Bottom Bracket Chain Tensioner
http://labs.yesspro.com/products/etr-b
Yet another breakthrough conjured up in the Laboratories of Yess Products. The ETR/B does what no other chain tensioner can do. By applying the spring tension around the chain ring, it allows the rear drop out area to be simple, uncluttered and lighter. No more deraillers sticking out and getting caught in anything! This can be used with or without our current arsenal of tensioners.
These BB-mounted tensioners are designed for hardtail bike frames with ISO/English (MTB) bottom brackets. They will not absorb the chain-pull commonly found on full suspension frames.
BRAND NEW! in box! never used!
