Reducing the weight on the GS 500

[the_knudman]

Hey all

I am thinking of buying a GS again after not having one for 2-3 years. I am now riding a 100 bhp Yamaha, but there is just something about that GS i used to have, that I can't let go.
I think it was the nimbleness of the bike i can't let go of.

Anyway, I'm thinking about making a GS project, taking a GS, change the suspension front and rear with that of a RGV 250, and do everything possible to get the weight down. After that the engine will undergo some tuning. I'm thinking: K&N clamp ons, race can, race camshafts etc.

What I want to know, is how much can the weight be reduced to, so I can set a realistic goal to myself. To begin with engine weight reduction will not be considered.
So, how low can you get it? 140 kg? (290 pounds?)

I think 140 kg is plausible, if you swap all the fairing parts with a single layer race fairing parts, use lighter suspension components, remove the backseat, install smaller battery, lighter tank, remove the dashboard, install race can system, remove rear footpegs, swap the front footpegs etc...
Basically building a purebred racebike with front- and rearlights, so it is approved for the road.


Am i nuts? Or is it possible?
How much do the racebikes viewable in the hall of fame weigh?

Greetings
Christian

[Church6360]

don't forget to ditch the counterbalancer. need to get stuff rebalanced, but that is a way to drop weight and rotational mass in the engine.

[BUZZIN]

I'd ditch the steel chassis and go with aluminum.  Then you could go with a steeper fork rake, so she'll really steer quickly.

[94suzuki500]

don't forget to ditch the counterbalancer. need to get stuff rebalanced, but that is a way to drop weight and rotational mass in the engine.

The counter balancer is there for a reason, just like wheel weights.  But on another note, i would try putting a 2 stroke engine in the gs. That would be real awesome and the pipes would look really cool.  And it would weigh less too i think.

[RVertigo]

try putting a 2 stroke engine in the gs.

Then you could find your way home by scent!

[94suzuki500]

haha ya, they sure are all smelly, and I think they are higher maintenance, but it sure would be cool.  I have a wicked plan for a project bike but I dont have much money to do that, and I would rather ride than work the whole time and not have money.  Why doesnt it just grow on trees?

[RVertigo]

Why doesnt it just grow on trees?

It doesn't?  

I'd better take that Ferrari back then!

[Church6360]

94suzuki500 Posted: Fri Jun 10, 2005 5:07 pm    Post subject:  

Church6360 wrote:
don't forget to ditch the counterbalancer. need to get stuff rebalanced, but that is a way to drop weight and rotational mass in the engine.

The counter balancer is there for a reason, just like wheel weights. But on another note, i would try putting a 2 stroke engine in the gs. That would be real awesome and the pipes would look really cool. And it would weigh less too i think.

you would need to get the bottom end rebalanced, but if max power and min weight are your goals, it seems ok.

but yeah, a wicked two stroke would be awesome.

[werase643]

320-330 is more realistic goal
but you will be seriously pissin up a rope to get there

[John Bates]

Try these BlackStone Wheels.  Weigh 2.2Kg (less than 5 lb.)

[Roadstergal]

Try these BlackStone Wheels.  Weigh 2.2Kg (less than 5 lb.)

Better watch the potholes - CF doesn't bend, it shatters.  Surely there must be some forged rims that are lighter than stock?  I know, stop calling me Shirley...

[werase643]

they do make lighter wheels that fit the GS
one problem
they are worth(cost) more than the rest of the bike


hi Shirley

[the_knudman]

Hey again

I would like to keep the frame of the original GS due to regulations i Denmark, where I live. Cornerning the steeper fork rake, you can always just buy new dog bones (or make them your self) and lower the front - this will also improve the handling.

Concerning the engine, removing the counterbalance and having the engine rebalanced is an option, but not somthing I will do before other things have been seen to. I think the money is better spend on a head from a GS 450, which has 4 valves pr cylinder.
I do not want to mount a 2-stroke in the GS because of the higher maintenance, the smell and because i like 4-strokes better. Otherwise, why not just buy a RGV or RS 250....

I'm hoping the wheels on the RGV 250 are ligther than on the GS, as I am planning to use them instead of the stock wheels.
Magnesium wheels are not concidered due to the high price.

When it comes to weigth I have a friend who runs a GS for some sidewagon speedway thing. With no brakes and no suspension in the rear and all things except the strictly essentials left, he reduced the weigth of his GS to 102 kg ! (225 pounds!). This is extreme, I know, and I would never go for no suspension in the rear or no brakes.
Brakes add about 20 kg (45 pounds), suspension 6 kg (15 pounds) and then ligths about 2 kg (4,5 pounds) if you find the rigth ones. That brings us to 130 kg (287 pounds). And then some odd bits and parts would bring it up to 140 kg (310 pounds). Maybe a few kilos more.
The 290 pounds mentioned earlier was a mistake from my part (or the calculator....).

cheers
Chris

[mjm]

.... I think the money is better spend on a head from a GS 450, which has 4 valves pr cylinder.....
cheers
Chris

Can you give some more information on a GS45o with 4 valve heads?  My 1980 GS450 was a two valve ancestor of the GS500 - or did you mean highly modified heads from an air/oil cooled GS750?

[werase643]

you will have to weld up the ex ports and relocate them inboard to clear the frame rails.

there is a GS400 that was imported to canada / europe that had the 8 valve head
had one
sold it to guy with a 450....easier than all that welding/machining

[scratch]

Chop the subframe and seat and make it look like this:

[Faxxxy]

try putting a 2 stroke engine in the gs.

Then you could find your way home by scent!

You can charge the city for fogging for mosquitos..

[Faxxxy]

Stop picking up fat chicks..