I'm looking at upgrading to a newer and lighter crankset, but I can't decide between 2 or 3 gear setup. I currently have a 3 gear crank with a 8 speed cassette. Looking at moving to a 10 speed cassette with either a 2 or 3 gear crank.
The question is, what am I sacrificing other than the obvious additional gears. Will I miss the other gears? What are others running?
I would take 2 approaches, depending on what and where you are riding :
- On a roadie, stick with 2 up front and 10 on the back. A compact crankset with 34/50T up front and 11-25 at the rear would give you ample low down gearing for nasty climbs, and big tall gearing for the long stretches. You might think that this is too tall a gearing for killer climbs, but its surprising how much of a difference the low weight of a roadie makes.
- For more cross country work, 3 gear crank is always useful, and gives you a go-anywhere ride.
In an ideal world, you should have a good roadie AND a solid mountain bike AND an urban assault fixie !
Assuming this is staying on the same bike with the same crank length, it should be relatively easy to figure out what you need. (If on a different bike, wheel size is also a factor).
Figure out what gears you use on your current bike, not what it has, but only the ones you actually use. Then count the teeth on them (front and back), if it's a stock bike this info may already be available on line or you may already know it. Next take the ratio of chainring teeth to cog teeth. This is what you want your new crankset to provide.
There are to potential factors in making this selection. The first is overall range. Ideally the If this is the same at both top and bottom, you will have the same climbing and max speed (approximately anyway). If the new one has a higher highest number, it will have a higher max speed. If it has a lower lowest number, it will have a easier climbing gear.
The second issue is step size. If the new crankset you are looking at requires larger jumps (greater difference between succesive ratios) you will feel more of a jump in power requirements between one gear and the next. If it has smaller differences you feel less of one. If you are constantly shifting two gears at a time, larger jumps shouldn't be a problem, if you feel that your current setup sometimes requires to much of a change between gears, then you probably want smaller ones.
I swtiched from a triple crank on my C-dale to a standard double ) 53/39T. I didn't so much miss the 30T ring of the triple except on really tall and long climbs. A good upgrade would be a compact crankset as suggested. Depending on how strong you are there are 50/34T setups and 50/36T. I have a 50/36T setup as I rarely need that lower range.
Another key factor you have to consider with changing drivetrains is the shifting systems. Some derailluers are specific to triple setups and don't work all that well with double setups. So its not always as simple with just swapping out the crankset. But if your going from an 8spd to a 10spd you are going to have to replace all that anyway.
Sad to say but unless you love that frame you might be better building a bike from the frame up. I just did that with an Argon 18 Krypton frame and fork with all Dura-Ace 9spd drivetrain for less than $1200.00 bucks.
no doubt in my mind-go for the compact 50-34 and a 12-27 10 speed-it really makes a difference only having the two rings at the front- a lot less shifting
Nike+ Integration
ericbuzzelli
giro-d-steve
paul.d
MapMyRun.com,
MapMyRide.com,
MapMyWalk.com,
MapMyHike.com,
MapMyFitness.com,
&
MapMyTri.com