modifying kit sprocket for coaster brake hubs

bairdco

bairdco

a guy who makes cool bikes
i built a bike awhile ago and took these pics of my simple method for making the kit sprocket fit a coaster brake hub without having to modify the dust cap or spend all day grinding away at it.

simple, easy, and self-explanatory...
 

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what happened, is i don't care enough to make it perfect. it's a kit sprocket.

the hole's big enough to clear the hub, so it's easy to line up straight, and you can't tell the middle hole is off center once it's all mounted up on the bike.

it's a 5 minute fix. ten, if you line it up perfectly.
 
thats all it takes.maybe a smaller hole saw to fit original hole and start the pilot from that.
but if all it needs is close.good enough.
thanks for sharing.
 
The center hole doesn't need to be perfectly centered. All you're worried about, or should be, is that the outside diameter, the sprocket teeth, are concentric with the hub. The center hole could be egg shaped as long as it clears the dust cap.

Thanks Baird.

Tom
 
HI,

Technically if it is egg shaped it is out of balance BUT since the off balance portion is so close to the axle center line for all practical purposes you would not be able to feel it.

(the further away from the axle center line you are the more difference being out of you would feel....example, if you attach a 3 OZ weight to sprocket close to the axle you probably would not feel much if anything BUT if you took that same 3 OZ weight and attached it to the rim of a 26" wheel you would probably definitely notice something was wrong).

Andrew
 
and, we're talking about a crappy, rubber mounted sprocket bolted through the spokes, and being driven by a vibrating chinese piece of junk motor.

"out of balance" pretty much describes the entire bike...:)
 
bairdco said:
and, we're talking about a crappy, rubber mounted sprocket bolted through the spokes, and being driven by a vibrating chinese piece of junk motor.

"out of balance" pretty much describes the entire bike...:)
Click to expand...

Yea, but if you can limit the number of areas out of balance you can cut down on some of the vibration.
 
i guess i shoulda just said the best way to modify the sprocket is by throwing it in the trash and buy an adapter instead.
 
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