Wheel develops nervous shake by end of lap 1

Shovas · Oct 13, 2017

My AccuForce feels smooth in the forces I'm feeling throughout lap 1 including low and high speeds but by the end of lap 1 I'm always encountering this 'nervous shake' that ramps up with speed. I experience good FFB in iRacing, AMS, and others, so it's something with up with this combo in particular.

It almost makes me think it's a tire warmup thing. I make sure not to get on the grass or hit anything (I have damage disabled anyway) but it still happens.

Any ideas?

Is there some force that comes in as the tire warms up or something else about the car 'comes in'?

William Wester · Oct 13, 2017

Did you consider flat spotting, very easy to do with some cars in rF2.

Emery · Oct 13, 2017

To further William's point, turn on ABS aid and you probably will stop locking your brakes which causes the flatspots. Or you can adjust the car's setup so there's less brake pressure.

Edit: AMS doesn't simulate flatspots. I don't know whether iRacing does. AC & pCARS do, but their effects seem more mild than rF2. I only have a Fanatec v2 rather than an Accuforce, but compared to my real-life racing with flatspotted tires, rF2 is a match... I could see the effect possibly being too strong with a direct drive wheel.

Shovas · Oct 13, 2017

Ah, good point, I'll try that

Shovas · Oct 13, 2017

Wow. It was lack of ABS. I specifically went around the track very carefully, with ABS disabled, and that shaking came on by the end of lap 1. I turned ABS on and went 3 or 4 laps and it felt very smooth all the way even though I wasn't so careful and even spun off with another car.

Strange that the effect they use for flatspotting feels very noisy, very rattly, not like a 1-2-3 style I would expect from flatspots. Not that I would know as I've never felt a flatspot but I imagine it doesn't feel like that...

Anyway, much thanks!

Emery · Oct 13, 2017

Well it's not an "effect", rather it's calculated from the force on the steering rack. In real life, big flatspots are wicked-bad above about 50 mph while small flatspots are merely annoying. Small flatspots become more bothersome above 100 mph.

John-Eric Saxén · Oct 14, 2017

Shovas said:
Strange that the effect they use for flatspotting feels very noisy, very rattly, not like a 1-2-3 style I would expect from flatspots. Not that I would know as I've never felt a flatspot but I imagine it doesn't feel like that...

Flat spots cause a massive imbalance in real life and when you drive 200+ kmph you can't feel the individual falt spots because the tire rotates so fast. This is how Lewis Hamilton describes running with one:

"Honestly I didn't even think about the stewards," Hamilton told Sky Sports F1. "I was more concerned with the flat spot that was just rattling my brain for 17 laps. I couldn't see the braking zone for Turn One. It was such a big vibration I was worried the suspension would break."