Originally Posted by
JiveTurkey
Shimano can do 10-speed beyond 28T, you just need a MTB-type derailleur (e.g., Deore) to handle the larger cogs and greater capacity, and a wider-range 10-speed cassette. Found an 11-32T and 11-34T 10-speed cassette at Harris Cyclery, but they're expensiive ($160):
http://sheldonbrown.com/harris/k7.html#10
Your setup of 50/34T and 11-28T is probably plenty low enough for most people though, except for loaded touring.
Leave it to Sheldon Brown and his comrades at Harris to find a way to do 34 teeth on 10 speed cassettes.
I know it would take a mountain RD, but I didn't realize anyone was making larger cogs for 10 speeds yet.
Not a great technology hurdle to do it, just didn't think anyone had done it yet.
I actually had considered using an LX derailleur on mine just to allow for larger cogs when available, but I am one of those types that doesn't mind pushing up the hills I can't ride. At 50 years old, I have other things I care more about than the ego boost of never walking.
But I should be OK on almost any hill anyway, especially as I lose weight.
Thanks for the heads up on the 34 tooth 10 speed cassette in case I run into anyone that wants/needs one.