i found the same issue with the aluminum bars ... installed miner carbon bars I had lying around and it helped a lot (100+miles/week) ... end the ergon grips.l, but the Specialized BG are decent enough s
I anticipated this problem with a very stiff frame and fork....so opted for the Turbo X with Rock Shox air-adjustable fork. Very nice fork. I haven't experienced much numbness. Once or twice I re-positioned my hands and all was good. I should add that my commute is 28.6 miles one-way. I carry the middle sized charger with me to work and charge at work for the ride home.
The condition is called Neuropathy. It's not something to be ignored, keep fitting the bike until the issue is resolved. There's no way to exercise nerves. Numbness, tingling, burning and cold are all symptoms of compressed and aggravated nerves and can in time be permanent. No one knows how much time or aggravation can cause permanent damage, everyone is different. Neuropathy in the hands can come from the the cervical spine, thoracic spine or just centered in the wrists and hands. If you can't resolve the issue on your own, get the bike professionally fitted. I'm not a medical professional or a bike fitter, I suffer from permanent Neuropathy and have for more than 20 years.
the Ergon GP2 grips helped me. The numbness is not as bad on the Turbo as on my old bike but this may be due to the reduced ride time for the same distance. I've found the stock saddle on the Turbo pretty good so far, no numb feet. I'm hoping that a rack and panniers will alleviate my arms, hands and back when I'm not carrying a backpack with 10-15kgs in it!
I went Ergon GP5 grips (with the long curved bar ends). These grips not only help due to their shape, but the long bar ends give me multiple hand positions. I also flipped the stem upside down to lower the bars for a more aerodynamic riding position. If I want to cruise in a semi-tuck, I use the forward position of the bar ends. See pictures: