Manual traction control

[Big Tea]

It might be semantics but the “onset of wheel spin” to me is retrospective ie the wheels have started slipping.

The idea here is to tell the driver how far they are from that happening.

Do you drive, ride or do anything that you think that an alert of slippage would be useful? Do you drive karts?

I've ridden MTB for 30 years and I raced* motorbikes for a couple years before I had kids and in these activities, though not car racing, I think any sort of alert would be too late. I'm handy in a kart**

Am I missing something? How does a secondary alert beat the backside, the guts or rest of the body in dealing with lack of traction?

* Slow, but I won the final 2 races I where l entered
** I beat my son mostly

I go along with this. By the time your brain has processed a light telling you there is slip, your body has already detected it and taken the appropriate action. Unless of course the system is not allowing the driver to get close to the limit, in which case it is slowing him down.
There are also circumstances where it is beneficial to be just "the wrong side of the line"

[AR3-GP]

Slip is not bad fyi. iirc, you are faster with slip. The optimum amount of slip depends on the tires which is why the cars that have traction control and ABS have so many settings to fine tune it. Ducati also does this very effectively on their MotoGP bikes. I think the optimum can be around 20% slippage. That might be from Milliken's RCVD but honestly can't remember where I pulled that from...

[CMSMJ1]

20% slippage in a traction event on a motogp bike? That seems to be really high - it'll have the tyre in all kinds of trouble for durability in a race.

I recall the various diagrams/graphs etc ref the slip relating to the peak traction - think it was relatively old book by Sal Incandela - but this was when technology was not as advanced.

I don't doubt that the quality of the TC in current motogp (as we're talking bikes) is amazing - as when it fails, it spits people off and hurts them. The intrusion really does have to be organic and reliable to support the feel of he riders at the edge of the gip.

[Greg Locock]

20% longitudinal slip would leave you no margin for lateral g on a production car tire, and woud be well past peak grip for a high speed tire. F1 tires have max grip at around 3% slip. Maost of the curves in RCVD are based on crossplies, not radials.

[AR3-GP]

20% slippage in a traction event on a motogp bike? That seems to be really high - it'll have the tyre in all kinds of trouble for durability in a race.

I recall the various diagrams/graphs etc ref the slip relating to the peak traction - think it was relatively old book by Sal Incandela - but this was when technology was not as advanced.

I don't doubt that the quality of the TC in current motogp (as we're talking bikes) is amazing - as when it fails, it spits people off and hurts them. The intrusion really does have to be organic and reliable to support the feel of he riders at the edge of the gip.

I didn't say a MotoGP bike runs at 20% longitudinal slip. I said it depends on the tire. There will never be a 1 size fits all answer. I was just recalling the notion that slip is desirable both in longitudinal and lateral accelerations. Some very old books proposed a one size fits all answer when as you say, the technology was not very advanced.

Also it's possible that I imagined the 20% value. It's been ages since I've been through RCVD.

Also, it's a dynamic thing. Tire slip is not sustainable if you can't cool the tires between your slip events.

[Farnborough]

I can't attribute it reliablly, but read a few years ago that Moto-GP tyres had longitudinal absolute peak approaching 15% when new and also dependent on track surface, dropping away to 5~7% at race end, hence the use of "end of tyre" torque mapping in keeping it in protection range at race end.

Bastianinni being notable for preserving at race start, to later hold advantage at race end over the others.

[PlatinumZealot]

Slip is not bad fyi. iirc, you are faster with slip. The optimum amount of slip depends on the tires which is why the cars that have traction control and ABS have so many settings to fine tune it. Ducati also does this very effectively on their MotoGP bikes. I think the optimum can be around 20% slippage. That might be from Milliken's RCVD but honestly can't remember where I pulled that from...

Required slip is just a result of using rubber for tyres. The material requires a bit of stretching to grip the surface better.