No expert here, but I will share my recent experience. I started commuting regularly summer of 2013. I was on my MTB with rubber grips. I also have those goofy bar extensions that I like to use when climbing. The also provide an additional set of locations for hand positions. despite several different gloves, grip change and wrapping the extensions with bar tape, my hands always end up getting numb after about 10 miles.

This years I started riding one of my road bikes that is much more stretched out when using the hoods. No pain! This is a really puzzling scenario set. I tend to set all my bikes up with dimensions of the saddle, bars set relative to the BB.

The biggest impact was changing from gloves with padding to a pair without! Better on both bikes!

https://www.universalcycles.com/shop...s.php?id=69049

I think strengthening your core can have a big impact too. When it gets stronger, you will need to readjust your saddle and maybe your cockpit configuration. I don't sit on the saddle as much anymore and feel the 3 points of weight distribution are a bit more even.

Your results may vary.