'83 GS750E Streetfighter Build

Ok, so the swinger is in, and now it's time to mount the top of the shock and the linkage, and brace the frame. Anyone know what type of steel to order, all the online places sell it by alloy type.

For tube thats in a stressed area such as the top shock mount you need 25mm dia 2.5mm upwards wall thickness cfs2nbk, for the brace in the V of the frame both sides 25mm dia 2mm wall thckness erw will do & keep the weight down any flat plate can be 5mm upwards in thickness mild EG nothing special

Ok, so the swinger is in, and now it's time to mount the top of the shock and the linkage, and brace the frame. Anyone know what type of steel to order, all the online places sell it by alloy type.

The tophat should sit on the inner lip of the swingarm pivot like the attached image. The ID is the diameter of the GS swingarm bolt, the OD is the ID of the swingarm bearing, and the length is such that it sits INSIDE and FLUSH the swingarm pivot sitting between the internal swingarm spacer and the lip on the inside of the pivot. The swingarm will still rotate on the swingarm bearings this way identical to the way the stock GSXR tophats work. Make sure you grease up your tophat and your pivot bolt well before installing.

Looking good!

I have been away from mine for about a yr and a half.
Starting back on it once I get over this ankle injury.
I still need to finish the USD front end and new tank.

Good Luck on your Build-
I am going to keep watching it.

Peace,
Ron

WOW!!! That's a much better price than I was quoted! There is a variance in production of either the measure I am using as compared to yours, or the swing arm as compared to your, because I am measuring 226mm, which doesn't give me any clearance for top hats. I noticed the pivot bearings have seals in them, and that there is room behind them. Maybe it would be possible to narrow the swinger to gain the clearance, rather than weakening the frame. There is lots of material on there.

How much did your machine shop charge you to do that, because the only one in town here that will even consider making something like that wants $150 to do it, opposed to the $32 I have invested in the bushings. I'm stuck on a budget cause I'm a single dad, but I don't want to skimp on safety or something that could affect freeplay or alignments ya know. How thick is the brim part of your tophats?

IIRC it was one hour of CNC shop labor which came out to $60. The brim on the tophat is pretty thin - don't remember exactly but it's 1-2 mm max. The brim acts a dust cover for the pivot bearings really.

I brought the swingarm down to the machine shop to have them measure everything and make sure it'd fit for this application.

The swingarm you're using is 225 mm at the pivot so minus the stock GSXR tophats it'll slot right in.

How much did your machine shop charge you to do that, because the only one in town here that will even consider making something like that wants $150 to do it, opposed to the $32 I have invested in the bushings. I'm stuck on a budget cause I'm a single dad, but I don't want to skimp on safety or something that could affect freeplay or alignments ya know. How thick is the brim part of your tophats?

You're on the right track except for the fact you're using the stock GSXR swingarm bushings....

Ditch the stock GSXR tophats and get some made that sit flush inside the GSXR pivot. You'll gain enough clearance that you don't have to remove any material from the frame or swingarm. You don't want the brim of the tophat to go outside the swingarm as you lose clearance.

The most critical bits are that the OD fits inside the swingarm bearings, the ID fits your pivot bolt, and the overall length including the brim of the tophat is flush with the swingarm so it'll fit in the frame.

If I could do it over again I'd probably get these made out of bronze but 440 stainless is very hard and gall-resistant.

So I finally have time to post a complete update. My kid got a hold of my camera and had the date set wrong somehow....
Anyway, I have learned that the pipe in between the pivot bearings is just a spacer to keep the bushings from contacting the swinger to eliminate friction. This pic is with only one bushing fully installed


And this pic is with the other side fully inserted which causes this one to have a 1mm gap for the swinger to float in


The total width from bushing to bushing is 233mm, and the clearance in my frame is 226mm. The plan is to now make the swinger gap as small as possible by trimming the insides of the bushings, and taking off as little material as possible from the frame, unless I can figure out a way to narrow the swinger. I also keeping in mind taking off equal amounts of material so that I can have my swinger lined up in the middle of the frame, and keeping wheel alignment in mind as well. If anyone has any ideas or knowhow on that, please feel free to chime in!

Now to the matter of hanging the swinger once I get it into the frame. The GS uses a 16mm pivot bolt, and the GSXR uses a 22mm pivot bolt.


So I got these cool precision machined bushings that are capable of a 4,000lb load each! They were supposed to be press fit into the original bushings, but they are not, which would allow them to slide all the way through the pivot area. With that in mind, and the fact that there is already one pipe in the pivot, I'll just add another one, to keep the reducer bushings out where they belong, and hone out the inside of this one enough for the GS pivot bolt to pass through.


Any input from anyone more knowlegable than me or with a better idea than me, feel free to add your input please.

Looks good so far. I like it!!!!

Trust me, I am. Haha!! I recognize you from over there. I just haven't posted yet. It's hard to find time to upload pics cause I'm usually doing it from my phone. Got an update coming later...... Stay tuned

Or, you might consider Vintage Fighters

Nice build, by the way! I'll be watching with interest!

If you are building a fighter you REALLY should be on this forum dude....

www.customfighters.com

Trust me, I am. Haha!! I recognize you from over there. I just haven't posted yet. It's hard to find time to upload pics cause I'm usually doing it from my phone. Got an update coming later...... Stay tuned

If you are building a fighter you REALLY should be on this forum dude....

https://www.customfighters.com

[NoBars]

I remember that article...

Have you considered a oilcooled gsxr 750 or 1100 motor? I have always thought that could be a really cool bike. Ii would think 750 motors are pretty cheap nowadays, everyone wants an 11. I bet it would fit nice.

Wow good point tone! I had already planned to do some frame bracing, and I do like the way that 80GS1000 did his mount, so I'm gonna have to get some things mounted a lil bit more solid, and then see where the shock wants to be mounted and then add my bracing. I'm also planning to use a much smaller battery too, so that will help with space issues.

Hey 80GS1000, what did you do about the tube in the swinger between the pivot bearings? Did you do anything to center it, or just let it sit in there?

It's just a spacer for the pivot bearings so I didn't worry about it. Take a look on the Bikebandit.com 05 GSXR 1000 swingarm schematic. Here are some tips on creating your monoshock mounts and steering geometry if you want.