Poor air delivery or Weak Diaphragm?

[landshark_IPA]

The “tug” is likely due to the hose reaching its limit due to the way you wrapped it behind your neck? Do you use a swivel adapter?

I started with a fixed 90deg, but that didn't allow enough slack. I then went to a 120deg swivel, but that still came in from too much of the side. I now have a 90deg swivel from XS Scuba and it is wonderful.

It's important to note that the "tug" was extremely mild. I was simply looking for a setup that made the regulator seem as invisible as possible. The Comfo-Bite with the 90deg swivel is just that; it is a complete dream to dive with. I was simply looking for solutions where no problems existed.

 

[sea_ledford]

I was going to suggest you likely bit down too hard when molding the mouthpiece, but looking at the unmolded one, seem like it is just too small to begin with.

But with a long hose, or any primary donate system, you don't want a molded mouthpiece anyway. That is what you'll be giving to an out of air, possibly near panicked diver. Trying to give them something that is either too small to get their teeth around, or so big it makes them gag, will not help with their mental state.

Looks like you settled on the correct solution ultimately anyway!

 

[Capt. Bas]

The majority of "don't mix and match" is marketing (vendors wanting to upsell the whole package)

In Europe/EU its a different thing. The sets are certified as a specific combo. Using a different 1st or 2nd stage combo as used during the certification proces can lead to insurance problems.
The complete set will get a "type rating" and officially this is even included the hoses.