Chain & Sprocket Sizes
- Thread starter prunty
- Start date
This topic comes up a lot.
For those of you who aren't all that familiar with gearing the bike, some criteria.
What works for someone else,in most cases is not going to work for you.
First and most important,skill level.Be humble or realistic when evaluating your riding ability.The more skilled the rider,the more gearing that rider can manage.And are you getting better,think kids clothes,if you are improving as a rider,gear a tooth higher,youll get there.
Where do you ride most of the time.If you are the kind of rider that rides a lot of diferent terrain,stay up a tooth.Better to have to use some clutch or force yourself to carry a little more speed in the tight stuff,then run out of gears in transfer sections or open terrain.
What do you ride,more cc the higher gearing you can manage.A 300 can run 1-2 teeth higher in the same terrain as a small bore 125-200.The 250 maybe a tooth higher.Keep in mind all things being relative.Same rider testing gearing in the same terrain on the same bike.
Rider weight.Be realistic here.
Riding style.
Power characteristics of the bike.Aside from cc.If you spent a bunch of money to build a bike with high torque characteristics,you will negate most of those gains by gearing the bike too low.
13-49 is a good middle bench mark.A tooth up or down is a fine adjustment.Anything beyond that you will begin to change the characteristics of the motorcycle exponentially.The power characteristics need to be in relative relation to the gear box gearing and ultimately the final gearing.
Tire size will effect what gearing you choose.I run IRC M5B 120/80 almost exclusively on everything except the 300.Its a low profile tire,which means the gearing is lower and it spins easier,so 1 tooth smaller on the rear sprocket would make up most of that difference.A trials tire would be just the opposite and then some due to lack of wheel spin.
12 tooth sprockets are risky,hard on the chain,they throw chains,break teeth,wear faster,and I swear just don't seem to get the power to the back wheel as well.Large rear sprockets are hard on your chain guide,will in many cases actually create drag.So gotta gear a little lower now to compensate for increased drag due to gearing lower,scenario.Hard on rollers and more chain equals more stretch.Large rear sprockets get in ruts,glance off rocks,pickup sticks and run them through the sprocket.Not kidding.
The tighter the loop between sprockets the better in general.
There are just too many variables for one rider to suggest to another rider what gearing he should run unless they ride together.
Hope this helps
For those of you who aren't all that familiar with gearing the bike, some criteria.
What works for someone else,in most cases is not going to work for you.
First and most important,skill level.Be humble or realistic when evaluating your riding ability.The more skilled the rider,the more gearing that rider can manage.And are you getting better,think kids clothes,if you are improving as a rider,gear a tooth higher,youll get there.
Where do you ride most of the time.If you are the kind of rider that rides a lot of diferent terrain,stay up a tooth.Better to have to use some clutch or force yourself to carry a little more speed in the tight stuff,then run out of gears in transfer sections or open terrain.
What do you ride,more cc the higher gearing you can manage.A 300 can run 1-2 teeth higher in the same terrain as a small bore 125-200.The 250 maybe a tooth higher.Keep in mind all things being relative.Same rider testing gearing in the same terrain on the same bike.
Rider weight.Be realistic here.
Riding style.
Power characteristics of the bike.Aside from cc.If you spent a bunch of money to build a bike with high torque characteristics,you will negate most of those gains by gearing the bike too low.
13-49 is a good middle bench mark.A tooth up or down is a fine adjustment.Anything beyond that you will begin to change the characteristics of the motorcycle exponentially.The power characteristics need to be in relative relation to the gear box gearing and ultimately the final gearing.
Tire size will effect what gearing you choose.I run IRC M5B 120/80 almost exclusively on everything except the 300.Its a low profile tire,which means the gearing is lower and it spins easier,so 1 tooth smaller on the rear sprocket would make up most of that difference.A trials tire would be just the opposite and then some due to lack of wheel spin.
12 tooth sprockets are risky,hard on the chain,they throw chains,break teeth,wear faster,and I swear just don't seem to get the power to the back wheel as well.Large rear sprockets are hard on your chain guide,will in many cases actually create drag.So gotta gear a little lower now to compensate for increased drag due to gearing lower,scenario.Hard on rollers and more chain equals more stretch.Large rear sprockets get in ruts,glance off rocks,pickup sticks and run them through the sprocket.Not kidding.
The tighter the loop between sprockets the better in general.
There are just too many variables for one rider to suggest to another rider what gearing he should run unless they ride together.
Hope this helps
mtnmanseth
New member
After looking into this a little more, I happen to agree. I didn't realize the bike already has been geared down (to a 12T CS) and definitely didn't want to add 4 whole teeth to the rear sprocket (more potential to hit rocks/damage chain/need new chain), so I'm keeping it as is. I only experience issues with 1st being barely too tall on very steep sheer rock climbs (think Slickrock trail @ Moab) here in SoCal. But I'm definitely getting better at single finger clutch work and lunging up steep, stairstepped climbs. In short, 12/48 will stay until I wear it all out. Then, I'll replace with a new 13T CS, install the new 50T rear, and a shiny new chain.
Good advice here, thanks again!
Last edited:
gasser
New member
I know some people have a bias against 12 tooth counter shaft sprockets but lets be realistic a 12/48 combo will feel almost exactly like a 13/52 sprocket combo. The only reason it won't feel exactly the same is wheelbase will be increased about 3/4 inch with the 12/48 combo and same length chain. Yes the chain will wear a little faster but the difference is very, very small if you take proper care of your chain. As for tooth breakage and throwing chains there is absolutely no reason to believe it to be any different with a 12 tooth cs than it is with a 13 tooth cs.
They break teeth because you are trying to send 36-50 horsepower to the rear wheel with one less full tooth carrying that load.Dont look at it as 12 of 13 which is a decent enough ratio.Look at your 12 tooth countershaft sprocket and look at how many teeth actually have a full bite on the chain.Now add one full tooth to that.It is huge.Now think about how your chain isn't always tight depending upon what the rear suspension is doing at the time and how much slack the chain has in it at any given time those few teeth you do have do not have a full bite and will be carrying much of that load on the tip of the teeth.
As far as throwing chains see above paragraph and add the fact that you have significantly decreased the circumference of the chain at the countershaft.
memphis2857
New member
Chain & Sprocket Sizes
13/48 is factory gearing. Most switch to 13/50 in my neck of the woods. I am not exactly sure how many links the chain is. For some reason 120 seems right.
Easiest thing to do is count the teeth on the sprockets and then count the links on the chain. Then you know for sure
Sent from my iPhone using Tapatalk
13/48 is factory gearing. Most switch to 13/50 in my neck of the woods. I am not exactly sure how many links the chain is. For some reason 120 seems right.
Easiest thing to do is count the teeth on the sprockets and then count the links on the chain. Then you know for sure
Sent from my iPhone using Tapatalk
Thanks for the number. I just don't understand why all those spec are not in the manual.
cheers
Any number about Front and Rear Sprocket? I read that you need to specific one to fit on your wheel.
