New rear sprocket???

i have never used the sprocket specialist sprocket but i have seen it and it does look trick. i have used both sunstars and renthals on my yz 250f and both of them wore pretty quickly. if you are not concerned with the weight maybe just use a steel sprocket because they wear much better. i might try some ironman sprockets next, i hear there pretty tough.

I run Sprocket Specialists sprockets. I ride mostly woods and I put a 52 on my 04 CRF450 last year after the first week I had it ... I havent worn it out yet to any great degree so far. It is lasting a long time. Like a whole year riding mud, sand at least once a week for about 35 mile rides.

Buff
Go get an IronMan sprocket!
One year warranty and it is awesome looking. It weighs slightly more than aluminun. I have one on each of my KTM's and they are showing zero wear since I put them on in November. Aluminum is a waste of $.
dirttricks.com will hook you up. These guys are riders!

I've seen pics of a Sprocket Specialist sprocket that came apart (on KTMtalk). Go IronMan.

Aluminum sprockets are only a waste of money if you don't properly maintain your chain and sprockets.
How would you attribute many folks having great success with aluminum sprockets?

A year? I have an aluminum with 3 on it. No wear whatsoever.

BTW...I've heard zero bad about the Steath so far until this thread.
Be aware that just becasue one guy had a sprocket fall apart, doesn't mean the sprocket was bad. Who knows if the guy had it on properly or what the situation "really" was.

When they come out with an aluminum sprocket with a one year warranty, I'm all over it. In the mean time...

Also, if I had someone giving me free aluminum sprockets, like many top riders, I wouldn't have to worry about longevity.
Jaybird, if you've gotten 3 years on an aluminum sprocket, on a 4stroke YZ, you are the man. I assume you ride on dirt more than once a month.
KTM sells the sprocket with the steel outer ring, and they work very well from what I've seen. I know a guy who rides in the desert on a CR500 and he's had an Iron Man on for 3 years :thumb: . Money well spent!

jim, why are you so angry? :eek:

I'm pretty OCD about my bike hardware so I typically like to run aluminum rear sprockets and then change rear, front and chain (regardless of oring or not) when the aluminun wears out. Call it a hobbie.

Jim,
It takes far many more muscles to frown than it does to smile.
I smile each and every time I hear someone claim that aluminum sprockets are junk because I know for a fact that it isn't so.

If you don't have any luck with an aluminum sprocket, then you are doing something wrong.
I'd give you a year garantee on an aluminum if I knew for sure you knew how to maintain it. I'm fairly certain at this juncture you don't.

A steel or spacecraft titanium sprocket is a great thing for folks who would rather not pay attention to good maintenance. It can handle your bad maint. BUT your chain and other components can't.
Ask your hard-sprocket garantor if they will also garantee the chain you buy.

The sprocket I mentioned above is not on the Yz4, but it matters not. There isn't a dirt bike made than can deform an aluminum sprocket with it's brute force.

I'm with Jay on this one. I commonly got 1yr+ out of my alumimum sprockets on my CR250 riding 3-4 times/wk. It's all in the maintenance (and good chains) :thumb:

Jaybird said:

There isn't a dirt bike made than can deform an aluminum sprocket with it's brute force.

Click to expand...

I was interested to discover that Superbikes commonly do destroy aluminum sprockets (but we're talking nearly 200HP...not a dirtbike) and that teams run steels on nearly everything (even 600 Supersports) at places like Daytona.

umm has anyone thought of using a sidewinder sprocket

there more but do seem to last longer on big bore bikes

but cost seems to be the only down side

The sidewinder aluminum sprockets will last no longer than any other quality machined aluminum sprocket.

i was talking about there ti moly ones

It doesn't matter the size of the bike, as I've stated. A sprocket that got deformed would have deformed on a 426f or a 125...it's NOT the bike. IF your adjustment is proper, and you lubricate properly, then the only thing that deforms the sprocket teeth is a worn chain that has a longer pitch than new.

Yes if you run a super-duper, ti-moly, spacestation grade hard-ass sprocket then no, it won't see this enongation of pitch right away....in fact it will probably give you that year that they garantee. BUT it WILL most definatley , without a doubt, 100%ly, cause your chain to wear faster than it would have.

I get so tired of saying this...it seems futile....
The dirt biking public is victom to marketing crap. And their anecdotal experiences do in fact back up the claims of the hard sprockets...but what about your chains?

So many folks are running chains that are stretched out of specification and they have no clue about this, and why? Because they have no idea about how to measure a chain, nor do they even want to attempt it. And their sprocket is so hard it gives them no visual to let them know they are running a dangerously worn chain.

Good lord folks...buy hard sprockets and keep spending money. It's good for our economy. Vic will love you for it too.

What amazes me is the time and money folks spend on certain aspects of their bikes, yet they will argue to the ends of the earth about their chain drives.

Actually, I'm just BS'ing...it's best to buy a steel sprocket, and a ring chain, and you will never have to worry about a thing accept squirting a lil WD-40 on it once a month.
Heck you don't really even need to keep them cleaned or adjusted properly. Just throw the stuff on and ride. To hell with what's proper.

But make certain you run race fuel in your clapped out KDX's.
I hear thats the bomb!

Angry Jay,
That has a nice ring to it! You are obviously annoyed. Don't take these things personally. I love the sprockets I use, that's why I recommend them. I would routinely get over 6 months of riding on an aluminum sprocket, so calling them a waste of money was harsh. Also, the place I get my sprockets from manufactures them on the premises. Therfore, they can gurantee them. They do not manufacture chains, so they do not warranty them.

I don't understand why, acoording to what you say about maintainace, your sprockets don't last forever. You should never ever have to buy a sprocket. They should make chains out of aluminum too. :p

Now, forgive me for acting out of character, but Mike LaRocco just won the Indy supercross and I am very happy :yeehaw: .

angry jim said:

You are obviously annoyed.

Click to expand...

That is the truth.

angry jim said:

Also, the place I get my sprockets from manufactures them on the premises. Therfore, they can gurantee them. They do not manufacture chains, so they do not warranty them.

Click to expand...

That couldn't be futher from the truth.
The fact that they manufacture their sprockets on the premisis has nothing to do with the reason they can warranty the hard sprocket. It has to do with them knowing exactly what I know about chain/sprocket maintenance and knowing what seems to be conventional wisdom about chain drives in the dirt biking community.

Jim, when your aluminum sprocket had 6 months on it why did it wear out? Also, was the chain worn out, or was it ok?

Jay, I like what you said about the o-ring chain and the WD-40....now you are on to something!

I still say maintenance or no maintenance, if the average rider would just replace the chain when it becomes worn, the sprockets would last a long, long time. I've put a new chan with 1/2 worn out sprockets on several bikes, and predictably the sprockets don't show any sign of ongoing wear until many rides later when the chain starts to wear.

Systematically replacing the sprockets with the chain is hogwash, but that topic has been beat to death already with both personal experience as well as the laws of physics.

Naturally, some of the premium super duper sprockets will last longer, but it's false economy to spend 2 times as much for a sprocket that only lasts 1.5 times as long.

Jaybird, how is pitch defined/measured on a sprocket?

When referencing a sprocket, there are two dimensions that are pertinant. 1) Bottom diameter 2) Pitch diameter

The Bottom Diameter is the circle around the sprocket that coincides with where the rollers sit in the sprocket.
The Pitch Diameter is the circle around the sprocket where the pin centers of the chain are when the chain is properly tensioned and nested on the sprocket.

The pitch of a #520 chain is 5/8", or .625".
For the sprocket to properly handle a chain, the teeth must be cut so that they coincide with that .625" pitch.
If you have a 52 tooth sprocket using a #520 chain, the circumference of the pitch diameter will be 10.351". The circumference of the 10.351" dia. is 32.512".
You'll find that if you divide 32.512" by 52 (teeth) you have .625", which is the correct pitch for #520 chain.
When machining the sprocket, after the first gear valley is cut, the holder needs to advance 6.923 degrees to cut the next valley. (360 deg. / 52 = 6.923 deg.)

When the sprocket rotates on the bike, the working face of the tooth on the driver sprocket pushes on the chain roller causing it to advance. Inversely, the chain roller on the driven sprocket pushes against the working face of the tooth, causing the sprocket to advance.
In a perfect world when no additional forces are at work, this perfectly matched pitch between chain and sprocket tooth will never become deformed and can continue to produce work forever.
However, there is friction that occurs on the chain parts that causes wear, and as a result, the pitch of the chain starts to change. When the chain pitch starts to change, the chain can no longer fit perfectly in the valley between the teeth.
You now have a miss-match of pitch between chain and sprocket. When this happens, the bottom of the chain roller will no longer sit in the bottom diameter of the sprocket.
It actually starts to ride up on the working face of the tooth.

The further towards the outside diameter of the sprocket you go, the less metal there is on the tooth, and less meat there is on the working face. On an aluminum sprocket, the energy that the chain places on the tooth can actually start to cause the tooth to deform. The extent of this deformation is in relationship to how much the pitch has elongated from it's original pitch.

When a hard sprocket is used, the elongated chain tends not to be able to deform the sprocket tooth. However, due to miss-match of pitches between chain and sprocket, the chain still rides up on the working face. Also, there is still the same amount of force placed on the hard tooth as there would be on the aluminum.
Since there is always an equal and opposite reaction to every action (who ever thunk that up had it together, dun you thin?) the energy that would normally deform the tooth is placed back on the chain parts themselves.
This actually accelerates the wear on the chain. Even moreso than what you would have seen with the aluminum.

From all this you get a couple of things...for one, and probably the most important, no matter what type of sprocket you run, the longer amount of time you can keep the chain from elongating from wear, the longer all parts of your chain drive will last.
What happens lots of times is that a rider has no idea of what length his chain is. He only knows that with an aluminum sprocket he gets a visual from the teeth wearing and knows from that, that it's time to change out both chain and sprocket.
With a hard sprocket, the rider doesn't have a visual. So he continues to run the chain, even though it's worn and elongated past where it should be. Even running it to a point where it's in danger of actually breaking. It will eventually start to deform the hard sprocket too. But, you will probably have a dangerously worn chain by that time.

Bottom line....no matter what sprocket you run, if you measure your chain and never run it past ~1.5% of it's original pitch, you will never wear out the sprocket....aluminum, carbon steel, or titanium.

If you are happy with paying outrageous prices for chains and sprockets that last one year, then so be it.

I'll be happy running mine 2-3 tmes longer and paying half as much as you.

We will all be happy as clams, si?

So I'd be a millionare if I patented a chain that was 2% over pitch? :eek:

No, millions of them exist already, and are in service.

unless its running slicks on tarmac :)

sorry, that was a newbie f*** up

Thank you Jay, for taking the time and effort to type out that very thorough explanation. :thumb: ...a few of us have been quitely listening over the years :cool:

My pleasure, JTT.