur.

Precisely the opposite; it's the half step setup that allows me to do the bulk of my shifting with the rear derailleur, when it counts.

With a wide cassette in back just shifting the RD covers the vast majority of riding circumstances. With a road double or compact setup I'm always doing double shifts to get on a different ring whenever the grade turns suddenly up or down -- which is precisely when you don't have much time to do a double shift.

OTOH, if you are riding along on a steady grade, the wind shifts and you have a thought that you could use a 7% different gear, a double shift is fine because you aren't in a rush to get to the next gear.

Interesting take guys, and I won't argue with you. Choice is good.

Have ridden tandem/single bikes in 30-some states. Have cycled at sea level and many times at 9,000+ ft. elevation. Ridden east/west coast and much stuff in between.
Prefer, and have, a triple on our tandem and also on my single. So far have only covered 300,000+ miles on bicycles and my knees (at age 76) are still fine. Doing 100+ miles weekly, year 'round.
Our motto: better to have it and not need it than to need it and not have it.
Hell, ride a fixie for all we care . . .
Pedal on!

I don't think a *properly adjusted* triple shifts any worse than a *properly adjusted* double or compact. Therefore, I don't think you will get improved shifting moving to a compact, all other things equal. My triple shifted like butter, and my current compact double shifts like butter.

Other than that . . . choose the gearing you like, and don't tell somebody else how ridiculous their gearing is.

Well said.

I'd do the compact double. I had a 42-52 on my hybrid, with a 13-21 7-speed. Never used the highest two or three gears, and always seemed to be "bringing up the rear" of the pack while riding. Considered a triple for a short time, but then realized I have to change the rear derailler to a long cage. That made the change too expensive. So, I just swapped out the chainrings to 38-46. It really helped alot. I can run the top gear without pulling my knee sockets out, I have a lower couple of gears for hills, and I can keep up with the spring chickens. Plus, the rings were good condition used @ $4 each! Best $8 upgrade I ever made!

You do not necessarily need a long cage rear dérailleur with a triple. I use an Shimano Ultegra ss with my triple. No problems.

As for shifting ease, the triple with sti index shifting has zero problems. My 30 year old double with friction down tube levers and campy nuevo record dérailleurs is horrible by comparison. I'm always having to compromise which gear combination work without undue noise and also having to dick around with the position of each dérailleur after a shift. The triple with the Ultegra is butter smooth.

You do not necessarily need a long cage rear dérailleur with a triple. I use an Shimano Ultegra ss with my triple. No problems.

I agree... and also use a small cage with no issues.
http://i17.photobucket.com/albums/b90/compost_bin/bicycle/IMG_3064.jpg

Total chainwrap is 31 teeth, and allows for a very small lightweight close ratio rear cassette, and yet still has a gear range of 31 to 104 inches. When there's no horizontal roads in your area, and everything is either a grind or a scream, you just gotta have a triple. ;)


Greg

I never claimed to be a spelling bee champ. Cant find a legitimate thing to say so you attack my spelling. good on you bro.

Not true that was my second post in this thread.
I was referring to your dismissing the Appalachians as not real mountains. They run from eastern Canada to Georgia and they are very real. They include Mount Washington which has the meanest annual hill climb in the country and the beautiful Blue Ridge Parkway, one of Lance Armstrong's training areas for the TDF. BTW they are also appoximately 300 million years old.

Ok, but not in WV or southern PA where the poster I was replying to rides

Also compared to rockies or alps or such they are a bit of a joke, for the most part

Seriously triple cranks are rediculous for all but the most extreme riders.

This coming from the same guy who prefers to suffer in a single gear all the time. If I'm "extreme" (I use every gear of my 52/42/28 triple with 12/27 cassette on my commute) then you are a kook ;)

Also compared to rockies or alps or such they are a bit of a joke, for the most part
No they are not. The grades in the Appalachians and their various alter egos (Blue Ridge, Smokies, etc.) obviously don't go on for miles and miles as the grades in the Rockies or Alps, etc. but they can be dreadfully steep. Ever hear of Brasstown Bald?

I've ridden the Rockies a fair bit and the grades are extremely long and the altitude a definite factor but the pitches are relatively mild. They can be difficult riding but so are the Eastern mountains, just in a different way.

I don't know where in VA you live and ride but some it it is very mild and some is pretty hilly so your perspective will depend on your location.

Like I was saying find out what you need on the low end and what you need on the high end. Gear your bike for these two cogs, and i guess decide how many increments you want in between

I think that the popularity of compact doubles has revealed another significant factor: Your favorite flat road gear.

The knock of compact doubles is that, when you make the front chainring shift, you may have to do a double rear shift to access the next gear in sequence. If the only time that you have to do that is at the base of a big hill, that's not too bad. If you find yourself making frequent chainring changes on the flat, it's a PITA.

If your favorite flat road gear happens to fall near the center of the cassette, compact cranksets can be good. If it falls near either end of the cassette, you're going to hate a compact.

If your favorite flat road gear happens to fall near the center of the cassette, compact cranksets can be good. If it falls near either end of the cassette, you're going to hate a compact.

I'm so happy that I looked at the gearing that I'd get with a compact double before purchasing one. I'd have been cross-chaining constantly or doing lots of double shifts any time the road was close to flat. With the 42 middle ring on my triple, I'm near the center of the cassette in those same conditions. The only downside to my preferred gearing is the preference of triple crankset makers for 39 tooth middle rings now. Luckily, Stronglight still makes new cranks geared the way I want and there's plenty of NOS 9 speed stuff around too most of which has a 42 tooth middle ring.

The moral of the story is gear range isn't everything. You have to consider your actual riding style as well and see if it "fits" the gearing. Personally, I feel that 9/10 speed cassettes make gearing decisions a lot easier too as you can get a wide range cassette without much of a trade off.

No they are not. The grades in the Appalachians and their various alter egos (Blue Ridge, Smokies, etc.) obviously don't go on for miles and miles as the grades in the Rockies or Alps, etc. but they can be dreadfully steep. Ever hear of Brasstown Bald?

I've ridden the Rockies a fair bit and the grades are extremely long and the altitude a definite factor but the pitches are relatively mild. They can be difficult riding but so are the Eastern mountains, just in a different way.

I don't know where in VA you live and ride but some it it is very mild and some is pretty hilly so your perspective will depend on your location.

+++ to this poster

I am from New Mexico - live and ride all the time in the rockies. I have ridden in the southern Himalaya - for a month in northern Yunnan Province, right on the tibet border - 22,000 foot peaks. Riding at elevations up to 14,000' - one hil was a climb of 8,000 feet with grades up to 10%. I just finished a tour of Adirondack park and so far the steepest grades I have yet seen were in New York State! I never saw a grade over 12 percent in CHINA! I saw two that were 19 percent in New York, and a few over 15, several over 12. In my part of the rockies - grades usually less than 8%.

for me SEEMS much harder to get my loaded bike (100 pounds of bike, water, and gear) up a 1/2 mile 19% grade then it is to climb for 30 miles at 7% from 6,000' to 14,000 feet of elevation.

the appalachians are real mountains. its just that the grades are not long. THANK GOD

I think that the popularity of compact doubles has revealed another significant factor: Your favorite flat road gear.

The knock of compact doubles is that, when you make the front chainring shift, you may have to do a double rear shift to access the next gear in sequence. If the only time that you have to do that is at the base of a big hill, that's not too bad. If you find yourself making frequent chainring changes on the flat, it's a PITA.

If your favorite flat road gear happens to fall near the center of the cassette, compact cranksets can be good. If it falls near either end of the cassette, you're going to hate a compact.

+1, Couldn't have said it better, really didn't like my compact until I moved to a junior cassette 14-25. Now, I'm right in the middle.

I'm so happy that I looked at the gearing that I'd get with a compact double before purchasing one. I'd have been cross-chaining constantly or doing lots of double shifts any time the road was close to flat. With the 42 middle ring on my triple, I'm near the center of the cassette in those same conditions. The only downside to my preferred gearing is the preference of triple crankset makers for 39 tooth middle rings now. Luckily, Stronglight still makes new cranks geared the way I want and there's plenty of NOS 9 speed stuff around too most of which has a 42 tooth middle ring.

The moral of the story is gear range isn't everything. You have to consider your actual riding style as well and see if it "fits" the gearing. Personally, I feel that 9/10 speed cassettes make gearing decisions a lot easier too as you can get a wide range cassette without much of a trade off.

Well put! :thumb:

Before I chose my road gearing setup. I first took note of the range of ratios I used for each road condition... broken down to these three.


1. Climbing

2. Upgrades/Headwinds

3. Level/Downgrades/Tailwinds

I assigned one chainring to each condition. And then picked the crosschain-free rear cassette ratios to fit the ones I used for each situation. The results have greatly increased riding comfort. With so so many gearing options today... you can pick exactly what you want.:thumb:


Greg

Well put! :thumb:

Before I chose my road gearing setup. I first took note of the range of ratios I used for each road condition... broken down to these three.


1. Climbing

2. Upgrades/Headwinds

3. Level/Downgrades/Tailwinds

I assigned one chainring to each condition. And then picked the crosschain-free rear cassette ratios to fit the ones I used for each situation. The results have greatly increased riding comfort. With so so many gearing options today... you can pick exactly what you want.:thumb:


Greg

This is a great method.

My perfect double would be a 45 & 30t, I could maintain 15 to 21 mph on the flats using the middle 4 cogs on a 12-27 cassette and ride up and down rollers in the 12 to 30 mph range without shifting the chain-rings. The 30t small chain-ring would help me climb any hill. I know this would work very well, I used a 1 X 10 drivetrain with a 44t chain-ring and a 12-27 for 4000 miles this year.

I went with a 50/39/30 triple instead. The 39t middle chain-ring helps me maintain a 14 to 20 mph on the flats using the middle 4 cogs on a 12-27 cassette and I can ride up and down rollers in the 10 to 25 mph range without shifting the chain-rings. The 50t is for any situation where a slope, tailwind or draft keeps me above 21 mph for any length of time, but I avoid the last 4 cogs on the cassette to keep the chainline healthy. The 30t small chain-ring will help me climb any hill.

Michael

I agree... and also use a small cage with no issues.
http://i17.photobucket.com/albums/b90/compost_bin/bicycle/IMG_3064.jpg

Total chainwrap is 31 teeth, and allows for a very small lightweight close ratio rear cassette, and yet still has a gear range of 31 to 104 inches...

I stand corrected. I hadn't considered using a straight-block on the rear hub.

...As for shifting ease, the triple with sti index shifting has zero problems. My 30 year old double with friction down tube levers and campy nuevo record dérailleurs is horrible by comparison. I'm always having to compromise which gear combination work without undue noise and also having to dick around with the position of each dérailleur after a shift....

Yeah, you do have to do more work with a friction system. I just never considered it enough of a bother to pay for the added cost of indexing.

I stand corrected. I hadn't considered using a straight-block on the rear hub.

Yeah... it's a little unorthodox mating a MTB triple to a TT cassette, but it works super.:thumb:

You end up with a really nice wide, yet seamless gear range... without the heavy weight, double shifting, and big gearing gaps of a large rear cluster.

Even though the RD is running at the edge of its reasonable chainwrap limits, an inadvertant large-large shift doesn't blow anything up. With mostly one tooth jumps and a couple of twos, indexing is not needed. You can basically yank the lever any old direction you want and the chain goes right there without a complaint.

I'm just a transportation/pleasure rider, and am not a "racer" type... but it just feels so good pedalling with ultra close gears. The racing cycists are really onto something there.:thumb:

If you are using your overly large small ring on occasion stick with the triple and even replace the small ring with a 24. It works with a little extra coaxing on the shift. Low gears aren't important until you don't have them and have to push the bike.
If you are young and or very strong you don't need much in the way of gearing, but.....

mostly commuting, fairly flat, but I have at times used my "granny gear"

I'm mostly concerned with mechanical advantages besdides weight

Defintely go with the compact double unless you regularly ride in hilly area. Cleaner and quicker shifting.