[Wharf Rat]

I been researching, and pretty much decided based on what Ive found, to order the Ciro cup holder. But, is there any real benefit to perch mount, or bar mount? I was thinking bar mount because I could adjust where its mounted, but then looking at the bars on the Roadmaster, there really isnt much room to move it around much. Second question, will the big ass drink holder still hold smaller bottles fine, like for instance a 20 ounce soda bottle, or would that flop around in there? And lastly, am I overlooking a different drink holder that is better? Thanks

Mounting locations are a personal choice. I can see benefits to handle bars as well as highway bars.
I have had some type of cub holder on every bike I have owned since 1989.

The latest it the Bigass holder by Ciro.

Amazon.com: CIRO Black Big Ass™ Drink Holder with Black Perch Mount : Automotive

Buy CIRO Black Big Ass™ Drink Holder with Black Perch Mount: Cup Holders - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

They are pricey. But, so far, they have not spilled a drop, or lost a cup. Even when the bike got dumped. A 0.5 l bottle might slip out. I find they hold large styrofoam glasses from a convenience store just fine. But, we have been using 32 oz mugs, Rtic or Yeti, or no name, all hold ice great.

Amazon.com: Beast 30 oz Tumbler Stainless Steel Vacuum Insulated Coffee Ice Cup Double Wall Travel Flask (Aquamarine Blue)

Amazon.com: Beast 30 oz Tumbler Stainless Steel Vacuum Insulated Coffee Ice Cup Double Wall Travel Flask (Aquamarine Blue)

www.amazon.com

 

[Wharf Rat]

Can the Ciro be mounted so the ball is on the bottom? I have KST bars and think it will be too high.

I am not exactly sure I follow your question.
The mounting arm from Ciro attaches to the bars with its own clamp. I can see how the support arm might be too tall on KST bars, but I think you can invert the clamp so the cup holder sits lower.