SRad and later K series Swing arms into Slabby

[markfoggy]

Ok, I'll admit that this should really be in the Water Boiler section, but still the same general architecture, so I'll stick to the busier part of the site.

Now this comes up due to investment in a frame that comes with a logbook, which seemed like a good idea for later down the line, seems that I've strayed into later swing arm spindle sizes by mistake, so am thinking, kill several birds with one stone, so am looking at tunnel style swingers and plate style linkages.

Now doing some quality fabrication and getting a grown up to do the Electric Glue to a high standard is not an issue. I'd also have no issue with messing around with the Geometry to get everything working beautifully. I'm just interested in the potential pit falls. The rear frame spreader that holds the knuckle and engine mounts on all Slabbies is a fairly substantial piece of kit, so sticking stresses into it from different directions does not look too fraught with danger, but....

Ok Guy's what do we know?

 

[boilerdude]

I'm no expert. But I reckon I would think about grinding stuff to fit rather than tweaking the frame.

[markfoggy]

Sorry I've not explained myself very well and am in danger of making myself look a right Twunt, mainly because I had forgotten how the linkages worked on SRads and then got confused between K series GSXR and the later L series.

Ok, I'm set up to use a WP arm, but wanted to move to the overbraced WR and later swinger. The trouble is finding one, so I started to look at later arms.

Now the plan is to weld a new suspension linkage mount point underneath the current rear spreader section and delete the current rear linkage mount.

Now my initial thought was, this should be relatively simple and I can modify the geometry by changing the location of this point and fabricating flat triangle plates to control the actual suspension rate. I own a copy of Tony Foale's geometry modelling software, so no biggy. Trouble here is that triangle plates only go for L series suspension i.e. this decade and going this route would  mean me having to buy a new shock with a roller bearing in the lower eye, can't use the shackle that I have got. :Face Palm: emoji

http://www.partzilla.com/parts/search/Suzuki/Motorcycle/2011/GSX-R750L1/REAR+CUSHION+LEVER/parts.html

Next up is K series, Which should be doable, but I would have little control over the geometry. 

http://www.partzilla.com/parts/search/Suzuki/Motorcycle/2006/GSX-R750/REAR+CUSHION+LEVER/parts.html

The trouble that I can see above is that getting it to work well would need a new wishbone or a pair of adjustable dog bones with a rose joint at each end. Now fabricating a new wishbone is a welding job, so getting needle rollers to work would be very complicated and time consuming. Doing it on rose joints would probably work for a while, but in truth it's a bodge and I cannot see how I could install needle rollers at the chassis mount, even more complicated than fabing a wishbone.

So then I'm left with Srad/Busa/early K1000, trouble is that I really dislike the look of the arms.

http://www.partzilla.com/parts/search/Suzuki/Motorcycle/1998/GSX-R750X/REAR+CUSHION+LEVER+(MODEL+W-X)/parts.html

Anybody got any inspiration that I can draw on?

 

 

 

 

Edited December 24, 2016 by markfoggy
Clarity.

[markfoggy]

Oh, just to add, Fooked if I'm building a bell crank from scratch to give the suspension control that I want. 

Bell crank = Knuckle in another language, it might be possible, but fabrication as a welded component would require serious accurate jig work and CNC out of billet would be even more expensive. It's all about time.

[Gsxrsam]

You can buy an adaptor to use modern stuff........ Danm54 i believe it was......

 

[Rossco(Iceman Josros)]

6 hours ago, Gsxrsam said:

You can buy an adaptor to use modern stuff........ Danm54 i believe it was......

 

I thought this was for the Slingshot frames .......... but if it's not I'm interested 

[Jaydee]

3 hours ago, Rossco(Iceman Josros) said:

I thought this was for the Slingshot frames

Correct. 

[Jdeac1981]

Have a look at my latest post in forsale section. Arm is original 750/1100 arm that has been top braced. Just something to think about. Custom But it is a slingy arm. Must be easier 

Edited December 27, 2016 by Jdeac1981

[markfoggy]

Well that is very pretty, I will think about it.

I suspect though that a little lateral thinking is about to get me in very deep shit.

[clivegto]

Top shock mount from a scrap frame to lower bottom mount this was for a r1 arm.

[clivegto]

[markfoggy]

As I thought, going under the rear spreader makes a lot of sense.

Liking the Use of angle to make a top shock mount.