Mountain Biking - Handlebar and stem choice - how important

I have been trying to adjust the cockpit on my new Rockhopper and I have developed some questions. I changed out the stem and handlebars to the ones from my old bike to get a better fit and eliminate some numbness in the hands from not putting enough weight in the saddle, (I think that was the cause). The handlebars have less sweep and the stem is longer and has a greater incline(15 degrees I think).
I want to go to a handlebar with no sweep, primarily because the way I naturally hold the bars my hands would fit best on a bar with no sweep, does anyone make a riser bar with no sweep?
I do not know if I should shorten the stem from the long one I am using to a shorter one. Is control and turning noticably better with a short stem compared to a long stem?
I have also noticed that after hitting a tight singletrack that I am thinking about shortening the width of my bars, does anyone have any advice on this?
Will it affect the the decision making process when choosing a stem and bar set?
I am on a 19inch and I think that I have a pretty standard arm, leg and torso length for my height,
(6 feet).

If your hands are numb, you don't want a bar with no sweep. As you already indicated, you are putting too much weight on your hands, and not enough on the saddle. A no-sweeper will not help.

A riser bar with a 9 or 10 degree sweep is what you want. If your natural hand postion is a zero degree sweep, you are sitting waaaaaaay too close to the bar.

You also want to look for a smallish length stem - 100mm or less. Ideally, your LBS will let you try a few options to see what feels best for you. A short stem is more precise (ie. quicker) - but possibly "twitchy" in unexperienced hands on tough single tracks.

Yes, a smaller width bar is usually best for single track, but ideally you want a bar that is approximately as wide as your shoulders to allow optimum hand placement.

You may also want to try different saddle heights to alleviate some of your hand problems. Lowering the saddle 1/2" to 1" may help, as it allows you to sit more upright putting more weight on your butt, and less on your hands/forearms.

Again, see if your LBS will let you try some different stem/bar options.

Thanks for the info Shane. Right now I am as far back as I can get, my hand position does not seem to change and my arms have a good bend in them, I may just have a weird body thing going on. I sat on a 21 inch Trek 4300 just to see if I should be on a 21inch in stead of a 19 inch and it was obvious that the 21inch was too large for me. I do have somewhat broad shoulders, so maybe the sweep is too much because of that. With the handlebars that have more than 5 degrees of sweep I have to tuck my elbows in to match my hands and the sweep. If I ride normal then the bar does a diagonal across my palm instead of parallel with my knuckles. I will hop on some bikes at the LBS and see if I can find a setup that I can match.
You don’t happen to know anyone who sells a decent 30.9mm setback seat post do you?

Hi! Just want to ask: if I adjust/rotate my handlebars (see picture) to possibly get a better angle, do I have to re-adjust the brake & shifter cable tension?

Hi! Just want to ask: if I adjust/rotate my handlebars (see picture) to possibly get a better angle, do I have to re-adjust the brake & shifter cable tension?

no you wont have to reajust anything.

to the other guy, try a shorter stem. one of my friends went from a big frigen goooseneck(xc stem) too a short riser just a bit longer then a dh one(about double). it sat him back further and his riding improved alot.

no you wont have to reajust anything.

to the other guy, try a shorter stem. one of my friends went from a big frigen goooseneck(xc stem) too a short riser just a bit longer then a dh one(about double). it sat him back further and his riding improved alot.
Actually he will. The levers should be at about a 45 degree angle sort of like a Q
http://img220.imageshack.us/img220/7894/leverpos6vq.jpg

Actually he will. The levers should be at about a 45 degree angle sort of like a Q
http://img220.imageshack.us/img220/7894/leverpos6vq.jpg

What does that have to do with cable tension?

You don’t happen to know anyone who sells a decent 30.9mm setback seat post do you?

I believe Thomson offers one.

But again, a setback seatpost will move your body positiion further back again, and will be putting more weight on your hands and arms again.

What you should be trying to is sitting more upright and/or move the handlebar closer/higher towards you. A setback post is moving you in the wrong direction based on your problem's symtoms.

I think I am going to put on a shorter stem and drop my seat about an inch to see how that feels, I know that finding a comfortable setup is something that I need to work on, it is not like someone can say do this and this and this and it will be perfect. I will probably buy some really cheap stems and make adjustments until I find what is both comfortable and keeps me in a good position for power and control.
Thanks for the advice.