Up shifting and fast riding.

Hi all. I am new to bikes after alot of years away.Now realise what I have been missing. I am a mechanic on cars, so am a little bit green on the understanding of the sports bike gear box and up shifting. My 2003 Yamaha600R Thundercat revs to 13000 revs. I love the bike , but under full throttle which I have not quite attained, the pull on my arms and hands is such that I found it difficult to clutch shift up the gears as I felt I needed my full grip under the G force of acceleration. Could anyone give me tips on up shifting without the clutch and any tips when really tonking it.  Thanks Peter  

It's basically just timing. Some like to preload the shifter with their foot so that when you let off the throttle a bit, the transmission immediately shifts to the next gear (a motorcycle's constant mesh transmission is made so that it will not upshift under load); others just nudge the shifter when they back off the throttle. Note that you don't have to back off the throttle completely; you just back off just a bit, and at the same time make your upshift with the shift lever.

Note that using your trunk muscles (your abdominal or stomach area) and legs helps avoid using too much of your arms to maintain your body position on the bike. When you're hanging on for dear life to the bars, it puts unwanted steering input into the bike.