imo, they are crap !!!
I had a pair, and decided to replace them w/ a pair of Intuitive slider/spools.
don't put those yamaha spools on if you ever want to swap them out easily.
The bolts are not a solid part of the spool (either machined or welded). In fact, the bolt unthreads out of the spool, meaning the bolt is threaded in both fwd and reverse thread directions. This way when you put them on, you are both tightening the bolt into the swingarm and into the spool. When I tried to remove the spool, it simpy unscrewed the spool off the bolt, leaving the bolt in the swingarm. Let's just say I'm glad I only used Blue locktight since I was able to muscle the thing out with some channel locks after grinding some small groves into it w/ a dremel for grip, but it could have been BAD.
just my 2 cents.