1100k handling upgrades

[Mackk]

Hey guys, wondering if there is a go to set up for the killer K?  Il be riding it on the street only.  I'm planning on having the bike down to the frame and built back up. My plan is to keep it stockish looking, but certainly upgrade braking and handling. A few questions...

1. Is keeping the original swingarm the way to go with upgraded suspension and tires? With it being shorter than the rest it should turn in and out better..no?

2.  89 came with a 160 rear tire, than they widened it in 1990 along with longer swinger...I assume that was for high speeed stability.....obviously tires have come a long way since 89, I would assume the 160 allows for better handling.....but I don't wanna be getting wobbles at high speed either, so considering upgraded suspension and modern tires what size is better.

3. My thought on suspension was to rebuild the forks with new internals to keep the stockish look and upgrade the rear shock. Will this be enough improvement for the street?  Reccomendations on shock and fork internals ?

Any other thoughts regarding suspension and handling very welcome.

 

Cheers

[dupersunc]

I run a 750m with an 1100l motor, used mostly for road with 5-6 track days a year.  It's got 10mm shorter dog bones which raise the rear 20-25mm, a Wp rear shock with a stiffer 500lb rear spring. At the front I run stiffer .95Nmm springs, with stock, rebuilt internals. Tyre wise I run 180/60 on a 5.5 rim, and 120/70 front. It handles a treat on track, but the front springs are a bit stiff for road use.

For road I would go with a 180/55 rear, as the 180/60 is a race tyre profile, and maybe .85 front springs, along with the other mods she'll handle a treat.  Modern tyres make a huge difference to these bikes, and they're as stable as you like, even with some quite extreme geometry you don't needed a steering damper. Sort the brakes too, rebuilt calipers and decent pads, with a good aftermarket mastercylinder are definitley worth while upgrades.

[Oilyspanner]

As per DS - reworked forks, decent  quality rear shock and front/rear set-up , plus tyres makes a huge difference - you can use the bike genuinely hard with no worries. Losing the heavy standard system makes a big difference too, you really notice the drop in weight, I liked the look of the standard twin silencers, but I'd miss the lack of lard and extra urge if I changed back. A well set-up Slingshot is great fun to ride, still takes more effort to hustle than modern stuff, but I bet you'll have a bigger grin after a ride.

Nice bike btw !

[Mackk]

3 hours ago, dupersunc said:

I run a 750m with an 1100l motor, used mostly for road with 5-6 track days a year.  It's got 10mm shorter dog bones which raise the rear 20-25mm, a Wp rear shock with a stiffer 500lb rear spring. At the front I run stiffer .95Nmm springs, with stock, rebuilt internals. Tyre wise I run 180/60 on a 5.5 rim, and 120/70 front. It handles a treat on track, but the front springs are a bit stiff for road use.

For road I would go with a 180/55 rear, as the 180/60 is a race tyre profile, and maybe .85 front springs, along with the other mods she'll handle a treat.  Modern tyres make a huge difference to these bikes, and they're as stable as you like, even with some quite extreme geometry you don't needed a steering damper. Sort the brakes too, rebuilt calipers and decent pads, with a good aftermarket mastercylinder are definitley worth while upgrades.

Thanks for the detailed answer, il definately be upgrading brakes as well!

 

Cheers

[Mackk]

1 hour ago, Oilyspanner said:

As per DS - reworked forks, decent  quality rear shock and front/rear set-up , plus tyres makes a huge difference - you can use the bike genuinely hard with no worries. Losing the heavy standard system makes a big difference too, you really notice the drop in weight, I liked the look of the standard twin silencers, but I'd miss the lack of lard and extra urge if I changed back. A well set-up Slingshot is great fun to ride, still takes more effort to hustle than modern stuff, but I bet you'll have a bigger grin after a ride.

Nice bike btw !

Thanks for the info, i will definately be switching the stock system out. Good to know about stability......with all the hype about the "killer k" from back in the day....the shorter swingarm had me a little concerned.

Cheers

[crashtester]

I have the same model. I have an Ohlins rear shock and the forks have upgraded springs and Racetec gold valves. Swapped out the rear wheel for a 5.5 inch one. No stability problems on modern tyres. With braided brake lines the standard brakes are adequate for street riding.

[Mackk]

39 minutes ago, crashtester said:

 I have the same model. I have an Ohlins rear shock and the forks have upgraded springs and Racetec gold valves. Swapped out the rear wheel for a 5.5 inch one. No stability problems on modern tyres. With braided brake lines the standard brakes are adequate for street riding.

Cool....are u running a 180 tire?   If you are how's the handling compare to the 160? I'm more about corners than top end speed.....Sweet bike man! 

 

Cheers

 

 

Edited October 17, 2016 by Mackk

[crashtester]

Yes, running a 180. Can't give you a direct comparison with a 160 as I upgraded the suspension and swapped the wheel at the same time. The combined changes were a massive improvement. If you source a 5.5 rear wheel for it you will also need the corresponding cush drive for the chain to clear the tyre, as the one on the K is a little narrower. Also get the torque rod arm as the K one will rub on the tyre, although I think some people just bend it to clear. The wider wheel will put the chain alignment out by 3.7mm (I think I am remembering that correctly), which you can get away with or get an offset front sprocket made. Also, the 180 tyre won't fit inside the hugger.

[dupersunc]

2 hours ago, crashtester said:

Yes, running a 180. Can't give you a direct comparison with a 160 as I upgraded the suspension and swapped the wheel at the same time. The combined changes were a massive improvement. If you source a 5.5 rear wheel for it you will also need the corresponding cush drive for the chain to clear the tyre, as the one on the K is a little narrower. Also get the torque rod arm as the K one will rub on the tyre, although I think some people just bend it to clear. The wider wheel will put the chain alignment out by 3.7mm (I think I am remembering that correctly), which you can get away with or get an offset front sprocket made. Also, the 180 tyre won't fit inside the hugger.

The 5.5 rear wheel has a completely different sprocket carrier to the narrower wheel, so you'll definitely need that, the sprocket is different too.

[Oilyspanner]

One other thing you'll notice once the suspension is sorted, is that you can trail brake into corners without the bike standing up and wanting to head in some other direction - my bike did this when I first picked it up, not nice at all - at least it made my mind up to buy a Nitron shock and rework the forks almost straight away. It's worth spending a little money to get things right, our bikes tend to be keepers, my N is as much a part of me now as one of my legs !

I think the K's 1 inch shorter swingarm only makes the bike slightly more wheelie prone, it will steer slightly quicker too - stability is still good, it's not really very short and the modern front ends have much sharper geometry, plus our bikes carry more twitch absorbing weight.