F650GS (single) Swing arm swap ideas

[Gangplank]

So reading through the F650GS fork swap thread... and after trading my F800GS for a F650GS and a bundle of cash I got to thinking...

What is the chance that there is a swing arm out there that could replace the F650GS steel (read heavy Mo-Fo) swing arm with an aluminium swing arm off a dirt bile and then using either the Dakar shock or some other bike's shock as a replacement

Ideas, thoughts, concepts....

And don't tell me I'll shoot my eye out. It either can or can't be done.

[Gangplank]

I'm planning to take the F650GS down to a buddy's shop and take some measurements. From there we'll figure out what older swing arm might fit and do some weighing.

Thoughts on why and what - the stock F650GS is a fat biotch. You can lose some weight by taking off or swapping out some things.

Front End Swap = ~15 lbs
ABS Pump = 4-8 lbs
Swap Exhaust = 6-8 lbs

That is 25+ lbs right there. How much do ya think could be gained by this?

[Aquatic]

Here is the swing arm

https://www.dropbox.com/s/bt4rv9rt1o...WING%20ARM.PDF

If anyone wants any more details, let me know.

[Gangplank]

Well now that's cool!!



Why do you have a CAD of the swingarm?

Next step is to compare those measurements to various replacement options & especially ones that are readily available?

And then its what shock would fit & have an 18" wheel built if needed.

[TobyG]

You could always try and find one of the infamous Touratech aluminium swingarms. You know, the ones they offered to refund your money on if you sent them back, after they broke a couple in the Dakar 2002. They didn't sell many of those, in the first place.
I am only aware of 5 of those still out there, so assume that there's a dozen or two of them still in existance.

Not that you'll find one...

These are extremely light, however. And they look way cool.

Other than that, you could contact a company building custom swingarms (Krueger and Junginger in example).

[Aquatic]

Originally Posted by Gangplank

Well now that's cool!! Why do you have a CAD of the swingarm?

Next step is to compare those measurements to various replacement options & especially ones that are readily available?

And then its what shock would fit & have an 18" wheel built if needed.

For this very reason. Done a bit of research. You can cut the weight by roughly 30% if you build the exact same swing arm out of chromoly. The added strength means you can use a thinner section. But forming it is lot harder.

[Gangplank]

Originally Posted by Aquatic

For this very reason. Done a bit of research. You can cut the weight by roughly 30% if you build the exact same swing arm out of chromoly. The added strength means you can use a thinner section. But forming it is lot harder.

I'm hoping to rind a replacement that I can use.

The shock is going to be tricky but stranger things have fit other bikes in this world. Sportbikes do all sorts of swaps that work for race bikes, etc.


From the Forks Conversion Thread:

Originally Posted by LoJack

It's about 13 pounds. What does your average 600cc Alu swing arm weigh?

I looked for a while for a replacement and think that an ATK swingarm might fit, but don't know for sure. I wasn't able to find one for a while and then sort of left it. Most are too narrow for the Dakar's Rotax. I'd still be interested in replacing it if I knew what to look for. Maybe you just need to find a motorcycle salvage yard and bring some measuring tools.

Hmmm... Seems the stock swing arm should weight more than 13 lbs no?

[LoJack]

Originally Posted by Gangplank

Hmmm... Seems the stock swing arm should weight more than 13 lbs no?

I'm almost positive that's what it is. I remember thinking if I could find/build something that weighed 8 lbs I'd save 5 lbs. After a while, I decided it would be easier and cheaper to find something....

I could be wrong on though because it was over about a year ago, but it's certainly no more than 15 lbs.

[Gangplank]

Don't supposed anyone knows where to get the measurements for other swingarms?

Looking at some from ATK?
G650X Challenge?
Any other suggestions

[LoJack]

I was contacting people that had stuff on ebay. Some never responded, but others were happy to send measurements.

G650XChallenge swing arms have an asymmetrical pivot. The left side is outside the frame. Maybe it'll work, but I don't know.

[Gangplank]

I asked someone on Fleabay and the stock unit weighs 15.85 lbs so about 16. Wonder what a regular dirtbike swingarm weights?

[TobyG]

No idea, however, the Touratech Aluminium one weighs 8.8 pounds. The front part is cast aluminium, the rear part is aluminium profiles.
The reason they made this swingarm in the first place is, aside from saving weight, having full chain adjustability using an 18" rear and gaining 30 additional mm of rear travel (280 mm, you could only get 250 with the stock swingarm).

[Aquatic]

Originally Posted by TobyG

No idea, however, the Touratech Aluminium one weighs 8.8 pounds. The front part is cast aluminium, the rear part is aluminium profiles.
The reason they made this swingarm in the first place is, aside from saving weight, having full chain adjustability using an 18" rear and gaining 30 additional mm of rear travel (280 mm, you could only get 250 with the stock swingarm).

Do you have that as a 3D model or only pictures?

[LoJack]

Originally Posted by Gangplank

I asked someone on Fleabay and the stock unit weighs 15.85 lbs so about 16. Wonder what a regular dirtbike swingarm weights?

Gotcha,

[TobyG]

Originally Posted by Aquatic

Do you have that as a 3D model or only pictures?

I only got those 3 rendered files and real-life pictures.
If you want to see anything in particular, I can check if I got a pic or I can take one the next time I get a chance.