Been to all where you are planning, never rented, buy, ride ship home for mine. Route 66 is rough in sections with little up keep off the black top, if you are going to the Chicago factory and following route 66 stop off at the Kansas City Missouri factory better IMO. Sturgis is over rated but got to tick it off the bucket list for sure, stay in Deadwood good party town, ride out of there each day lots of other events happen in towns near by Hulett & Sundance are close by.
Do a chopper flight over the Canyon, Dam and Lake Mead from Vegas. Presuming this is happening in 2018 ? Warm attire recommended if not ! Enjoy and look forward to hearing your tails on the trails. Cheers.