Just wondering if they did, because it seems like if you put the sideplate from the sx on to the s it would give the s a dual braking system.

No, this will not work.  There is no hub or clearance to accommodate the centrifugal brakes on the S spool, not to mention the S brakes lack the metallic disk necessary for the magnetic brakes to even work.  I suppose you could try an STX sideplate, spool, spool shaft, and possibly the extra spool support bearing (? not sure about this) on an S reel, but at that cost, just buy an STX.

No, this will not work.  There is no hub or clearance to accommodate the centrifugal brakes on the S spool, not to mention the S brakes lack the metallic disk necessary for the magnetic brakes to even work.  I suppose you could try an STX sideplate, spool, spool shaft, and possibly the extra spool support bearing (? not sure about this) on an S reel, but at that cost, just buy an STX.

Ok. I figured that it wouldn't work, but thought that it may work. Anyway, the reason I ask was that my friend just got a SX for $50. He really hates the magnetic only brakes but loves them on his STX. I figured that I would ask for him.

No, this will not work.  There is no hub or clearance to accommodate the centrifugal brakes on the S spool, not to mention the S brakes lack the metallic disk necessary for the magnetic brakes to even work.  I suppose you could try an STX sideplate, spool, spool shaft, and possibly the extra spool support bearing (? not sure about this) on an S reel, but at that cost, just buy an STX.

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