MORE BOTTOME END

[mr. big time]

For everybody who comes to this site and wants to know how to get more bottom end. First things first...aftermarket pipe. I run a Motoworks and I know that it helps out alot with bottom end. Get a 13 front sprocket....trust me that alone helps out alot. If its too much bottom end then drop one tooth in the rear. Tag metals makes sprockets for front and rear, and I know that hot seat powersports has them as well, and they have them anodized as well. The cheapest front 13 is on ebay, and it is brand new...I had one.

Also the shaft where the front sprocket goes on is thredded in the middle, you need to take a short metric bolt, with a fairly good sized washer and put it on there, The little ring that holds it on does break off sometimes, and you will loose your sprocket.

[r0wland]

how much on the top did you lose w/ the 13 tooth on the front?

[driver311]

<div class='quotetop'>QUOTE (Robbie @ Dec 6 2008, 12:09 AM) <{POST_SNAPBACK}></div>

Quote:

how much on the top did you lose w/ the 13 tooth on the front?[/b]

It will take alot of mph off the quad. 13t front sprocket is more of a bandaid and is a cheap way to have the feel of more bottom but all it really is doing is making the gears shorter so it feels to have more bottom. When all it is really doing is allowing the quad to get into the higher rpms where the quad makes more power. A nice stepped pipe, big filter setup and tune is the real way to start off with more bottom. Bike will feel way better all around. Paired with maybe 1-2 up in the rear and the quad would pull way harder. From there go with high comp piston or decked head for even more bottom and mid. That setup would yield huge bottom and mid and push about 10whp peak more than stock for cheap.

[mr. big time]

<div class='quotetop'>QUOTE (driver311 @ Dec 5 2008, 06:09 PM) <{POST_SNAPBACK}></div>

Quote:

It will take alot of mph off the quad. 13t front sprocket is more of a bandaid and is a cheap way to have the feel of more bottom but all it really is doing is making the gears shorter so it feels to have more bottom. When all it is really doing is allowing the quad to get into the higher rpms where the quad makes more power. A nice stepped pipe, big filter setup and tune is the real way to start off with more bottom. Bike will feel way better all around. Paired with maybe 1-2 up in the rear and the quad would pull way harder. From there go with high comp piston or decked head for even more bottom and mid. That setup would yield huge bottom and mid and push about 10whp peak more than stock for cheap.[/b]

You are right, but now are telling a bunch of money that they may not have. I don't always use the 13, only for certain tracks, like one that are in the trees with tight trails, or a real tight mx track. But at alot of other tracks I use the 14, and have never changed the rear.

[ds450mx]

Nice to know. thanks for the tips

[TNT]

Actually to change the torque or rpms for a given mph up or down it’s better to change the rear sprocket since going to a smaller front sprocket requires the chain to turn at a smaller radius causing more friction and wear. It’s always a good idea to change the chain if it's not new when changing sprockets and visa versa since these surfaces are made to wear together with respect to the chain roller.

The 09 comes with a 13-38 and we noticed a dip in torque at low third. A 5-6% change down would be good so,

38/13= 2.92 stock sprocket ratio

40/13 = 3.07 new sprocket ratio

(new ratio / old Ratio) - 1) * 100 = change as a percentage.

(3.07/2.92) - 1) x 100 = (+ 1.0513 -1) x 100 = 5.13 % change from stock down.

Positive % trade top for bottom, negative bottom for top.

I could figure this out better if I knew what rpm I had at low third but I can try this and experiment without a dyno. 5-6% changes are good to try at a time, any less won’t be felt, any more might be too much.

[allbones512]

tnt youre saying put a 40 tooth sprocket on the back will help quite a bit