Originally Posted by
oilman_15106
Check this out: Sram Apex road group. I know riders with Sram Red setups that have gone to the Apex rear der. with an 11-32 10 speed cassette. Combined with a compact front this offers quite a bit of low gearing.
http://www.bikeradar.com/news/articl...p-review-25053
I've used the Sram 11-32 ten speed cassette on my road bike with a compact crank, see:
http://www.bikeforums.net/showthread...t=ultegra+apex
My Cyclocross bike has a triple crank with 50, 39 & 26 chainrings in combination with a 12-27 ten speed cassette.
This provide close gearing on flatter rides but still offers low enough gearing for difficult 15-20% climbs. Very tight gear spacing is available from 16 to 31 mph. Frequent changes on the front chainring are avoided, the 39t chainring is good up to 23 mph and covers most flat terrain riding. The 26t chainring can cover all of steeper climbs, up to 18% or more.
My road bike has a compact double with 50 & 34t chainrings in combination with an 11-32 ten speed cassette.
This provides low enough gearing for the steepest climbs. Tight gear spacing is available in a limited range from 18 to 22 mph. Gearing spacing is twice that of the other cassettes, larger changes in cadence are required with almost all gear changes. Frequent changes on the front chainring are required on flat terrain, the 34t chainring is good up to 21 mph. Steep climbs are possible for all riders.
The Sram Apex 11-32 ten speed cassette in combination with a compact crankset performs on rolling terrain perfectly. I'm able to use 34t chainring and the nine of the rear cogs (12-32) for any uphill situation at speeds less than 20 mph. Steep hills are easy, with a smooth 60 rpm cadence @ 5 mph. That's a real knee saver and makes a long, hilly day much easier. I'm also able to use the 50t chainring and nine of the rear cogs (11-28) for any downhill situation at speeds over 15 mph. As long as the terrain is rolling, up or down, the gearing is golden.
The problem is on flat terrain. Even small changes in speed create the need for shifting of the front chainrings and double or triple shifts at the rear. It's too easy to cross chain on the small chainring or to be on the 17 or 19t cog while on the big chainring.
Now that I'm riding the flat routes near my home in Illinois, I've pulled the 11-32 and put a 11-23 cassette on the wheel. I've also put a standard crankset with a 50 & 39t chainring set on the bike. I'll be able to stay on the 39t chainring up to 25 mph. This will reduce the need to shift to the big chainring to a few times an hour. I'll have a few hills that I'll have to grind out on the 39 & 23 combo, but these are less than 10% and less than 1/2 mile in length.
There is no one-size-fits-all in gearing, but if I had to use just one drivetrain it would be a triple crank with 50, 39 & 26 chainrings in combination with a 12-27 ten speed cassette.