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Best gearing for a 2003 CR250?

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Sep 6, 2003
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#1
I ride on a 4-5 acre motocross track and sometimes ride some large open phosphate mines. The stock gearing of 13/48 was ok but I had problems powering through corners in 3rd gear at the track. Shifting down at every corner isn't easy going through sandy ruts and whoops. I put on a 50T rear and now it seems geared too low. 3rd gears now feels like 2nd. It's great through the corners but it winds out very fast and I have to shift to 5th gear on the straights and it's not even a very long straight! The tranny ratios are way too close in my opinion. Has anyone tried out something like 14/49 or 14/50 before? Thanks for any help.
 

Faded

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Jan 7, 2003
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#2
Trade your 50T rear for a 49 and run the 13 up front. This will split the difference.

13/48 = 3.69 (stock)
13/49 = 3.77
13/50 = 3.84
14/49 = 3.50
14/50 = 3.57
14/53 = 3.78 (good luck w/your chain!)

14/49 and 14/50 will only make your problem worse (geared too tall)...
 
Last edited:

James

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Dec 26, 2001
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#3
I have used 14/48 for a while. It puts second gear about halfway between stock second and third and makes about a 5mph increase in top speed over 13/48 (7 mph compared to 13/50).

13/49 makes a 1mph difference in 3rd gear pinned compared to 13/50. I'd say save yourself some money and get used to the 48 or the 50 rear.

13/50 is "best" for me.
 
Last edited:

motometal

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Sep 3, 2001
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#4
13/50 is my favorite also.  I've wondered if 13/51 wouldn't be even better for tight tracks.  But remember, 1 tooth is only 2% on the rear, so you really need to move it 2 teeth to make a significant change. 

If the bike doesn't seem to rev out properly, is the main jet lean enough?  If you happen to have the stock main jet, you may try leaning it, but I recommend running at least 50% race fuel to be safe.