Sprokets and Chains...

[bigredhead]

ok.. someone please tell it like it is.

For the longest time.. i've been told and lived by the " You replace everything as a set.. at all times "....

But i read posts of " I replaced my rear sproket as it was shot.. but my front was fine " ....

What's the rules here ? :)

[short4stuff]

Hmm i'm not really sure, but I would say for the longest life of everything change it all at once. its just if the front sprocket is abit warn well the chain is going to stretch abit and then the back sprocket is going to wear to the same as the front... Get it?

[bigredhead]

Hmm... my friend is putting new front and back sprokets on his trike with the same chain...... i questioned it but he says the dealership sold him 2 front and 1 rear sproket so he can change back and forth between gearing...

His current front has chipped teeth, and his rear is ok.. not slipping but is worn.

I'm thinking he's gonna ruin his sprokets with his old chain.. tho is does APPEAR ok.. determining chain wear is a difficult thing.. unless i simply don't know how to look for it.

God i love shaft drive.

[OldSchoolin86]

It WILL wear quicker when you don't replace everything, especially when your front has chipped teeth.

[BIGCRIP28]

i always hear to change it all for maximum life.

[thedeatons]

So, taken from the world of mountain biking and sportbikes... :

Chains stretch over time, for this purpose Park Tools makes a chain wear gauge that allows you to check the life of your existing chain and decide whether it needs to be replaced. Another way to check is by using a small machinist's ruler, that will measure to 1/64 of an inch. You should only need the 1/16" side for the test. This test will require you to contact the manufacturer of the chain, whether it be DID, Regina, KMC, etc. and ask their pin to pin measurement. They should be able to give you a measurement for a new chain, and a maximum tolerance measurement, as in "not to exceed 1 inch (for example) from the center of one pin to the center of the next pin".

Regarding swapping matched pairs, I have read some on the subject involving the vehicles I mentioned above. The simple fact is that chains stretch quicker than sprockets wear, unless you are using aluminum sprockets, then there may be a different rule. You can tell if your sprockets are worn by an elongation of the half circle that makes up the space between the teeth. It will be in the direction, or on the side that the chain is pulled from. Looking at the sprocket from the side of the bike with the chain and drive sprockets, with the front sprocket being towards your left, there will be elongations towards the left side of the half circle, when looking between the top teeth of the sprocket. The reason being is that the chain is pulling it from the left.

I am of the opinion/belief that if your sprocket looks fine, and you could even measure the half circle using some type of home-made half circle template, and if everything looks fine, then you should be able to keep the sprockets. In most cases, with our steel sprockets we should be able to replace the sprockets at the very most every second time you change the chain. Chain stretch will largely depend on keeping the chain properly lubricated and cleaned. A good chain cleaner such as one used for bicycles that submerges the chain in solution and brushes the pins/links is the absolute best way to go if they make such a thing for ATVs/dirtbikes.

I have a link to an article that shows a Kawasaki ZX-11 dynoed before a chain and sprocket swap and then after, with no other changes, and there was a 6hp gain. Granted, these items were pretty well worn from a lot of big bore power, but keep in mind some people have a 25 year old sprocket on their ATC/ATVs.... Hopefully this helps you out some. I personally would contact the manufacturers about testing rather than going for personal opinions. James

[sblt500r]

you should replace all as a set. its cheap insurance to a broken case. and the new parts will wear faster.

with the chain on and adjusted, take the chain on the rear sprocket and try to pull it off at a link and it shouldn't move off the sprocket that much if it does then you need a new chain. about half a link is too much.

[bigredhead]

Cool.. thanks for the info guys..... much apreciated !