motorized bicycle 44 to 36 tooth sprocket swap

[Norman]

You have to cover the spokes on both sides with the fiber washers to protect them if you don't
then your spokes will soon be toast.
proper way to install the rear sprocket
like building a sandwich
starting on the out side
sprocket
fiber washer
spokes
fiber washer this one needs to be cut only so you can get it over the axle.
metal backing plates
bolts need to be installed with the bolts head on the sprocket.
Nuts, washer, lock washers are on the inside of the wheel.

 

[otis]

hey guys, I have the 48cc Grubee skyhawk,old style carb,i honed out and cleaned up all port manifold and exhaust, but didnt actually touch the ports on the cylider itself,this did nothing it still didnt get full rpm's it sounded like it had a govenor still.so i took the cylinder off and matched up all ports best i could ,took a lot of metal off cylinder por,planed head a bit reassembled and instead of topping at 45kmh the rpm's keep revving to 51kmh/31mph {i have GPS} it vibrates a bit and is a bit too high rpm's for cruising but its awsome that thier tere when u need em, i have stock plugs,caps,wires and carb {except i honed it right out} but am looking to change that,I have lots of torque but want more speed without more rpm's so im gonna gear down from my stock44T to one size smaller around33T maybe anyone know the cheapest place to order from and what kind of gains ill get?? and anone know how to get vids from ps3 onto here or youtube? thanxxxx for helpevwryone i love this forum wicked, happy rippin

 

[Gator Wrestler]

Try here for sprockets
bicycle Motorized BIKE GAS ENGINE - 9 hole 32T sprocket - eBay (item 190374288212 end time Mar-20-10 18:36:23 PDT)

OR

bicycle Motorized BIKE GAS ENGINE - 9 hole 36T sprocket - eBay (item 150415827847 end time Mar-20-10 18:36:23 PDT)

The 32 is as small as you can go with the standard bolt to the spokes mount. You can go with other sizes but it's in the DIY area of building.

Tom

 

[Tim_B_172]

Norman, I always love reading you're how-to type stuff. But I just thought that I would add a little tip for everyone else. If you don't happen to have a dial indicator, you can still find the high spots on the sprocket and all you need is a marker. Once the sprocket is bolted to the spokes, put the wheel on the bike. Then support the rear end to hold the back wheel off the ground, or just turn the bike upside down. Then spin the wheel fast enough that it will free-wheel for 30 seconds or more. Once it's spinning take the marker and place it close to the surface of the sprocket until the sprocket just touches the marker. As you move in closer, the high spots will touch first, stop there and now the high spots are marked and you can make adjustments to the bolts in that area. You can steady the marker against the frame to make it easier. After the adjustments, clean off the marker ink with alcohol or any kind of solvent and do it again, adjust again and do it again until the marker leaves a solid line around the sprocket. Easy as pie.

 

[bairdco]

that's my method, too, Tim.

 

[moronic_kaos]

On a coaster brake you can actually use the brake arm to help support the marker (I use chalk). It would be a pain to try and mount it there but just use it to help support your fingers which will steady your hand & the marker.

Might not be accurate to 0.015, but it seems to work OK.

 

[severedcorps]

what is the difference between the 44 tooth and the 36 tooth?

 

[bairdco]

what is the difference between the 44 tooth and the 36 tooth?

eight teeth.

 

[Biker Dalton]

hi, i have a 20" back ties...what size of sprocket should i use...some say 30 to 32t...why that size sprocket..please tell me the pro's and con's...its all new to me...by the way i'm using a clam-shell on the hub. thanks for the help

 

[epicboy]

WOw you got skillz - this was the hardest part for me to do in my build. I did somethings similar to what you did, and still can't get it spot on. If and when i have the money i am definately going to invest in the manic mechanic set up. But you did a great job. nICE>>>

 

[happycheapskate]

about 5 mph, with the common china engines. I got a 38tooth 5hole from Bikeberry, and drilled my own holes.

Bikeberry.com now sells the 36tooth 9 hole sprockets for about $20.

It keeps you from red-lining your engine all the time just to go 25-30mph.
It basically runs the same but you will have to pedal assist at takeoff and through thick grass. Otherwise, you should be able to cruise along just fine, and climb hills ok.

eight teeth.

 

[happycheapskate]

If you have a 20" rear wheel, just get a double threaded track hub and put a 20 or 18 tooth track cog on the left side, with lockring.

hi, i have a 20" back ties...what size of sprocket should i use...some say 30 to 32t...why that size sprocket..please tell me the pro's and con's...its all new to me...by the way i'm using a clam-shell on the hub. thanks for the help

 

[Arnie]

I wanna buy the 36 tooth sprocket but I need the dished so my Chain will line up. any problems with yours lineing it up.

 

[happycheapskate]

I am using a dished 38 or 36t sprocket that was originally sold for Front Freewheel Systems. I drilled my own holes and milled out the center hole for my coaster hub. Bikeberry sells the 36 tooth flat sprocket (9 hole) for $20 here; http://www.bicycle-engines.com/hole-sprocket-black-p-342.html They listened when buyers wanted the 36.

I am using a KMC Z 410 chain, so it doesn't have to be absolutely perfect. I have not had any trouble since using this chain. They are $5 each so I stocked up. The chain that came with the kit was not flexible at all and jumped easily. I cannot fit a wide chain.

If you want to fit a wide chain, use both donuts in the rag joint, or get a Ped Power sprocket adapter ($50, also lets you free coast for pedaling)

I do not know where to get a dished one, but you could use the old one as a template and make a spacer out of metal or plastic, like a cutting board from the dollar store.

 

[sketchman]

The 32 is as small as you can go with the standard bolt to the spokes mount. You can go with other sizes but it's in the DIY area of building.
Tom

I had a 24t on my rag mount. Just have to get a little creative.

 

[retromike3]

I went from a 44 to a 36 and how I did it was to use a Shimano six bolt hub and a King's adapter. I switched the bolts over to allen key type and had to blue lock tight them in because they rattled loose. I also went with a tuned pipe for more power and I can get about forty on the flats, according to my Iphone app. The thing I like the best is that the RPM stay at a level that doesn't seem to shake the engine apart. (Skyhawk 66.) My gas milage seems to have not be too bad I went over twenty mikes on less than a quarter gallon of gas.

mike

 

[mapbike]

I ordered a 32T from BGF the other day, I may put it on a 24" wheel on a bike I have in the works, I figured it would give me real close to the same gearing as the 36T I have on one of my other 26" wheels.

 

[TANGO]

First I must say you did a Fine Job on that Wheel / Gear Set up .

I am most Likely going to go with a Husky Wheel with the 3 Speed Set up with a Hub adapter and 40 Tooth Gear . I guess the main thing I want to ask is if you really want that gear to run true . I think your best off with a Hub adapter . And the 40 Tooth gear should be the best of both worlds in gearing no ?

40 Tooth Pirate Sprocket for the Manic Mechanic Hub Adapter

 

[mapbike]

First I must say you did a Fine Job on that Wheel / Gear Set up .

I am most Likely going to go with a Husky Wheel with the 3 Speed Set up with a Hub adapter and 40 Tooth Gear . I guess the main thing I want to ask is if you really want that gear to run true . I think your best off with a Hub adapter . And the 40 Tooth gear should be the best of both worlds in gearing no ?

40 Tooth Pirate Sprocket for the Manic Mechanic Hub Adapter

Yep 40T sprocket is a good all around for most, but I like the extra speed at less RPM's I get with the 36T, I have a 41T on one bike a 36T one a bike and a 34T on another, I plan to go to a 36T on the one with the 41T pretty soon, that way I can get a comfortable 30MPH without over winding the engine all the time. the 40T is best if someone lives where there is a lotof steeper hills for sure or maybe even bigger.

 

[TANGO]

Mapbike I am a Die Hard Gear Head . So I want some off the Line response . Sure I know it's not a Motorcycle . That's why I was thinking of going with the 40 Tooth . But you know how these Gears work out and I thank you for sharing this info with me . I will be using a 66cc Super Rat yes Marked as a 49cc Ha-Ha being a Larger Engine if I run the 36 Tooth Gear how well will it take off from a standing start or will it buck and Lug ?