Sprockets Custom Made Sprocket Adapter

Scootmeister

Member
Local time
5:46 AM
Joined
Mar 15, 2011
Messages
153
Location
Inner Banks, North Carolina
Sometimes you can't find exactly what you need for your MB and you just have to make it yourself. With a few basic tools and a little time thinking things through, you can make a component that meets your needs as well as a vendor supplied item. In my case, I needed to be able to easily swap sprockets on my jackshaft to change gear ratios. I had a standard 17 tooth sprocket with 5/8" bore that resulted in gearing that was too low for cruising. So, I purchased a keyed 5/8" steel collar with set screw and 1 1/8" reset ($4), a 3 1/4" diameter steel washer with 1 1/8" bore ($.89), five 5mm x .80mm hex head bolts (on hand), and a 24 tooth bolt on sprocket from Sick Bike Parts($5.95). Replacement sprockets are available from SBP up to 48 tooth. The first step was to dress the washer bore to a true 1 1/8" since the galvanized coating reduced it slightly. The second step was to carefully mark the 5 mounting holes on the washer. I used a chart in the Craftsman manual shown in the photo to determine that a 11/64 drill is appropriate for a 5mm x .80mm tap. Once the holes were drilled and tapped I removed the galvanized coating from the back of the washer and spot welded the washer to the collar. Locktite could be used to secure the mounting screws, but I will use locking nuts instead. This $11.00 adapter works great and gives me the flexibility I need. DSCN2968.jpgDSCN2969.jpgDSCN2967.JPGDSCN2970.JPG
 
Good job!, it's not that easy to mark and drill holes so accurately with basic tools. I did something similar on my bike although not for the same reason, it never occurred to me you could buy a huge washer like that, I turned mine myself.
 
Thanks, Perilous. Now you've made me envious, being able to turn things with a lathe! You can find these large washers with either a zinc coating or a galvanized one. The zinc ones are better for this type of application because they have a more uniform surface, but I try to use what I have lying around in my junk bins. My washer is 1/4" thick so there are plenty of threads to hold the mounting screws.
 
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