yeah it really depends. When i show up for the local group ride I'm fast. When I trian solo I'm pretty fast.

When I show up to a good Tri I'm a piece of dog crap on the side of the road.

Reletively speaking though I can train solo at about 20mph on my roadie for about 80 miles, I'll do a rolling half Ironman at 21mph on my TT bike and I get smoked by the strong guys all the time. I think that i'm better than slow, but far from fast.