My bike has a compact crank (34/50). As the larger chainring is often too large for the speed at which I ride, I use the smaller one most of the time. However, since it is compact I find myself having to use the smallest cogs in order to maintain a reasonable cadence. I'd say my most common gear is 34 in front and third smallest cog in back, although i also frequently put it in the second smallest. Although i never use the smallest cog with the small chaingring, i'm worried about cross-chaining and it's possible effects on my drivetrain, the first of which I've noticed is a very faint squeaking noise every so often, though I'm not sure where it's coming from. Any suggestions on how to avoid crossing my chain (if it is actually a problem). I was thinking of possibly getting a larger inner chainring, does that make sense?

If the larger inner ring gives you the low gearing you need, go for it. It might make chainring shifting smoother as well (smaller drop between rings).

But try using the trim on the front shifter first - that should minimize the chain rub when cross-chained.

Get a fixie!

You have just learned why I will not give up my 39 ring. With a 12-27 on the back of a 53-39, I rarely get out of the 39 ring, It takes me up hills, and as fast as 20 mph easily within my spin range. I really do not sweat crosschaining on a double. My chain has lasted 4000 miles!!

Just shift more or learn to spin at a higher cadence if that's too hard. Honestly cross chaining isn't as efficient, but it's not that bad. I catch myself every so often doing it and I get over 7500 km out of my chains.

Have one, got it before my road bike. It sure is a hell of a lot easier to maintain, and shifting gears is a breeze ; ), but I grew out of it as my road bike.

You could put a 36T ring on instead of the 34T... although if you're riding the 34 all the time, then personally, I think you just need to build more leg strenth. Ride the 50 more. There's always the option of a different cassette... you could put an 11-23 on there if you're in your 34 most of the time, and then you probably wouldn't cross chain as much.... assuming you've got a 12-25 or 12-27 on there now that is. If you have a 12-25 or 12-27, you need to ride the big ring more.

There is usually some overlap in the ratios available between the large and samll rings. Learn to shift both levers when you are running out of cassette. I shift up to the big ring and down three on the cassette in one shift. Works the same way shifting down. I run 52-39 with 12-27 in the San Gabriel and Sierras and havent had to got to "w" gear yet.

I do this a lot and it can get annoying. I think I'm an obsessive shifter, I change gears like every 15 seconds, the route i ride (the Central Park drive) I guess could be considered "rolling", which probably gave me the habit.

Anyway, in terms of a solution, I could ride more in the 50 and lower my cadence, or get a smaller cassette/a bigger chainring, correct?

I used do the same thing, from 39 to 53 in front and down three on the cassette. It's annoying because my preferred range on the flats lies in the overlap between the two, so sometimes I just crosschain on the larger ring.

What is your cadence, that you are able to stand riding in the 34t chainring?

I live in the midwest, so it's all big ring, and I'm still in the mid-90s.

Peek between your legs when you're not sure.

If you're concerned about cross chaining, you don't have 20 gears.

I don't worry about it.

I'm not quite sure but my guess is around 90.

I know this is a pretty general question, but is the general consensus that when on a flat section of road one should be in the big chainring?

The Op could really use an all rounder 42 chainring. Perhaps a triple chainring might have been a better choice for him and just not use the 53 big ring at all and limit use to just the 42 and 30 rings. Just a thought.....or get a true touring triple.

Unless you have a tornado coming at you across the corn desert, a Nor'Easter bearing down on you, or some other miserable form of headwind...probably.

+1 (I do worry about pcad though)

If you ride at 12 mph on the flats then the big ring is probably inappropriate. OTOH, if you're cruising at 22, then the big ring is probably necessary. It all depends on your speed. Have you used Sheldon Brown's Bicycle Gear Calculator? I've found it helpful to plug in my ring sizes, tires, and cassette and then select MPH at my target cadence in the "Gear units" selection box. This gives a chart that allows you to see what speed you would be at for each gear combination. I used this information to figure out that for the riding I do, and plan to do, a triple was more appropriate than a compact. Here is an example I ran for a compact crank, 700x23 tires, and 12x27 cassette.

But I ride so much that my chains and sprockets need replacement on a semi-regular basis ANYWAY. Particularly chains. The last time some guy next to me told me I was cross chaining turned to him and said 'Yeah, AND...???'

He did not have a response.

Go figure?

I'm old school. I like half step gearing, what I call it anyway. 49-52 chainrings and 14-24 6speed in the rear. This way you use the frt. and rear sprockets in an alternating fashion to move through your gears. Low is around 50 in. and top is 100+ in. But can anybody really turn anything bigger than an 88 for very long anyway. Cant figure why people have 12 tooth sprockets!

cross chaining...imo...doesnt matter as long as you arent making any noise.

I think people take this way too seriously. Just ride and cross chain, it makes very little difference to longevity of chain and cogs

I have the same issue. My most comfortable combo on the flats/semiflats runs on the 39 with the upper end of the cassette or the 53 on the lower end of the cassette. I wish I had something like a 39-50 with a 12-25 (currently running 39-53, 11-23.

Could I run a 50 tooth chainring on my 9 speed Ultegra crank? This would make my large ring more useful.

To me the real test for a compact crankset has to do with your favorite flat road gear. You'd like for it to fall right in the middle of the cassette, probably on the big ring. That'll give you two or three "trim" gears in either direction without cross chaining. The issue isn't just the cross chaining itself, it's finding the appropriate rear cog after making the big jump in front chainrings. That's a momentum loser.

It sounds to me like you might benefit from a cassette with larger cogs. That would probably let you ride the flats in the big ring and the middle cogs and avoid cross chaining. Save that 34 for the hills.

Unless I'm feeling lazy and coast, I regularly use 53x12 when going downhill.