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Old 08-12-08, 08:33 PM   #1
b3nsonx
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Explaination of gear ratios

ok, ive searched and haven't really found my answer.
What do the numbers for the gear ratios mean?

for example, the bike im looking at is a DK Rage, which has a ratio of...39/14
What does the 39 do and what does the 14 do? (i know the 39 is the chainwheel and 14 is freewheel)
What happens if you raise/lower these numbers in various combinations?
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Old 08-12-08, 08:47 PM   #2
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If you lower the chainwheel number it will be easier to pedal but with slower acceleration.
If you lower the freewheel it will make it harder to pedal with fast acceleration.
The normal is 39/14
36/13
33/12
30/11
28/10
25/9
23/8
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Old 08-12-08, 09:20 PM   #3
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so when adjusting these ratios, do you need to do anything to your chain?
Or is the standard 1/8 good for all ratios?
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Old 08-12-08, 09:53 PM   #4
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the length of the chain may differ in length depending on the size of chainring and freewheel/driver that you desire to run. The 1/8 is just merely the width of the chain this is depending on the type of riding you wish to do and what chainring and f/w or driver thinkness that you are using.
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Old 08-12-08, 10:29 PM   #5
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Originally Posted by PRIMO22 View Post
If you lower the chainwheel number it will be easier to pedal but with slower acceleration.
If you lower the freewheel it will make it harder to pedal with fast acceleration.
The normal is 39/14
36/13
33/12
30/11
28/10
25/9
23/8
wait...so if you lower the chain wheel from 39 to 36, you are making it easier to pedal, and if you lower the freewheel from 14 to 13, it will be harder to pedal...
So going from 39/14 to 36/13, what is the total result? because as you described, they should cancel each other out, with one making it easier to pedal and one making it harder to pedal.
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Old 08-13-08, 12:37 AM   #6
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It'd still make it easier to pedal. But if did something like 36/12 or 36/11 it'd get harder to pedal.
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Old 08-13-08, 02:25 AM   #7
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it's all in the math guys...
the key word... RATIOS...
quoting b3nsonX to give you a mathematical equation example,
" So going from 39/14 to 36/13, what is the total result?"

39/14 = 2 & 11/14:1 ratio, in generic terms this would be roughly at 2.79 freewheel rotations to 1 rotation at the crank (this will be shortened to "X"fwr : 1 cr in the future),

and 36/13 = 2 & 10/13:1, which would be a 2.77 fwr : 1 cr ratio

as you can see it's not much of a difference in ratio due to lowering both numbers on both sides...
sooo... if you want a more drastic increase in acceleration with a 14 tooth freewheel one should lower the chainwheel's teeth to the 36 tooth one instead of decreasing both thus making it a 36/14 ratio, equalling 2.57 fwr : 1 cr...
sure... it may not seem much, but lowering a ratio by .2 would mean less work to accelerate to top speed, BUT this will theoretically reduce your top speed...
to make it worthwhile though one should probably to go lower than that to make full use of your power on the street course, half pipe, or other such discipline... optimum would probably be, with a 14 tooth, 34 or 33 on these types of riding...

now apply these principles to the posted ratios...
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Old 08-13-08, 11:37 AM   #8
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oh, i get it.
thanks
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Old 08-13-08, 12:34 PM   #9
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he forgot 22/8.

and it will actually feel harder to pedal at first, the lower you go. i used to run 44-16 ( who hasnt at one point in time ) and then i switched down to 25-9. at first it felt harder to pedal, because theres a lot more power going into each individual cranking motion.
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Old 08-13-08, 07:09 PM   #10
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he forgot 22/8.

and it will actually feel harder to pedal at first, the lower you go. i used to run 44-16 ( who hasnt at one point in time ) and then i switched down to 25-9. at first it felt harder to pedal, because theres a lot more power going into each individual cranking motion.
I know i didn't want to get a very long list. I noticed a difference when I switched too. It not that much harder to pedal. Just takes a little time getting used too.
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Old 08-14-08, 01:51 PM   #11
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yea, like 5 minutes haha. it doesnt take like any time at all.
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Old 08-14-08, 06:32 PM   #12
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I said a little time 5 mins is a little time.
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