how to rake a stock frame?

[YouFancy650]

hey guys im interested in raking my stock frame a little bit so i can run a longer front end and keep the frame parallel to the ground. Does anyone have any pics or info on how they did it? anything will help, thanks guys!!!

 

[TwoManyXS1Bs]

Just a quick rambling outline of how I raked mine back in '74.
Strongly encourage the welders and frame builders here to chime-in and crotique this method.

Starting with a side view of a standard frame.


The frame gusseting will have to be removed to do this method.
Draw a line perpendicular to the backbone thru to the downtubes.
Where this line meets the front of the downtubes will be the pivot point for the rake angle.



Depending on the amount of additional rake, and material removal, this needs to be planned carefully.
The idea here is to cut the backtube equally from both sides of the centerline, so that the ends will align after bending, to make a non-jogged butt-joint.
I wanted to be as close to the neck as possible, so had to calculate the sine of half the angle to find a suitable setback distance.



I wanted a total rake of 45°. Stock rake is 27°, so needed to cut-out 18° pie sections, 9° either side of the centerline.

The downtubes will also be cut as pie-sections, centered on their perpendicular line.
The cut lines are shown in red.



Do not cut all the way through. The front of the downtubes need to remain uncut.
This is the pivot point for the rake job, and retains strength in that area.

After cutting, chamfer the edges for welding. Tube slugging is recommended.
I fashioned a short piece of tubing that I could fit thru the pie-cut and slid forward into the neck side of the backbone.

Slide a pipe through the steering neck, lash the top of that pipe to a rear section of the frame.
Heat the pivot points of the downtubes and tighten the lashing, pulling the pie-cut joints together.

Then weld the joints. I used chrome-moly rod back then, to match the metalurgy of the frame tubes.

And, this was the final result:



More info:

http://www.baycitydesign.com/xs650/
http://www.xs650.com/threads/newby-chopping-a-72.26419/
http://www.xs650.com/media/raking-the-neck.5552/

 

[member3480]

This one here I did a while back was just cut 3/4 threw on both front down pipes and cut back bone and it will drop down a little. I have done them with cutting off front and re welding it back in the position I wanted but you really need a jig to get it perfect.

 

[chizler62]

By stock frame do you mean swing arm? After market hard tail?

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[YouFancy650]

thanks for the info Twomany that really helps me out!!!!!!! and by stock i mean a stock frame that i will be welding a hardtail to. I also want to raise the neck or backbone of the frame too anyone have any info on doing that?

 

[Metal Wizard Machine]

If you want to go up and out you're gonna need to remove the neck completely. Doing this right means using a jig.

You can rake a neck without a jig, as long as you know what you need to cut.

My question is what kind of welder and experience you have? Not that experience means that someone is automatically qualified...I know "welders" who I wouldn't let weld a coat rack, let alone a frame.

 

[YouFancy650]

ya i know to use a jig, and i have a great welder and experience welding im not asking for the obvious info i was just wondering if someone had a thread on here on how they did the fab part just to compare on how i plan on doing it

 

[Metal Wizard Machine]

Well, what's your plan?

If you want to go up and out, it will involve cutting the neck off, slugging patch tubes, and refitting.

 

[TwoManyXS1Bs]

You might find some ideas in threads that contain "gooseneck"...

 

[chizler62]

If you're welding on a hard tail and want a higher back bone that results in a slacker head angle? You can get whatever head tube angle, rake, trail, wheelbase, rear trial, ground clearance, seat height, standover, bar height numbers you what. Without cutting the head tube off. (If you use the common hack jig that uses flat bottom mount tubes it will be harder)
Are you looking for numbers and the math?

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[member3480]

There are companies that sell goosenecks and I don't know if that is what you are looking for or not. I have done many frames and with a good jig you can set the angle and height and go up if that's what you are looking for. Do you have a picture of a bike that is close to what you want. I don't remember of any thread on going up just GOOSENECKS. Most of the ones I did that had to be raked I removed the front and changed the backbone and welded everything back up. I am doing a frame now that I stretched 5" in the middle to set the motor back so I have room for a small Turbo to be inside the frame and not hanging off the front of the motor close to the front tire. I think and agree with others you need to draw it out and get the numbers together to make sure its true and tracks perfect.
Here are some pictures is this what you are trying to do?
OR
the last picture is this what you want?

 

[angus67]

Kidding on that last picture rite?
Anyways, I've been putting off responding since I haven't done it, but soon I will, cbr600 Ina 650 frame, .
But I'm thinking you will want to do the stretch/ hard tail before the neck so you can see exactly what you want, keeping it level and all.

 

[YouFancy650]

SO im looking to do something like this but maybe with a little more rake to it

 

[YouFancy650]

like this

 

[YouFancy650]

I know I could probably buy a frame but whats the fun in that, i love metal fabrication and building everything myself and the frames i have seen for sale are all goosenecks and none of them go up just out

 

[Metal Wizard Machine]

If you're welding on a hard tail and want a higher back bone that results in a slacker head angle? You can get whatever head tube angle, rake, trail, wheelbase, rear trial, ground clearance, seat height, standover, bar height numbers you what. Without cutting the head tube off. (If you use the common hack jig that uses flat bottom mount tubes it will be harder)
Are you looking for numbers and the math?

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He's asking about a tall neck that's close to stock rake....so like I said, up and out. He's asking about a stretch without knowing how to word it.

There's no way to do it without cutting the neck off because all the tubes that junction at the neck need to be modified.

He'd want to cut the neck partway down the downtubes and just behind at the backbone (leaving room to slug on dt) extend and mod the down tubes for length and split, weld it back, then mod the backbone and extend to meet.

Common method would be to either make a new backbone or to splay cut and close to change the angle.

The thing is, this is all going to have to be done along with the hardtail because every measurement affects something else.

Pretty lofty ambitions for a first frame mod project really. Not that it can't be done, but it's not a simple chop.

Honestly, if you're intent on this just build a frame from scratch man. Much less hassle.

 

[Metal Wizard Machine]

Also, don't forget to factor in fork length.

 

[YouFancy650]

ya im going to get my springer front end and wheel before i do any fab work on the frame so i know how high and far out i want to go