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Some comments in the Newbie post reminded me of something I have been looking for help on for a while. I understand the basics of gearing and by basics I mean I understand that shifting to a smaller gear means I can turn a higher cadence with the same effort and vice versa, but that is about it. Can someone explain a little more indepth about gearing or point me to somewhere that I can learn more?

2011-05-20 16:35:10

requisite sheldon brown reference:

the quick and dirty version: turning a large chain ring in the front (left shifter) and a small cog in the rear (right shifter) will be more difficult to push, but will turn the wheel at a higher speed (at constant rpm).

i can discuss the physics too, if you like.

2011-05-20 16:58:42

Sheldon is, indeed, a good introduction.

Here's some others:

This is for racers, but triathlete's so it is seriously endurance which ahs lot in common with more moderate speed distance riding (like if you want to travel and still have energy when you reach your destination).

Here's one for touring, which has a lot in common with utility biking.

I think a lot of the disagreement over gearing you see on this board has more to do with macho or non-macho than anything else.

Constant cadence is good.

2011-05-20 17:05:55

Constant cadence/effort is a good thing.

Unless you want to start custom designing your gears, I would suggest just biking a lot and learning the relationship between particular ring-cog combinations and effort; this way you can look at what's coming up and "know" what gear you should use (well, more or less). If you want to get analytical about it, you can plot your gears to better understand what you have. Here's one of my bikes (suitable for hills and for around town).

@HV: Yeah you're right. Worse, it's something I yell at people for all the time. Anyway:

abscissa: cog size

ordinate: gear-inches

lines are ring sizes

The small table has the actual values

2011-05-20 18:00:07

a pox upon all you who don't label your axes!

2011-05-20 18:08:00 The Ultimate 10-Speed Touring Cassette!
Designed for Shimano's Shadow technology Mtn Bike components, This cassette can be used on a touring bike with a traditional Deore MTB rear derailleur by replacing the B tension screw with a 4mm x 20mm bolt. We tested the set-up on a Gunnar with 105 STI 5600 levers and it shifted flawlessly! Number Series Price Sprockets Weight CSX145 SLX HG81 $69.95 buy button 11 13 15 17 19 21 24 28 32 36 364g
2014-11-08 13:02:54
Why are we reviving a thread from 2011?
2014-11-08 15:34:08
sorry didn't notice. "never mind"
2014-11-08 16:55:06
Like a fine wines, a thread can mellow with age. Perhaps even improve. It's a toss-up whether this is one of them. Let's see.
2014-11-08 17:00:50
It's a useful chart, one I wish I'd remembered existed from when this thread appeared the first time.
2014-11-08 19:34:56
Well, @Stu, divine intervention aka @Mikhail has interceded on your behalf and given you an opportunity to bookmark! :D It is useful, I was just pointing out its age before anyone else responded to someone who probably isn't even reading this thread anymore.
2014-11-08 19:42:18
Why are we reviving a thread from 2011?
New development for touring and randoneuring.
2014-11-09 00:11:53
"New development for touring and randoneuring." Not new to me! :P Be careful if you run that setup, Shimano was having some issues with freehubs self-destructing because the 36t cog on a 700c wheel was causing too much torque. They redesigned their Deore level hubs because of it (M525 replaced by M529).
2014-11-09 06:22:29
@Vannevar I’ve updated my gearing since that post, my granny is a 20 front / 36 rear now. You are my new hero!
2014-11-09 20:13:03
Not new to me! :P
So you have setup working with STI shifters?
Shimano was having some issues with freehubs self-destructing because the 36t cog on a 700c wheel was causing too much torque.
Well, this is expected. I don't think there are problems with this setup on any 29-ers if you use initial sport level setup.
2014-11-09 20:58:40
I have the XT hub on my 29 MTB and it is horrible. I'm getting it replaced for the 2nd time in less than 18 months. For reference, I literally almost never use the lowest gear and probably have a combined total of 20 minutes on it, split between two freehubs. It's just a very badly designed component.
2014-11-10 09:43:18
@Mikhail I just mean that the Harris Cyclery page has been up for a while. I don't use STI, I use Campy. My largest cog is a 34 which is bigger than I really need (with my triple) but it's what was on the last cassette I bought. I wouldn't consider freehub failures as "expected" since it clearly took Shimano by surprise. Whatever the case, use at your own risk. Just pointing out a potential point of failure that isn't obvious (maybe obvious in hindsight, but that's not the same thing). @UnrealMachine, I hear that a lot. So far my XT hub has held up but I haven't taken it off road. Still, I think I'll probably go DT Swiss for my next touring wheel build instead of XT.
2014-11-10 17:26:37