Getting some wheelspin!

[atomichurley]

Just curious because i always try to do it, When i am riding on gravel or grass ect and i'm going slow (just enough so the bike doesnt stall) i give it full throttle and try to get some wheel spin going but never seem to get any ?

Can any of you guys do this, if so whats your setup (high comp heads, expansion chambers ect) and what type of tires are you running? also what are some good methods for dooing a good wheelspin while mooving?

I'm running 66cc rse 66cc hp II engine (high comp head) 44t sprocket. my rear tire is just a basic kmart mountianbike tire with about 50% tread left and almost finished with running my bike in.

 

[motorpsycho]

it's because of the gear ratio and wheel size. there just isn't enough torque to spin the tire on one of these bikes. they are geared (with the 44 tooth sprocket) to give you a cruising speed of around 20-25 mph with 26" wheels, without over revving the engine.
now if you went with a 66 tooth or bigger rear sprocket, then you might get it do do a burnout in loose gravel while you roll through it. but then you would lose a TON of top speed. it's not like a dirt bike with a transmission with gears. a dirt bike is geared pretty low in 1st gear and that's how you get a ton of acceleration (and wheel spin) on take off. i would not pop the clutch on one of these to try and do a burnout because you would probably rip some spokes out, or the engine would just die.
I can get my bikes to do burnouts, but i have to put my feet down, squeeze my legs against the seat and slightly lift up on the seat with my legs.
i'm running a 66 c c on one bilke and a 48 cc on the other.
both have 20" rims and 41 tooth sprockets.
with the 20" rims i get a little more bottom end torque than if i had 26 inch rims.

 

[wackey101]

i try to as well my bike is moded more than yours(what eveer you told us) i have i have thooth sprocket as well and i had a kmart tyre with about 50% tread(now brand new) on loose gravel i have done it by going sloww rev the **** out of it pop the clutch and and wiglle yourn back end a little i have done this but only a few times doesnt work all the time with the brand new tyre not at all i cant

 

[atomichurley]

f**k its been raining all today and i was riding out the front of my house on the grass i was going slowly pulled on the front brake and gave her full throttle............it was fun until i got going fast when the wheel got traction and i went flying over the handlebars. here are some pics

http://s872.photobucket.com/albums/ab283/nickhurley_333/Motorised Bike Crash 1/

 

[wackey101]

cool badluck but i really like your bike great desgin fo these enigines

 

[blue 48]

stock 48 rock solid motor 26" front 24" rear 44 tooth and about 25 psi in a 1.95 tyer it hangs out on corners (PICS COMING SOON)

 

[loquin]

Pretty sure you could do it with a staton nuvinci... ($)