Frame interchangeability 79 frame with 80 Special frame

[cmills83]

I built a custom tracker on a '80 special frame with an '80 engine and apparently I can't register this frame/vin. I found a deal on a '79 frame but are the engine mounts, tank mounts, swingarm and forks able to bolt up to the '79 frame from an '80?

 

[fredintoon]

Hi cmills,
and are you SURE you can get the '72 frame registered?
If so, cut the '72's VIN out and tailor it into the '80's steering neck.

 

[cmills83]

Ok I found a '79 instead of a '72 and edited the thread. If it's got a title I can get it registered no problem. Is a '79 interchangeable with the swingarm/tank/triple tree?

I could switch the vin, not sure my welding skills would be seamless enough to pull it off though.

 

[nj1639]

'79 will be fine for swapping '80 parts, even if the '79 turns out to be a Standard model. Worse case is a rear disc brake swingarm on the '79 and you can swap swingarms and cure that.

 

[jay760]

The triple tree is interchangeable, just needs a minor modification where the top bearing sits, it just needs turning down farther on the shaft and a small spacer made to go on top to take up the space

 

[XSLeo]

This situation is one many people get into. The PO says something along the line of "it's easy to get a title". I always say to them is "If it's so easy then get one and I'll be back."
I never buy anything with out good paper. Unless I know I'll never register it.
If the 79 is a Special then the swapping all the parts off the 80 to the 79 is easy. If the 79 is a standard, then you may find seat fitment a bit of work.
Just get good paper on the 79, if no good paper keep looking.
Leo

 

[fredintoon]

Hi cmills
the only difference that'd upset a swap between a '79 and an '80 frame is the different seat hold downs and that don't matter if you are building a tracker as the seat hold downs will be amongst the first things to meet Mr. Sawzall.
But like Leo sez, FIRST, get the frame papered in your name. Don't spend an hour or a dollar on the build until that's done.

 

[cmills83]

Yep, that was an expensive lesson to learn, I don't buy anything untitled now. And in CA if the registration from the previous owner is expired you have to pay all the back fees as well until it's out of the system (usually 10 years).

The frame is actually a 76, everything still the same as the 79?

 

[nj1639]

Make up your mind......lol

 

[cmills83]

ha dude told me the wrong year. It's a 1976

 

[nj1639]

'76 will be the Standard frame and probably lend itself better to a tracker style. The forks were 34mm on the '76. I'm not sure on the steering stem length between the years '80 and '76....... Thinking they're the same but should get that confirmed. Maybe have the seller give you a measurement or wait for an informed reply here......

I'll add that if the stems are the same then you can upgrade with your 35mm forks and triple tree from the '80, no problem.
Thinking '74 and up had the same length stems.

 

[650Skull]

34mm, (74-76), and 35mm, (77-83), front ends, (triple tree and crown), are interchangeable with all Standard and Special frames from 74-83.

You will need to shift the Disk brake system brackets over to the 76 frame.
Some pics, post #7................. http://www.xs650.com/threads/how-to-mount-an-sf-fluid-back-wheel-brake-system.48582/#post-493415 ......... the frame, in pic 2, is a 75B with the Disk brake brackets swapped over. This frame is set up for the Mag wheels, Disk brake rear.

 

[gggGary]

I think you'll be fine swapping forks, using the 80 on the 76 frame. The upper shock mounts are different standard to special all years, the specials are about 3/4" forward and down of where they are on the standards, same shocks will fit fine on either.

 

[weekendrider]

Rear master cylinder fitment?

 

[nj1639]

cmills83, what rims are you running, mags or spokes? Curious minds would like to know.

 

[650Skull]

cmills83, what rims are you running, mags or spokes? Curious minds would like to know.

+1, Important information............

..80G SII or 80SG hasn't been established. Makes a difference to a, straight swap, to an, adding brackets swap

 

[gggGary]

I think we're out in the weeds here, He's asking about a fairway shot.
"
I built a custom tracker on a '80 special frame with an '80 engine and apparently I can't register this frame/vin. I found a deal on a (76) frame but are the engine mounts, tank mounts, swingarm and forks able to bolt up to the (76) frame from an '80?"

YES!

Nothing wrong with answering questions a guy doesn't know to ask though. Not that that's every helped me............

 

[cmills83]

Thanks for the replies, I hopped on another project but now back to this one!

This has been sort of a frankenstein bike from the beginning. I bought an 80 special frame and engine and put everything else together. The rear wheel is an 18" with a drum brake off a 77(?), front wheel is stock, both wheels are spokes, tank is off a 78(?), forks are off an '80 the rest is all custom.

So it sounds like I'm good to go on swapping the '80 triple tree/forks onto the '76. To my surprise my $400 titled parts bike actually runs, I'll find out how well this weekend. Worst case, the '80 engine mounts are the same as the '76 correct?

 

[cmills83]

It'll come down to which engine leaks less oil. My 80 leaks a bit out of the left exhaust port and this '76 engine has a leak underneath somewhere.

 

[cmills83]

and 650Skull - it's a 3G0 vin so looks like a 1980 US-G model