less teeth on sprocket

5 replies to this topic
  • yz450f_rider

Posted June 10, 2004 - 07:54 AM


hi guys if i dropped a tooth or two on my yz450f would it help the top speed on the bike without takin away a lil' too much low end punch ?

is there any other way to increase top speed?

  • John_Lorenz

Posted June 10, 2004 - 08:44 AM


Two teeth will raise the top speed
and reduce low end.

I do not know the ratios I believe reducing two in the back is like raising 1 in the front.

I would guess you would gain 10 maybe 15 or more mph on top I dont know. Great for desert

  • DrThumper

Posted June 10, 2004 - 09:59 AM


Increase the top speed? What? It isn't fast enough for you?

All kidding aside, I wouldn't drop the back more than 4 or 5 teeth or you'll start losing a lot of torque.

I ride stock (14/49) in the desert...fast enuf for me, and 14/52 in the mountain trails, lots of torque for hill climbing.

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  • gonzo

Posted June 11, 2004 - 12:59 AM


I would suggest just throwing a 15 on the front and keeping the rear stock.

  • Frostbite

Posted June 11, 2004 - 02:14 AM


I have a 12, 13, 14 and 15 tooth front sprocket and a 2 tooth smaller rear sprocket. I think 1 tooth up front is equal to 4 teeth on the back. With a 2 tooth smaller rear I can cut the effect of changing the front sprocket gearing in half, so I have 8 ranges to choose from. I usually just swap the front sprockets for a quick gearing change and no need for a different length chain. I bought a set of chain adjuster helpers so they're not so unsupported when the wheel is all the way back in the swingarm.
I use the smaller front sprockets for tight trail riding in summer and large front w/small rear for flat out runs on sled trails in winter. With the high speed setup my bike won't pull redline in top gear on hardpack but helps to soak up the revs when I hit the soft stuff.

  • Vet28

Posted June 11, 2004 - 02:30 AM


The front is 14 teeth, the back is 48...14/18=.292%...ie. the front is 29.20% as large as the rear...dropping 1 tooth off the front, is like adding 3.425 teeth onto the back. Dropping 1 tooth off the rear is equal to adding 0.292 teeth to the front. Just keep using a factor of 0.292. Simple suggestion...if you want more top speed and more useable low end go to a 47 rear only, if you want less top end and more low pull (why) go to 49 rear.


p.s. I like the 47 rear for day to day MX...except super tight tracks, then stock.


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