Crf450 Gearing

[1redrider]

We are racing a Lonestar framed 02 CRF450 quad on dirt track and oval, mostly 1/4 mile and smaller indoor events. We are running 12/36 gearing. The motor is the motorcycle motor, runs strong, but it seems we need more low end snap. Does anyone have any gearing reccomendations? Other ideas that night help? It's like he's always almost a gear too high if that makes sense. Lots of top end, but sluggish on the bottom. Any help appreciated. Thanks!

[quad_quazy]

I have the same problem and I'm running 13/38. I run indoor arena-x and TT's. I found that I was running my exhaust to wide open-not enough backpressure. I designed a baffle type system to give me more and it helped but I still have that problem a little. Are you running a free flowing exhuast? I have a TC supertrap and a FMF powerpomb headerpipe. It's hard to describe the baffle system. I went down to a muffler shop and we took a piece of exhaust pipe the same diameter as the pipe going into the muffler. then we basicaly welded a piece of metal in the middle to completelly block off the air flow. then on one the inlet side se cut a hole to let exhaust gasses into the "can" and then another hole on the exit side to let the exhaust out. The exhaust being diverted into the "can" produced enough backpresure for a lot more torque. Like I said, that is hard to explain. If you need more explanation I might be able to take some pictures of it this weekend and email them to.

[1redrider]

We're running a Sparks pipe. They claim it's not the problem? I heard the 03-04 stock 450 cam offers more torque than the 02 model, we might try that?

what gear are these tracks run in? if there not in 5th then gear the bike down for mor etorque and shift more......

if your using 5th then play with your tire size and perhaps lose some weight on the bike.


the cam should help, so will the baffle, also shortening or lengthening the stinger on the pipe can help also.

[1redrider]

He's running mostly in 2-3rd gear. 12-36 is what we run. Can't go any smaller in the back or any larger in the front (no room). How much can we cut the alum can from the spartks pipe? Will this really help? Thanks for the reply!

[toby400ex]

Originally posted by 1redrider
He's running mostly in 2-3rd gear. 12-36 is what we run. Can't go any smaller in the back or any larger in the front (no room). How much can we cut the alum can from the spartks pipe? Will this really help? Thanks for the reply! Well that shouldnt be a problem since or low end you want a smaller front sprocket and bigger rear sprocket:huh

[1redrider]

Isn't like 1 tooth in the front is equal to 6 in the back when changing? What would be good for a short indoor track, like a 42? Thanks

[Chanman420q]

1 tooth in the front is approximately equal to 2.5 in the rear, so either go 39 rear or 11 front

[quad_quazy]

you should be able to run a 13 tooth. 13 is stock on the 03/04 bikes. If nothing else you would have to get an aftermarket casesaver. Shortening your pipe could hurt the lowend torque. Sparks puts a lot of reaserch in their pipes and it probably the best like it is. You might look into the cam.