I have a 4130 backtrail x3 frame and I really want to put al my parts off my mosh on it because the frame will fit me better. The left rear tri is bent in a bit though. There is no way I can bend it back by hand is there anything I can do?? Thanks for the help!!!

Steel can bend back, maybe go to a mech shop so they can reline the frame.
It happens. Happy you got steel, Alu no way.

Aluminum is a pain

Does alum weaken more when bent or is it just to soft?

Aluminum typically snaps instead of breaking. It is actually a much stiffer metal than steel is when made for bikes because it is made thicker. With steel, there is some flex in the frame (a tiny, tiny bit) that helps it last longer. With aluminum, there is less flex in the frame, so the metal has to absorb the impact of everything you throw at it. (not including grinds) So, aluminum will wear out after a certain amount of time no matter what. If you have a steel frame, then if you aren't grinding it, the frame could last you ten times as long as an aluminum frame. Well, it obviously depends on how hard you are on the bike, but it is possible to get 5-10 years out of a steel frame if it isn't something you grind on.

For your dropout, you can take a large adjustable wrench and lock it around the dropout and VERY carefully bend it out slightly. You can also just have your dad or a friend help you pull the back end of your bike open slightly to allow you to pull the rear wheel out. If your dropout is bent around the axle, like a C with the axle in the middle, then you want to pull out a hammer or a large tube of metal that you can wrap around the dropout and bend it down to open it up. It is very damaging to your dropouts to not protect them from that kind of abuse, and there is stuff you should look at to protect them. It may cost you 20 bucks... but a new frame costs a lot more than that.

Bmxtrix got it in a nutshell, steel you can bend back and everything but aluminum just snaps when you try.

I would try to find a machine shop to do it, I'm sure there are several around, unless you know someone that works with metal profesionally. however its never a bad time to learn, and with a bent frame, if you didn't try you'd be at a loss anyways, so of course its worth it to try to straighten it, all I can give you advise wise is to not hit the frame directly with a hammer, try bending it by hand or with leverage, and don't worry about cracking the paint, it'll happen!!

Good luck!

Ya a bike shop can do it, like pzgx3 said you can get someone that works with metal or maybe even a mechanic or something.

sweet do you know how much it will cost like an estimate

I have no idea, I have never bent my frame or had to get it fixed. It usually depends how much work it will take. If it takes hardly any work it won't be that much. I'm guessing around $15 $20 or something around there, but it all depends how bad the bend is.