Last Friday I upgraded my agricultural equipment. The XT is for sale and a Yamaha TT600R has taken over. Now, being semi modern, the TTR has these straight spokes, no bend at the hub end. Some of these on the drive side of the rear wheel are really loose. How do I tighten them ? The nipple thread is "a bit" reluctant to move and of course all that happens when I try to tighten is that the whole spoke turns. Do I grip the spoke with some pliers ? Some trick I don't know of ?