Thanks Kyle and Tyler. I guess we are hovering in the right direction since our attempts have included just about everything mentioned with the exception of struts and a soft seat.
Interestingly, we saw a lot of 206 karts setup in ways that were counterintuitive to traditional (2-stroke) setups this year trying to manage the softer tire, including the use of old tires.
For the AM29 I’ve been told if you run the front bar you almost have to run the seat struts for the optimal setup.
No bar with no struts is a great setup for hard tires or medium tires. My club runs Lecont reds and I ran well no bar, no struts. Although the driver one spot in front of me in points ran the bar and struts and also ran well.
Soft I’d give the stiffest bar and struts a try.
I just got an AM-29 and I am running it in our light 206 class at 340 lbs on SH2s. I have found that:
I have spent a few practice days now just honing my driving style to accommodate this before starting to make chassis adjustments.
My first step was to reduce the front track width to tame the oversteer on entry, which has worked. I next started narrowing to reduce oversteer. I think I have the widths close to where I want them and the balance is improving.
I had the chance to swap karts for a few sessions with some very good drivers, who both had the same feedback - twitchy steering and rear instability.
My next planned change is to reduce Ackerman (on the column first, then the spindle if needed) to reduce the twitchiness. Am I on the right track here? Has anyone else experienced this on this chassis?
what pills are you guys running on the comet eagle?
We usually ran 3 dots top and bottom, caster out.
Can you take caster out or increase negative camber? Both would be my next steps to remove twitchiness from the front. The added benefit is the negative camber will help the kart roll more freely on exit.
I am at the most negative camber (1.5 boxes) and minimum caster I can get out of the stock pills.
I have higher offset pills that I can try, would you recommend I start there or test the Ackerman first?
Weird questions: How tall are you and what seat are you using?
I’m 5’10" 160 lbs, using the Tillet T11VG (very soft) seat
Seem reasonable. I’ll leave any help from here to the Birel experts.
Not a birel expert by any means but I was shocked how twitchy and front positive it was when I drove an Am-29. I think the Ackermann is a good idea. Also what is your rear like. The wheelbase and chassis height adjustments make a big difference in my experience with that kart. Of course front bar and seat struts are a must on that chassis too but assuming you have those.
Thanks, I have the bar and struts in. I am in the middle on wheelbase and high on the ride height in the rear. Width is at 131.5cm.
Are you looking to change Ackermann or steering rate? Sometimes people swap the two terms around and personally steering rate would be the next thing I’d consider.
I’m not sure, I just want the front end to calm down. My plan was to go up on the steering column (this reduces the rate?) and if I need more, move the tie rod mounts on the spindle to the hole closest to the center (actual Ackermann, right?).
You got it. 
I would try steering rate first because it doesn’t affect the handle so much as it affects the driver feel. The Ackermann will probably help too but is more of a handling change.
It is interesting to hear from others that this twitchiness is something inherent to the chassis - this is such a common chassis, I have no idea why it would be set up like this out of the box. I swapped with two drivers, one of them struggled to keep it out of the barriers, let alone set a decent time.
Wouldn’t he need to go less on the negative camber? Getting the spindle flatter to the ground will decrease the jacking effect for a given caster since even “low” caster is pretty dramatic.
I find negative to reduce the contact patch and reduce how heavy the front end is.
Right, but if it is twitchy on entry and he’s trying to pull out caster, going negative on camber will fight him. Less contact patch also means you need more input to get it to turn and then all of a sudden the extra camber will bight. Flattening the tire will take less input to initiate the turn and jacks the rear less.
I don’t like any of this tuning advice.
Slam the front and rear low and put the caster back in.