Crf450r Chain, sprockets and gearing

[Friesen]

I recently bought a low hour 2006 CRF450R. The previous owner replaced the chain and sprockets prior to the sale. The stock chain was replaced with a Renthal Gold O ring. I went to swap out the front sprocket and I noticed rub marks on the engine case from the 'wider than stock' chain.

Question: is there a c/s spacer for the CRF when running a wider chain?

The local honda dealer said I needed to replace immediately and buy a new 'narrow' chain designed for the CRF. Is this true? or is there a spacer?

Gearing question:
I want more low end grunt. Currently, I'm running a 13/49. My previous bike cr250r I had geared 14 front - 50 rear and it was great for the type trail riding I do in Northern California / Lake Tahoe area.

do I swap out the 13 for a 14?

 

[elcamino12sec]

It is possible that the previous owner installed the front sprocket backwards. Surley your not the only crf450 owner that has an oring chain. Try turning around the front sprocket around and see what happens. Of course put the bike on a stand and spin the back tire for inspection before you go ride it. As for gearing, try a 51-53 tooth rear sprocket, should be able to pick up a steel sunstar unit pretty cheap.

 

[Friesen]

Good question.
I know the 'groove' that has the stamped info on it is facing the engine and the smooth side is facing out. I'll check the manual.

Gearing... I received different advice on this. some say go to a 14t front, others have said to go to a 12t. But I'm concerned about the excess wear of the 12t front.
Maybe a 13t and a 51t is the answer?

Anyone have any experience with this combo?

 

[Friesen]

just found this for those that maybe interested.
Fastway makes a crankshaft spacer for 5 bucks designed for crf's with an o ring chain.

I think I'll order it and check it out.

 

[Spokes574]

I used the DID 0-Ring chain and have no issues.
Yes - Fastway does make a front sprocket spacer - try that.
For gearing, all magazines say to always go up on the back
and not the front. Reason is that going up on the front puts
more wear and tear on the chain.
Stay with your oring - else you will be adjusting your chain often.
I never had to adjust my DID Oring.

Spokes574

 

[Friesen]

My spacer came today from Fastway, price $4.95.
I did a quick test prior to the install.

On the front sprocket, I placed a piece of thick paper between the oring chain and the engine case and pushed the chain over (on the sprocket) and tried to pull the paper out and I could not. The chain had pinned the paper against the engine case. Then I installed the spacer and repeated the same test with the paper and the paper could slide out.

The spacer is very thin, but thick enough to get the chain off the engine case.
Nice alternative to spend $80 for a new narrow oring chain.

 

[BSWIFT]

I want more low end grunt.

The CRF450 already has a ton. Are you trying to prevent stalling and just want to lug the engine? Go up one or two teeth on the rear sprocket and look into a Rekluse auto clutch. Ride the bike and get a feel for it before making too many changes. You'll like it.

 

[lwsmithjr]

Reason is that going up on the front puts
more wear and tear on the chain.

I think he meant down on the front.....going smaller on the front decreases the bend radius on the chain and causes it to wear faster.

13/50 was stock on the '02 - '04 CRF450's. In '05 Honda dropped two teeth off the back without changing internal ratios. On my '06, I preferred the 50 rear. Made 3rd gear more useable on the track and didn't have to shift as much.

As for sprocket ratios, if you go UP one tooth on the front, that would be like going DOWN 3 1/2 teeth on the rear. I'd take BSWIFT's advice.......

 

[Friesen]

Thanks for your advice. I think I'll try going up 1 tooth on the 'driven' sprocket.