Gear ratio for 1/8 drag?

[CJdoodlebug90]

I estimate im making around 11hp..I know thats not alot but its just a start. Right now I have a 15 tooth clutch with a 70 tooth sprocket. What rear sprocket would give me max top speed in 1/8 mile? My weight is 215lbs

 

[David wulf]

Do you have have TACH on your bike ?? You will need to gear so when you pass the 660 mark you are at the peak RPM 's . What I mean by peak is the top RPM's your motor is making power .

Oh did you ever figure out what the knock in your motor was ?

 

[DBMonster85]

i run a 12 tooth clutch and a 60 rear sprocket on a doodlebug and i cash out right at the end of the 660. i do weigh a lot less and the bike is fully built with a bully 2 disk but it seems like a lot of people run real close to my gearing or a 13 on the clutch with the 60 on the rear. there are so many factors that play into it though. David is right you have to get a tach and just test. its the only way to know.

 

[CJdoodlebug90]

Think I needed longer pushrods..took em out and spun motor over and didnt hear anything. ..put em back in and set lash and there it was again...I ordered longer ones from nr racing

 

[CJdoodlebug90]

Yeah was trying to get some type of starting point..think I might have went too high on clutch teeth going with a 15 tooth. Gonna order a 54 tooth sprocket and see what happens. BY THE WAY... HOW DO I GET A PROFILE PIC LOL?