GS Front Fork Swap

[Eldogfarmer]

Are 78 GS 1000E fork tubes the same size and length as 83 GS 1100E?

[salty_monk]

Yes. Mine runs a set of 83 with cartridge emulators.

[Eldogfarmer]

Great, i am going to pull my bent fork tubes and insert the 1100 tubes. Thanks

[Eldogfarmer]

I have a set of 83 forks but not sure where to get the block off plates for the anti-dive feature

[Rijko]

Just a warning to compare the fork legs and tubes :
the GS1000 inner tubes have no extra holes in them for the air connection at the lower triple tree clamp.
The 3 GS(X)1100E 1983 models (ED/ESD/EZ) all do have those.

Distinguish between inner tubes, outer tubes or whole fork legs - guess you are replacing both complete fork legs ?

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[Suzukian]

There's a whole front fork, and triple tree set up on EBAY for $219 dollars right now. Has crossover tubing for air suspension, and includes anti-dive units (I love mine, would never remove them, they have to be working to be of any use though).

Link = https://www.ebay.com/itm/27548080503...temCondition=4

[Grand Rouge]

I have a set of 83 forks but not sure where to get the block off plates for the anti-dive feature

These guys are a 'block off plate source" The price.....well.... I asked if there was a discount available. Got mine ...delivered.....less than a hundred dollars.

Suzuki Anti-Dive Bypass (fastfromthepast.com)

[Suzukian]

Just curious, why did you bypass the Anti-Dive? Every bike that the rider said the anti dive caused mushy brakes, when I disassembled them, I found the brake mount sliders dry. After a good brass wire brush cleaning, and greasing, the bikes performed fine. In my experience, it was always something else that was causing the problem. My anti-dive works so well, when I ride the bikes of other people, I find it hard to deal with the nose dive. Whatever floats your bowl, that's fine. I'm just curious. I have come across many people who blocked them off, and ended up putting them back on, or finding out that they had water in their fork fluid, and rust was preventing the units from operating properly.

I find them to be such a positive feature of these bikes, I just have to ask.

[dweller]

I made my own anti-dive block offs. Sonic straight rate springs, gold valves, just a great setup. Transformed the handling of my GS11E. If anti-dive was a good idea, we'd still be seeing it on modern bikes. It went away for a reason.

[Grand Rouge]

Just curious, why did you bypass the Anti-Dive? Every bike that the rider said the anti dive caused mushy brakes, when I disassembled them, I found the brake mount sliders dry. After a good brass wire brush cleaning, and greasing, the bikes performed fine. In my experience, it was always something else that was causing the problem. My anti-dive works so well, when I ride the bikes of other people, I find it hard to deal with the nose dive. Whatever floats your bowl, that's fine. I'm just curious. I have come across many people who blocked them off, and ended up putting them back on, or finding out that they had water in their fork fluid, and rust was preventing the units from operating properly.

I find them to be such a positive feature of these bikes, I just have to ask.

When I serviced forks.....bushings, seals, wipers, sonic springs and gold valve emulators etc....proper sag and of course correct spring rate selection and quality fork oil, all combined to transform fork action. The anti dive units were no longer necessary......were perhaps not an add on that might have been beneficial to some...never made it for me.... I have owned my GS since new. Never had spongy front brake....proper bleeding.....but....the wee bit of fluid displacement to operate the anti dive pistons...caused fluid transfer port(s) to be blocked.....brake lever travel was more than without the anti dive. Additionally.... cleaned up the look..in my opinion...of lower fork. I enjoy short lever travel, firm feel...have upgraded brake hoses too......easy to modulate......and...IF one is riding on the street......'grabbing a handful of front brake' not a good technique. Squeeeeeeze that lever ......smooth fork action.....not a lot of dive......always good control.

[salty_monk]

We don't see them on modern bikes because the shim stacks in modern cartridge forks provide much more controlled compression damping. Apart from sometimes causing a mushy lever some racers complained about a lack of feel and also a lack of grip at the ragged edge.
I guess this makes sense, if the fork props the bike up under hard braking then less weight is transferred to the front wheel hence less pressure on the front tyre = less grip.

[Suzukian]

I totally understand what you guys are noting. I don't disagree, I'm just having a different experience. I only need two fingers on my front brake in any situation. I see no listing for 1983 GS750ES cartridge emulators. I wish I had a good set of blue prints, I could make a set.

I had toyed with the idea of changing the bikes suspension to see if I could get radials on the bike, and getting a larger front wheel would enable a wider variety on front wheels. The bike doesn't seem old to me because I've had it since new, but let's face it, it's an old bike that still handles fantastic. I think the 16" front wheel and it's reduced gyroscopic precession contributes to that. About the bike propping up under hard braking, the anti-dive prevented the bike from diving (in my experience) and it's ability to grab is either something I just got used to, or is different from cartridge emulators.

If any of you guys have a link to cartridge emulators that would fit my '83 GS750ES. I can't find any. The Front forks were changed from a parts bike I got that had only 5K miles on it. These forks are like new. It would be interesting to try the emulators out though. A blueprint would be even nicer. I have some really nice Brass stock, and could easily make a set of these. Thanks much for your valuable input.

[salty_monk]

Racetech's ones for the GS1000/GS1100 are the ones you want. Or you can buy the ones from MikesXS for a 35mm fork and turn up some adapters, they work fine too. I have a drawing for the adapters somewhere....

It would be simple to make a full set with a lathe and a mill if you had a set on hand to copy but less so without that. You'd also need to find the correct strength spring (within reason as it's adjustable)..

[Suzukian]

Racetech's ones for the GS1000/GS1100 are the ones you want. Or you can buy the ones from MikesXS for a 35mm fork and turn up some adapters, they work fine too. I have a drawing for the adapters somewhere....

It would be simple to make a full set with a lathe and a mill if you had a set on hand to copy but less so without that. You'd also need to find the correct strength spring (within reason as it's adjustable)..

I do have all the machines, prints are what I would need. I have a SouthBend 9" back gear lathe, Milling machine, compound rotary and milling tables, so banging them out wouldn't be a problem. I'm not an engineer though, and I know my limitations. Even having the wrong size one in my hand, I could reverse engineer it and make a CAD drawing to get the rest of the dimensions through parametric scaling. When you say "turn up some adapters", is that a sleeve for the O.D. size?

[Suzukian]

This page put it all together for me. Without you guys inputting, I was blind to realizing that it's basic fluidics. The link below really explains it for people like me who need visual cues. Thanks all for the info!

https://racetech.com/PAGE/TITLE/IP%20FMGV%20BOLT%20TYPE