Time required to transition to Tri bike

Depends on your current flexibility and how aggressively you were fit.  Even though I've had the same tri bike for 3 years, I don't ride it the whole season.  And after not using the bike for a while, it takes me about 3-4 weeks before I can ride and stay aero for an entire 50 mile ride.

For me, my shoulders takes about 1-2 weeks to adapt, but it's my neck that takes longer.

I posted a similar question last spring.  I was depressed that I couldn't enjoy my expensive new QR because my neck hurt.  I didn't really believe that it would get better.  I'm happy to report that after a couple of months it did get better to the point where three hours in the aerobars (aside from some periodic stretching and hill climbing) was just fine.

Now that I've been riding my road bike during the off-season, I'm sort of not looking forward to having to readujst.  But I really have loved being back on the road bike.

+2

With 230 miles, it does sound like more time would be helpful. I wasn't fully used to it in a 50 mile ride by that point (we're about the same size too). How long are you staying in aero continuously? I go in and out every few minutes, building up the "in" time bit by bit each ride.

Also, how is your breathing? Can you inhale deeply enough? For me, going more narrow could constrict my breathing capacity some, until my shoulders became more used to it and stretched out enough. This was more on the outside of my shoulders though. Where are you feeling it? More up on top? That would be more in line with just getting used to being in aero.

My bike was comfy right away, but 'staying' in aero took awhile. (I haven't ridden my bike in months now, so if I went out today, I'd probably have trouble dropping down for much more than a mile, but it builds quickly.)

Correct order is get fitted THEN shop for a bike. (Buy the bike that fits, not get fitted to the bike you buy...)

I took to mine and aero was reasonably comfortable from day zero, but I already had been riding my hybrid MTB with aero bars on them so it wasn't as dramatic a position change as from hoods or horns would be.

Fit is paramount, and sometimes a rider ultimately finds they are riding a bike that is not optimal for them due to the geometry.

I'd say aero is like when you need to build up to swimming longer distances.  Push a little harder/go a little further each time and the cumulative effect will build quickly enough.

Agreed.

It took me around a year to get everything dialed in (fit & comfort) and to have my back/neck/gooch adapt to the forward leaning position.