Live Fast Motors Sprocker Adapter Problem

[masterfowler]

I bought the clamshell sprocket adapter for a coaster brake and I'm having an issue with the the coaster brake spacer piece that extends the arm out to make room for the sprocket. It started splitting apart on the side facing the inside of the brake. Do you think this is due to the aluminum not being strong enough or is there something I could have done that allowed to much pressure to be placed on that to make it bend? The only time I can think of is one time my chain dislodged and locked the brakes up and i skidded to a stop. Any ideas on what I can do better to keep this from happening? Has anyone had a problem like this? Im thinking about bending it back and making a mold and casting another one in aluminum and getting a steel band to go around the outside of it to stop it from splitting apart if it's due to the aluminum being weak. Their is a picture attached to show what I'm talking about.

 

[The_Aleman]

My opinion, I don't think aluminum is sufficient for that spacer, unless it was machined out of a billet. AL is generally much too soft.

Maybe if it was machined from heat-treated 6- or 7k series billet it would work. Cast? ehhh...

 

[GearNut]

Forget about using aluminum for that part. Go with steel instead. If there is a steel yard somewhere in your neck of the woods, get a piece of DOM tubing the same ID and OD of the part. Cut to same length and grind and file the notches to suit. Not hard to do at all, it just takes a little time and patience.
Much cheaper than having a machinist cut one out of billet, much, much stronger that the failed one you have now or any cast part.