General Cycling Discussion - Straighten Me Out!

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Captain Crunch
01-20-02, 06:59 AM
In discussion on gearing I sometimes get confused with the terminology.
For instance, someone will mention a "bigger" gear, someone will mention a "higher" gear, and someone will mention a "lower" gear and they are all referring to the same gear. This can become very confusing when I read the posts.
What is the proper and correct terminology for gearing? Are the "harder" gears the "higher" and "bigger" gears (which is what I have always thought) or are they the lower gears because the chain is lower on the rear cog set.
People have been talking about spinning in higher gears and this seems to go against what spinning is all about. I thought the idea was to spin in a lower gear because it was easier on the legs.
Thanks
Mike
roadbuzz
01-20-02, 07:15 AM
I don't know what's "proper and correct," but I interpret bigger, higher, larger, or whatever to refer to gearing in the gear-inch sense, which is the same as the automotive sense. The rear wheel turns further with respect to crank revolution.
Again, I'm not sure if there is actually any proper way to talk about gear ratios, but..."bigger" or "higher" refers to a gear in inches. So, that means, for example, to shift to a "bigger" or "higher" gear, you have to shift down the cassette or to the big ring.
"Smaller" or "lower" gear refers to a smaller gear in inches. For example, to shift to a "smaller" or "lower" gear, you should shift up the cassette or to the small ring.
Hope that helped,
velo
MichaelW
01-20-02, 08:20 AM
A lower gear is one with more mechanical advantage, ie a bigger chainwheel and smaller cog, and represented by smaller gear inches.
Gear inches are
(no of chainwheel teeth)/(no of rear cog teeth) x wheel diamter.
and varies between 25 (very low) to 120 (very high). Most riding is done between 30 and 90.
You also need to factor in crank lenth to get total gearing ratio.
The "spinning in a high gear" , referred to the actions of top class professional riders. They spin, like all good riders do, but they have such power that they can do this at a higher gear ratio than us mere mortals.
Captain Crunch
01-20-02, 10:14 AM
[QUOTE]Originally posted by MichaelW
[B]A lower gear is one with more mechanical advantage, ie a bigger chainwheel and smaller cog, and represented by smaller gear inches.
I agree that a lower gear has more mechanical advantage but that would be a larger cog in the back not a smaller one.
Would mechanical advantage and a therefore a lower gear not be increased with a larger cog??? Mechanical advantage means that you can do work with less force and putting the bike into a smaller cog would not make less force.
For exampe if you are climbing a hill you will put the chain in a lower gear because less force is needed to propel the bike up the hill. This is mechanical advantage.
MichaelW
01-20-02, 10:22 AM
Would mechanical advantage and a therefore a lower gear not be increased with a larger cog??? Mechanical advantage means that you can do work with less force and putting the bike into a smaller cog would not make less force.
I stand corrected. Sometimes you know what to say but the words come out the wrong way. Thanks
Everyone here has given you the right answer. Now I will give you another one:
BIG gears at cassette and SMALL gears at chainrings is LOW gear.
SMALL gear at cassette and LARGE gears at chainrings is HIGH gear
Shifting UP at the cassette is Lower gears
Shifting UP at the chainrings is HIGHER gears
It's all very confusing.
There is a mathmatical formula for determining "gear inches" luckily, I don't know it, or I'd bore you to tears with it.
But you are absolutely right about spinning. Easier is faster. If you develope a set of legs that allow you to spin a 11/53 ratio at 100 rpm, or higher, I NEVER want to ride with you!
Captain Crunch
01-20-02, 10:30 AM
I am glad that you have all "straighted me out" on this subject. Thanks for all your help.
I thought I knew what was going on and it turns out I did (for once). I guess the odd time people just get confused and get higher, lower, bigger, smaller mixed up when posting.
You are right about not wanting to ride with someone spinning a 53X11. Although they wouldn't be riding with me for very long. I would need a telescope to keep up with them.:D
I usually just remember it this way:
Big gear=:(
Spinning=:)
Originally posted by JonR
I usually just remember it this way:
Big gear=:(
Spinning=:)
:lol: Except big gear on a downhill... :D
velocipedio
01-20-02, 11:48 AM
Can anyone spin a 53x11? That's about 60 km/h... Push it maybe, but spin it? Arnaud Tournant, maybe...
pat5319
01-20-02, 06:12 PM
The only way to (try to) avoid confusion when referring to what gear you're using is, to use the number of teeth in the example, ie: 53X19 53 teeth in front 19 teeth in rear ( hence my "handle")
Gear inches= number of Chainring teeth divided by number of freewheel/cassette teeth multiplied by tire size ie: 16, 20, 26, and 27(use for 700c) ei: 53 divided by 19 multiplied by 27=75.315 or a 75 inch gear. This value has nothing to do with the "real world" but is an "easy" way to compare gears-
39/14 X 27=75.214
I always thought/was taught:
A big gear was one that was aproaching or above 100 inches
( usually/or in big chainring)
A little gear was approaching or below 50 inches
( usually/or in small chainring)
Shifting up or grabbing a gear was adding inches
Shifting down or dropping a gear was losing inches
Of course the definition of what a "big" or "little" gear is depends on one's ability/strength etc.
Ride Gearfused ye have always with you
Pat
MichaelW
01-20-02, 06:49 PM
When people rode Ordinary (Penny Farthing) bikes, the gearing was set by the diameter of the wheel. Bigger wheel = bigger gear. Only tall people could ride the bigger wheeled bikes.
Gear inches are the diameter of a Penny Farthing wheel which would give the same ratio of pedalling to distance covered.
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