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Chain & sprockets

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I want to go to a 50t rear sprocket on my 2011 crf250r and get a new chain. any suggestions on brands & type of chain and steel or aluminum rear sprocket.

Chet

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Regina x-ring chain with a supersprox rear. I can't tell you the last time adjusted the chain on this 450.

He busted a piston in half right over the wrist pin this sunday. No other damage, just a lot of oil blow out and smoke. Pretty lucky!

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I personally think that O ring chains arent good on a 250f. They are pretty stiff and I think it drags down the motor a bit. Arent you heavy as well FZ1 guy? Id get a renthal package with a did ert 520 gold chain, BTO sports has killer deals. Ya you'll have to adjust it more but it wont rob power. Your going to a 50 tooth sprocket for a reason, you want more bottom end. dont get an O-ring chain.

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I personally think that O ring chains arent good on a 250f. They are pretty stiff and I think it drags down the motor a bit. Arent you heavy as well FZ1 guy? Id get a renthal package with a did ert 520 gold chain, BTO sports has killer deals. Ya you'll have to adjust it more but it wont rob power. Your going to a 50 tooth sprocket for a reason, you want more bottom end. dont get an O-ring chain.

according to tests posted in the numerous other o-ring/standard threads this is not true.

according to new test data once an o-ring chain is warm, less than 5 minutes, the amount of drag over a non o-ring chain is barely measurable and definitely not noticeable to the average rider.

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Sorry your right peak HP isnt changed. I mean, a heavier (O-ring chain) will slow acceleration. Its standard physics. Its like having a heavier flywheel. Peak HP is the same it just is a little slower off the bottom. And this I know.

"As for the chain size difference it is only logical to understand that the Chain is like flywheel weight and once moving it doesn't restrict Horsepower. It can feel like more flywheel weight though. Say you take a YZ250 and run it on a dyno. Now put a heavier flywheel on it. Do you think it changes peak horsepower ? Or does it just slow down the acceleration response a bit ? I have had a bit of expericance with small bores and Oring chains"

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I'm running a DID VT2 Narrow X-Ring and 14/51 gearing. Pretty solid combination for Hare Scrambles/Desert/Prairie terrain - The extra (minimal) weight of the rubber O-rings is off-set by the narrower chain design. Supposedly this is also a lower resistance design chain - It seems to spin much freer than my previous full-width DID X-ring chains. But best of all, I have 6+ race hours on the chain and have adjusted it once.

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I'm getting ready to put new sprockets and chain on my 05 250. I'd like it to feel like it has a little more bottom end. I think I counted 49t on it. If I bump up to 50-52 will the stock length chain (114) still fit?

Thanks

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Depends on how far back your current axle is from the front edge of the axle guide slots.

If you have a minimum of a half inch of adjustability forward, you might be able to use up to 51T rear without adding another link. If you are using a new chain, you might as well go for a 116 link chain and trim it to fit correctly.

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I went with a Supersprox Stealth Sprocket and an RK GB520MXU chain. The chain only had a little stretch (initial stretch) and nothing else after that. The sprocket looks brand new still too.

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