I have (until I convince myself that I merit something more roadish) a 2010 Trek Navigator 2.0. Yeah, this is definitely a case of buying the first bike (in years) to learn what I should get for the second one. It has a 21" frame, which is the seat tube length if I understand correctly. I'm 6' 2" and all in all the bike fits OK, even if it is a very upright geometry. I have the seat properly raised, etc. (saddle height is about 48" IIRC).

Still, I tend to go numb after a fairly short while. When I do, I realize I've slid forward and am no longer sitting on my sit bones. If I slide back, I'm comfortable and the numbness abates. However, I don't stay there without concious attention and effort. This bike has an adjustable stem and I could lower it (which helps a little aerodynamically), but that would probably make the sliding even worse. The saddle is already tilted back a little, with the nose higher than the back.

Is this most likely due to poor adjustment / fit, saddle type or what? It's definitely a comfort bike style saddle, but when I'm up on it properly, it's OK. I wear riding shorts with a chamois, BTW. The frame has a 68 degree seat tube angle and I wonder if I'm just too far back from the handlebars and need something with a more vertical seat tube... ? I guess I could raise the stem a bit, but the last thing I want is to be even more upright.

It may be that I just need to bite the bullet and move on to a road bike instead of trying to make this one do something it's perhaps not designed to do?

Or not? Any ideas?

Thanks.