Part 5 – the Swingarm debacle #1
So, with a frame, yokes, forks and even wheels already sorted, or on their way to being sorted, I just needed a swingarm to make this project roll.
I’m often excitable, responding to “good ideas” with impulsive action. I have thus shopped my way into, and out of and then back into a swinging arm cul-de-sac. It’s still not sorted. I’m currently on swingarm idea #6.
Swingarm #1. GSX1100 Katana
The stock Kat arm is not only weedy, but ugly. Get rid, replace. At least that was the original idea…(see Swingarm #5…)
Swingarm #2. GSXR750 Slabside
After planning to use a Slabside arm (one of which I borrowed from Grumpy1260 to offer up), upon a closer look I realised I just didn’t like it. It was wider across the pivot than needed too – to me, that’s a heavy modification. So, I started over and looked for…
Swingarm #3. GS1200SS
I hastily bought a very rare twin-shock swing arm from a Suzuki GS1200SS. The SS is a sexy bit of 80’s endurance-styled kit, which has never been officially imported into Europe. A twin shock arm = a quick fit (in theory).
Because (in my head) the SS was a 1200 Bandit based model, and I know a Bandit arm into a Katana is a simple fit, I thought I was doing a marvellously clever thing by purchasing this very rare item immediately I saw it on eBay.
Well, here’s the bad news. Once it arrived it took 3 minutes with a ruler to work out it didn’t fit (actually it took 10 seconds; the last 2 minutes and 50 seconds were spent in denial) Turns out the SS wasn’t based on a 1200 Bandit, instead, it’s roots are in a Japan only model called the Inazuma. This has a swingarm pivot wider than the deck of most aircraft carriers. Result? For Sale; Clean GS1200SS Swingarm £85 inc. post. (still for sale as of 16 May 2014!)
Swingarm #4. 1200 Bandit
Sometimes following a tried and trusted route is just what is needed. Within hours of realising I’d messed up, I made good by removing a 1200 Bandit arm from the several thousand tonnes of Suzuki spares you’ll find at Grumpy1260. Fortuitously they also had some custom made top hat spacers needed to sleeve down the Bandit arm’s pivot to work with the narrower Katana Spindle. Ace.
The Bandit arm is chunky, and fits straight in with the top-hat spacers, it does need the twin-shock mounts welded on and needs the big lump of residual Aluminium from the monoshock mount taken off.
Why then do I no longer love the Bandit arm enough to push on with using it? Even I’m struggling with that one.
Swingarm #5 (Don’t get excited…it’s the same as #1).
In my first proper dry build of the frame I used the original Katana arm to simply start looking at the shock lengths needed. You know what happened then? All the grief of “welding this, removing that, space this out” left my head. Calm befell me. I liked the feeling so much I thought – why don’t I just use this? Brace it, if I really want more strength, job done. Simple.
Well, not that simple. I’m writing this just the day after the Katana arm arrived back in my head as a viable choice. Already I have laboured through hours of indecision and internet-bothering to discover that twin-shock XJR400 swingarms (Swingarm #6) are nigh-on a straight fit (and that’s proven – someone else in Japan has already done the measuring and fitted one!)
Some day soon, I hope to write something that says I have chosen and fitted a swingarm. If that doesn’t happen, please someone, stop me from buying any more to try, and make me actually fit something.
Hi – looking for info on a GS1200SS and BLAM! here I am (thanks Google)!!!
Just wondering if you still have the swingarm handy and if you can kindly help measure some dimensions? Pivot width, length, shock mount distance from pivot…etc.? Thanks!!
Phil
Hi Phil,
I do have the arm, and here are the dimensions you need, and also some you may need that you didn’t ask for…
Front pivot width excluding cups – 232mm with cups 237mm
Front spindle diameter 20mm, rear spindle run measures 20.7mm so I guess that’s a 20mm spindle too.
Front spindle centre to beginning rear spindle run 540mm (meaning 550mm between spindle centres at minimum chain adjustment)
length of rear spindle adjustment run 45mm (25mm usable adjustment)
Width between shock mounts = 270mm at narrowest point
Width in-between arms measured at rear spindle = 260mm
Width between outside faces of arms measured at rear spindle = 332mm
Distance of shock mount (at the perpendicular) on a line drawn between front and rear spindle centres 485mm
Distance of shock mount hole centre above that same line between spindle centres 65mm (this is important when working out shock length – ask me how I know…!!)
Hope that helps!
PB