Would Tri-Bars be advantageous for a 260 mile 2 day event At the end of August I am organising and completing a solo 2 day bike ride for charity that will be around 260 miles in length. 

The longest I have ever done is 105 miles in one sitting, about 6 and a half hours in the saddle. 

The first day of my event will be about 175 miles and I am estimating about 12 hours saddle time. 

I was wondering if using Tri-Bars would be advantageous with regards to the extra position it will give me, or would I be better sticking to the ~4 positions I currently have on my drop handles? 

I have never used Tri-bars before but have a pair in my garage. My bike is a Felt F-85 road bike with quite aggressive geometry.
I would suggest attaching the bars and doing some test rides.


Is your bike, with it's aggressive geometry, stable when using them?
Are you comfortable using them?
Does this new position provide some relief, or is it just more annoying?


I think you're the only one who can determine if they'll be an advantage to you. In general, I'd think the extra position would be an advantage.

Even with 4 positions on your standard drop bars, being able to take weight off your hands and put it on your elbows might be a welcome relief, even if it's just for a short period of time.