Topic: 78 CB750 Bobber Project

[Nick_701]

Not much progress, trying to get the dimensions correct and rework the frame.





This is not the final resting place

[traveler]

.....I think you just ruined the frame.

without anchoring the frame down (i.e.not welding or bolting the head tube down before cutting), the tubing can shift and move.  Now, your frame may be crooked.  It will ride cock-eyed and is damn dangerous.

you'll always wonder why the bike dosen't track straight, and why the rear tire wears out so fast.

Don't forget to put slugs between your pipes before you weld!

~Joe

[TCSOHCB750CAFE]

Not trying to be a dick, but there's a reason for saying like "Just because you can doesn't mean you should".

As aformentioned, not jigging that frame was a mistake.

I've seen stock frames that were out of straight to start with, not to mention what happens when someone cuts them like you have.

Good luck getting it straightened out. You're gonna need a jig, clamps, O/A setup, a pry bar, someone who is REALLY good with welding and knows how to move heat around, and a lot of cash to pay the guy with the headache when that things straightened out.

Just some advice: Just cause you see the douche bags on OCC work on bikes and make it look easy (which they do because they don't actually do much work.... they're hacks), doesn't mean you should just hack and tack.

-j

(Credentials- Certified welder and professional fabricator/machinist by trade, bike fab guy since 14 years old, and owner of a frame jig.)

[Nick_701]

I have been busy... I'll post pictures of my JIG at a later date

[Cheffish]

Looks perfect!

[Nick_701]

So when I started this project I didnt know i would go this deep.  After cutting thr frame andtrying to make it work, nothing looked like I wanted.  I knew i needed a jig just didn't know how to do it. I spend a lit of time lookinh at othwr jigs and how they were built but it was gonna coat money.  Money I didn't have.  So when I found a computer sever frame, i looked at it and told myself yeah I could use that.  Here are a pictures of the bike in progress on the jig I built for free.

[Nick_701]

This is about 6 months after I started… I found an old server computer rack that I could make a frame out of. It was heavy, square and perfect for what I was going to do with it. Here we go…



 
Front fork support

 
Rear axle supports and started on frame rail supports

 
Getting there



 
Now all of this took months of work I’m probably at 9months now and it’s all downhill from here. I plan on adding 6in of stretch to the rear and lowering the ride height a little bit.
 
O yeah I had custom plugs built for the frame tubing, better welding and straight frame rails

Once I built the jig and assembled the frame, I took it to Mike at “Old STF” cycles, so that he could verify my frame was straight and true and to tig weld everything together.
 
Here is how I got it back…

 
Finally got to put the tires on and see how I did.



 
I really like this one because I can see how it flows, I picture it together and how it’s going to work out

 
Now that the frame was together I started buying the other things I needed

 
Handle bars, dirt bike, I needed them to clear the tank at full turn, I will be cutting them down 2-3in on both sides after I get proper controls

 
Biltwell seat and bracket, only new thing on this bike so far

 
Think its and old BSA fender, I liked the shape but the radius was to big

Fixed fender and this is about where I am now.


 

 
 
Stay tuned for more progress, waiting on oil tank kit and some other stuff. Wish me luck.

[Cheffish]

Looks good so far. What are you doing for fender struts?  Off topic, but how you likin that WR? I've always wanted one

[wedoo2]

Nick, this is a great project and you have spent a lot of time on it.  I'm glad that the frame is hidden beneath the tank now.  I didn't think it looked that good before.  I suppose that you are going with some type of pod/velocity stack set up?  Also, there is not a ton of room in that space between the wheel and the motor and you have to fit an oil tank, battery and electrics in there.  Got that figured out yet?

If you need encouragement, then here you go....You go man.

[JustinLonghorn]

Yes sir, I am on board.

[SOHC Digger]

Project looks like it's going in the right direction now.  I can tell you from personal experience that if your frame is not perfect, you are going to hate your whole bike.  It might look good, but frames that are not straight or improperly welded will not track right and will wobble, and eventually crack, and you don't want your frame cracking or even wobbling when you're doing 70.

But where you're at, it looks great!  Stick with it and be patient!  I'm almost four years into my project and it seems like forever, but it's been worth every step!

[Nick_701]

Ok guys and gals i have made some progress and am still working on it as we speak.

Here it goes....
Got my oil tank, no pictures cause its at a local shop getting welded up and channeled for the chain.

Ordered a new (used) brake rotor on ebay

Old

New


Welded the holes closed on my fender



Got some new tires


Got a free set of 4-2 headers, THANKS MATT
Had to rework them to fit my bike, my headers have a flange and no spigit off the motor, so cut the flange off and did a little welding, they fit good now

Not bad for a mig, i think, im no professional so i like the job i did


Cool cross over design





Thats what i got for now, prob gonna do the fender, foot pegs, seat pins and headlight tomorrow, before work lol

Stay tuned

[SOHC Digger]

No #$%*, I have the same pipes for my bike and I have only seen them one other time before.  Seems like they are coming out of the shadows.

[Nick_701]

Yeah i got lucky cause i was gonna have to build some but they work great now...

OK i need everyones opinion cause im just not sure,  so im doing my rear fender struts and am trying to make up my mind, let me know what you think

remember the fender is not as wide as the frame so from the rear they will have to come in toward the fender

Rear Option 1:


Rear Option 2:


Rear Option 3:


Side Option 1:


Side Option 2:


So please let me know what you think, example rear opt 3+ side opt 1

THANKS

[Cheffish]

Rear 2. Side 1

[Nick_701]

Not the greated pictures but i will take better ones tomorrow, this is what i came up with before work today...




Stay Tuned

[wedoo2]

Very cool

[Nick_701]

Here is what i finished today...







Thank you all for the comments, i will adding more til its done

[valt]

Just wanted to say that you are doing a really awesome job here. Definitely interested in seeing what the finished product is going to be like.

Side note, do you know what you are going to use for a oil tank?

[Nick_701]

I got an oil tank kit from bungking.com and having a local shop weld it up with a channel for the chain its 5in round and should work good ill post pictures when I get it back

[Nick_701]

I made some more progress so here are a bunch of pictures for your enjoyment...  I get my oil tank tomorrow!

Some pictures of me and my friends bike working hard:





I rolled it down the driveway, lol



Built a flat metal bender from a piece of pipe i had:




Lower fender mount:




Paint ideas, just used painters tape trying to get an idea, Im open to ideas, I like blue actually and want to keep black, wanna keep the bike kinda dark:





Let me know what you think

[WhyNot2]

scribed

[Toxic]

Great looking build ... I can't wait to see how it ends up.

Post pics of your channeled oil tank when you get it back

[lucky]

If it is leaking through the welds I would grind out your welds and reweld it, maybe you have a friend who welds or find a vo-co school that offers adult ed classes in welding, if your new to welding please take care on the frame as proper welding and fiting is what will give you all your strenth, where do you live???

DO NOT weld on a tank that has had oil in it.

Great job you are doing on the bike. Looks like it will turn out very well.

[Free Booter]

looking good.