I've been riding for 40 yrs., a photographer for 30 yrs., college photography teacher for 15, and written/photographed for several MC mags for 12yrs. Trips have taken me from Arizona to NC, Wisconsin to Texas and every place in between and I've had a lot of fun doing it. No close calls, riding-wise, so far.
I almost always ride with a helmet - open face with safety shades, no shield. Often with D series or G-10 around my neck, both for stopping and shooting (with helmet on if it's just a grab shot, or to shoot while riding). If I've been shooting for a while off the bike, I may ride down the road a bit with the helmet clipped on. Generally, not too far sans helmet.
My Honda PC 800 has internal storage space and I strap a box trunk - from a BEEMER I once had - on the passenger seat, and my Lowpro camera bag on top of that (2 bodies, 3 lenses, flash, etc.). I generally work out of the bag still on the bike if I'm not too far from it.
Tripod or monopod goes behind the passenger back rest. You've got to have a tripod of some size, because you'll often need to do a self-portrait ride-by shot, and you'll want to include an evening/nighttime shot or two.
Important items and things I only need at my evening stop get locked, laptop, etc. Stuff they can have if they want it bad enough to take it stay in the unlocked box. Camera bag always goes with me if I'm away. If it starts pouring down, I put the Lowpro in the waterproof truck.
They are correct in that you have to pack carefully. On longer trips, plan to wash some, or extend normal wearing.
One of the magazines I freelance for is RoadBike. It has a great article for riders who want to shoot/write for them, and what they look for. Also, some great tips on doing it right. It's the April issue.
The weight of all that gear takes its toll on rear tires, though. Oh, well. A price that must be paid.
Hope this helps. Have fun. Take a look at my website if you like - www.cruisetheozarks.com (haven't updated it over the winter but it might be of interest.
Pictures attached: Self-portrait w/G-10 around 4-Corners; Shot w/ G-10 on bike around Taos; Packed bike at Farmington, NM, Lowepro strapped on top of trunk.