http://www.google.com/search?q=chain%20tensioner#q=bicycle+chain+tensioner&bav=on.2,or.r_gc.r_pw.&fp=3e7f5c8c9ada6c87&hl=en&revid=1759615520
I personally wouldn’t
or
To join, you must be at least 13 years old and agree to the terms and conditions