Best sprocket and chain setup for a 2009 450f

[JTM18]

Just wanted some suggestions on what people think is the best sprocket (brand & number of teeth) and chain for a 2009 yz450f

thanks folks

[JTM18]

i forgot...i ride mx

[DPW]

My personal choice is Ironman Sprockets and DID 520 VT2 chain

Stock bike I'd go with a 50T rear sprocket.

Aftermarket exhaust the stock gearing is good..

[Gunner354]

We have over 300 hrs on the stock sprocket and the DID erv3 chain. Amazing the stock sprocket shows very little wear.

[JTM18]

i've only got 16 hrs on my bike...I think my chain may have been a little to loose...whats a good rule of thumb of having your chain at the right tension?

[JTM18]

I've got an fmf exhaust...stick with the 48T then?

[Ga426owner]

Ironman sprockets and DID ERT chains work well for me....but your question on number of teeth depends 100% on the track. For most riders stock or a 50 is probably the best anwer....

[Centrespike]

Ironman front & rear with a Sidewinder (10k lbs) chain. Over 50 hours on that setup never have to adjust. Looks like new.

[grayracer513]

IMO, You can't do better than the Regina ORN6. With this chain, it almost doesn't matter what sprockets you select to run with it as long as they are of reasonable quality. "Stretched" chains (worn to a longer than specified pitch) are what wears sprockets out, and when the chain doesn't stretch, the sprockets last far longer. The OEM Sunstar on my '06 is 2.5 years old now, along with the Regina chain. Both are only now due for replacement.

When buying new, I prefer AFAM or Pro Taper fronts, and Tag Metals rears.

Gearing selection depends on what works for you in your situation. Stock gearing on your bike is 13/49, and it's quite common among those who ride primarily MX to use a 13/50.

On chain tension, the rule of thumb is to follow the manual. With the bike up on a stand, grab the chain at the rear chain slider bolt and lift up as far as it will go. Measure down to the swing arm. You need AT LEAST 1.9 inches here, with the max recommended being 2.3".

It will LOOK loose, but trust me, you need that much to maintain slack throughout the suspension arc.

Does this look loose?:

It isn't. In fact, that's what the minimum slack looks like:

THIS is what happens when you run it too tight:

[Gunner354]

Graycar choice is probably good but DID new erv3 have a very high strength and uses a rivot master link. Had to buy the Motion Pro tool. Was a little scary first one I did but I have done 2 other bikes and I'm glad I went with the rivot master link. Never a worry about loosing a master link clip. The chain is very expensive, but I guess you get what you pay for in this case.

[JTM18]

Gray racer....thats exactly what my chain looks like...i only have 16 hrs on my bike and the rear sprocket is worn...is there something im doing wrong? seemed like it happened fairly quik (last couple of rides).

[DPW]

Gray racer....thats exactly what my chain looks like...i only have 16 hrs on my bike and the rear sprocket is worn...is there something im doing wrong? seemed like it happened fairly quik (last couple of rides).

are you running the stock chain? The stock chain in my opinion should be replaced before the new bike is ridden.

[grayracer513]

are you running the stock chain? The stock chain in my opinion should be replaced before the new bike is ridden.

That was my response, also; sounds like the attack of the OEM chain.

Mark the end of one chain pin then start at the next pin, counting that as #1, and count to 20, then mark the 20th one. Wedge a rag in the sprocket, or otherwise hold the chain tight, and measure from pin 0 to pin 20. New, ti would be 12.5". If it measures 12 11/16" or more, it's too long.

Like DPW said, the OEM chain should be replaced on delivery.

[JTM18]

Gotcha....thanks fellas

[BlackT5]

Grey - I love your go - no go gauge for the chain. I think I'm going to build one. Using a machinist ruler is easy put time consuming.

[grayracer513]

Yep, it's simple, but fast and accurate. Remember to take into account that the spec in the book is measured to the pin center and cut the block accordingly.

[BlackT5]

Yep, it's simple, but fast and accurate. Remember to take into account that the spec in the book is measured to the pin center and cut the block accordingly.

That is interesting. I was under the impression that it was the air gap distance below the links to the bolt head. That means my chain has been a little loose. I shoot for 2.000 below the link. This last time I had 2.200 and did not tighten it up. Boy there was alot of slap.

A big thanks!

[Polar_Bus]

That is interesting. I was under the impression that it was the air gap distance below the links to the bolt head. That means my chain has been a little loose. I shoot for 2.000 below the link. This last time I had 2.200 and did not tighten it up. Boy there was alot of slap.

A big thanks!

There's nothing wrong with a little extra chain slap... better to slap, than to snap (as in snap the rear wheel hub) You would be amazed at how quickly moist sand can pack into a sprocket and really tighten up a chain....

[Gunner354]

Is the block sitting on the swingarm or the chain slider? What are the dimensions of your block?

[grayracer513]

Is the block sitting on the swingarm or the chain slider? What are the dimensions of your block?

The chain slider bolt is the point you measure from, so that's where it sits.

1.875" & 2.25"