new chain and sprockets for 04 yz450

my chain has stretched and everyone says to change your chain and sprockets at the same time is this true and whats a good set? :lol::lol::banghead::banghead::lol:

Yes indeed always change the chain and sprockets together. I have a renthal kit on mine with the renthal o-ring chain on my 05 450 and I have alot of time on the bike with this set up. no stretching no you can get the set up for under 130 dollars.

Parts such as the chain and sprockets work together and wear together. Mating parts should be replaced at the same time whenever possible. I also just replaced my stock chain and sprockets with Renthal and they are holding up very well.

I am thinking of altering the sprokets on my yz450. I want to go down one notch in the front and up two notches in the rear. On the street bike this setup increased torque and put the power band in a more usable range.

Does any one have any feedback on this modification?

Yes indeed always change the chain and sprockets together. I have a renthal kit on mine with the renthal o-ring chain on my 05 450 and I have alot of time on the bike with this set up. no stretching no you can get the set up for under 130 dollars.

I was going to recommend the Regina O-ring chain (Regina makes the Renthal chain). It has to be the best/toughest chain I have ever used. I used it with aluminum sprockets on my 426 and went from June of 2004 to December 2004 (when I sold the bike) with only two adjustments. That was with at least two rides per month on it too.

I recommend the Renthal/Regina o-ring chain without hesitation.

im running the renthal combo also. the rear sprocket showed signs of wear after only two rides! the chain seems to be better than the stock did. i wiil probably replace the renthal with a sunstar.


I would bet lots of good money that you had your adjustment too tight.

No way ANY new set will start to wear the rear sprocket that soon. Especially if you had a ring chain mounted.

You should look into that before blaming brand names.

With a bike as powerful as a 450F, you should always replace sprockets when replacing the chain. You would eventually ruin your new chain if the sprockets are worn. The teeth will be curled forward. Replace your sprockets.

The power of the bike has nothing to do with the chain and sprockets wearing out.

The chain is rated for the brute strength of your bike and then some, and the sprockets will only deform when the chain elongates from wear.

The reason that you hear the recommendation for EVERYONE to change out both chain and sprockets as a set, is because most never measure their chain. If you DO measure your chain on a regular basis, and not run it past ~1.5% of it's original length, there will probably be NO signs of wear on your sprockets and you can change only the chain out.

Changing both out is a rule of thumb, not a manditory requirement. Especially if you are running a super hard steel rear. It will fight any growth of the chain far past the 1.5% mark. Most hard steel rears won't start to see wear from a worn out chain until the chain reaches ~3% elongation. One reason I never recommend folks use a hard steel rear, as it can mask a chain that is way past specs and in to dangerous zone.

IRONMAN SPROCKETS ! ! ! Can't go wrong with them. They are a little higher but well worth it. I also like the Regina O ring chain.

Ironman or Titax Ultralight steel sprockets and DID Gold X-Ring chains

Ironman Sprockets with an o-ring chain.......

Anybody use the regina zrd or gpz chains they have? There supposely the best there is. Ironmans are the best sprockets you can buy!!!!!

I agree completely with ironbird.....Get the Ironman sprockets, along with a Regina "o" ring chain; way better combination than that stretchy stock chain. The origianl Sunstar sprockets are actually half decent components, however just go with the Regina chain/Ironman sprocket combo and be done with it.


I'll also recommend the Ironman sprockets. Been using them myself for a couple years now. Stellar wear resistance plus they'll replace them free if they wear out within a year. The Regina z-ring chain (ZRH model) is supposed to last a bit longer than the Regina o-ring, but either would be a tremendous improvement over stock!

i ended up w/ some weird ass steel sprockets and a RK x-ring chain... have been good to me so far... i dont spend much cuz sand takes its toll on em..

my chain has stretched and everyone says to change your chain and sprockets at the same time is this true and whats a good set?
I also recommend the Regina sealed chains, either ORN or ZRH, even over DID, based on my experience with both. Those who favor Renthal R1 Gold chains should know that that chain IS a Regina ORN. You just pay more for it with the Renthal logo on the sides. Tag rear sprockets appear to wear better than other aluminum cogs I've tried, and their fronts are also excellent. If you're pretty sure you know what you want to keep for gearing, step up to Ironman SS rears.

Should you always replace the chain and the sprockets together? Not necessarily. It depends on why any one of the three drive components is being replaced. If your chain is "stretched", whether the plates were actually stretched, or whether it has worn the pins and bushings beyond a serviceable limit, the odds are that it has also damaged the sprockets, especially an aluminum rear. In that case, all three generally need to be replaced.

But, with modern sealed chains such as the Reginas, it is possible, even likely (it's happened to me several times), to wear either of the sprockets out before the chain is worn over limit. This can especially happen on bikes ridden in a sandy or muddy environment. The wear pattern this creates is more or less opposite that caused by a chain that's worn over length.

A stretched chain causes the sprocket to have "hooked", or "bent over", "ratchet" appearance at the teeth. Rear sprockets hook forward, fronts hook back. This is because the distance between two rollers is greater than the distance between teeth, and the teeth get worn, or even bent, out of the way.

But when a sprocket is worn by by a chain that has remained close to the right length, it wears straight into the load bearing side of the tooth without dragging across the tooth points as it is pulled off of or onto the sprocket. On the rear, this looks like the teeth have gotten very thin, but they are not pulled forward. On the front, it can wear far enough into the face of the tooth that it causes the teeth to look hooked forward, and close inspection will show that there is no wear at the tooth point, as there is with a stretched chain.

And how do you know if the chain is still OK? The wear pattern on the sprockets is an indicator, but the best way is to measure it. There's a procedure in the manual. Be sure to check it in several places around the run, and check that the chain tension is consistant at all points. All it takes to cause trouble is one badly worn bushing and pin.

Gray brings up a good point...

Ring chain users need to pay extra attention to your chains. It is very important that ALL of the sealing rings on each reel remain intact with no tears or dry cracks. Allowing water and grit into just one reel can cause that particuaar pitch to grow far faster than the other ptiches in the chain.

When this one bastard pitch travels around the sprockets, it places undue stress on the sprocket teeth, just as if the whole chain was elongated past specs.

This one bad link can wear and eat away the teeth. And when you measure the chain, if you don't have that bad link in the mix, you will not even know it's there. So, you should measure several sections of the chain to make sure that each section meausres typical with tho others.

Just one reel being over-length is a hard thing to see with a simple measurement, as it adds very little extra to the total length.

And as such, makes it just about neccesary to visually inspect each and every ring to see if any visible damage has occured.

Sand riders and those who neglect lubing/cleaning your chain on a regular basis, beware.

It should be obvious, with what I explained above, that the method of simply pulling the chain away from the rear sprocket to see if the chain has elongated is not sufficient to show a worn link or section.

If you really want to check your chain for elongation the proper way...

Use a set of verneer calipers. Simply pick two rollers that are lets say 8 pitches in distance.

Meaure the outside-to-outside of the two rollers on each end of the space, then right that down. Then measure the same section inside-to-inside of the same rollers, and write that down. Add the two measurements together and then divide them by 2.

Write that down.

Assume your first outside measurement was 5.450"

Your inside measurement was 4.640"

5.45" + 4.64" = 10.09"

Now divide that measurement by two and we get 5.045"

We know that a eight pitch section (9 total pins) of chain measures 5 inches. (.625" x 8 = 5")

So, the section of chain we measured is 5.045 inches, which is .045 (45 thousanths) longer than a new pitch chain section.

One percent of growth of an 8 pin section would measure 5.05"

So your section was under 1 percent elongation.

This method takes into account any wear at the rollers, that simply measureing perfectly from pin center-to-pin center cannot give you.

You can run a chain until it reaches approx. 1-1.5% before the sprocket teeth will see any deformation due to the chain growing.

When a standard roller chain grows, it is normally a linear increase of length, and can be estimated by hours of run time.

However, when a ring chain starts to elongate, it is going to be a very short time before it is trash. The lube that was injected internally has now depleted and there is nothing protecting the pins and bushing from wearing.

It will show a very fast increased elongation...much faster than the standard chain of the same length. You can continue to lube the standard chain, but the ring chain is on a fast pace to the trash can.

For this reason, you should change out a ring chain when it grows past 1%, and you would be fine keeping the stanard chain on untill it has grown to ~ 2%.

The standard chain will still take time to reach the 2% mark, whereas the ring chain will be there in no time flat. And if you aren't anal and check your chains regularly, the ring chain will have damaged your sprockets before you know it.

Just a word of advise...

A hard SS rear sprocket will resist any deformation due to wear from a elongated chain. It will not give you any warning signs that the chain has elongated until the chain reaches a point of approx +3% longer than new pitch.

As a result, if you do not get the chain off the bike soon after it has reached 1% over, the hard sprocket will put energy back onto the stretched chain and help to kill it even faster. And not only will the chain see undue stress because of the hard rear, but the front sprocket will also see an accelerated wear. And all because the super hard rear sprocket fights deformation.

This is one of the reasons so many claim the super hard rears to be so grand, yet they claim their chains are crap.

Sure , they offer a one year replacement guarantee, but who wouldn't if they know that the sprocket was too hard to allow deformation with normal chain elongation. Coupled with the fact that they are charging 2-3 times what a regular sprocket would cost...they can afford to offer such a warranty.

If one reads Ironman's warranty info, you will see that they will only replace the sprocket when it has seen .025" difference from the new profile.

Folks, yes..the sprocket is tough as nails, and will last and last, and if you are good about pulling maintenance and measure your chain on a regular basis, then you will have no problems at all with the Ironman...or an OEM aluminum sprocket for that matter.

But is you do NOT take the best of care, your superhard rear can CAUSE problems that you wouldn't normally have.

Even Dirtticks, Inc. (Ironman Sprockets) states on their website:

"As a sprocket wears the roller slowly eats into the driven side of the tooth."

The picture they give to go along with this statement shows a sprocket with worn teeth. But the wear is indicative of an ELONGATED CHAIN, and not due to "sprocket wear". The sprocket didn't simply wear to that profile from time and use, it was the CHAIN that had ELONGATED that damaged those teeth.

And from all the chains that were run on that particular sprocket (according to the mfg) they had to be allowing those chains to run way past safe running specifications. In other words, you would have to let your chain get dangerously stretched to cause that sort of damage to a hard steel sprocket.

The sprocket wear they show on the picture is from chain stretch, and NOT the sort of wear from normal use and trail grit that Gray was describing.

when i tried the ironmans,for one the quality of the cut looked like a shop class student with an acetylene torch manufactured it(still even had slag on it!) they replaced it with one that wasn't so bad but still made me shake my head. after using it i found it transmitted alot more harshness to the chain and trannie,enough so that i quit using it. my DID had never needed adjustment so many times as when i had that sprocket on(and yes the whole set was new and well maintained and not over adjusted) i now use the sidewinder tri-metal with their ti-chain,and this combo is smooth as silk. i'm guessing that the aluminum center buffers the tool steel hardness eliminating harshness :banghead: but no matter how you look at it i've not adjusted this chain since install (around 600 tough miles) its a little more money but worth it i'd say,they even seem to be reducing the prices to near normal :banghead: a bit of advice no matter what you buy make sure and align them with a straightedge and do not trust the adjustment marks :lol:

I run the same. Its not cheap, but its definately a high quality set up.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now