Right hand going numb

Probably cyclist's palsy, you may be leaning on your hand too hard and impinging a nerve

Or. maybe pinching a nerve in your neck. It might possible for the neck to be twisted to much and putting too much pressure on a nerve.

I have only been 'seriously' (and I use that loosely!) biking for about 3 months now and noticed at first both hands going numb or tingly. One day at the gym I tried out the spinning bike - it has a video you can watch and ride along with a virtual trainer. I noticed the trainer was very relaxed in his upper body, even swayed a bit with his tempo. Since then I have made a conscious effort to loosen up my shoulders, arms, and grip on the handle bars, and my hands don't go to sleep at all anymore. Maybe you were distracted that day and didn't realize you were tensing up. I am certainly no expert, but relaxing my upper body solved the problem for me.

Good luck!

Thanks for all the advice. Once again I appreciate it.  T minus 14 days and counting to my first tri.

The good news is that you have another way of giving yourself a "stranger."

Is it your whole hand or only part of it?  If the pinky and ring finger are relatively unaffected, you might have some mild carpal tunnel.  The fact that you are experiencing symptoms only on one side makes me think it has less to do with putting too much weight on the hands overall, since if your were, I would think both hands would get affected. 

my right hand was numb this morning as well.  By the end of the ride it was hard to shift because loss of feeling.  I drink with my left hand and I mainly shift/brake on the right side.  This makes me think my left hand does not have as much pressure on it and keeps it from numbing. 

I had this problem early in my cycling 'career' -- both hands, but one (also my right) much worse than the other.  I was leaning too hard on the bars.  I shifted more of my weight to my core.  Problem gone.

I might be off base here but a weak core can result in more of your weight being supported by your arms and, in turn, your hands/wrists.  Try some core strengthening exercises and when you ride be conscious of how much you're activating your core.  The upper body--from your chest on up--should be rather loose on the bike and the hands shouldn't do much in terms of support--they're used more for steering, balance and shifting.  The bulk of your torso support should come from your core--low back, abs, obliques--and when that is lacking your upper torso 'sags', with the support shifting from the midsection to the hands. 

When I first started riding I had a similar issue, my hand--right hand mostly--would go a little numb, and my right shoulder and neck would feel impinged. I found that with more core activation--a conscious effort to keep the midsection 'tight' and my back relatively straight and strong--the numbness dissipated.

It very easily could be something else, there's a million little things that go into bike technique that could be involved here, but in my experience a little core activation went a long way.

Good luck, hope this helps.

Again thanks for all the advice, I think it is probably a mix of everything said here.  Rode again today and concentrated on keeping as much "pressure" of my hands and wrists as possible and I didnt have any numbness.  I guess I was just gripping a little to hard. thanks

Same for me when I first started riding motorcycle.  I was nervous so I had a "death grip" on the handlebars.  That and combined with leaning all my weight forward on the bars caused my hand to numb.

I had this problem at first on my road bike because the bar was very hard and I wasn't wearing any gloves.  I added the gel padded wraps and cycling gloves and the problem went away.