In {TAIL ~ addition}, the skirt valve typically lacks a spoke to hold the center of the valve in {HEAD ~ place}, and therefore lacks the problems associated with the spokes catching foreign objects 
In { TAIL ~ addition } , the skirt valve typically lacks a spoke to hold the center of the valve in { HEAD ~ place } , and therefore lacks the problems associated with the spokes catching foreign objects
OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH