View Full Version : 3 rings vs 2 rings

06-25-2008, 08:38 PM
I have a 2 ring crank set on my road bike. the guys I ride with have 3. I find that on hills I completely lag and can't keep up. In If I was in flatlands 2 rings might be ok but here in Oregon there are hills no matter where you go. How much difference does the 3rd ring make?

Should I push through until I'm a stronger rider?

06-25-2008, 09:11 PM
Depends on the rider and also the rear cog. I have a triple but only use it when towing something with my trailer. Otherwise I just leave it in the middle, rarely even using the big ring as I tend to coast on the steeper downhills. I also have a 34 rear cog, so I can go pretty low anyway. Maybe you could try a new cassette first. My riding is mainly commuting which involves carrying lots of weight in both panniers, for what it's worth. Lower gears though, won't make you go faster, it just makes it easier to turn the cranks due to greater mechanical advantage. I don't know if hills (or riding, for that matter) are something new to you or not, but they do get easier with time. The stronger a rider you are, the less daunting they become.


06-25-2008, 10:13 PM
Thanks. I think your right. If I just persevere a little longer the big hills will get easier.

06-26-2008, 08:03 AM
Maybe you could try a new cassette first.
Ditto. Consult w/ a bike shop on your rear gear changer's capacity (god I hate the word derailleur - the Brits are much more sensible and call it what it is). Many road bikes have deraiilleurs that won't take a megarange cassette.

06-26-2008, 10:11 AM
I like my knees.
I like my pain free knees.
I want them to stay that way well into my "golden years"
I live in Oregon.
My bikes have triples.

Trying to make a double chainring system as versatile as a triple is difficult at best; it might be impossible on certain frames. The same might be true for installing a triple on certain other frames.
What do you ride now?
What kind of riding do you do?
How much money are you willing to throw at this?

06-26-2008, 10:49 AM
Triples weigh more. There is necessarily enough of a gap between the front derailleur cage and the chainrings that there is a possibility of "dropping" the chain, especially when going into the smallest ring. More gears means more of a chance to be in the wrong gear :)

The overlap between the small and middle chainrings is mathematically rather dumb; you'd think somebody at Shimano would understand gear ratios :D. You have a lot of front/rear combinations that differ from one another by as little as one or two percent. Fondling the number of teeth on those two chainrings only ever so slightly would make the overlap so much more useful.

Doubles don't offer quite the same range of gearing, either high or low--even "compact double" cranks have this limitation.

I have a triple. Speaking as a rider over the age of thirty, I prefer to "Lance Armstrong" my way over a hill in order to spare my knees. In other words, I use a higher cadence, which replaces outright force on the pedals (and hence my knees) with more muscle movement, which emphasizes cardiovascular output.

You put out just as many watts with either setup, and you'll feel just as tired at the top. No silver bullet here, but I think that unless you're a competitive racer you'll appreciate the triple. Consider it an investment to avoid orthopedic surgery in your 40's.

06-26-2008, 11:16 AM
Thanks for all the great advice.

After I finish a hill my knees hurt really bad. For this reason it would be worth the investment to switch to 3.

06-26-2008, 11:42 AM
I've tried to follow the advice of trainers who push the idea of spinning vs. mashing the pedals. For me, it really works. I actually ride further, smoother and faster spinning at a high (90-ish) cadence. I'm just not strong enough to spin like that up a real climb without a triple.

I've done semi-scientific tests riding up Rocky Butte and I can do it considerably faster spinning in my "granny gear" than if I force myself to do it all in the middle ring. There's a bunch of physiological thinking behind it, much of which is explained in Fred Methany's excellent ebook, Basic Training for Roadies. I got it from roadbikerider.com. (And no, I'm not shilling my own book here, different Fred!).

And I agree with others who point out that spinning is easier on the knees, which at 44 is a must for me!

However, I don't think the extra weight of a triple is very significant considered as a percentage of the whole bike (even though a triple typically requires a long-cage rear derailleur and longer bb spindle). I ride the Ultegra gear on the road and, once adjusted, I haven't dropped a chain or missed a shift in 1200 miles. The stuff just works.

06-26-2008, 12:14 PM
Sounds better than gear changer to me.

Derailleur. I hate typing it, but don't even think twice about saying it.

Used to work at Cane Creek and they'd get all these great British MTB magazines. Man they were a hoot! Wish I could get a hold of some of those.

06-26-2008, 12:46 PM
I've seen "derailleur" anglicized as "derailer" in some articles, but no online dictionary seems to accept this spelling. That's how most people I know pronounce it anyway, so it doesn't really sound all that foreign.

06-27-2008, 08:04 AM
When I was shopping for my new bike, one of the requirements I had (besides "not pink") was that it had to be a triple.

I've got knee problems from a couple years of aggressive co-ed soccer, and I like being able to go up hills without killing my knees.

I definitely subscribe to the "spinning" up the hills vs "mashing"!! It's saved my bacon during longer rides, it means I can finish the ride instead of falling over in pain in the middle.

And because my new bike is so light, the weight of a triple really isn't a problem; it would be more effective for ME to lose weight than for my BIKE to lose weight! :)

06-27-2008, 09:26 AM
<oops, I guess djasonpenney had mentioned it... anyway...>
Funny, a thread like this would go this long without it touched on...
There is a third option...as stated in the title... a Compact setup which allows for a wider gearing on two rings. For example, one of my current favorite hill climbing setups has a 34-48, while my traditional 2 ring setup has a 39-53.
I also have a couple of triples (yes, I've got a lot of bikes!) which the road bike (as opposed to my tourer) has the 30-40-50 rings, so the compact is a good compromise between the standard double and triple. I have on occasion spun out on my compact, but I'm hitting 45mph+ at that point so it's not all that bad.
You then can dial in to your own comfort zone by playing with the cassette configuration. Just thought I'd add that to the mix.


06-27-2008, 11:21 AM
As previous post replied, a compact crank is a good way to go, but you can also change your rear cassete. I have a 50/34 compact w/ a 25 rear cog and a 53/39 standard crank with a 28 rear cog and they are about the same gearing. I ride over the west hills through Washington park to work and don't really have a problem and Im 54 yr. old.

06-27-2008, 01:56 PM
Divide the number of teeth on your chainring by the number of teeth on your cassette cog. This gives you the gear ratio. (You can multiply it by the circumference of your wheel to give gear inches, but unless you're debating the virtues of a Bike Friday versus a 700c wheel, that's not interesting).

I run a 52/42/30 on the front and a 12/27 on my rear. This works out as:

30/27 is about 1.11.
34/25 is about 1.36.
39/28 is about 1.39.

How much difference does this make? Well, I started out with a 39/25 (1.56). When I upgraded to a 27 (1.44) it made a significant difference riding through Bull Run, even though that's only 8% relative difference.

(I'm a bit overboard with the tandem, which has a 24 tooth on the front and a 28 on the rear. 24/28 is about 0.86).

My point is that you can really spare your knees by changing the gearing, but you might not feel that a double crank (even a compact) gives you enough range. Your mileage may vary :-)

I have a 50/34 compact w/ a 25 rear cog and a 53/39 standard crank with a 28 rear cog and they are about the same gearing. I ride over the west hills through Washington park to work and don't really have a problem and Im 54 yr. old.

07-01-2008, 09:50 PM
+1 for a triple

07-02-2008, 08:15 AM
(I'm a bit overboard with the tandem, which has a 24 tooth on the front and a 28 on the rear. 24/28 is about 0.86).

Hmmm, doesn't look overboard to me! I run early-90's mountain triple combinations on both of my bikes. They're both '90-91 Diamond Back MTB racing bikes. The frame geometry is about the same as a current touring bike, just really overbuilt for off-road use. They came equipped with all the brazings for touring. I run a 24-38-48 rings up front, and an 11-34 cassette in the back. This makes for a great urban assault / year-round-commuter bike when equipped with 2.1" conti town & country tires. In 48/11 I spin out just north of 32 mph on the flats, and the 24/34 combination wants to climb a wall. I often have fellows on racing bikes pull ahead of me when I'm stopped at a light because they assume that I'll be going too slow. I always take the opportunity to draft them to their max sprint, then pass at the nearest hill. It must be humiliating to be passed by an old schlub on a 20-year-old mountain bike with kitty litter pail panniers. Mechanical advantage is your friend. : )