Jack Shaft
- Thread starter gokart25
- Start date
If you ran a 9 tooth & 54 tooth at 3500 rpm it would be around 45mph, but you still have the offset issue. So with the Jack Shaft it make it easier all around even if it doesn't seem to be easier.
That's a 6 to 1 ratio
9 tooth
54 tooth
5000 rpm = 64 mph`
No motor we use redlines at 3500 rpm and the 99 cc HF
motors won't pull much over 45 mph
So you would need an 80 tooth sprocket to go 45 mph
with a 9 tooth sprocket and I don't know of any centrifugal
clutches that use as small a sprocket as a 9.
`
Dracothered numbers look correct to me and could be done with a 212cc and a smaller rider using this calculator:
Speed Calculator For Go Karts and Mini Bikes
http://www.diygokarts.com/speed-calculator.html
Speed Calculator For Go Karts and Mini Bikes
http://www.diygokarts.com/speed-calculator.html
i dont have a jack shaft i have a 60 tooth rear sprocket with 9 tooth output on the trans from a 4 g tranny.. i do 20 mph tops but then again im 300 lbs.. lol ive wanted one of those kits but who has 200 to shell out anymore
The 4G tranny is the jack shaft.
That makes your bike have 2 final drive ratios not one.
20 teeth
80 or 100 teeth
9 teeth
60 teeth
You could run a EZM Q Matic or Jackshaft Assembly for 79cc HF & 99cc Predator
from AGK
http://www.affordablegokarts.com/mm...ode=A&Product_Code=2600&Category_Code=MTRBK79
You could do a direct belt drive with hand clutch:
Homemade Motorized Bicycle - Belt Drive - Harbor Freight 2.5hp Greyhound
https://www.youtube.com/watch?v=BJL_q_jU3Vw
you would still have to off set the engine way far to the one side which will cause its own problems.
The cheapest and easiest way to use a HF 99cc would be to use
11t #35 clutch and 20" wheel on a rear rack, IF you could mount a
72t rear sprocket. This would give 45 mph at 5000 rpm. Rider would
probably need to be under 180 lbs. and need to pedal up to 10 mph.
11t #35 clutch and 20" wheel on a rear rack, IF you could mount a
72t rear sprocket. This would give 45 mph at 5000 rpm. Rider would
probably need to be under 180 lbs. and need to pedal up to 10 mph.
then there is the problem of the bike never wanting to stay upright thats a heavy engine to even consider rack mounting
Indeed.
My 2 stroke over rear is about 25~lbs in total with rear rack mounts included. I couldn't imagine a 30lb motor plus the mounts
Many of the ebike racers mount their batterys higher than i would expect.
For racing there may be an advantage.
With a 20" wheel at least your mount would be would be 6" lower than
on an 26" wheel.
One of Scotto's early race bikes was a 196cc on a rear rack:
For racing there may be an advantage.
With a 20" wheel at least your mount would be would be 6" lower than
on an 26" wheel.
One of Scotto's early race bikes was a 196cc on a rear rack:
