14T or 15T front sprocket?

[Ride1Rob]

I'm in the process of getting ready to order a front sprocket for my sons 125. The sprocket on the bike is a 13T. Since I've done mods to the bike I'd like to make his gearing taller. Only thing is I'm not sure which sprocket size I want to go with. Is anyone out there running a 15T front and if so how does the bike perform with it? Thanx!

[WOLFPACK]

I would think a 15T would be a bit much. I can't remember what gearing we went with on Bobby's bike after we built the motor.

Call Rob at (219)322-9669 he should be able to help you figure out the gearing. He'd be glad to help!

[hanzito]

i have a 15 on my sons but he is running a 160 motor and i lowered the read and it is too short. i have to change the rear again for more top end

[silicaman]

The gpx160cc that i just got has a 15t on it. I am just getting it installed, and have not started it yet. What oil did you break it in with? What oil cooler with yours? Also I am uncertain on whether to put the 125cc 14t sprocket on or leave the 15t that came on the 160cc gpx?

[WOLFPACK]

Use only Honda GN4 oil in these motors as the clutches seem to be tempermental.

I'd advise using the 15T sprocket first as it will probably be the one you end up running.

Shane

[silicaman]

Thanks for the info.

[YZ120]

we are running the 14t on a stock 125.
mainly ride desert trails and @ times i think a 15t would be better although w/ the 14t he always has the power to get out of trouble.

[Ride1Rob]

Yeah, after modifying the motor the stock gearing is not tall enough. Have a 14t on the way and will see how she runs with it. The bike now does very strong donuts in 3rd gear with me on it.

If anyone is interested in a ported/polished stock head, crower g2 cam, highcomp. piston and stock cylinder, stock oil cooler, stock exhaust, stock carb, etc... let me know.