1984 GS1150ef rebuild!!! renew!!

[wyly]

So after restoring my 84 GS1150ef I thought about selling it but I can see that I'll never get much for it so I decided to create something new and savage.

First objective, reduce weight get it under 500lbs. New headers on order from Hindle only 10lbs! Oems headers were 32lbs, centerstand was another 3 lbs, now my old fattie should come in at 499 dry.

Initial target met and I can see there's a lot more I can remove(fairing is 8lbs). Wheels and forks, there's gotta be a weight saving there! plus a improved suspension and handling.

Ive been looking at Gsxr forks and wheels does anyone know what years if any I do a direct swap?

I've read the 93-95 Gsxrs are a direct swap for 80-83 katanas but I don't know if that applies to the 84 GS1150ef

 

[Guest]

Pretty much any year GSXR forks can be made to work if you get the correct conversion bearings to bolt up the GSXR steering stem in your GS frame(check out All Balls Racing), verify the steering stops on the GSXR triples are good on your frame, and account for the fact that GSXR forks tend to be much shorter than your stock GS forks. You can get fork extender caps for 2000s era GSXR 750/1000/Hayabusa forks which get your ride height back in the stock ballpark. GS bikes are heavier than GSXRs so the GSXR forks need to be resprung accounting for GS bike & rider weight (check out Racetech).

If you are doing the front end, are you also considering swapping the rear end too (swingarm/wheel)? Mixing radial tires on the front with a bias ply tire on the rear can lead to some sketchy handling so you need to look into replacing at least the rear wheel with something that can handle a radial.

 

[limeex2]

Not sure what a set of 1150 carbs weigh, but by changing from oem to GSXR1100 carbs on my 1100 I saved 7.2 lbs and gained 8 hp. Not sure of hp gains or loses on a 1150. Ive got my GS1100 down to 462 lbs wet.

 

[Rob S.]

...I've got my GS1100 down to 462 lbs wet.

1982 GS 1100E 462lbs? Wet?!? (Half tank?)

Got me beat by about 105 lbs.

But I can sleep at night knowing my Sporty weighs almost exactly the same. And makes only one third the power.

I think Suzuki was the first of the big makers to discover that weight is the enemy. I'm so old, I remember when Harley advertised that their bikes where heavy enough so that a passing big rig hauling heifers wouldn't blow you out of your lane. Any body else remember that? More weight was a good thing. At least according to Harley.

 

[Guest]

The fork extenders would only work on forks that are the same diameter at the upper and lower clamp positions. The GSX-R1100 forks 93-95 have small diameter for upper clamp and larger diameter for lower clamp. If you lowered the fork with extender it would no longer clamp at the lower position.

+1. My GSXR1000 forks can only be extended by 3" for this reason.

 

[limeex2]

1982 GS 1100E 462lbs? Wet?!? (Half tank?)

Got me beat by about 105 lbs.

But I can sleep at night knowing my Sporty weighs almost exactly the same. And makes only one third the power.

I think Suzuki was the first of the big makers to discover that weight is the enemy. I'm so old, I remember when Harley advertised that their bikes where heavy enough so that a passing big rig wouldn't blow you out of your lane. Any body else remember that?

Gauges are removed tach only, different seat, handlebars, wire wheels(18"F), non-bias ply tires, yosh exhaust/cone eng muffler, no center stand, Busa rear sets, 530 chain, GSXR1100 carbs, fox shocks, FZ1 rear caliper and balance of oem r/brake system gone, excess wiring,relays,sensors,horns ect, 1/2 tank yes. It all add's up. Its my old race bike only updated by the forum and lights so its barely legal. My signature pic is the bike, less the fairing. Circa 1981?, amateur racing at Daytona bike week. We dont get checked by the law for gauges,horns,signals unless we are having to much fun. Some officers just dont have a sense of humor.

 

[wyly]

Pretty much any year GSXR forks can be made to work if you get the correct conversion bearings to bolt up the GSXR steering stem in your GS frame(check out All Balls Racing), verify the steering stops on the GSXR triples are good on your frame, and account for the fact that GSXR forks tend to be much shorter than your stock GS forks. You can get fork extender caps for 2000s era GSXR 750/1000/Hayabusa forks which get your ride height back in the stock ballpark. GS bikes are heavier than GSXRs so the GSXR forks need to be resprung accounting for GS bike & rider weight (check out Racetech).

If you are doing the front end, are you also considering swapping the rear end too (swingarm/wheel)? Mixing radial tires on the front with a bias ply tire on the rear can lead to some sketchy handling so you need to look into replacing at least the rear wheel with something that can handle a radial.

I in tend to swap out the entire front end. There's huge amount of technical data to sift through some years of gsxr 1100s are very close in fork length and they run a 17" tire vs the 16" oem. If I can find the right year it would make it a much easier conversion. Rough estimate for my fork length now is 790mm, a '93 1100 gsxr is 770-775mm, include the swap to a 17" wheel and it should be close to stock ride height.

Rear wheel is going as well hopefully without a swingarm swap, I've come across builder sites that claim to have a 180 rear on older katanas not sure how they managed that.

 

[wyly]

Not sure what a set of 1150 carbs weigh, but by changing from oem to GSXR1100 carbs on my 1100 I saved 7.2 lbs and gained 8 hp. Not sure of hp gains or loses on a 1150. Ive got my GS1100 down to 462 lbs wet.

How heavy were your 1100 carbs?...my oem 1150 carbs weigh 8lbs, new mikuni rs36 weigh 9lbs, so Ill be gaining a bit

replacing the 12lb battery when it dies with a Li-On will reduce my weight another 10lbs to 489lbs. If I remove the fairing I can reduce it to 481lbs. Not sure I want to do that just yet relief from the wind on long rides is nice.

I've no doubt I can achieve low 470ish weight.

 

[limeex2]

How heavy were your 1100 carbs?...my oem 1150 carbs weigh 8lbs, new mikuni rs36 weigh 9lbs, so Ill be gaining a bit

replacing the 12lb battery when it dies with a Li-On will reduce my weight another 10lbs to 489lbs. If I remove the fairing I can reduce it to 481lbs. Not sure I want to do that just yet relief from the wind on long rides is nice.

I've no doubt I can achieve low 470ish weight.

Sorry, my mistake. 1100E Carbs= 7.7lbs GSXR1100 carbs= 4.5lbs or 3.2lb weight savings. Another weight savings that I havent tried yet (sorry for stealing your post) for people with spoked wheels is using 3M 4412 tape and eliminating the inner tubes. Tubes are around 3lbs of unsprung weight which is pretty hard to find and expensive. https://www.youtube.com/watch?v=AGyeA12terU or https://www.youtube.com/watch?v=lniuSPDtDgM

 

[wyly]

Sorry, my mistake. 1100E Carbs= 7.7lbs GSXR1100 carbs= 4.5lbs or 3.2lb weight savings. Another weight savings that I havent tried yet (sorry for stealing your post) for people with spoked wheels is using 3M 4412 tape and eliminating the inner tubes. Tubes are around 3lbs of unsprung weight which is pretty hard to find and expensive. https://www.youtube.com/watch?v=AGyeA12terU or https://www.youtube.com/watch?v=lniuSPDtDgM

no need to apologize any tips on weight savings are welcome. Some may apply to me, some to others it's all good.

With all weight saving there's personal options as to what the trade offs are and dollar cost. My fairing for example, eliminating the fairing will save 8 lbs but I lose wind protection, I'm not sure the weight loss is worth that trade off. I already have a complete headlight assembly($250) if I do choose to ditch the fairing. The Belly pan has to goregardless to make room for the new headers. New-er wheels, suspension and brakes will save a few lbs but what's at what cost?

If I switched to GSXR 1100 carbs to save the a three lbs would I get the same performance increase that Mikuni RS36s offer? Three lbs less or more HP/torque?

 

[wyly]

Modifying the rear seat into a fiberglass cowl with additional back support like the mid '80s Slabsides. It will shave a tiny bit of weight at the same time, the cowl is lighter than the seat pad and I'll be eliminating the rear pegs and on hanger completely. In the future if I choose to do it I can move the battery electrical components to the seat pan, and still I get keep the tool box under the pan as well.

Using the old seat I added a bit of foam from an art supply store and wrapped it with packing tape, foil tape then waxed it. The height at the rear is unchanged it's only slightly raised a the front to allow for the attachment of pad for my back.
I've never worked with fiberglass before it requires a few more layers to strength and some minor alterations but it's progressing.

 

[salty_monk]

Stock & not... All parts used are GSXR apart from the Ducati monster shock.

IMG_0656 by salty_monk, on Flickr


IMG_3552 by salty_monk, on Flickr

More pics uploaded here https://www.flickr.com/photos/11104522@N04/with/48900617281/

 

[wyly]

cowl done, sort of. Ran out of clear coat but I have more work to on it so there may be a few scratches on the way.

How do I attach it to the pan??? I was planning on using Dzus quick release fasteners but the pan and cowl are at different angles so I'll likely need to modify the pan for that to work.

Then I need to get out the sewing machine and make a cover for the back pad that goes above the seat. And figure out how to attach that from the inside of the cowl.

It would be easier just to buy a new ride (like a Kawi Z900 or KTM900 Duke) but then what would I do all winter?

 

[Guest]

View attachment 59637cowl done, sort of. Ran out of clear coat but I have more work to on it so there may be a few scratches on the way.

Looking good! I like the way it flows with the rest of the bodywork on the bike.

 

[Carter Turk]

Honda 954rr upper triple allow the use of slightly shorter forks.
Don't know all the details, but ur fellow Canadian in BC (katman), may have some older posts on the subject from the archives.

 

[dorkburger]

Following.....

Losing the passenger pegs / hangers also cleans up the overall look. But you?ll need to make a muffler hanger, which I?m assuming you already know.
There are loads of 1150s modified in many ways over at Old Skool Suzuki. You can find plenty of suspension / wheel swap info there as well.

 

[wyly]

Following.....

Losing the passenger pegs / hangers also cleans up the overall look. But you’ll need to make a muffler hanger, which I’m assuming you already know.
There are loads of 1150s modified in many ways over at Old Skool Suzuki. You can find plenty of suspension / wheel swap info there as well.

Passenger pegs are easy enough to remove the entire hangers is trickier, there is more than just a muffler attached to them; rear brakes, shift linkage and drivers pegs. I can chop them shorter and remove a couple lbs in weight but I'm not confident it'll be aesthetically pleasing when I'm done.

I'll check out Old Skool Suzuki and see what ideas I can borrow.

 

[wyly]

Honda 954rr upper triple allow the use of slightly shorter forks.
Don't know all the details, but ur fellow Canadian in BC (katman), may have some older posts on the subject from the archives.

I've been warned not to go with shorter forks a shorter fork with the 16' wheel I have could make for some very twitchy handling. I have a mechanic/technical advisor who is a suspension and tuner expert who works the WorldSBK circuit. He wants to measure the geometry of my GS if I intend to do any fork swaps and advises a larger front wheel 17" or 18".

I'd like to have inverted forks but he says the forks I have can be vastly improved by removing the anti dive, adding Race Tech Emulators and springs. None of those mods comes cheap, finding a complete front wheel/inverted fork/brake/triples/clip-ons assembly for a similar price would be my preferred option. Not many later model forks come close to the length I have now, if I recall correctly the 93-95 GSXR1100's ccme closest to recommended the fork length.

 

[dorkburger]

.... brain fart on my part. I forgot that those carriers hold all of that. I have seen them substantially cut down.

 

[wyly]

Looking good! I like the way it flows with the rest of the bodywork on the bike.

thanks' that important to know, I was concerned I had rounded the the corners too much, the goal was for it to look like it belonged on the bike like the mid 80's Slabbies. I'll have much better lower back support too.


Total cost to build it somewhere between $200-250, not inexpensive but there's no aftermarket cowl available for the 1150 that I could find.