Legs; OK! Lungs; not!
Join Date: Apr 2009
Location: Coral Springs, FL
Bikes: ''09 Motobecane Immortal Pro (Yellow), '02 Diamondback Hybrid, '09 Lamborghini Viaggio, ''11 Cervelo P2
Sorry to see that no one has responded, so I'll give you the benefit of my experience, albeit not directly related to your question.
I wear a singlet trisuit. It has a very thin pad, so as to not weigh you down on the swim, or interfere with the run. But it does not provide much padding for the bike.
Now on a sprint or even an international/olympic, (10 - 25 mi ride) if you have enough base miles that is enough padding. You may not be comfortable, but if you have a proper bike fit you should be able to endure the 30 - 70 min of minor discomfort.
Now it's a bit of a different story for a long course tri (56 - 112 mi bike.) Here comfort and bike fit are critical. And due to the longer overall times, transition time is a little less important. So here's what I do.
I have a trisuit with a very thin pad. They are available as a singlet or a two piece kit. On sprints and most olympic/international distances, I don't bother with any additional padding. Transition time is critical, and I can endure the thin pad for the "short" time involved. But for half and full ironman distances, well, that's a much different story. First, transition time, as a percent of the overall race, is much smaller. Taking a little extra time to provide extra comfort is well spent. Second, if you are comfortable, you will perform better. So in these case, I put on a pair of good quality bike shorts (NOT BIBS!) I can take them off after the bike, and they really provide a lot of extra comfort with no real penalty.
SO, to get back to your question, since the trisuit is in contact with YOU, the make up of the shorts is not a matter of endurance or fleece. It's what provides the proper level of padding of the distance involved.
As for me, I cannot ride with out some sort of chamois lube. Perhaps it is the heat and humidity of So Fla, but I cannot ride very far before the "boys" start to scream if I dont have some chamois cream. And I don't use anything very expensive. I get a Walgreens knock off of Eucerin for about $10 and it lasts 3 months riding 3 or 4x a week. I put a nice gob in my trisuit before the swim, and it stays all day.
Good luck, and try different things until you find what works for you.