GSXR K4 Swingarm Swap

[yoda]

Will the 600 brake discs fit up to the 750 brakes by the way? i get the impression its the same front end for both but havent looked up the specs

[El Gringo]

Its not a straight fit, the K3 discs are 200mm and the K4 are 298mm, so i need 10mm spacers under the calipers, but it's a quick fix.

Have a look here, http://old-skool-suzuki.proboards.com/thread/612/fork-conversion-chart

Lots of useful info

The K4/5 600 and 750 FE are the same discs but the K0-K3 and K6 onwards are different

[El Gringo]

So as it turns out, this swingarm swap is no where near as simple as i first thought......................

Got it all fitted up with the front end and wheels, but the linkage is no where close, the dogbones are almost horizontal which means theres absolutely no suspension travel, it's solid 

Here's where i'm at, you can just about see the issue with the linkage

On the plus side I think it looks awesome!











Also turns out i don't think i need the caliper spacers, they seems to fit ok at first glance

Will update when i've had a better look at it

[Catrocentos]

It's looking great.
 At the adaption will be difficult the bandit more special!
Keep it up, the end result will be great reward for good work.
Greetings from a fan.

[El Gringo]

Cheers Catrocentros,

Just ordered a k5 1000 rear linkage which should help (i hope)

Got a couple of funky ideas for the tank and i should have the tail unit back from being narrowed next week too.

[El Gringo]

Right a bit more of an update

Using a K5 1000 linkage, some FZR1000 dogbones and a bit of ingenuity i think were almost there

Removed the centre stand, and, using a long bolt all the way through and some spacers the linkage now fits in the middle of the stand brackets rather than the normal mount.



This should give it the required angle to compress the shock

Just need to make the shock longer to get the required angle of the dangle (so the brace doesn't hit the subframe)



I also got my tail unit back from being narrowed and made a start on thinning down the seat pad to match

[Unique]

Hi Chris
Looking good! Good work on the tail unit and seat.

Though I don't want to throw a spanner in the works at this point but are the centre stand mounts stronger enough to be used as a cushion lever mount as the two "stand brackets" were only decided for standing the bike on and not decided for the forces that the shock compression may put on them?... You may want to beef-up the mounts?

The normal mount is a lot heavy then the "stand brackets" mount even though they are two of them, can't look at mine as the "stand brackets" have been cut off my bike long time ago.

If you are putting the bike through our UK' M.O.T Test? Will the tester pass it?.   

Has the bolt got the right yield strength!

Sorry to be a downer? But Safety first!.

[El Gringo]

All valid points Unique

My thinking behind this, the thickness of the doubled up centre stand brackets is equal (if not slightly thicker) than the standard linkage mount. I may add some plating from the standard bracket down to the stand brackets just to be sure.

This mod is a common modification on Bandit 12s using the later type swingarm and whilst the mounts aren't quite the same as the 400 the weight is much much more. There are guys on the Bandit forum running them on track bikes with no issue.

On the subject of bolts, i did quite a lot of research on bolt grades and spoke to quite a few people regarding a suitable replacement. It is a very grey area, some people say absolutely no to stainless whilst others have used it with no bother.

I err'd on the side of caution and followed the advice of an engineer and race fabricator on another forum who suggested a High Tensile bolt would suit, so i went for an HT 12.9.

It is very difficult to tell what the standard bolts are and i've not been able to track down the markings on the Suzuki bolts.

On the subject of the MOT Tester, i know a very friendly one.......

He passes my GSXR1100 streetfighter and modded CBR400 with no problems.

But i agree, this sort of thing should not be done without careful consideration

Cheers

Chris

[Unique]

All valid points Unique

My thinking behind this, the thickness of the doubled up centre stand brackets is equal (if not slightly thicker) than the standard linkage mount. I may add some plating from the standard bracket down to the stand brackets just to be sure.

This mod is a common modification on Bandit 12s using the later type swingarm and whilst the mounts aren't quite the same as the 400 the weight is much much more. There are guys on the Bandit forum running them on track bikes with no issue.

On the subject of bolts, i did quite a lot of research on bolt grades and spoke to quite a few people regarding a suitable replacement. It is a very grey area, some people say absolutely no to stainless whilst others have used it with no bother.

I err'd on the side of caution and followed the advice of an engineer and race fabricator on another forum who suggested a High Tensile bolt would suit, so i went for an HT 12.9.

It is very difficult to tell what the standard bolts are and i've not been able to track down the markings on the Suzuki bolts.

On the subject of the MOT Tester, i know a very friendly one.......

He passes my GSXR1100 streetfighter and modded CBR400 with no problems.

But i agree, this sort of thing should not be done without careful consideration

Cheers

Chris

Hi Chris
Sounds Good, Looks like you'll done your research, and sounds like you are knowledgeable about such matters.

Just wanted to make sure you had used careful consideration and bring it to everyone's attention who may do a similar mod.
Also handy to know a very friendly MOT Tester, 

Derek

[El Gringo]

Cheers Derek,

Its a good point, without research these things could certainly be dangerous (even with if your not careful!)

I should also own up, i have got a bit of previous practice on these things.

My GSXR1216 and Z400 were both in Streetfighters magazine





And at the streetfighters show in London 2011





I've also built a pre65 BSA trials bike, my NC23 and various other streetfighters

[Unique]

You must have read my mind Chris! I was thinking send some photos of your past builds!!! Man after my own hart, great builds, that's what bikes were made for.

Something I like to do more of... if I every finish the b4

 Cheers for the photos, Derek  

[El Gringo]

Thanks Derek

Another bit of an update, managed to get the shock extender marked, drilled and fitted last night.

Despite the angles and so on being a bit of guess work we now have functional rear suspension, quite stiff but  i need to set the static sag yet.

Also it's ended up with the back being way high, so some slightly longer dogbones may be in order - although i can't drop the back to far as i want to maintain the gap between the swingarm brace and the subframe.

Also definitely going to need to machine some swingarm extensions, it's really a very short wheelbase now and looks very ood.

[El Gringo]

Hi All

Update to follow shortly, i have been working on this a little bit but its slow progress

Front end now has calipers and mudguard and later today i should be picking up my new top yoke from the guy who does my accurate machining, so i can start on the bars and electrical gubbins

Swingarm is now finished other than a couple of little things

Had a change of plan on the seat unit - the mito one just didn't look right. Have been working on the seat and side panels

[El Gringo]

A mate of mine has machined me up a new top yoke to suit the GSXR750 front end

I didn't get any pictures of it fitted as it was dark









Hopefully i'll be able to pick up the pace now and make some head way on the rest of the fabrication bits i need to do, undertray, side rails, seat trims etc

[yoda]

Oooh shiny! Very nice, those sort of things mark out a bike as different. I like your previous builds too, that Z400 has a nice stance about it