My Tadpole Project (update--overdue)

[srdavo]

i gave up on the rear wheel turning thing .

Jerry....look at this..... http://www.sidewindercycle.com/products/sidewinder.asp
thank me later....lol

I just bought this..... http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=97964

a buddy emailed me a 20% off coupon!!
another bud printed it for me...
and another gave me a ride to Joplin to pick it up!!!
great to have buds!!

79cc 4 stroke..... ( a real 80!!!)

fired it up....sounds tough!!

Van... thanks for your insights on the 4 strokes!!

 

[thescooterguy]

great price on the motor !!! does that take the 5 to 1 right sided tranny ? kinda looks like it .from the picture u can almost see the other side where it mounts

 

[skyl4rk]

The Greyhound is a low rpm motor, 3600 recommended max rpm, so you will have to do some gear reduction calculations. I did a few on a spreadsheet, one for chain primary, one for belt primary. Personally, I would go for a belt primary and do a slip clutch. These are both geared very high, higher than I would like. I would probably go with a 40 or 44 tooth wheel sprocket which would increase the reduction but also lower the top speed. If you want the spreadsheet, let me know.

	Speed Calculation - Jackshaft Chain Drive						

	Motor Sprocket	11	teeth				
	Jackshaft Input Sprocket	36	teeth				
	Jackshaft Output Sprocket	11	teeth				
	Wheel Sprocket	36	teeth				
	Wheel Diameter	26	inches				
	Primary Reduction	3.27	ratio				
	Secondary Reduction	3.27	ratio				
	Overall Reduction	10.71	ratio		

	Motor rpm	1000	2000	3000	4000		
	Wheel rpm	93	187	280	373
	Wheel Speed	7	14	22	29 mph
							
	Speed Calculation - Jackshaft Belt Drive						
							
	Motor RPM	3600	rpm
	Motor Pulley	3	diameter				
	Jackshaft Input Pulley	10	diameter				
	Jackshaft Output Sprocket	11	teeth				
	Wheel Sprocket	44	teeth				
	Wheel Diameter	26	inches				
	Primary Reduction	3.33	ratio				
	Secondary Reduction	4	ratio				
	Overall Reduction	13.33	ratio				

	Motor rpm	1000	2000	3000	4000
	Wheel rpm	93	187	280	373
	Wheel Speed	7	14	22	29 mph

 

[srdavo]

below are a couple pics of my telescoping boom & bottom bracket. (can it still be a BB if it's sticking out front? lol)
and 1 pic with the greyhound sitting on the frame.

skyl4rk,
thanks... lots of info to wrap my head around.

your final numbers to both chain & belt drive turned out the same, with different ratios. Below is what I came up with on the belt drive (13.33:1) using the specs you provided...(I don't know about spread sheets, so I penciled in the last line, so to speak)

Speed Calculation - Jackshaft Belt Drive

Motor RPM 3600 rpm
Motor Pulley 3 diameter
Jackshaft Input Pulley 10 diameter
Jackshaft Output Sprocket 11 teeth
Wheel Sprocket 44 teeth
Wheel Diameter 26 inches
Primary Reduction 3.33 ratio
Secondary Reduction 4 ratio
Overall Reduction 13.33 ratio

Motor rpm --1000 ---2000 --3000 ----4000

Wheel Speed- 6 ----11.6 ----17 -----23 mph

 

[thescooterguy]

shes coming together, definitely road worthy

 

[Alaskavan]

Looks like 1, possibly 2 idlers will handle the power side of your chain run. I run 1 >geared< idler on that side and then teflon tubing to get around under the engine. Mine sits a lot lower than yours will. The reason I emphasize a geared idler is that it's Much quieter than the round ones with a lip to keep the chain in place. I use an idler out of a deraileur, with a couple of fender washers on each side just in case the chain gets froggy. The return is a lot less critical.

 

[srdavo]

I've got something a little different in mind for the pedal chain. Hopefully I'll have some results to show, tomorrow.
good tip on the geared idlers....thanks.

 

[thescooterguy]

this is my only experience with a long chain drive and i haven't got the courage to get on it if i find someone to ride it i will send a video .there is a chain tension er in the middle
http://i480.photobucket.com/albums/rr161/thescooterguy/stackedbmx003.jpg
http://i480.photobucket.com/albums/rr161/thescooterguy/stackedbmx001.jpg

 

[machiasmort]

SrDavo,

Is that a special kind of hub on the front rims? I know they ain't forked on each side which is why I ask.

 

[srdavo]

Jerry... that's a killer looking tall-bike! Come on, Bro....climb up there & have a spin....

mort,
I don't know if the hubs are special.... but they are HEAVY duty. (these are built for horse carts)
that's a 5/8" grade 5 bolt, being used for the spindle. Normal spindles, used for these are 14mm.
I am putting 'compression tubes' inside the hubs, to support the inner races of the wheel bearings. (this will keep the bearings from trying to meet each other, inside the hub.... due to side to side pressure from turning)