Sprocket "phasing" when changing up your chain/sprockets

Hi folks

Been reading a lot of sprocket swapping threads lately where riders canvas forum members for the best  drive train choices based on the ideal gear ratio with no emphasis  on retaining an even chain/ sprocket wear...

To get the most bang for your drive sprocket and chain buck.. i thought i'd post these links that show how one sprocket with an odd number of teeth allows your chain to hunt a different sprocket position per revolution and wear evenly .. sounds kind of deep... but it only means ordering a 1 tooth difference in sprocket size ..

... you can decide with examples from three industry sources/links ... ...  


http://sheldonbrown.com/chain-life.html
Two type links in chains that wear differently to compensate for in T count matching.

http://www.fbchain.com/news/70-why-havi ... -you-money
“A sprocket with an odd number of teeth will offer at least double the service life of a sprocket with even teeth.

See if this one don't confuse ya to look into this more
http://www.thorncycles.co.uk/forums/index.php?topic=4655.0

First, could you fix the third link please? Thanks.

Second, what you're saying makes sense, but I have a question.
A 13/48 setup would last longer than a 12/48 or 14/48, but what about both sprockets having an uneven number of teeth like 13/49 (vs 13/48) ??

For the chain/sprocket set to last as long a possible, do both sprockets need to have an uneven number of teeth or only one of the sprockets???

Personally I think that there is so much physics involved that this probably doesn't apply very well to motorcycles. I see how this would work in a nice tight consistent industrial application or even a well maintained bicycle. But on a motorcycle between the constant accelerations and decelerations the sprockets are constantly allowed to "hunt" as the chain bounces up and down going from slack to taught not to mention all thats going on every time the suspension is compressed.

That said I'm sure there is an ideal tooth count and sprocket pairing and calculated number of links. And I will look into this when changing my chain/sprockets, I'm just not sure if there would be any gains on a enduro motorcycle.

Evol wrote:

First, could you fix the third link please? Thanks.

Second, what you're saying makes sense, but I have a question.
A 13/48 setup would last longer than a 12/48 or 14/48, but what about both sprockets having an uneven number of teeth like 13/49 (vs 13/48) ??

For the chain/sprocket set to last as long a possible, do both sprockets need to have an uneven number of teeth or only one of the sprockets???

1]Link fixed
2ab] remember the larger the sprockets the longer the chain "that changes the math"...

On question 2b ] odd and even.
here is the best example on gearing set ups right from gearing commander site:

http://www.gearingcommander.com/base/gc_howto27.htm


For anyone who didn't read down through the provided threads.. phasing is when you re-install a chain the same way it was taken off {on each sprocket} so the wear pattern remains the same.

I noticed some of the other threads popping up on this issue... i'm not trying to sell anything here just making folks aware of sprocket changes =cause and effect.

Speaking from experience with off road bikes and race atvs...

The bigger the front sprocket the better for wear, even tooth count be damned.

A 14 will out last a 13 which will out last a 12, been there done that on my atv that I had for 10 years.

The larger front sprocket bends the chain a little less making the chain last longer which out weighs the odd wear even tooth sprockets cause.

On the wrr stick with a 13 or 14 front and run what ever rear you need to for the ratio you want.

All this odd wear/phasing talk goes right out the window as soon as you ride through some mud, water or sand, the dirt causes more harm and wear than any of that crap.

Biglake wrote:

Speaking from experience with off road bikes and race atvs...

The bigger the front sprocket the better for wear, even tooth count be damned.

A 14 will out last a 13 which will out last a 12, been there done that on my atv that I had for 10 years.

The larger front sprocket bends the chain a little less making the chain last longer which out weighs the odd wear even tooth sprockets cause.

On the wrr stick with a 13 or 14 front and run what ever rear you need to for the ratio you want.

All this odd wear/phasing talk goes right out the window as soon as you ride through some mud, water or sand, the dirt causes more harm and wear than any of that crap.

I guess that would open the another window to chain maintenance/cleaning  eh.... All these points add up to things WRR forum riders can think about when deciding what's best for your "own"circumstances after a day out ... so why not have all the info in this drivetrain thread.. and include  atv chain /sprocket contact area experiences  as important considerations too?


I'm in dirt area's as much as i can be and drive the bike to and from the dirt home{or at least plan to ..it always doesn't work out that way.}
I religiously have only used wd40 as chain lube but as everyone knows thats controversial    .. but still spray the chain anyway when back out on the asphalt to ride home...and happily get at 10,000 + kms out of a aftermarket o ring chain.For me the WRR was purchased because of a site that boasted a bike that drove from Mexico to Alaska and is still ticking..others may be in the same high mileage dual sport boat.

best of luck!

If it was a big fast street bike that never seen dirt and you wanted your chain to last 40-50000 kms phasing might be an issue but on some thing that gets used off road dont waste your time worrying about phasing and even tooth counts on the sprockets, it just doesnt matter on a 250 dual sport.

I only mentioned the atv as I had em for years and found them to be twice as hard on chains and sprockets as bikes so you can notice what last longest faster.

I also had a klr650 (the stock chain and sprockets lasted 20000kms on it), couple of xr200s, gasgas 250, kx 250 and the WRR, running the biggest front sprocket you can is always the way to go even if its a 14 with an evil even tooth count lol.