sprocket dimensions

[Al.Fisherman]

The problem using a caliper as I did, the points are not exact, as they are drawn out from the sprocket. So the measurements are as close as I could get. It's not like measuring a shaft or bearing as they are not varied points

 

[choppermke]

kewl thanks

 

[choppermke]

so from that pic it looks as if they are not equaly spaced correct?

 

[Al.Fisherman]

No they are. When you put the rag joint together, the metal spacers that go behind the rubber can be rotated. If you don't understand I'll take a picture of the sprocket with the metal plates over the sprocket.

The 9 holes form a nonagon....Degrees in a nonagon 180(n - 2)
n is the number of sides
n=9
180(9-2)
180(7)
1260 degrees

Each hole being a vertex, you have 9 angles each of 140 degrees.

 

[Al.Fisherman]

so from that pic it looks as if they are not equaly spaced correct?

 

[choppermke]

sorry about that

see my problem is that the last rag joint i had tosted my rim and through me during a 10mph turn because of the torque on the spokes. so now im trying to put together an adapter. so the distance from x to the center of the slot should be all i need to make a 9 hole bolt cercle, but u might be beter able to tell me if this is true. u seen to be an engineer and know your stuff. im used to havng a cad file and mastercam. sorry about that

 

[Al.Fisherman]

see my problem is that the last rag joint i had tocoed my rim and through me during a 10mph turn because of the torch on the spokes. so now im trying to put together an adapter. so the distance from x to the center of the slot should be all i need to make a 9 hole bolt cercle, but u might be beter able to tell me if this is true. u seen to be an engineer and know your stuff. im used to havng a cad file and mastercam.

I can't figure out what you are saying. one time you said the rag joint touched your rim (how can this be?), then you say you were throne off because it touched your spokes (all rag joints touch the spokes). Not all 44 tooth sprockets have the same 9 hole pattern. I'm working on one I have to make the center hole so the dust cover will fit into, but the mounting holes are different and I have to drill 9 new holes.

Is this what you want to make?
.........Both sprockets are 44 tooth--->

 

[choppermke]

sorry again i guess that answers it at the same time if they can be different patterns than i need to pull mine and put calipers on it. thanks for the help though. i will post my results when i do. thanks again

 

[loquin]

You could consider the width of the 'slots' in the sprocket to be the hole 'diameter' d. (ref the edited pic, attached)

If you measure the center hole diameter (which you did) and the distance between the edge of the center hole and inner edge of a slot (S1), you could calculate the innermost possible mounting circle. And, if you measure from the edge of the center hole and the outer edge of the slot (S2), you could calculate the outermost possible mounting circle diameter.

It's my guess that the slot is configured so that the middle of the slot corresponds to the desired mounting hole circle, but, they knew that the tolerances they were getting were poor...