should these be strong enough

[minibikesrule]

Hi guys this is part of my jackshaft for my motorized bicycle.
A 55 tooth sprocket will be welded to the flange.
i was wandering if these welds would hold with a 49cc 2stroke at about 3hp.
the flange is welded to the end of a peddle which will make the jackshaft.
i welded it at about 80 amps with a 6013 rod. i brought the welder when i was 12 and taught myself to weld now 2 years later and the $100 (NZD) is still sweet as ever.
when i finish the bike i will probely make a new thread in minibikes. its gonna have 7 gears that were originally on the bike with a ratio from 14:1 to 30:1.
Hopefuly it works.
Max

 

[BradenM]

Thats great mate, it will definitely hold.

 

[Pellethuntr2]

Looks sound to me...

 

[mike75925]

i would say fill the gaps as two stroke love to vibrate. i can't visualize what you are doing. that is a crank end where the pedal used to go, right?

 

[mike75925]

does your engine have the gear reducer on it? my pocket bikes would tote me when i was 180lbs

 

[minibikesrule]

yea its the end of a crank. it goes from the engine to the reduction to the jackshaft to the wheel.
have any of you used bike chain before do you think its strong enough?
Thanks

 

[mike75925]

you mean bicycle chain, right? well it is bigger than the o.e. chain, but i wouldn't bet on it.

 

[minibikesrule]

yea it kinda sucks because its at the last part of the gears so it has more torque on it than the other parts. then again the other day i ripped my vice of the bench trying to remove a bike sprocket with the chain wraped around the sprocket and then into the vice and a 3 foot piece of steel tube on the other side of the casette. instead of the sprocket unscrewing the vice came of the bench and the chain didnt break

 

[mike75925]

what were you triing to do break the chain?

 

[minibikesrule]

naa trying to remove the sprocket thought it was a screw on kind turns out it was'nt

 

[mike75925]

riveted?

 

[mike75925]

one piece crank or three?

 

[minibikesrule]

it was'nt the sprocket that screwed on there was a ring that screwed on instead so i ground it off then the sprocket lifted off. not shure what type of crank

 

[mike75925]

ah so the crank/pedal arms were one piece. that nut is backward threaded, turns the other way.

 

[minibikesrule]

yea

 

[mike75925]

the pics are of your sprocket carrier, right? it will probably vibrate to pieces due to being unbalanced. if not it you and or the vehicle/engine.

 

[minibikesrule]

oh well if it does so be it but when the engine is doing 8000RPM
it is only doing 533RPM so that is considerably lower

 

[mike75925]

do you still have the original sprocket? from the engine.

 

[minibikesrule]

yea i still have it its also the clutch bell but it is 6 tooth and uses pocket rocket chain.
any way heres a simple picture of the setup
the black square is the motor with a 3:1 reduction.
the reduction has an 11 tooth sprocket which goes to the jackshaft which has a 55 tooth sprocket so at that point the ratio from the motor is 15:1.
the jackshaftt is the original part of the bicycle with modded pedals which have sprockets on. at the other side of the jackshaft there is a 14 tooth bicycle sprocket which goes to original sprockets on the rear wheel.

 

[mike75925]

ok, correct me if i'm wrong. you are running the engine via chain to a jackshaft that is right where the bikes drive sprocket was, then another chain on a separate sprocket back to the wheel? do you have a 18 or 21 speed drive sprocket stack that you are using? hey do you have yahoo messenger? i'm benjamin_gardiner2000