SX2 understeer - best tyres for astro?

[Cardnim]

Hi guys,

Im having loads of understeer when racing on astro. I normally race on clay/(mud!) and its fine there.

Ive tried laods of different set up sheets from here and Petit but cant seem to eliminate it (or even make it better!) and no one races the same car as me over here, so cant ask someone else.

Im thinking its tyres - as Ive only ever run mini-spikes or dBoots Terrabyte.
The terrabytes seem to make it worse!

What tyres should I be going for?
Ive seen a couple of guys racing staggered ribs on a 4wd wheel with no inserts. Would this work?

Sorry for the dumb question, but Im a bit stumped.

...oh, and Im pants at driving, so that probably doesnt help!

[jim76]

schumacher yellow minispikes in dry, and green in the wet.

if the astro is very grippy and you are suffering grip roll, then staggered ribs can help with this as they bite less than minispikes.

are you sure everything is ok with the car, diffs not loose etc?

[Cardnim]

Cheers for the advice Jim.
If Im honest, I would have to say that I just dont know if the diffs are too loose.

I have followed the manual to the letter (i.e. tighten up diffs, then loosen by 90 degrees) and then I went with one of Grant Williams astro setup sheets for oil weight, shock positions, etc.

The only thing I could say is that the diffs are maybe a little "raspy" when you rotate them in your fingers. I use Nuclear diff grease and its good stuff, but maybe my balls are shot (ohh matron) - would that make a different to the handling on astro? Like I said- seems much better on the clay/dirt.

Thanks for the help

[tony6187]

hi,i dont have a cat but was just wondering are you getting full lock on your steering?also have you set your camber link locations by the setup sheets? ill try to give you a rough guide to checking diffs (very difficult to explain without showing in person) hold the spur(be carefull the slipper doesnt slip)and one of the front wheels.then hold the other and try to turn it.it should be difficult to turn(hard to describe really how much resistence there should be) there should be some slip but it should require a fair amount of pressure.hope this helps (probably not)
p.s dont think stagger ribs will help they are more for when you are trying to tame down steering

[Cardnim]

Cheers tony - I actually think I understand the slipper/diff thing, so will give it a try,
The cambers are correct, but I get a heck of a lot of play in my ball joints - in the Cat there are 5 seperate ball joints from the servo to the wheel and all mine are loose.

Re: staggered ribs - just looked at the lovely RC Lazy boys website, and heres what they say about the ribs:
"Schumacher Cut Stagger Tyres – Yellow – Slim – U6759 They are just ace, both on 2wd, and as a 4wd front. Buy them, you’ll love them."

Im unsure what to do - Ive bought some yellow mini-spikes from an oOpler, but maybe i should go for these too? (dont have loads of money though, so need to make my purchases count)

On an American website, guys are talking about running Proline Calibers on astro!?
I already have a full set of them that I use for dirt (awesome when slightly damp) so maybe they would be good on the astro?

Sorry again for all the silly questions, but Im confused with all the choices and everyone advocating one choice over another.

EDIT -- Tony, just saw you are in Dublin - the race Im trying to get prepped for is on Wed 28th and Ian Hunter and Derek McCloskey are coming up to it (I think its Derek anyways!) and some other guys from Dublin. You shoudl come too - its going to be some good tough racing.

[Rich D]

Staggered ribs will give you less steering than minispikes. They are easier and safer to drive on but ultimately maybe a little slower on a lap.

You need to be on yellow minispikes for astro with some medium inserts. All astro is different, some astro tracks dictate worn spikes to be the easiest to drive on whereas others you need the edges to be on the spikes for ultimate grip.

Start with a new set of yellow minispikes ( from rc lazy of course ), cut the inner and outer row off the fronts and the outer row off the rears if you are finding that the car is grip rolling i the bends. TBH, i dont recall racing on any astro dry track where you dont cut the outer and inner off the fronts at least. I suspect that you may not be getting full lock if you are getting a lot of understeer. turn the car on, turn the steering all the way to the left with the transmitter and hold it there, see if you can move either front wheel left or right against the servo. If you can you need to adjust the end points on your tranny and/or check the geometry. Repeat for the right lock.

HTH

[ASKay]

Originally Posted by Cardnim

On an American website, guys are talking about running Proline Calibers on astro!?

Tried Proline Calibers both M3 and M4s all round on my SX3, and offered no grip at TORCH, like driving on ice, however it was a little wet....