are they anygood? How good are the heavy duty o-ring chains. I think kimpex is a cheaper manufactor which can mean there product is cheaper in quality. I know there electronics stuff is crap And I won't touch there engine stuff. The reason I am asking is I pick up this sproket I order and I see the sticker on the packing "KIMPEX" I though dam, So I don't know if I going to order the front sprocket and chain?

Never heard of it. I normally stick to stuff I have actually heard off, such as renthal or DID. Can get pricey but worth it.
Bump

the sled stuff is complete garbage, so i would assume likewise with bikes

go with renthal man

300 you say renthal cause thats what your buddy tells you is cool and carmicjael runs em. just casue its priceu doesnt mean its good. spent 260 bucks on chain and sprockets from sidewinder 2 years ago on my yz and i thought they sucked. the supposedly indestructable rear stainless sprockt had wear on it in 2 months. the chain rattled like a mo, and the front lasted 1/2 as long as my stock front. plus the whole set up lasted twice as long. the one advantage renthal has is their lightweight. but where i ride they last about a 1/4 to a 1/2 seaon due to the thin lightweight aluminum. but you save drivetrain weight with this set-up which helps. i have yet to use afam but they seem to have a pretty decent set up and also make quality products for street bikes. renthal makes good chains and so does d.i.d. any somewhat name brand manu should at leat be up too par. my bud put a moose rear on his 300ex and it lasted a really long time, but what he does to a bike in a season i will do in one day..... good luck

dude i have a RENTHAL, i ****in know, i dont go around taken info from others and sayin wut they said,

The kimpex rear sprocket looks a little thicker and is more heavy duty than the stock one. It definaly doesn't have the big holes punched out like the stock one,but I think they should of. I don't want a thin one or one that's made out of a soft metal. I am just not to sure about there chains. Is there such thing as a stainless steel sprockets man those things would last. Make sense though for the top big brands to keep light for competion reasons, but I could care less about weight.

some jap company makes stainless sprockets, JT or something. anywhoo thats where i get mine, cus AL doesnt last too long on a 400f. RK has the best chains in my opinion

Yep ALU sacks for sprokets... go with the real deal STEEL

and get an o-ring chain