'80 GS750 Brat build

I recently finished an XS650 bobber build and just picked up the GS750 for $350. I was looking for a CB750 since I used to have a CB550 and loved it, but for the price I couldn't turn down this clean running GS. I thought I might go cafe on this one, but the more I look at the "brat" style I was drawn to that look. Simple really and not a ton of work to do. The XS was a ton of fab work as I made most of the stuff myself and didn't just order a bunch of stuff to slap on it so I'm looking for something a little less involved here. Here's a couple pics of the XS.






Here's the GS, when I got it last week. My wife and I had to unload it in single digit temps and well below zero wind chills...stupid






This bike is clean enough and a good enough runner that I'm really not going to do a ton to it. I don't even plan on taking the motor out of the frame or stripping it down completely. Much of it will remain stock for now, headlight/controls/gauges/airbox/side covers etc. I will likely remove the filter box and put a UNI on its place behind the side covers, but I'm not doing anything to the exhaust yet so I didn't want to fool with upsetting the balance with UNI pods on each carb. Maybe down the road. This will likely be a purely cosmetic affair on the cheap. I even have paint left from my XS build that I will use on the tank/side covers...might even be a matching paint job, or a negative of the XS paint.

I have a couple of cat eye turn signals that I didn't use on the XS for the front and I'll get a tail/turn/brake/plate bracket for this...that with a 25degree rear hoop should work out ok. I will likely make and upholster the seat also. I'm looking forward to getting this done before summer...fingers crossed.

I was able to get 40min or so to play around with the bike. My rear hoop came in and I needed to get the rear fender assembly taken off. I feel like I need to cut the inner fender down some and use it to keep the water/dirt/mud off of the back of the battery box and other electronics, but I'm not sure yet how I'm going to do that.
Stripped rear end...


Now I've got to figure out how far back to cut the frame for the hoop position. I'm thinking I want to have just enough seat to be able to ride 2up on occasion which would probably put the end of the flat right above the rear axle extending the up curve beyond 12:00 on the rear tire and giving a little more "fender" like effect of rooster tailing water off the rear tire.


Took the alien antennae type mirrors off. I have a bar end that I'll put on there once I put the new grips on. It looks better already, although I should have waited to take the pic until after I took those ridiculous turn signals off haha

I finally had both the time and motivation to get out and work on the suzuki again.

I measured 6" back from the cross brace and cut off the rear of the frame...that didn't take long


Wow, that's long...looks like I have some more trimming to do.


I ended up cutting 1.5" off the frame tubes and another 3" off the ends of the hoop. That got me here, which seems about right to me.



Then I had an idea as to how to close up the bracing under the frame tubes. I didn't want to just slap a flat piece on and weld it over the opening I thought maybe I could make it look a little better with a slight angle instead of being perpendicular to the rear hoop.
When I cut back the additional 1.5" I left the bottom of the bracing there so I could bend it up and close up the opening. Once welded up I think it will look ok. I still need to decided whether I'm using an all in one tail/turn/brake light or if I'll need signal mounts also. If I do run separate signal lights I'll probably be putting those tabs in this area too.

Well, I was back at it tonight trying to decide what kind of tail/turn/brake/plate bracket combo I want to use and I was having no luck. I'm just not happy with what it will look like so I was looking around and found the old rear fender off my XS650 build and wondered if I could use it. I cut a quick piece of cardboard to at least make it look like there was a seat pan in place to give a more complete picture.

I took some pics both with and without the fender. I kinda like it with, but I'm just not sure what tail/brake light assembly to go with for that...without the fender I think I know what I'll use but with fender not so much. The fender will also further complicate the seat pan shape. Any opinions on the fender?

With or without?

I like it with the fender

Ditch the fender. Sticks out like a sore thumb.

That bike is a pretty cool score. Tons of potential. I like the brat style.....but what about a hardtail like your XS???? Hmmm just thinkin.

Have fun with it.

You had me at 'brat'

I'd go with different rear shocks, had those on my old cb360 and they nearly broke me

dude where are you located?

Madmannc said:

dude where are you located?

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Bowling Green, Ohio

Well, I've been putting of doing anything on the bike for a while but I've finally gotten the motivation to do at least a little bit of work finally.
Part of my lack of motivation has been in part because I was waffling back and forth about this rear fender. I just wasn't looking forward to trying to make tabs for it and getting it to mount level and straight with it floating on a board on the rear tire. I finally bit the bullet and jumped in because I didn't want to have to buy another tail light since the one I already bought was a fender mount unit.

Here are the tabs

tacked in and welded up...still needs leveled and a front bracket




Not too bad for holding a the brackets in one hand, turning on the gas and welding with the other while keeping the everything in place...ridiculous...should have made a jig of some kind.


decided to use plywood as the seat pan...but needed a curve in the tail so I soaked it and clamped it in place


It wasn't enough lift so I ended up having to clamp it to a 2x10 with a 2x4 behind the end but didn't get a pic. It was just enough curve


Got the new grips put on finally and the new smaller turn signals


I welded in tabs for the seat, drilled holes in the pan for bolts, painted the pan, then used an electric knife and flap disc to shape the foam from my old xs650 seat then spray glued it to the pan...not too terrible



Meanwhile I sand blasted the rusty section of the fender, still need to weld a front bracket for the fender, and get the primer/paint flowing.

Tonight I think I'll start the upholstery for the seat.

I didn't get any upholstery done last night but I did get the front bracket done for the fender. I mocked up the fender, turns, and seat to get an idea of what it's gonna look like and I think I like it. The seat seems a little long, but I wanted to still be able to ride 2up at times so this seat should accommodate that.

I went ahead and used the turns for the rear mount bolts. I think it'll work ok.


front bracket


mock up

Subbed, always good to see another gs750 on here, like what you are doing so far man. Now if I could only find some time to finish one that's lying around here..... somewhere.

I went ahead and added some foam to the nose of the seat because the back of the tank sits so high I didn't want an inch gap above the seat. I hope this works out alright.


This is some vinyl I had left over from a previous seat project and a $3 piece of scrim foam (with the fabric backing...sew foam it's also called) from the upholstery shop down the road. I spray glued the vinyl to the foam and started sewing. My machine wasn't working so well and was a little underpowered for getting through the foam and vinyl so I had to actually make 2 passes for every pleat. At first I was resigning myself to having to give up and take it to the shop and have this done for me, but I pressed on. It was taking a while and left me with a bit of a bulky stitch but it was ok. I marked the lines at 1.5" and left some at each end for a seam.



And done


I laid the seat on it and marked out the seam line for the top panel and cut 1/2" or so outside that line


I marked out and cut my side panels...one sewn on one to go


I think it'll work, I would loved to have sewn a french seam along all of the seams but the machine wasn't going to allow that. I'm lucky I got this much done. I think it'll look ok once I actually pull and staple it tight.

I ended up busting out the machine again and working on the curved seam around the back of the seat. It was lumpy, a bit uneven, and a bit too baggy. Once that seemed better(no pun intended) I decided to start stapling it trying to make sure I was pulling evenly all the way around. I started with a staple just to hold the front, back, then side to side. After those 4 points were secure I started slowly working across the front and back then down the sides. It took a while but I'm really happy with how it turned out. It's by no means perfect, but for what it is it will do a fine job. The front panel isn't perfectly symmetrical but that will be under the edge of the tank so I'm not too concerned about it...even if it wasn't hidden it isn't like you can look at the seat straight on from the front anyway.

Great job on the seat. Thats on my to do list.


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Pilgrim9283 said:

Great job on the seat. Thats on my to do list.


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Thanks Pilgrim9283. A youtube video of how to stitch the seams on the skirt side panels before finishing the seats edge stitch helped me a lot.

Looks good man. This makes me regret selling my GS550 brat that I did a few years ago. I think that these GS's are totally underrated and over shadowed by the Honda CB's. Keep up the good work.

Nice looking bike Paydan, I have have a feeling once I get this one done it's going to see more ride time than the xs650 hard tail I built.

Was just looking at your seat pan and hoop. Can you tell at what angle they are turned up? Im making both and am thinking 20 degrees up looks about right.


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Pilgrim9283 said:

Was just looking at your seat pan and hoop. Can you tell at what angle they are turned up? Im making both and am thinking 20 degrees up looks about right.


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I know it's no more than 20, if I remember correctly it's closer to 15