78 gs750C direct swing arm swap?

[HarlemShake]

First post in the forum,

I’m sure there’s a thread out there about this, but apparently there’s no search function in the forum ♂️.

Riding season is over, I’m in the PNW, and while the bike is down for the remainder of the year, I have some modifications I’d like to do.

my main thing is a wider swing arm, I’d like to fit a bigger tire on the back. Does there happen to be a direct fit out there? I’d like to put a 6” tire on the back. Any advice would be helpful. If not, what are some solid conversions you could recommend. I’m open to either staying with the dual shock or a mono shock.

I plan to also do the GSXR fork conversion on it. Thanks for any and all the info.

[1978GS750E]

Ugh...........yeah............ there is a search function on the forum. I typed in "GS750 swingarm" and got 13 pages of results. You gotta dig around to find what you want!

Oh, and welcome to the madhouse!

[dgates1]

Click on the “Advanced search” and select Titles Only. Might drill in a little better.

[unfocused]

Not a direct fit as frame parts need removed. Mainly the passenger foot peg brackets as the swing arm will hit it.

However I have good news. With my 77 GS750, all I needed was some bushings for a 2002 GSXR 750 swing arm to mount using the original pivot bolt. Stock GSXR bushing and the replacement bushings w/the original GS pivot bolt.


Swingarm bushings.png

[unfocused]

The GS750 engine with the sprocket side clutch actuator won't work. Can't use a wider sprocket. I swapped in a GS1000 engine for this. Then I swapped in a GSX750 engine and didn't need to space the sprocket at all. There is a post some where on the WWW where a guy tried to build a different actuator for a single sided swingarm on a 77 GS750 frame... yea, it didn't go well but he did get it to work...

This is my 77 GS750 frame with the GS1000 engine and a 5/8" offset drive sprocket. I also have full 2002 GSXR suspension in working order installed here. It no longer looks like this. It's in pieces LOL

Resized_20210808_141903.jpg

[unfocused]

However, You can swap in a GSX750 engine, full gsxr suspension w/rear strut instead of shock--- shameless plug :-)
Heavy mods for rear of frame. Gas tank issue - look at the dents in the front of what I believe is a 650 fuel tank.
2002 GSXR front triple bolts right up with All Balls 99-3515-5 bearings...

You lose a lot of steering mobility and lean angle...





Lowered 1.jpg

[rphillips]

Heard of this kind of thing before, and wondered where you mount the monoshock, or do you weld tabs to the swingarm to still use dual shocks... OOhhh, no dual shocks any more.

[unfocused]

This is my other 77 GS750 frame with 2000 1200 Bandit stuff... This works better for a daily. Still need the rear mods to the frame and I did install the 1200 engine... no offset sprocket needed.
Bandit triple tree with the 2002 GSXR steer stem and the same afore mentioned bearings.
No mods needed to the tank - factory steer stop needs removed and a replacement is easy.

All this information might change your mind LOL.
This is all recent experience as I'm still building both bikes. Foot pegs are a PITA with this setup but I do have answers for this. Still in progress as I'm waiting for swing arm bushings.
PM for more info if needed.


Resized_20241109_153110.jpg

[unfocused]

Heard of this kind of thing before, and wondered where you mount the monoshock, or do you weld tabs to the swingarm to still use dual shocks... OOhhh, no dual shocks any more.

For the GSXR suspension I welded in brackets to mount the shock. works well but you lose the center stand. When swapping in the GSX or GSF engines, you also lose the side stand.

The Bandit stuff in the 77 frame - I took a different approach since I had a complete bike that had been laid over. I am taking the rear tubes with brackets from the GSF frame and welding them into the GS frame. saves time, allows the use of stock center stand and shock mounts. I am also going to use the GSF side stand bracket and weld it into the frame.

It'll be a couple of weeks before I can get all of this done. Hopefully over the T-Day holliday...

[salty_monk]

Posplayr and a few others had a bandit swingarm on an 1100E from memory. The way they approached the suspension was to have some "eyes" welded on the top of the Swingarm to take a clevis shock & keep the dual shock arrangement. Just another idea to think about...