Sprocket Gearing?

Kade075

Member
Posts
6
Reaction
8
I ride a 250 XC-F. What kind of gearing combos would you recommend for higher speeds?
 

jon coleman

Well-Known Member
Posts
7,098
Reaction
3,889
start with 1 tooth bigger primary, should be enough wheel adjust meant to use stock chain& rear sprocket, quickest cheapest desert upgrade, after that???
 

Rslhc

Well-Known Member
Posts
115
Reaction
129
Love the questions you've been tossing out Kade.

Jon is right, adding a tooth to the front sprocket is a good start (taking 3 away in the rear has the same result). From there its a bit of trial and error to get the speed/rpm range you are wanting.

For instance, I run 14/48 for every day desert riding on my CRF450X (Stock is 13/51), but I will bump to 15/48 for baja type higher speed riding. This may or may not be what you need as I have no pumpkins in my barn. haha

Also, for questions this specific, it may be better to use the Bikes forum next time. 'Desert Racing' is definitely more active, but seems to have less bike content here. The 'Bikes' section may be a bit more sluggish on the response, but you will get bike guys who can usually give better insight.
 

jon coleman

Well-Known Member
Posts
7,098
Reaction
3,889
I ran 15/38 on the KX, good for 113MPH on the pavement in Baja.

My KTM 300 is 15/45. A little short for the desert but good all around. If I was doing more single track I would go back down to a 14 front.
my current whip is 14 45,works ok at Plaster city& Mc Caines, 85' yz 250got from a vet sra guy, all pro circuit motor work& suspension from the 80s , suuuper desert plush;)
 

slim01

Well-Known Member
Posts
122
Reaction
100
I wouldn't focus too much on your highest top-end speed, once you hit the tight stuff or the whoops your average speed will be decided. Suspension and fitness will make more of a difference in my opinion. Once you get tired or fatigued you wont be able to hold the throttle wide anyway, and if you do there's a higher chance of coming off, and hard.

Ive got a big bore YZ250 built for a desert race over here which will do 170kph+ (105mph) indicated on the GPS. It was awesome on long, flat sections but once I hit the whoops my speed dropped considerably because the suspension worked me too hard.

I'd suggest go up 1 tooth on the front or drop a couple off the back and ride everything until you feel you can handle more speed. If you're wanting to do longer races like V2R as you mentioned in another post, work on your own strength and get you're riding technique, you'll be much faster overall.
 

jon coleman

Well-Known Member
Posts
7,098
Reaction
3,889
yup, its about AVERAGE speed, you can do 150, but if you spend an extra 5 minutes in the pits,5 in the whoops,& 5 more in the twisty bits, that 15 minutes drops your 150 mph top speed down to 55mph, so its All about always keep moving comfortably quick in All the areas, thats how i raced jeepspeed, , go a little slower,in the rockey nastys, but, if no flats, quicker time overall!almost won ,,, once...doggonit...
 

Attachments

Top