Sprockets??? Which one to Change
#1
08-12-2010, 06:37 AM
Join Date: Jan 2010
Location: Far North New Zealand
Posts: 120
Sprockets??? Which one to Change
Was reading an Aussie magazine the other day and it seems that most race teams do there gearing changes at the rear sprocket. What do we think???
#4
08-12-2010, 11:08 AM
No big deal as long as you don't want to change the final ratio drastically.
The more tooth the sprocket has, the less impact removing or adding one will have.
Soooo....It is cheaper to play with the front sprocket.
If your need is to have a very low final ration you will find out you have to buy the smallest front sprocket available and add some tooth on the rear sprocket if it is not enough...
Removing a teeth on the front is simplier, and you don't need to change the chain. To have the same effect on the ration you would need to add 3 tooth (or so) on the rear sprocket...but the chain will probably be too short !
Hope I don't get you confused...
The more tooth the sprocket has, the less impact removing or adding one will have.
Soooo....It is cheaper to play with the front sprocket.
If your need is to have a very low final ration you will find out you have to buy the smallest front sprocket available and add some tooth on the rear sprocket if it is not enough...
Removing a teeth on the front is simplier, and you don't need to change the chain. To have the same effect on the ration you would need to add 3 tooth (or so) on the rear sprocket...but the chain will probably be too short !
Hope I don't get you confused...
#5
08-12-2010, 02:21 PM
switching to a 13T on the front will give you more low end power, that's what most of us do who ride off-road most of the time.
ACOLE - what is your goal, trail riding or highway higher end speeds? That will ultimately determine what sprocket/s to change.
As NDERY mentioned if you change the rear to a larger sprocket, you will need to buy a longer chain so take that into consideration when determining what sprockets you want to replace
Also check out:
http://www.gearingcommander.com/
for some good estimates for changing gear ratios, chain, sprockets and associated RPMs coordinating with speed.
Think about the following when deciding what to change as well:
Whenever feasible to obtain a specific ratio, avoid using a smaller than stock front sprocket. The smaller sprocket requires the links of the chain to turn a tighter radius, which increases friction and decreases the life expectancy of the chain (by decreasing the life-expectancy of the o-ring seals of the chain).
Adding sprockets with additional teeth will require a chain with a higher link count to compensate for the longer path the chain now needs to take. Using sprockets with fewer teeth will require a chain with less links to cover the same adjustment range.
Unless you very recently replaced your chain, always replace chains when replacing sprockets (and visa-versa). The two surfaces are designed to mate and wear together (the sprocket-tooth/chain-roller interface) and use of a new sprocket with a worn chain can quickly ruin the sprocket... similarly, use of a worn sprocket with a new chain will quickly ruin the chain.
ACOLE - what is your goal, trail riding or highway higher end speeds? That will ultimately determine what sprocket/s to change.
As NDERY mentioned if you change the rear to a larger sprocket, you will need to buy a longer chain so take that into consideration when determining what sprockets you want to replace
Also check out:
http://www.gearingcommander.com/
for some good estimates for changing gear ratios, chain, sprockets and associated RPMs coordinating with speed.
Think about the following when deciding what to change as well:
Whenever feasible to obtain a specific ratio, avoid using a smaller than stock front sprocket. The smaller sprocket requires the links of the chain to turn a tighter radius, which increases friction and decreases the life expectancy of the chain (by decreasing the life-expectancy of the o-ring seals of the chain).
Adding sprockets with additional teeth will require a chain with a higher link count to compensate for the longer path the chain now needs to take. Using sprockets with fewer teeth will require a chain with less links to cover the same adjustment range.
Unless you very recently replaced your chain, always replace chains when replacing sprockets (and visa-versa). The two surfaces are designed to mate and wear together (the sprocket-tooth/chain-roller interface) and use of a new sprocket with a worn chain can quickly ruin the sprocket... similarly, use of a worn sprocket with a new chain will quickly ruin the chain.
Last edited by PSUdude85; 08-12-2010 at 02:38 PM.
#6
08-12-2010, 02:42 PM
Join Date: Nov 2005
Location: Washington
Posts: 21,060
Stock....14-42...not bad but for a fat guy like me I needed a little more low end power on the trails, That helped a lot, but was not the final solution. Changed up the rear to a 45 and that really helped, and I could still do 60 down the road. 
Then with the pipe and jetting, well that just made the bike absolutely perfect in my opinion. I'm working on the next mod which is free by the way, dropping 60 lbs. 8 down and 52 more to go. YIPPIE!!!!!!!!!!!!!!!!!!!!!!
Then with the pipe and jetting, well that just made the bike absolutely perfect in my opinion. I'm working on the next mod which is free by the way, dropping 60 lbs. 8 down and 52 more to go. YIPPIE!!!!!!!!!!!!!!!!!!!!!!
#9
08-13-2010, 12:20 AM
Join Date: Jan 2010
Location: Far North New Zealand
Posts: 120
Sprockets??? Which one to Change
Hi all.
Thanks for all the comments.
The thing is that on the weekends I will be doing track & trail and during the week I will be on the tar.
So I was looking for a good all round combination which a 13T front sounds like.
www.gearingcommander.com answered alot of my questions. Great site. Thanks PSUdude85
I'm told it can be quite difficult removing the counter shaft nut. Any tips???
Quote: (Whenever feasible to obtain a specific ratio, avoid using a smaller than stock front sprocket. The smaller sprocket requires the links of the chain to turn a tighter radius, which increases friction and decreases the life expectancy of the chain) (by decreasing the life-expectancy of the o-ring seals of the chain).
Anybody experienced any excessive wear when they changed to a 13T front sprocket.
Also, i have done 2100 klms with the current sprocket and chain set up.
Is it ok to change just the front or am I going to have to replace everything
Thanks for all the comments.
The thing is that on the weekends I will be doing track & trail and during the week I will be on the tar.
So I was looking for a good all round combination which a 13T front sounds like.
www.gearingcommander.com answered alot of my questions. Great site. Thanks PSUdude85
I'm told it can be quite difficult removing the counter shaft nut. Any tips???
Quote: (Whenever feasible to obtain a specific ratio, avoid using a smaller than stock front sprocket. The smaller sprocket requires the links of the chain to turn a tighter radius, which increases friction and decreases the life expectancy of the chain) (by decreasing the life-expectancy of the o-ring seals of the chain).
Anybody experienced any excessive wear when they changed to a 13T front sprocket.
Also, i have done 2100 klms with the current sprocket and chain set up.
Is it ok to change just the front or am I going to have to replace everything
Last edited by ACOLE; 08-13-2010 at 12:25 AM.