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GEARBOX SPROCKET 21T - 5 SPEED TRIUMPH 72-ON - EMGO
Same component, shown as 57-4782
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Also known as95-90321
Listed in parts booksNot catalogued by year yet

GEARBOX SPROCKET 21T - 5 SPEED TRIUMPH 72-ON - EMGO

21-tooth gearbox output sprocket for 5-speed Triumph gearboxes, 1972-on.

PN · 57-4782/21T
Available in 6 versions:

This is a gearbox sprocket, 21 tooth, off the output end of a 5-speed Triumph gearbox from 1972 onward. It's the sprocket that the primary or final drive chain wraps around as it leaves the transmission, so it's a wear item that any rider putting real miles on a unit-construction Triumph will eventually need to swap.

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The catalog lists this one as an Emgo-supplied part, cataloged as 57-4782/21T with 95-90321 as an alternate number for the same piece. Since our records are thin on this one beyond the basic listing, get the tooth count and gearbox generation confirmed against what's actually on your bike before ordering.

Sprocket wear shows up as chatter, chain skip, or a chain that won't stay adjusted even after you've taken up the slack. If the sprocket teeth are hooked or worn unevenly, it's time for a new one, and it's worth checking the mating chain and other sprocket at the same time since they tend to wear as a set.

$39.49
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