How to bend steel?

Gentlemen, I wrecked my CBR600 F2 a few years ago being a squid trying to do endos and with my DD getting dismal gas mileage and the fact that my parents are sick of it taking up space in their garage, I'd like to get it back on the road so here I am asking for help.

First thing is the subframe is bent down and to the right. This is where the seat, the battery tray, and rear lights are mounted to, can I just unbend it? Would I then have to worry about it failing due to metal fatigue?

If I can bend it back, how? I broke a 2x4 trying to twist it back, try 2 2x4s? heat? I don't have a welder, don't know how to weld, I have small propane torch but doubt that will get hot enough lol. racheting straps? I don't have anything to attach the straps to for leverage. I've read some forums suggest taking it next to a big tree and using the tree.

Any ideas welcomed and appreciated.

strap it down so the shock isn't absorbing any force. chain/bottle jack and a maybe some mapp gas for heat and pull it back into shape. Maybe have a shop weld in a gusset or two when you're done to keep it from moving around again.

Yea, use mapp gas. Not expensive, the tip should run around $20.

Pending pictures of how bad it is, you might be able to bob it off and rig up a custom seating and lighting arrangement.

(not real keen on the look of the last one, personally)

If you're planning on taking the wife/gf/mom/frat bro along with you on the back, you're back to bending it straight so you can retain the extra seating space.

The bend is right about where the subframe meets the frame, I'll have to grab some pics this weekend when I swing by my parents.

Thanks for the suggestions I will give it a go and report back in the coming weeks.

In reply to JohnInKansas:

I am very tempted to make something like this out of the Triumph ST I have in pieces (like 1000 pieces) in my garage (and buddies garage) but the time to do it and make it decent (and get SWMBO on-board) is hard to justify. Anyone want a 955i project?

Is there one nearby that has a blown engine? Swap your junk into his frame?

914Driver wrote: Swap your junk into his frame?

Anywhere else and this statement would be considered perverted.

I have a project in mind for that ST engine - but I have to get the TR4 out of the way first.

In reply to singleslammer:

Oh damn you. Damn you for saying that.

How much do you want for it?

(Would you like me to build it for you and sell it back to you?)

Here is a nice F2

JohnInKansas wrote: Pending pictures of how bad it is, you might be able to bob it off and rig up a custom seating and lighting arrangement.

Thanks. Now this will haunt me

In reply to akamcfly:

Try doing another endo and fall to the other side?

Lol no more endos I just want to commute! My (heavyset) buddy was doing them effortlessly and not on purpose so I just had to try it. Ended not so well for me.

Those bobbers look great, I just don't know how I would rig it up, I think the bend is close to where the subframe meets the frame.

Here are the pics I snapped yesterday, they don't show much, but the frame bends to the left and slightly down (I said right, earlier, didn't I? old age dyslexia?)

Can I use the swingarm for leverage or is that a bad idea?

This is on the left hand side, only real evidence I could find of where it could be bent

About an inch and a half above the blue tarp, you see a rusted section, that's bent down slightly as well.

That bobber F2 looks nice, mine will never look that good.

Ninja edit; photobucket rotated the 2nd and 3rd pics and I don't know how to fix it. 3rd pic should be rotated 90* counter clockwise, that tube with the cracking paint at the weld should be going upward.

Don't use the swing arm for leverage that is asking for trouble.

Is the part that is bent the piece with 3 holes? If so just use your propane torch with a ballpeen and a body shop dolly. Heat it up red hot at the bent parts and wack it between the two until it looks flat.

akamcfly wrote:

JohnInKansas wrote: Pending pictures of how bad it is, you might be able to bob it off and rig up a custom seating and lighting arrangement.

Thanks. Now this will haunt me

Yes, I'm horny now.

jere wrote: Don't use the swing arm for leverage that is asking for trouble. Is the part that is bent the piece with 3 holes? If so just use your propane torch with a ballpeen and a body shop dolly. Heat it up red hot at the bent parts and wack it between the two until it looks flat.

Ok, no on the swing arm.

The whole ladder assembly is shifted to the left (pic 1, starts from around where the the wires are hanging all the way to the back) If you look at the subframe in relation to the rear wheel you can see how it is shifted out of alignment.

Ninja edit 2; looking at the pics at work show them to be oriented correctly. Damn you photobucket.

Maybe use a come along and some 2x4s and get creative. Only brace against the areas that are connected to bent stuff. Go slow and check your measurements often.

The third picture down shows paint cracking right above a weld.

I would probably remove the paint from any weld areas and inspect them thoroughly! If that was on my mountain bike, I would be really careful. Those are usually the start of cracks.

If you don't find any structural issues, I would heat with map gas and have somebody help to pull / beat that straight. Check afterwards for cracks as well.

Finally, i would probably add some bracing to the area.

In reply to DuctTape&Bondo:

I would look around for a local welding shop. I worked at one while in college that was a combo welding & motorcycle shop, and the owner would easily fix stuff like this all the time. And for not much $$$ since it isn't real bad, well for someone with the tools and experience anyway... For what you would have in buying map gas, and the frustration, I know you would come out ahead having the right shop fix it for you.

If you want to give it a go yourself, I would suggest hanging the back of the subframe from an I beam in the garage. Don't forget to steady the front of the bike as well obviously Then with the bike hanging by its own weight in the rear, heat up the bent areas of frame and a good bit further up the tubing so you don't create a weak area from the heat. Once the bent spot of the tubing is red hot start working it with hammers to straighten it. You will have to bend back past the point of straight just a bit as it will spring back to the bent direction as it cools. Thats more or less how we did it at the shop.

You could also use a bottle jack against the top of the tire and push up on the subframe as long as you can find a way to hold the frame itself down. DO NOT put that force into the shock and linkage at all, it won't take it.
Good luck
Paul

Don't use a jack on the tire. If you get enough force to bend the steel you can have enough force to damage the tire, bend the axel, ruin the bearings or shoot the jack across the garage.

I bought a F3 that was crashed to turn into a race bike and I used a large pipe to bend the subframe back. I forgot about that until I saw the pictures of yours. I put it in the triangle of the subframe just in front of the cross over part that the seat bolts to.

This was in 1997, so my memory is fuzzy. I wasn't going to perfect since it was a race bike, but remember doing it cold and jerking it up and down and slowly getting it where I needed it. Probably had a friend sit on the bike to weight it down.

I also did something similar on another bike. I tied it down to my open trailer, put the trailer in the garage and used heavy ratcheting tied downs to pull the subframe up on a dirt bike.

Ride it, if it is too funky to acclimate to prop it up against a tree and drive into it. Ride it first and see what it needs.

Thanks all, I think I will give it a go myself. Hopefully I will be able to report back in a few weeks with how it goes.