Compact Gearing

[IndianChris]

Just ordered a road bike with a compact drive 50/34. Just looking for your input on the compact drive as opposed to a standard drive (53/39?) and as opposed to a three chainring setup.

At first I really wanted the three chainrings because my neck of the woods has a lot of hills but when I found out the bike comes with only two, I started doing the research. I can have it upgraded to three like I originally wanted but that will be additional $$$ and right now I'm scraping for pennies as it is.

With a little research, the compact 50/34 is actually better for the hills from what I've read...but not sure why.
As for the higher gears, an 11 tooth cog in the back (50/11) actually provides a higher gear than 53/12.

What is your gearing like?

 

[TCD]

I'm riding 52/39, 13-24. Never had a granny; I seem to do OK with 39. The 34 should be a nice lower size compromise between 39 and granny. What will really make the difference is what your largest sprocket is; I think you can derailleurs that will handle up to about 28. By contrast, when I lived in Florida 30 years ago I had 13-19...

 

[Jay H]

Yes, a smaller (# of teeth) rear sprocket will give a higher overall gear than a larger rear sprocket....

Gear Inches = (# teeth front/# teeth rear) x tire diameter with lower gear inches equivalent to a theoretical lower gear..

Now, your rear derailleur has an impact on the biggest rear cog (lowest gear) that you can use, those descibed with a long cage derailleur will support a lower gear (more teeth) in the rear.. This is why you see a lot of Mountain Bike derailleurs on touring bikes, i.e. they come with Shimano's Deore line of der. as opposed to Tiaga/Ultegra/etc.

I think that a full set of three chainrings in the front is still better than any compact gearing. Take a look at full on touring bikes, you will still see a triple chainring setup. Perhaps it is fine for plain ole road bikes. I have a triple on my road bike, don't ever really use the granny gear much but it's nice to know it's there.

Jay

 

[KRobi]

I have the same compact gearing and like you wanted the triple. On paper the useful gears of a compact and a triple are similar without as many double shifts....but I ride on the roads of NH and not paper! I think the triple (ride a mtn bike as well) is nice on those big, long NH hills when you are not really up for cranking to get up. That being said, I have also thought about putting a larger rear cog on as my "low end" gear for the hills.

 

[bikehikeskifish]

53/39 x 12/25 (12,13,14,15,16,17,19,21,23,25). The "normal" distribution of my riding time puts the 53x15-17 under the high part of the bell curve. The steepest paved road in NH is Pack Monadnock's Auto Road - the last 300 feet is 22% where a 39x25 is acceptable (I used to be able to do it in a 39x21, seated )

The compact drives use a smaller bolt pattern, meaning your options are more limited.

For what it's worth, I can't say I've ever wished for an 11 in the back. Possibly on a downhill stretch of a time trial, but otherwise it's fairly useless.

Every few thousand miles look carefully at your rear cassette. You will notice the gears you use most will have a "shark find" curve in them, as compared to the 11, 12, 23 and 25.

For the hill lovers, this is a great site: http://www.northeastcycling.com/

Tim

 

[Jay H]

As far as gearing, I have a wall-monster on my Lemond as I run a standard triple crankset up to a 12-28 cassette in the back... I never really use the granny in it but like I said, it's nice to know it's there.

Right now, my commute is flat as a board, I could run it as a single speed if I so desire, it has horizontal dropouts. (allows you to adjust the chainlength w/o the rear derailleur by moving the rear wheel fore/aft)

p.s. check out Glade Hill Road in the catskills...

Jay

 

[Rick]

I am in the same quandary while looking at new bikes.
I drive my old 87 Cilo with 52/42 and 11/23 and it was fine on the flats along Lake Ontario and such years ago, but now I am in the bloody hills of Saucon Valley (all hills all the time) where you might gain 500 feet over a mile and It is too damn difficult (Plus take into account overweight 50 year old bike driver).
So in 03 I got a Trek FX 7700 with 48/38/28 and 11/32 and I can do the hills just fine, though some I am in first all the way.
But now in looking for a road bike I am considering a compact double. I have been using Sheldon Browns Gear calculator to help me figure out if I can go low enough with the compact - I probably can on all but the steepest longest climbs.
Guess I'll hafta lay off the donuts now....{..sigh...}

PS - You might be able to add a megarange cog (34T cog) by replacing the largest rear cog (likely 25T or 27T)

 

[lx93]

A compact crank will always shift more smoothly than a triple will. To each his own.

 

[HAMTERO]

What are you using the bike for? If unloaded (no panniers) compact should be fine. Easier to shiift and you can run a short cage derailleur like other have said.

 

[IndianChris]

Thanks all. Keep it coming.

"Wall-monster," that's funny J. The info on gear inches is very interesting. I'd like to compare the gear inches on the modified mtn bike I currently ride on the road to the new road bike (that I hope to have Monday) but there are a lot of other variables that will effect performance like wheel width, wheel tread, geometry, crank length, bike weight, etc... Will have to just wait and test in the field.

The new road bike comes with 50/34 and 12-25.

I wont be carrying any paneers on the bike. Will be using it on the hills where on a 35 mile ride I will gain over 3000 feet. For Long Island I think that that route is pretty impressive.
I hope this summer I can get to some of the hills you guys mentioned.

 

[smitty77]

Just for argument, keep in mind the triple setup weighs more than a double if you're the type into counting ounces/grams.

Since I've always been overweight, I couldn't see throwing $$$ to lighten my equipment when I could shed more weight off the driver for free.

I think my old C-Dale had a 39/24 low gear and it was fine for most hills on state-designated highways in New Hampshire. I struggled up the backside of Franconia Notch but that was at the end of a 50-miler. There are times I've wanted a 3rd ring, and then that thought vanishes when I recall that feeling of "moving but not moving" you get when spinning low gears on an MTB.

Also keep in mind it's not really a good idea to use the entire rear cassette when pedaling the inner or outer front ring so keep that in mind when comparing your potential arsenal of ratios using each setup.

 

[HAMTERO]

I would think you would be fine with that gearing. If you are worried, ask the shop if they can swap the cassette for a 12-27. They should charge you little or nothing if you do it at the initial sale. You may have to add a couple links of chain which will entail whatever connector link your chain uses.

 

[IndianChris]

ask the shop if they can swap the cassette for a 12-27.

Actually, what I would really like is the 11 tooth cog. But yeah, the 27 would be nice too for the hills.

 

[HAMTERO]

50 x 11 is 32MPH@90RPM according to Sheldon so that is going warp speed. With a 12 you are doing 29.3MPH@90.

There are 11-25 cassettes available if you want one.

 

[Lawn Sale]

Some good info here. My Cannondale came with a 52/42 and 12/21 setup, but it was too tall for the Maine hills, so I am now running a 53/38 and 12/23 (7-speed), and it has made a world of difference. It was a 13/23 (13-14-15-17-19-21-23), but I swapped out the 13 for a 12 and haven't regretted it a bit since I'm not cruising in that gear and use it just to reel in others or hammer downhill. We have a 0.9 mile hill locally that is 14%-15% grade and I have been up that several times, along with other local "hills of hell" on some of our rides. You might consider a swap to get the 11 on the tall gear with the 50 since you won't be in it all the time.

I have gotten much stronger by riding my fixed gear bike, which I love. I didn't think I'd care for one that much, but I greatly prefer it over the road bike, except in the large hills. I'm running a 46/17 (which is a 52/19 or 39/14 equivalent) on the road and 46/19 in the woods when I put the knobbys on it, both are ideal ratios for me. The lack of shifting and coasting has made me think more about how to ride and set up hills, along with strengthening my legs and lungs, and has made riding much more pleasurable. Fixed gear bikes can usually be made relatively inexpensively, or just make a single speed.

 

[Lawn Sale]

I'd like to compare the gear inches on the modified mtn bike I currently ride on the road to the new road bike (that I hope to have Monday) but there are a lot of other variables that will effect performance like wheel width, wheel tread, geometry, crank length, bike weight, etc... Will have to just wait and test in the field.

I have an application on my iPhone ("Bike Gears") for my fixed gear that takes into account most the variables you listed. Send me the info and I'll plug them in and give you the data. This one is also pretty decent, and here are a few more to play around with.

 

[bikehikeskifish]

You do not get the "pedaling circles" effect from a single-speed that you get from a fixed gear. Likewise you do not get the eccentric benefit of resisting pedaling as a braking mechanism. You cannot cheat on a fixie. I stopped riding mine a while back as I believe it was not sized properly and was causing sciatica.

The only times I ever use my 12 or 13 (53x12, 53x13) are in a downhill stretch while attempting to catch a group ahead, or in an individual time trial. Those are very big gears and pushing them without proper conditioning is not likely to be kind to your knees.

I currently run a 53/39 in front, and a 12-13-14-15-16-17-19-21-23-25 in the back. In racing years I would run a 53/42 in the spring and only use the 42, avoiding the steeper stuff, until I had accumulated some pre-set number of base miles, in the 500-1000 mile range.

Tim

 

[deanmacg]

I have an '08 Roubaix w/compact gearing - works great. You'll be fine.

 

[Lawn Sale]

You do not get the "pedaling circles" effect from a single-speed that you get from a fixed gear. Likewise you do not get the eccentric benefit of resisting pedaling as a braking mechanism. You cannot cheat on a fixie. I stopped riding mine a while back as I believe it was not sized properly and was causing sciatica.
Tim

This is true, but it's easier to go from a single speed to a fixed gear than from a multi speed to a fixed gear. Setting up hills is the same concept, but I believe easier on the fixie. The fixed gear also helps rid your legs of lactic acid buildup faster since they're moving all the time to flush out the system. When I went back to a road bike, I found I was riding around 2 mph faster over the same course and had a lot more stamina, with results in a very short time period.

Fixed gear bikes can be brutal, no doubt about it, they aren't for everyone. But, if you can ease into them without a lot of problems, they are a source of joy not found on a standard bicycle. I was told this but didn't fully comprehend or believe it until I built mine, then I was hooked.

 

[bikehikeskifish]

I went from a freewheel multi-speed directly to a fixie... the key is to learn to ride it on something pretty flat. You can't unweight the saddle going over obstacles, for example, simply by stopping pedaling and putting your weight on your feet. Yes, you can lift your behind up, but it is a different experience. They make hubs where you can turn the wheel around and have a single-speed freewheel on the opposite side which gives you both a fixed-gear and a single-speed in one bike. I have such a hub. Sheldon built the wheels and converted my old 10speed cro-mo Fuji I bought when I was 16... Yes, it has 27 inch wheels, not 700c.

Tim