I've got the same problem and changing out the handle bars won't solve the problem: it's carpal tunnel syndrome. I've been told that the vibration from the V-Twin aggravates it but maybe any motorcycle engine-design would do the same thing.

 

Another thing that was mentioned last year is to take a Potassium pill which seems to help. I went w PM grips this year and the bike feel much more responsive that w fat cushion grips I've used. I haven't put enough miles on yet but if you ever looked at a race bike they use skinny grips. I plan on the 1K Iron Butt here shortly so that will be a test.

 

My solution was a set of Khrome Werks +2 Sweeper bars and an adjustable backrest. I like the more horizontal position of the grips and they are more perpendicular to the center line of the bike than the HD Reach bars. Not so much like a wheel barrow. more like a dirt bike.

Don't miss out on the backrest. It helps keep you closer to the bars so it's less of a reach.

 

Throttle rocker solved 90% of my problem. I just palm the throttle for a while when my hand starts getting numb.

 

Same here..... after a few minutes numbness, just try to keep hands moving..
I installed the ISO grips with the palm rest and that helped ALOT....

if I don't move my hands for about 1/2 hr then i may get some numbness...
Some days hrs go by other days 15 minutes...

 

Kuryakan ISO for me!!!