inspired by joe petralli's 1934 cac speedway and just done with the painting. using arimitsu 2-stroke mist-blower engine and modified stihl clutch.
1934 CAC Speedway
- Thread starter denmasardhy
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- 1934 cac speedway
Very nice work on such an original creation! I bet that boardtracker mixed it up with its use of low CG technology to go around the track faster than everybody else!
That looks FANTASTIC! Tell us more about the drive section. Does the pedal crank freewheel or do ya just have to pedal really fast when under power? Did you make the tank?
below pic is the design reference for this build, Harley Davidson 1934 CAC Speedway by Joe Petralli. the entire dimension is scaled to 20" x 2.30 bmx tire so the chassis is smaller than the original design
the rear hub is coaster hub, so it will act as free wheel and brake when we pedal in reverse. for the left side, i make "left orientation" thread on the hub housing for the engine-driven sprocket. the engine is started by its original recoil starter and free as the stihl-modified centrifugal clutch is disengaged on low rpm. on higher rpm, the clutch is engaged and drive the pulley and then wheel sprocket. the pedal is freely when we run (we dont have to pedal very fast). similar case when we stop on traffic light, engine run in low rpm and clutch disengaged.
for the front wheel, its a modified shimano dynamo hub as i mount disc brake on it.
when we run out of gas, we can pedal the bike (bit heavier due to belt friction)
the fuel tank is hand made and at this moment still finding nice headlamp with tacho at ebay.
the rear hub is coaster hub, so it will act as free wheel and brake when we pedal in reverse. for the left side, i make "left orientation" thread on the hub housing for the engine-driven sprocket. the engine is started by its original recoil starter and free as the stihl-modified centrifugal clutch is disengaged on low rpm. on higher rpm, the clutch is engaged and drive the pulley and then wheel sprocket. the pedal is freely when we run (we dont have to pedal very fast). similar case when we stop on traffic light, engine run in low rpm and clutch disengaged.
for the front wheel, its a modified shimano dynamo hub as i mount disc brake on it.
when we run out of gas, we can pedal the bike (bit heavier due to belt friction)
the fuel tank is hand made and at this moment still finding nice headlamp with tacho at ebay.
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hello curt,
pls find below links for more detail on centrifugal clutch;
http://www.youtube.com/watch?v=3-SAGjUidZs
http://www.youtube.com/watch?v=kpVdQ8CIFsI
http://www.youtube.com/watch?v=dDZkaG4rnmY
pls find below links for more detail on centrifugal clutch;
http://www.youtube.com/watch?v=3-SAGjUidZs
http://www.youtube.com/watch?v=kpVdQ8CIFsI
http://www.youtube.com/watch?v=dDZkaG4rnmY
Yep know how they work,just wondering how your steil clutch was working.
Is that just like a chain saw clutch steel on steel
you are right, i use stihl 070 chainsaw centrifugal clutch as below pic. the sketch i used for lathe working can be found at below link
http://motorbicycling.com/showthread.php?t=46565
need to machine the shaft of the clutch shoe and bolted to the engine crankshaft flange/flywheel. also remove the drum back side sprocket and weld metal log, then machine to make the belt pulley.
http://motorbicycling.com/showthread.php?t=46565
need to machine the shaft of the clutch shoe and bolted to the engine crankshaft flange/flywheel. also remove the drum back side sprocket and weld metal log, then machine to make the belt pulley.
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hi curt
in my drawing, i use dual bearing to get better stability, but it consume space. normally one bearing will be enough, just choose the good one.
OK had to print it out and use a magnifing glass to see it. I am slitly color blind so some colors just blend for me makes it hard to see.
How about a needle bearing? About the clutch don't they screw on a chain saw? did you just bore that out?
How about a needle bearing? About the clutch don't they screw on a chain saw? did you just bore that out?
hello curt
apologize for the delayed feedback as i was occupied with my daily activities. please find enclosed pdf dwg for more detail on the modified clutch. i use ball bearing, put two in parallel. hope this help to give better picture
apologize for the delayed feedback as i was occupied with my daily activities. please find enclosed pdf dwg for more detail on the modified clutch. i use ball bearing, put two in parallel. hope this help to give better picture
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hello all,
just changed the engine mounting, add carb manifold and lighting. below is the link for the idle engine;
http://youtu.be/dwmm9ObeOe4
have a nice weekend
just changed the engine mounting, add carb manifold and lighting. below is the link for the idle engine;
http://youtu.be/dwmm9ObeOe4
have a nice weekend
