A typical standard crank comes with a 39/53 combination.
The idea with the compact is that if you use smaller chainrings up front, you can use smaller cogs in the rear to get the same ratios. Folks like to point out that instead of my 39x25, I could use a 36x23. Or a 34x21, sort of. Smaller cassettes and smaller rings need less chain, and all that means less weight.
That got me thinking a bit about gearing and my perception of what constitutes real gearing. Real like "this is reality" real, not real like "Dude I read that the pros use a 55x11 in time trials".
When I started getting into cycling the standard freewheel for "10 speeds" was (and still is) a 14-28. My 5 speed had the same freewheel, along with a 52T chainring, but it was on a Cotton Picker Schwinn Sting Ray.
Then I got a real 10 speed. I suffered with non-interchangeable chainrings for a year or two, then got another bike which immediately received a number of upgrades. One critical one was its crankset, a Sugino crankset with interchangeable chainrings. I bought it with a nice 48/34 combination, a predecessor to today's Compact cranks. I also got two five speed freewheels, one for "fast rides" and one for "hilly rides". I ended up on the "fast ride" freewheel all the tim.
Yeah, it was a custom freewheel. Yeah I built it. Yeah I was a gear geek.
Finally I graduated to my first real race bike, a Basso with Excel Rino and Campy Nuovo/Super Record, along with then-cutting edge Modolo brakes. For gearing my bike had the following set up:
I was a Junior and dying to use a "real" gear like a 12T. However I had to make do with my rules-limited (and a rule I think promotes excellent pedaling skills in Junior racers) so I stuck with my one freewheel. I did have one benefit though - in the 6 speed era, an 18T was an anomaly, and my almost-straight-block gave me nice, fine gear gradations. I could incrementally up my gears where my Senior counterparts would be going from a 19 to a 17 and back again. I therefore focused on using my unusual 16T and 18T cogs as much as possible. This would throw off less fortunate Senior racers who usually not only lacked an 18T but the 16T as well.
Then I turned 18. I could use Senior gearing. Screw the 16/18T advantage, now I wanted break legs by hammering a 53x12 all day long. I immediately put on a freewheel I'd bought a year prior and may have accidentally tested on a group ride or three, but purely because I'd put the freewheel on to see how cool it looked and then forgot to take it off before the next morning's group ride.
I used the shop resources to build custom freewheels, and fought hard to keep the even numbered (and rare) 16T and 18T cogs. Incredibly I used this extremely high "low gear" of 42x21 everywhere, even on climbs. To put it in modern terms, it's like having a 39x20 low gear, or perhaps a 34x18, and I lived in the same area for almost 30 years.
I have no idea how I did it, using those gears to get up those hills.
If I thought a course was "really hard", like a RR, then the end became something else, like 15-17-20-23. I've always preferred a close ratio in the smaller cogs since each shift is so big. The larger cogs, ratio"tightness" didn't seem quite so important.
At some point, just as I finished up with school, I started thinking that I was hot stuff on the bike. I decided that a 53x12 was simply too small a gear (although, based on my push style sprint, it had some basis in fact), and I went to the extreme - a 54 tooth ring.
I actually did well in a bunch of races and this became my standard setup for perhaps 10-12 years. I'd toss on a 23 when I could find it for races, or a 45T inner ring for crits, but otherwise my main variance happened in cranks - by this time I'd been regularly using a 167.5mm crank, and it took the 10-12 years to wear out my unique equipment.
Then 8 speed came out. Instead of adding a bailout gear ("Who needs a bailout gear?"), I added some more top end, as soon as the cogs were available.
I sometimes used a 51T ring (51/42, 11-21) in the winter and for slightly less than optimal sprints. My standard cassette lost me my unusual even cog ratios so the 51 made up for that - it gave me a range of gears not quite the same as anyone else's big ring. More than a few times guys came up to me after races and asked me how I pushed an 11 at a particular time - they felt bogged down, but since I had my chain over on the 11, they tried it too. I would grin and tell them I was running a small big ring.
About 15 years into my racing life my slightly shorter cranks wore out and I had to go get a replacement crank. Since I happened to be pretty broke, I ended up with some hand-me-down Campy cranks using a new-to-me bolt circle. This meant my various 54s didn't fit my new cranks so my gearing became sort of normal because I only had the hand-me-down's chainrings.
My racing toned down some, I frequented group rides less, and I, well, got old or something. Suddenly I gained about 15-20 pounds in a winter and never lost it, hitting the 160 lbs threshold. This additional weight, along with the lack of training, started telling on me. I eventually got a 23T big cog, but I justified it to myself by saying that this would allow me to use a 53x21 at Bethel and not be in the extreme big-big combination. Whatever the reason suddenly I had a 23T on my bike. I also put on one of my many take-off 39T chainrings because, well, my 42 might have been a bit worn. That's what I told myself. It wasn't because I needed the 39. No way.
In addition, since cogs started getting paired with other cogs (riveted together in many cases), swapping out individual ones became difficult. I had to stick with standard cassettes and this meant losing all my 16s and 18s. I still sometimes cobbled together something for weird situations, or just because I wanted to get psyched for an important race (the latter justifying some SRP titanium cassettes, or even Campy aluminum cassettes).
After breaking a lot of 8s speed derailleurs and such, I eagerly upgraded to the new fangled 9s with its nicer hubs, slick second generation Ergo levers, etc. I bought the mid-range Daytona group, before it got renamed to Centaur due to a trademark war with a certain race track in Florida. I didn't have custom stuff but I got a 14T.
I upgraded to 10 speed at some point, when I needed new shifters, cassette, chain, and my derailleurs started feeling a bit played. I had an original, 9s when 9s first came out, Daytona group on my bike, and the drivetrain felt like it was on its last legs. A handy bonus from work paid for a 10s drivetrain and a pair of wheels.
The 16T helped me immensely - the first time I rode 10s was at a Bethel race and I handily won the field sprint. I did well on this cassette ratio, winning races for the first time in 5 or 6 years, and racking up a few Cat three medals in the Nutmeg State Games.
When I got to about 39, I started borrowing my wife's 11-25. I liked it so much I bought my own. Yikes. I can say truthfully that I use this just for training - my racing cassette is still an 11-23.
Then, to my horror, I wore out all my 10s cassettes at once. I bought one more and put into use a nice 12-25 Record steel/ti cassette I thought I'd never use, but since it came with my bike, I put it in a plastic baggie and buried it in my spare parts box. 12-25. Ridiculous. I need an 11 tooth. I do. Really.
Now I have a beautiful steel/ti cassette for training, with a normal steel 11-23 for racing.
Fine, I have a 16T again, so that's nice for training, but it's titanium so it'll wear quickly. Arg. So I have a 16T but I try to avoid using it. Makes sense, right? At least the 12T gets used on descents pretty quickly.
When I first started thinking about this post (this summer), one of my less-than-smart thoughts was to go back to my "original gearing", i.e. a 21T large cog and a 42T small ring. I mean, come on, I weigh 70 pounds more than I did when I first started racing well, and I'm 35-40 pounds heavier than my 20s. Could I lose all that weight? I think not.
Yet I actually contemplated using the 55/44 (or is it a 56/45? I forget) set aside for the tandem. Thankfully I resisted this temptation successfully. I suppose part of it was because I can't even turn a 53x11, so what would I use a 55x11 (or 56) for?
My next thoughts were about going to Compact. I'd do it a bit differently, staying with a 51T big ring (since I think I can use a 51x11 in a sprint), an 11-21 cassette, and staying with maybe a 36T small ring. Or, in deference to my lack of fitness, maybe an 11-23 cassette. But then I lose that big big ring. Hmph.
And, of course, I thought about 11 speed. So sexy. So smooth. So... Eleven. Then I'd have that nice 18T again, the 16T too, and I could cruise comfortably on those big ring rollers in the 18T or roll the 16T on those long stretches of road when training solo.
(Think Breaking Away, idling along on the tree covered road while turning over the 18 so nicely, then POW your tire blows.)
Or in my case, reality blows. The "reality blows" bit is that 11 speed is not in my near future. I have too many bikes to upgrade, not that much budget, and my crit racing is fine with a 10 speed 11-23 (or, perhaps, an 11-21). I can't realistically think about dropping 30 or so pounds either, although I secretly think about 15 pounds. So my bike will stay as is. I'll train on the heavier Giant, with heavier wheels, an 11-25, and I hope that when I get back on the Cannondale I'll suddenly gain a whole bunch of speed. We'll see how it goes.
First things first though. I gotta go ride.