Are you supposed to hold on the brakes during a pitstop ?

[Slife]

According to this, Raikkonen's hand slipped off the clutch which spun the wheel causing the tire issue. But if you had your foot on the brakes (as I presume you should), then shouldn't it not matter if his hand slipped from the clutch ?

[George-Jung]

Is that not a bad thing to do, because of the heat in the disc's they can deform.. if you hold the brakes?

[matt21]

I think you have to hold on the brakes, otherwise the wheel guns will spin the tires and not the nuts.

[iotar__]

My intuitive answer would be yes. Didn't they have "brakes" sign? Edit: wasn't that during refueling after wheel change?

[Gaz.]

[Scootin159]

Yes, you'll need the brakes on during wheel changes for two reasons:
1) To keep the wheels from spinning wheel from spinning while using the wheel guns
2) To keep the rear wheels from spinning from clutch drag - multi-plate clutches like they use typically have quite a bit of parasitic drag, even when disengaged. If the car was in the air, with the gearbox in neutral, the rear wheels would still spin up pretty quickly - even with the driver holding the clutch. It might not be enough force to drive the vehicle forward (and especially not if the driver has his foot on the brakes), but it's enough force to spin the wheels while they're in the air.

The "brakes on" sign did have two stages during the refueling era - the first part "brakes on" was shown during the wheel change, but once the wheel change was complete (but fuel was still being delivered), a different sign was shown to the driver to put the car in gear and get ready to pull away.

[poolboy67]

i don't think brakes need to be on, because of this:

the wheel hub has studs which go into holes on the center of the wheel. the wheels are therefore not held on by friction. therefore once a mechanic has gotten the wheel on to the hub, he can hold the hub from spinning by holding the wheel. because both of them are basicly locked together by the studs.
the wheel gun is a very powerful tool, but not enough powerful to overcome a mechanic's grip.

so yes they could change the wheels without applying the brakes, but since the teams are really anal about minimizing risks and failure points, they have the brakes on anyway.

so how did raikkonen's wheels spin even if he did have brakes on? i think the drivers only apply a minimum ammount of brake pressure needed, because of the risk of heat soaking the pads. we've all seen smoking, and even on fire brakes at pit stops.
besides, the drivers are applying revs when they're in the pits, so even a little clutch slip will spin the wheels. even if some braking pressure is applied. these engines really do have the power and torque to do so.
and putting the car on neutral these days for a pit stop is too risky, and time consuming.

[Moose]

What on earth do you mean "the wheel gun is not enough to overcome a mechanic's grip"? The entire point of using wheel guns is that they can apply more torque to wheel nuts than mechanics' hands can.

[Scootin159]

I have a similar single nut setup on my formula car, and someone would have to some pretty impressive grip to hold the wheel while I torque the lug. Adding to that, mine only take 70 ft-lbs, F1 is closer to 500ft-lbs IIRC.

[bdr529]

What on earth do you mean "the wheel gun is not enough to overcome a mechanic's grip"? The entire point of using wheel guns is that they can apply more torque to wheel nuts than mechanics' hands can.

I'm sure he means the mechanic that is putting/holding the new tire in place and not the mechanic that is using the gun