Shaving pounds to add performance, ? on component weight

[Chuck78]

I'm trying to get an idea of what I will end up with and what parts I can easily swap out, delete, or modify to drop some weight, and what work and expense it will take to go the extra mile beyond the easy stuff. A guest post on the "Lightening the Load" topic helped out with some figures. Katman's site said the 1100's 630 chain to a $$$ Hayabusa 530 was 8 lbs savings! Sheesh! Others say 1 lb savings on 530 chain and sprockets (cheaper ones?) A 520 (narrower than 530, same length links) is lighter yet, but handles less power and wears out sprockets faster. Works better for wider tire retrofits like a 150 rear to avoid offset sprockets).

Here is where I am at so far as far as tentative plans and additional options, please help me fill in the blanks and correct me on any discrepancies:

1977 GS750B w/oil&gas&fluids 558 lbs dry weight 511.5 lbs

-8lbs GS1100E alloy swing arm swap
-22 lbs Mac 4-into-1 exhaust w/shorty muffler and home made baffle, shortening header 3-4"
-7 lbs center stand????
-4.5?lbs chop off passenger footpegs/tubular mounting frames, weld on tabs for muffler and newer alloy pass. foot pegs, shelve passenger pegs
-3 lbs chain guard
-?3-5?lbs detabbing frame
-?1? lb aftermarket 2.25" mini-gauge swap?
-?1.5?lbs removing excess wiring for cluster & gear indicator wires for 1-5 (leave neutral and common), remove stator's switched 3rd leg wire through headlight switch and back (1st gen GS models only)
-9lbs remove electric starter, gears, relay, and wiring
-10lbs??? delete battery add large value capacitor between + & - cables??? (I'm looking into proper battery delete options - capacitor vs tiny L-Ion battery to aid in spark on kickstart)
-1-8lbs swap heavy 630 chain for lighter but longer 530, weight depending on $$$ of 530
-2lbs OEM airbox setup to K&N pods
-3.8lbs Chrome fender removal OR -2 lbs trim down fenders
-?2?lbs remove cast steel footpegs, retrofit GSXR foot pegs and brake pedal???
-0.5lbs???? flat alloy motocross bar? or clip-ons
-1.5 lbs remove trunk and shave seat foam, section metal seat pan in rear to narrow, recover with bicycle gel seat recessed into rider position, remove side covers
-0.75lbs remove battery box, fabricate aluminum box in it's place to act as new trunk and to mount electronics onto.
-1.5lbs Hagon 2810 rear shocks
-3.5 lbs bolt on 93 GSX1100 Katana front rotor in place of rear rotor, '89-'10 GS500/'83-'86 GS550E rear caliper
-0.5lbs RF900R hollow rear axle
-1 lb have machinist friend make ft&rr axle spacers out of 7000 aluminum
----------------------------------
+/- 0lbs???? swap 1.85x19 steel front rim for 2.50x18 alloy rim, swap 90/90/19 for 110/90/18 tire
+2lbs remove heavy single disc front brake install lighter dual disc fronts (1.8lb/ea CBR900RR rotors vs 5.2lbs old rotor) 2 lbs extra for two twinpot calipers?
+3.75lbs??? remove steel rear 2.15x18 rim add 3.50x18 alloy rim, swap 110/90/18 for 140/70/18 tire
+1 lb add Tarozzi fork brace
+5 lbs weld in extra cromoly tubing and plates (highlighted red in photo) to stiffen frame according to the GSX/EFE-7/11 frame stiffening article on http://oldskoolsuzuki.info






Please advise on these moves, help with weight info or corrections on what I have guessed at or copied from the few posts that I have found on this topic!

ATTN: THIS LIST IS CONSTANTLY BEING EDITED TO SHOW ADJUSTED TOTALS AND ADDITIONAL PARTS SWAPS/RETROFITS

Current total if I go all out with all of the above future weight savings and parts retrofitting:
-87 lbs in savings
+11.5lbs in performance upgrades
75.5 lbs weight savings!!!!!!! Approximately 7+hp freed up!



437lbs dry weight
468 lbs w/ half+ tank of gas
482lbs w/full tank of gas and all fluids

LOOKIN' GOOD!!!!!
I can't wait to ride this thing with all these mods done!!! Money and time are going to push many of them off til next winter though, but I'm prioritizing the critical handling and braking areas

[JEEPRUSTY]

You could just go on a diet?
JK

[Chuck78]

Many members on here who heavily modify and/or custominze their GS's will say first thing to swap to a modern fork and cast wheels. I WILL NOT ride modern looking wheels, I own an old school Suzuki because I love the classic look and spoked wheels! I don't care for most mag wheels in general, but a few here and there look good, especially blacked out or blacked centers with highly polished rims. Modern forks take a fair amount of research and work to swap, and from what I have haerd it sounds like they are almost all much shorter height, which will really alter the geometry and steepen the steering A LOT, as well as reduce cornering ground clearance at the same time. I stuck with some GS650G dual disc forks up front (same 35mm tubes as the 550/650/750) instead of going with a larger 37mm GS1000/1100 fork because that is what the local vintage japanese bike junkyard had. I figure a Tarozzi fork brace will help plenty enough. I would've rather had some GS1000/1100 forks and triples, but they only had a leading axle model of the GS1000 forks, and so I stuck with the 35mm diameter tubes. Slightly lighter, but slightly more flex under hard braking. Torsionally, the fork brace will compensate.

Also, I know a GS1000 engine is lighter due to the removal of the kickstarter and the lightened crankshaft (750 cranks/rods are WAAAYYY overbuilt), but I'm removing the electric starter and battery, more weight savings than removing the kicker, and I love the kicker look and the physical interaction with the bike while kicking it over. I wanted to build the raddest old Suzuki kicker I could build... hence 1st gen 750 bottom + 850/920 top in the future.

Here is the only really good post I could find after scouring the forums:

Ive been obsessivley stripping weight off my 78 gs1000ec and have come up with some hard numbers by using an accurate digital postal scale at work. Here are some surprizing weight loss facts Ill share:
Front cast wheel=12.85lbs Front spoke wheel=10.4lbs
Rear cast wheel=15.05 Rear spoke wheel=16.20lbs
(wheel weights were rim only with bearings and axle sleeves intact)
EC model twin disc=8.2lbs N model single disc=5.4lbs
(all discs are drilled)
OEM airbox setup to UNI pods -2.05lbs
(4) OEM turn sigs to small aftermarket ones -1.6lbs
630 to 530 chain conv. -1lbs
(0.5 in chain and 0.5 in frnt sprkt; rear sprkt not included)
Chrome fender removal -3.8lbs
OEM Steel swingarm approx. 16lbs to GS1100 al. swingarm approx. 8lbs
(not verified by me, but seen on another post)
Thats all the single parts Ive weighed, however I have a seperate bag full of brackets and non-essential extras that weighs 17 lbs and climbing...some of the heviest pieces in there are the OEM twin horns, license plate/tail bracketry, passenger foot pegs/brackets, and much more...I tried to replace all non load bearing brackets with 1/8" thick al.
Saved 4.45lbs going to an aftermarket batt.
1.5lbs on new rear shocks
I dont have a accurate wet weight just yet but my guess right now is around 70lbs.
If any one knows what the exact weight of the stock twin pipe exhaust and the centerstand, please let me know, because I dont have these items to weigh...Hope this helps someone out there...

[Chuck78]

You could just go on a diet?
JK

I can't gain weight if I try! 5'10" 155 lbs in the winter!

[sedelen]

My GS1100 has more power than I can comfortably manage with all the weight a stock bike has?
I can't even imagine trying to get more out of it.

[Agemax]

you dont need that much frame bracing, it is way overkill for a 750 road bike!

[Chuck78]

you dont need that much frame bracing, it is way overkill for a 750 road bike!

I wasn't necessarily planning to add ALL that frame bracing, but I was intrigued and want the frame to handle as crisply as possible (i.e. let the suspension do it's job without any help from frame flex), and allow plenty of room for future improvements.

It's at 10.25:1 and 844cc's now with 4-1 and K&N filter, AND IT'S A REAL SCREAMER as-is, way faster than I had imagined. By next winter I will tear into the engine some more and add some 69mm GS850 cylinder jugs bored out to 72mm to fit some 920cc MTC Engineering 10:1 pistons. If I get rich, I might send my VM26's out to the Maxi-Bore guy and have the carbs bored out and reworked and modified intake boots installed as well. I'll be looking at a substantial power gain over the stock GS750, potentially upwards of 90hp or more if I have the flow bench carb work done.

I was also wondering how I could possibly swap a 2V head on that will bolt onto the 750 jugs and work with 750/850 pistons, that will allow me to run some BST34SS or BST36SS flatslide slingshot CV carbs... not sure if that is possible, but just a thought for the future. The $500 Maxi-Bore carb flow bench porting treatment may be better for the money.

Any idea on center stand weight? A CNC'd aluminum side stand was on my mind, but the bushing would worry me as to coming loose from all the weight.

[gsgeezer]

It sure is good to lose weight and drop some parts, too.
The previous owner has lightened my 1000, pretty well.
Of course you can't beat the rotor/wheel swap.
I also have gotten rid of stuff like the highway bars that came with it.

I was gonna change wheels, tires, rotors, swingarm, etc. but I have actually grown to like the spoked wheels, so I might just change rotors, sometime. Like you mention, stock turn signals are heavy, too. (I donated mine to somebody who wanted stock.)

Compaired to my old 850, (previous GS) the 1000's performance is a big improvement, even with a full load! (The PO did install a 3+ (I haven't counted) tooth rear sprocket.)
I don't seem to have much problem, on the "freeway" or TPK. It's nice to be able to merge onto a crazy road via very short entrance ramps.

[Chuck78]

the rule of thumb has been 1 HP for every 10#. Can you shed enough stuff to be worth it?

Going conservatively on the somewhat unknown weights, I figure I'll be dropping about 71.5 lbs, not including the option that I just thought about today after seeing some GSR posts, GSXR footpegs/mounts/brake pedal. That's probably up to 73.5 lbs savings. A Honda Shadow buddy of mine said he scrapes his pegs all the time because his bike sits so low, and the pegs are hinged to give in those occasions. Are Hayabusa footrests this style? I thought I remembered seeing one like that.


I will be adding maybe 9 or 10 lbs if I do that frame bracing, fork brace, Twinpot dual disc front brake mod, and 140/70 rear tire. So we'll say I can pretty easily drop 62lbs off while building the bike the way I plan to over the next year or so. Not sure if I will drop or swap the turn signals or chop the rear frame area behind the seat. Those two could get me several more pounds easily, but uncertain at present.

That's about 448lbs dry weight, lightened up by 64 lbs or so until some of you can give me some better figures on things like centerstand, etc. So not only will I be adding the equivalent of 6+hp in lost weight, the bike will be much easier to flick around in the twisties! I may (sigh) add some minimal crash bars to it in the event that I ever spill, but undecided for now.

[Agemax]

fit a smaller gas tank, every liter of gas weighs 1.6lb. less gas = less weight

[landspeedrich]

Centerstand weight

fit a smaller gas tank, every liter of gas weighs 1.6lb. less gas = less weight

Little number transposing going on here.One gallon of gas is 6.1 lbs.Imperial gal. is 7.3 lbsDelete my centerstand for my gs1100 miler bike build.Thought it was about 7-8 lbs.I'll double check tomorrow.
Don't believe your frame bracing will be 8 plus lbs.My bracing is around 4-5 lbs.The benefit of bracing will far outweight weight penalty involved.Believed I saved 18 lbs removing stock exhaust and installing V&H 4-1.

[Chuck78]

fit a smaller gas tank, every liter of gas weighs 1.6lb. less gas = less weight

True, but I want to be equipped for long rides into unkown (to me) remote mountainous regions, aka Kentucky and West Virginia, Smoky Mountains, etc... Trying to get a balance of practicality and weight shedding, so that if we take multi-day trip, I can have a sleeping bag and a few supplies in the saddlebags as well as some extra gasoline capacity, and still have a lighter total bike+gas+rider+gear than a bone stock GS750! Then on the in-town rides, and day trips to Hocking Hills State Forest, Southeastern Ohio, Wayne National Forest, etc. I will have a really lightweight vintage bike that is tricked out with all the best parts and workmanship my time and budget will allow, and will get to ride it to it's fullest potential, more than a close to stock bike ever had...

[Chuck78]

I don't believe your frame bracing will be 8 plus lbs.My bracing is around 4-5 lbs.The benefit of bracing will far outweight weight penalty involved.Believed I saved 18 lbs removing stock exhaust and installing V&H 4-1.

I figured on 4 lbs in frame bracing if I can get some cromoly tubing scraps from my machinist buddy, or buy some from a local place called Tubular Techniques. The rest of that 8-11 lbs I estimated was by adding a lightweight modern dual disc setup, which at ditching a 4+lb stock single disc rotor and adding two lightweight CBR900RR rotors at 2 lbs for the pair, that gives me a 2 lb allowance for the extra caliper and extra lines and fluid. Not sure how much lighter the Tokico twinpot Kawi Ninja calipers weigh vs stock GS calipers, but it may be less than 1 lb total weight gained.

The rest of the weight added will be in the much wider 140/70/18 tire, although ditching the factory steel 2.15" rim for a DID alloy 3.50" WM6 rim will still save me weight despite the much wider rim, so the tire weight gains will be offset, so maybe not adding a whole lot there, maybe 2.5-3 lbs, but my guesstimate could be totally off.
In the front, I am eventually going from a steel 1.85"x19" rim to a DID/Excel/Moose 2.50x18", so I will save some weight there to offset going with a wider tire just slightly smaller outside diameter to stock. Maybe 3-4 lbs total gained front and back??? Thought about a 150 rear but probably not necessary if going with a sticky compound like the Shinko's I have in mind.

[Chuck78]

lighter modern rear brake & rotor that is a bolt-on?

Although I got a nicer looking 80's GS rear disc rotor on this drag bike wheel (has the drilled fan slot pattern to save over my solid 77 rotor), I am wondering just how much weight I can save if there is an easy rear brake setup to swap over to in a more modern caliper and possibly master cylinder? By default I think the GSXR sounds like it could have potential for rear brake donation.

The GS rear discs in my experience are too grippy, they lock up too easily, so I'm not looking for more powerful rear brakes, just wondering if there is an easy way to shave 3-4 lbs off of the rear brakes with a modern setup.

The lockup could probably be adjusted by changing the throw of the foot lever, or rather where the master pushrod is actuated from on the lever. moving it slightly closer to the pivot could solve the lockup problem. I suppose I could also drill the crap out of the rotor, saving a lot of weight there at the expense of a few hours and a few drill bits and cutting oil. Reducing the area of the rotor from all the holes alone may potentially fix the inherent GS rear disc lockup problem.

[Chuck78]

With that tip on the V&H 4-1 and center stand weights, as well as lifting up the GS1100E chain gaurd I have sitting here and a few other thoughts, I've revised the weight savings to approximately 74-77 lbs depending on changing to GSXR rearsets and complete battery delete vs tiny Lithium Ion battery to help kickstart easier. Still have to research more on battery delete options.

So we'll say 75 lbs shed, 10 lbs added for frame bracing+larger tires+fork brace+lightweight dual disc upgrade. So we're down to about 446 dry weight, so we'd be at about 480 lbs with half a tank of gas & all fluids, 493 lbs with a full tank. This is sounding pretty fantastic! I can't wait to get this process started this spring, get the twinpots and Sonic springs in the front end with some Shinko or Avon tires on wider alloy rims... The SE Ohio twisties will be a new experience with all these mods and weight savings!

Rear brake opinions, and any weight corrections from my list, or other suggestions?