Page 1 of 1

The effects of gearing?

Posted: December 30th, 2010, 7:57 pm
by caseyracing222
Can someone help me understand exactly how it effects the bike when changing sprocket sizes? I would like to further my vague knowledge on it. I want to learn so that I can know what I can do for gearing changes on my new motor. Thanks :D

Posted: December 30th, 2010, 8:56 pm
by fastkart
It works the same way as your good old fashioned 10-speed bike.

Bigger on the front or smaller on the rear = less acceleration, but more top end... keeps the motor from winding out quite as fast

Smaller on the front or bigger on the rear = more acceleration, but less top end... motor winds out faster.

Depending on how much more/less you're needing, it's probably easier and more precise to change the rear sprocket.

Posted: December 30th, 2010, 8:58 pm
by caseyracing222
Thank you that made perfect sense, I have heard the added 1 tooth to the rear is equal to adding 3 to the front and vise versa, Is this true?

Posted: December 30th, 2010, 9:05 pm
by AlisoBob
Image


13 x 49 = 3.37 sprocket ratio.

Add 1 to the countershaft = 14 x 49 = 3.50 ratio

Take 3 off the rear = 13 x 49 = 3.54 ratio

Get it?

Taking one or adding 1 the the countershaft is WAY easier....

Posted: December 30th, 2010, 9:15 pm
by caseyracing222
I think I understand, currently I'm running stock gearing 14x49 which would be 3.50 and on my other bike I am using 14x51 which is 3.64 this bike barely has a second gear but pulls third forever, while the stock gearing struggles in third. BTW these are hillclimb bikes. has anyone had first hand experience with 14x51 gearing on a 5?

Posted: December 30th, 2010, 11:58 pm
by 100hp honda
using 14/51 and 14/52 on the 2 ktm's. works good but they have different tranny ratios than honda.

Posted: December 31st, 2010, 6:55 am
by AlisoBob
13 x 48 is alot less chain to sling around Clyde.

Posted: December 31st, 2010, 8:11 am
by Gmbond
I agree with you there bob

However a 13t is a tighter circle to wind the chain around which results in other issues, such as wear and drag from flexing the links in a tighter arc. Also can wear the slider on the swingarm more.

Really its a bit of a double edged sword as for offroad using the bigger rear sprocket makes it more vulnerable to rocks roots and ruts....

Posted: December 31st, 2010, 9:59 am
by Boise Synthetics 95
I found going larger than 50 wears the chain guard more quickly. I like 13x50 for trails. On the track we prefer more subtle rear sprocket gearing changes. Sometimes you find yourself between gears in a section and one tooth can make it right.