Love the bike. I have Yosh pipes and a big new airbox (name I have forgotten...the one listed on the forum and recommended) and the motor now rips.
The suspension has the rebound completely turned all the way up if I am saying that correctly. The bike is still too jolty and the rebound from going over a bump
in the road is harsh.

What are the best suspension mods to improve the ride for very fast street riding?

I rode a 2012 Suzuki 600 and the suspension was spectacular and stock...made the KTM feel
skittish and jolty by comparison.

With a good suspension set up the KTM would handle much better as it would be much more confidence
inspiring

Did you try going back to the stock suspension settings and start adjusting to your liking?

I know the settings have been posted here before. Or I could go to the owners manual and look.

Best of luck,

I'd say go back to stock, ride a lap of your favorite road, record what's wrong, make a single adjustment, ride again, compare, repeat.

I am not a suspension expert but would rate myself as a very good street rider. It's rare I find anyone who I can't keep up with.
The problem is the bike is jittery and going over bumps is unsettling the bike too much.
My understanding is this is rebound. That the suspension after compressing from a bump rebounds too quickly.

A very experienced rider and suspension expert turned the rebound all the way up on the forks and shock.

This helped a little...but not enough to feel comfortable pushing the bike super hard.

What is typical of what people have done?

I wrote down my settings the PO used and then tuned it back to stock per the manual. I then used the Sport Rider Mag recommended settings and which work well and then tweaked it from there. Every time I make a change I write it in an excel spreadsheet (anal like that) and make a note of what I liked or didn't. I have it really dialed in now. I do the same with all of our off road race and play bikes. Also, you didn't mention your weight or what springs you have

This is from Sport Rider:


KTM Manual Settings:

You don't mention whether you are talking about the front or the back feeling. On the back, in all the years I've been bothered with suspension, (which is not that long because in the old days you had preload and that was it

PS. One time I took my '07 SD to Paul at what was still Bracken's in South London for a check over and service. When I picked it up Paul took me aside and said that my bike was the best handling, sweetest ride SD he had ever ridden. And he had ridden quite a few I'm sure. Guess what? That bike was running on totally standard OE suspension on the bog standard settings that were from the manual for road riding.

Since then I have fitted a set of Black nitrite SDR forks, run an SDR back spring and now have a Wilburs back shock that I haven't yet set up properly. And I suspect that seven years after my trip to Paul is still doesn't handle as well as it did back then!

Since getting my SD a couple of weeks ago the only thing that's really bothered me is the suspension - it doesn't have the sublime suppleness of the demo bikes I've ridden in the past (and the SD's ability to smooth out roads that made my ZX-10R behave like a rodeo bull was one of the major pull factors in making me want one). I backed off the compression damping to the comfort settings listed in the manuel and it made barely any difference. My rear spring is marked with 170-185 - does this mean any thing to anyone, is it the spring from a SDR? I'll get the forks out and replace the oil, maybe they have too much in, and I'll see if can identify the springs - is there anything on them to say what the rate or part number is?
Thanks in advance for any help.

I'm pretty sure 170/185 is the standard SD spring, I've got a 2007 SDR that has a 180/85. I changed the oil in my forks for much the same reasons as you, the forks felt like a set of girders!. Bearing in mind the forks and shock on my bike may be different to yours, at the moment my suspension settings are ..

Front
Preload - 5 turns out (gives 27mm sag with rider)
Comp fully out (33/34 clicks out)
Rebound 2 clicks out

Rear
Preload - 18mm thread showing (gives 26mm sag with rider)
Low speed comp 12 clicks out
High speed comp fully out (3 turns)
Rebound 10 clicks out

This topic interests me as well; I have the same issues. The settings posted are a great help; what are the recommended sag values, or are we just going with the listed preload settings? edit...ahhh, I see Dickie's sag comments now..