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Main Area => General GS500 Discussion => Topic started by: quiktaco on January 14, 2008, 06:27:32 PM

Title: Cutting Weight
Post by: quiktaco on January 14, 2008, 06:27:32 PM
Was wondering if any of you have ever tried to cut/remove/drill/replace away weight from the GS.   I was into Cafe Racers for a while (although never had one) and it was always a big deal to get the bike down to it's bare minimum and have no extra frills and such (very lightweight and minimalistic racers).  Was just wanting to know if anyone has done this, and what they removed/or cut away.   Or if no one has, what types of things could be removed/cut/drilled to reduce weight.  Especially easier things that could be done, before getting into lighter wheels since that's an obvious one.
Title: Re: Cutting Weight
Post by: werase643 on January 14, 2008, 07:08:54 PM
remove all tail plastic and install one of them CF solo tails should save about...10-15#
same as on all bikes remove all  useless crap..

drill the rear brake rotor
AL rerarsets

wheels will be the most difficult to find that fit and are lighter

cheeze grate anything/everything that is not load bearing

Title: Re: Cutting Weight
Post by: scottpA_GS on January 14, 2008, 07:10:38 PM

Cool question...

I am not sure what common weight loss plans are for the GS  :icon_mrgreen: I would guess you could start w/


The rear fender
Airbox
Center stand
Exhaust center stand stopper
Bar ends

Chain guard?
Maybe a smaller headlight and signals?

Most of the seat and rear sub frame could go too  if you really want to make it 3 lbs. lighter :thumb:

Title: Re: Cutting Weight
Post by: jordanearl on January 14, 2008, 07:15:23 PM
go on a personal diet :laugh:
Title: Re: Cutting Weight
Post by: 04gs on January 14, 2008, 07:31:22 PM
I'm into drag racing pretty much everything i own.  As far as cars go, for every 100lbs you shed you will shed approx. 1/10th of a sec. in the 1/4 mile

But for bikes it is approx. every 10 lbs you shed you will shed a 1/10 in the quarter.
Title: Re: Cutting Weight
Post by: quiktaco on January 14, 2008, 07:52:05 PM
I'm already 145lbs @ 5'10", so I'm going to pass on that personal diet, that is the best thing for anyone who's got a couple extra pounds on them though. :laugh:  Anyways, those are some great suggestions.  I've already ditched the CA Carb crap, and have a lunchbox filter.  That alone simplified things a ton, and lightened up probably about 2-3 pounds worth of useless junk.  Rear fender is gone as well.

I hadn't though of drilling the rear brake.  Think this would be best done with a drill press, and some very fine measurements to stay balanced.  Is there a replacement brake for the rear that's already drilled/lighter?

What areas could be cheese grated.  Seems like there's not too much unnecessary metal.  Guess I haven't looked deep enough.  Hey, maybe cutting up the battery box, just a thought.

Is there a lighter battery that anyone has used?  Stock's around 10 pounds or so, I bet there's a good one that's a few pounds lighter...maybe smaller as well.
Title: Re: Cutting Weight
Post by: Absolute Rescue on January 15, 2008, 06:29:32 AM
Get rid of the stock exhaust can, that thing weighs a ton. Probably shave 5 or 10lbs by switching to a ti or carbon fiber one.
Title: Re: Cutting Weight
Post by: ben2go on January 15, 2008, 12:16:18 PM
87-89 GSXR 750 aluminum swing arm.It's not much but every gram helps.Right?
Title: Re: Cutting Weight
Post by: dgyver on January 15, 2008, 01:45:23 PM
I have hacked a lot off of different GS's for track bikes. Keeping it street legal makes it less fun.

The heaviest single part is the motor, weighing in at 140#. Not a lot that can be done, but what can be removed is not cheap like boring for larger pistons and removing the counter balance shaft where the crank would need to be rebalanced.

You will need a carbide drill or milling bit to drill the hard rotor. There is someone on www.wera.com that will modify your rotors, similar to Wave rotors.

I have fitted a smaller battery for the track but it is not large enough to run on the street. There are some other type of batteries that could be used but not cheap.

The sprocket cover has a bunch of material to remove. One area Ken was referring to cheese grate. I cut a large section out of it, primarily allowing access to the sprocket without removing the cover.
http://img.photobucket.com/albums/v64/dgyver/GS500/91GS500sprocketcover01.jpg

Besides what has already be mentioned...

Remove passenger pegs and mounts.
Aluminum exhaust hanger.
Shorten subframe.
Replace handlebars with aluminum clip-ons.
Aluminum rear sprocket.
Replace gages with an electronic gage, like Veypor.
Replace rear brake torque bar with aluminum.

Title: Re: Cutting Weight
Post by: quiktaco on January 15, 2008, 02:25:11 PM
Awesome ideas Dgyver.  These types of things are what I was looking for.  Maybe not getting inside the engine, as that would probably end up getting really expensive, but everything else is good old sawsall and dremel fun.  Any other ideas?  I'll soon be tearing into my bike, and I'll add to this list if I come across some good stuff.
Title: Re: Cutting Weight
Post by: ohgood on January 15, 2008, 06:08:18 PM
Quote from: quiktaco on January 15, 2008, 02:25:11 PM
Awesome ideas Dgyver.  These types of things are what I was looking for.  Maybe not getting inside the engine, as that would probably end up getting really expensive, but everything else is good old sawsall and dremel fun.  Any other ideas?  I'll soon be tearing into my bike, and I'll add to this list if I come across some good stuff.

A lighter gs... Hmm... Money is no object, directly after the sawzall...

You could pull a mold from your gas tank, make the new one half the capacity, and out of carbon fiber, yourself and save prolly 20 pounds right there. Being liquid is generally 6 pounds per gallon (US).

or just buy an old cracked one from a racer and half-fill the tank...

^ that's the biggest weight savings I can think of...

Here are some more, practical or not:

Carbon Fiber Wheels for $3200 shipped:
(http://www.ram.mc/wheels/BST/gallery/MOAW.gif)

Titanium bolts, nuts, washers, axels, = 10 Lbs or so.
Carbon Fiber clutch cable = a few ounces.
Get a lighter helmet, it will make your ride more fun too.
Carbon fiber soled boots = couple pounds saved
Remove the glass and bucket from the headlight assembly, go with LED assemblies = pound or two
Starter = a few pounds, you don't need that anyway, it's just for shits and giggles
Mirrors = you're going to be so fast everything will be behind you, farrrr behind you (couple pounds)

there, even without the super secksay wheels I saved you (best guestimate) 35 lbs. No diet, no 'light' beer involved.
Title: Re: Cutting Weight
Post by: quiktaco on January 15, 2008, 06:13:03 PM
Great ideas!  Not for the thinned wallet, but all of those together would get the bike pretty light.  I'm wondering how light this bike could actually get if most of these suggestions were applied...another thing i thought of is a battery eliminator.   Usually used on kickstarted bikes, but if you don't mind bumpstarting your bike everywhere, then it's possible...very illegal though since lights don't work without the motor running.
Title: Re: Cutting Weight
Post by: gmingst on January 15, 2008, 06:42:54 PM
If you run lighter weight oil it will help.  30w is almost half the weight of a 50w oil so that would be almost a 50% savings in weight there.

Regards
Graham
Title: Re: Cutting Weight
Post by: ohgood on January 15, 2008, 06:54:55 PM
Quote from: gmingst on January 15, 2008, 06:42:54 PM
If you run lighter weight oil it will help.  30w is almost half the weight of a 50w oil so that would be almost a 50% savings in weight there.

Regards
Graham

You new here ? You know any time you mention oil it turns into a flamewar, right  ?

OK, just pulling your leg, in return for the pull you just gave ;)
Title: Re: Cutting Weight
Post by: ohgood on January 15, 2008, 07:07:46 PM
OK, last one, you could fill 1/2 the tank with triple expanding foam, and consider it a huge weight savings... and get this, it's only..................

$1750 shipped !
(http://www.oppracing.com/image.php?image=pr311_1.jpg)

Title: Re: Cutting Weight
Post by: Jay_wolf on January 15, 2008, 09:38:17 PM
how about... tie like 500 Heluim Balllons to the bike ,savings ... about 190 ibs!!
Title: Re: Cutting Weight
Post by: quiktaco on January 22, 2008, 10:10:08 AM
I can't believe I hadn't thought of that...let's see, about 200lbs less of about 400 plus my 150ish...that's only 350lbs total!  I could drag race the bike, and the drag from the balloons would act like a parachute, which I'll definitely need cause I'll be going so fast.

If anyone has ever bought that CF tank, them they are in dire need of some friends, cause they are trying way too hard.
Title: Re: Cutting Weight
Post by: dgyver on January 22, 2008, 10:23:05 AM
I modded a sprocket cover the other day and weighed what I cut off. It weight a little over 1/2 pound. Not a lot by itself but do that a dozen more times and will add up.

Title: Re: Cutting Weight
Post by: Jay_wolf on January 22, 2008, 04:01:17 PM
get Aerodynamic ballons.. u no , Shaped Like Razor Blades, and use them all on the front , so u dont need a Front end , and Another saving!!!! , hmm , How much do fingers weigh? ud need like 1 or 2 on each hand .

hair. ears... Nose... Lips. alot of Skin ,and if ur feeling brave , maybe a Leg? , u for sure dont need any toes !!!
Title: Re: Cutting Weight
Post by: The Antibody on January 22, 2008, 04:44:44 PM
Cool Jay. You could slightly angle them downward for some killer downforce too. Stick the turns.

But seriously. I realize this would add weight, but just stick a second motor in there. Who cares about weight then. You could have the fastest GS ever. Think about it. 80 or so horsepower at your fingertips. RAW POWER! 




What?.... There are bikes with only one engine that have that much?



Aww shaZam!.
Nevermind.

  -Anti  8)
Title: Re: Cutting Weight
Post by: Jay_wolf on January 22, 2008, 06:36:30 PM
80 BHP!!!

Man of the future, Please speak about these *80 bhp* Machines u speak off!
Title: Re: Cutting Weight
Post by: GeeP on January 23, 2008, 12:20:50 AM
Fill the tires with Helium.  No, better yet, Hydrogen.  That should reduce the unsprung weight what, .0001 lbs?   :icon_mrgreen:

Lightening holes is where it's at.  Go at your bike with some holesaws and report back.   :laugh:
Title: Re: Cutting Weight
Post by: galahs on January 23, 2008, 01:14:26 AM
Drill the centre out of all your bolts  :laugh:
Title: Re: Cutting Weight
Post by: Affschnozel on January 23, 2008, 01:34:25 AM
Eat a lot of beans for those short bursts of acceleration on overtakes  :icon_mrgreen:
Title: Re: Cutting Weight
Post by: dgyver on January 23, 2008, 04:51:00 AM
Quote from: galahs on January 23, 2008, 01:14:26 AM
Drill the centre out of all your bolts  :laugh:

The newer GSXR's have a lot of bolts done this way.
Title: Re: Cutting Weight
Post by: galahs on January 23, 2008, 05:24:06 AM
I know its a proven weight saving method... just its going to extremes.



What aero mods could be done to a GS to improve its racing ability.

Mods to the rear fender, cowling is often where good gains can be made. Where does the tradeoff between lightweight, and aerodynamics kick in. ie:

No cowling = less weight
no cowling may equal more drag
Title: Re: Cutting Weight
Post by: Affschnozel on January 23, 2008, 01:20:03 PM
Here is Moto Guzzi's infamous dustbin fairing ,the only one that will make GS go 150 mph ,no kidding....
(http://www.motosolvang.com/images_new/large/1955_Moto-Guzzi-V8.jpg)

They were banned from  '57 GP due to instability in crosswinds...so don't try this at home  :nono:     :icon_lol:
Title: Re: Cutting Weight
Post by: quiktaco on February 14, 2008, 04:22:28 PM
Not that it's a lot of weight, but I removed my chain guard, mirrors (replaced with bar end mirrors), and front fender.  All together maybe 1-2 pounds.  Not only less weight, but I love the more minimalist look of it without all that crap too.   Things are coming together...just thought I'd give an update to the other couple things I found.  Oh, and I got new bars, which are about 2 pound lighter.  They're superbike bars, but I also cut 1.25" off of each side to narrow them in a bit, and now got rid of the bar ends that added a bit of weight also.
Title: Re: Cutting Weight
Post by: quiktaco on February 14, 2008, 04:28:15 PM
Forgot to ask, but does anyone know of a way to get rid of the exhaust?  Let me expand on that.  I'd rather have a cut off pipe that just came out under the bike for looks and weight, but I like the more quite sound of having an exhaust.  Is there any way to have the best of both worlds?  I saw another thread about fitting an muffler under the frame that started right at the front of the engine, but I don't know if that would actually work.  Just wondering if anyone had any thoughts on this.
Title: Re: Cutting Weight
Post by: quiktaco on February 14, 2008, 04:45:49 PM
Here's that thread I was talking about.  http://gstwins.com/gsboard/index.php?topic=25596.0