sprocket size

I'm a beginner to the mx track and would like to reduce the speed of 1st gear(and 2nd,3rd,and 4th) on my yz 450f. I end up riding the clutch over the big jumps and other areas just to get a feel for the track . I'm afraid that I'll burn up the clutch. Should I increase the stock 14 tooth front sprocket to a 15 or 16 tooth? :cry:

If you want to reduce shifting as much go a tooth down in the back. If you want a shorter gear ratio go up in the back one or two teeth (this will make you use the clutch more and is prone to stalling). Changing the front sprocket equates to a greater change than the back. You may go overboard if you change the front and miss your preferred setup all together. :cry:

In order to reduce the speed of first gear, you MUST either go down on the front or up on the back. Reducing the number of teeth on the front sprocket is the easiest (and cheapest) way to do it, but as mentioned above it makes a larger difference than a tooth or two of change on the back. I recommend trying a smaller front sprocket (one tooth less) and go from there. Front sprockets are usually about $15 versus $45 or so for the rear. Then when you get comfortable on it, put the stock front one back on and you're in business!!


Finally got a chance to experiment by changing my front sprocket from a 14 tooth to a 13 tooth. Exactly what I was looking for! A cheap, but effective way to reduce the lower gear ratio for a beginner mx'r!!!! :cry::cry:

keep an eye on your chain... a smaller countershaft sprocket = less teeth turning the chain at any given point, and it will turn around a smaller and tighter radius.. your chain will stretch faster and probblally fail alot sooner... you can get the same results by adding teeth in the back... -1 tooth up front = about +3.5 teeth in rear :cry: although I understand the ease and inexpence of just dropping the front, I probbably wouldn't recommend it.. also sometimes when a new sprocket is introduced itno a already broke in system it may have a tendancy to "chew" the chain or viceversa chain damages the sprocket.. I like to replace chain and sprockets as a whole to let them brake in together. goodluck :cry:

Good advise! I test rode the bike at the track and experienced alot of chain noise after the new sprocket installation. Tightened the chain a bit and seemed to correct it? At the end of the day, I noticed that there was some wear on the outside, top edges of all the links like it was rubbing on the front alum. chain stay/guard? One day prior to this I installed the new sprocket and drove it around the block a few times up to 2nd gear for a test ride. I'm not sure if that ride is what caused the wear marks on the chain since I didn't reinspect the condition of the chain after this ride? Will see:excuseme: I agree with you on replacing both sprockets with a new chain :cry:

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