PDA

View Full Version : Gearing questions



KeatonR
04-11-08, 02:33 PM
My Lemond Poprad came with a 46/36 front combo and an 12-25 rear cassette (9 speed). I've been reasonably happy with that setup for offroad use (mostly fireroad) and hill climbing, but when I started using the bike as more of a road bike, I started to have second thoughts.

I got a road wheelset, and that also has an 12-25 cassette. It's a pretty good setup for big climbing days, but I'm staying in the big ring for much of it. But on the flats, 46-12 isn't quite enough.

So question -- should I go to a 48 big ring, or switch out the road cassette to an 11-23 (which a friend gave me)? Which would be a more dramatic change? For all I know these changes would be equal. I'm no mathematician.

Mike T.
04-11-08, 05:08 PM
on the flats, 46-12 isn't quite enough.
A 103" gear isn't enough on the flat? At 100rpm that gear's doing about 31mph. You're national team material Keaton.

KeatonR
04-13-08, 09:19 AM
Well, I should elaborate: by "flats," I mean not in the mountains, which means there are some rolling descents. On any decline at all, I feel like I can run out of gear.

djs
04-13-08, 04:52 PM
50/34 12-27 is what I use and it works great

M_S
04-13-08, 06:10 PM
a 48-11 is what have and it seems really nice. You may never use the 48t on any kind of off road though. I'd go with an 11 tooth small cog and try that, personally. FWIW I have 38/48 with an 11-26 and fo most serious ofroading basicaly run the bike as 1x9 completely ignoring the big ring except on long fire road descents.

cachehiker
04-14-08, 11:54 AM
I find it pretty easy to spin out a 50-12 or 48-12 on faster road descents. I run my cross bike with a 48/38 driving an 11-28 with an XT mid cage derailleur. Rarely spin out the 48-11 with the 700x32c Randonneur Pros on the road. Only grunt with the 38-28 when I'm carrying a load of groceries up the hill to my house or riding actual (although beginner-intermediate) mountain bike trails with knobbies.

If I could find a compact double with 167.5mm crankarms that didn't cost a fortune, I'd probably switch to a 48/36 and keep the same 11-28 IRD cassette. I love it!