Rear Sprocket Offset?

GoldenMotor.com

PaperBoy2000

New Member
Jul 25, 2018
4
0
1
Hello, new to this forum, I will be working with a 80cc Chinese ebay kit, and a clearance Columbia 1937 model. I have gathered all items I think I need, and am now searching this website to try to see which way to install the rear sprocket. It may be self explainetory, but I do not have the items at my house in front of me, I'm working on it at another garage without internet (I only use a computer at home, and have a flip phone) and wanted to be prepared to not have to redo this item twice or more. I'm thinking I would want the offset towards the left, outside, to clear tire, but it looks like most internet pictures I see show the teeth offset inside towards spokes.
I am trying to keep everything OEM at first in order to get accustomed to how the thing runs before I try modifying things.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
rule of thumb is 'skinny tire dished in - fat tire dished out' - on some bikes this will move the problem from rubbing the tire to rubbing the frame

tensioner placement can sometimes get chain off frame

if that is a coaster brake bike, then hole in sprocket won't fit over hub cap (DO NOT just throw it away) file hole out bigger
 
  • Like
Reactions: PaperBoy2000

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Unfortunately...you'll have to fit it up, and see which way it has to go. (I'll bet it goes dished in)
I always have the sprocket dished in so the teeth are closer to the spokes.
I have never built one with the teeth out, and I have built fat tires and skinny tire bikes.
The important part is chain alignment.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
The worst problem I've ever had was one bike with whitewalls got a blackwall on the chain side from the greasy chain touching the tire lightly.