# Alfine : Whats this black plastic disk?



## synthesis (Feb 24, 2006)

Making build sheet for new bike.

Was wondering why some Alfines have this black plastic ring and some don't.
Obviously, looks better without it.

Why some without it?

d


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## vikb (Sep 7, 2008)

Chain guard....none of mine have it and I've never missed it.

Shimano Alfine CS-S500 Sprocket


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## sriracha (Jun 23, 2004)

yeah, it's just an optional sprocket with an outer plastic chain guide attached. I ran that sprocket on my suspension bike setup, for extra security. On my hard tail, I used the sprocket without the chain guide.


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