The chain guide 50 is secured by {TAIL ~ a support} 52 to {HEAD ~ the rail} 40 
The chain guide 50 is secured by { TAIL ~ a support } 52 to { HEAD ~ the rail } 40
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH