McLaren MCL39

[Farnborough]

Good detail image.

For those unaware, just below the mechanic's finger with ring on it there's a stud with nut to secure, this being the method of ride height control and trim for setup. There's a second (hidden) opposite this one on backside of that coupling.
It's located on the pushrod taking load from wheel into "bellcrank" and all that entails in spring & damping actuation.

The dull grey block to right of that fixing is part of a "shimstack" that can be substituted or added to in changing the effective length of that pushrod to lift or drop the chassis relatively in dimension against the spring component. Fairly easy to do, accurate in just change of component with the fixing undone, to then be secured against new block dimension.

Edit:- to add, this can't ordinarily be seen in running config as it has an aero "shield" sleeve in carbon fibre covering it in plain sight, but each of the four pull/push rod usually have this as method to fine adjust each corner precisely.

[De Wet]

https://www.facebook.com/reel/665906419417342

[SilviuAgo]

Tks to Ohad_Bark and to JunaidSamodien_ we have another view of MCL39 suspension. Ohad_Bark reveals the push-rod layout and internal elements like the rocker and heave element — components that teams rarely give us the chance to see up close.



McLaren’s suspension layout reflects a highly refined approach to balancing mechanical grip and aerodynamic stability — a combination that clearly contributes to the team’s strength in tire management and overall downforce efficiency.

[michl420]

I compared 2024 and 2025 sprint qualy laps.
Although the rear wing is considerably smaller, the top speed is the same or even slightly lower. And the 1 second gain is all in the slow speee.
Softer tire 2025.

[venkyhere]

I compared 2024 and 2025 sprint qualy laps.
Although the rear wing is considerably smaller, the top speed is the same or even slightly lower. And the 1 second gain is all in the slow speee.
Softer tire 2025.

Floor diffuser exit is much more aggressive => expansion and speed of exiting air is more severe. This means more downforce from the floor (hence the smaller wing) and since the floor air exit is diagonal (instead of parallel to the road), some of the downforce (not exactly vertically down, but a vector slanted rearwards) contributes to pressure drag (the typical age old caveat of downforce at the expense of drag) and kind of offsets the drag advantage from a smaller rear wing.
This is my amateur knowledge theory.

[AR3-GP]

On the grid in Miami

[AR3-GP]

Many theories are coming together at the moment about tire temperature control of the MCL-39. They have a particularly powerful heat extraction scheme in their brake tins which allows them to precisely heat and cool the wheel rim and thus the tire. I feel that the low straightline speed of the MCL-39 with the DRS open is a direct consequence of this. To cool something, you need to use flow energy. They are cooling their tires much more effectively than the others, thus it makes sense to find them at the bottom of the speed traps despite their skinny rear wings.

[venkyhere]

It's obvious McLaren have some non-linear thermodynamic device operating on their wheel hub.
My crude guess is that McLaren have the mechanical equivalent of an electronic transistor (operating in it's saturation region) where 'amount of heat' would be the current and 'temperature' would be the voltage. The implemention might be a multi-metal 'sandwich' in the construction of the axle/driveshaft to which the wheel rim and brake disc are attached. The brake disc will come in contact with the axle via one metal, and the entire 'heat sink' (wheel rims/wheel bearing/cooling ducts) would come in contact with the axle via another metal. The 'gate terminal' could be something equivalent to a bimetallic strip which reacts to a temperature threshold and opens/closes (or diminishes/enhances) the heat flow between the two metals, creating opportunity to maintain both tyre temp and brake temp separately as required.


Edit : just came to know from Redbull thread that someone called B sport has posted a video in social media, calling out the same idea. Trust me, it's a coincidence, I haven't watched that video. Secretly I am glad that the same idea occured to someone else, kind of allowing me a 'not that stupid afterall' notion about my thoughts.

[Watto]

It's obvious McLaren have some non-linear thermodynamic device operating on their wheel hub.
My crude guess is that McLaren have the mechanical equivalent of an electronic transistor (operating in it's saturation region) where 'amount of heat' would be the current and 'temperature' would be the voltage. The implemention might be a multi-metal 'sandwich' in the construction of the axle/driveshaft to which the wheel rim and brake disc are attached. The brake disc will come in contact with the axle via one metal, and the entire 'heat sink' (wheel rims/wheel bearing/cooling ducts) would come in contact with the axle via another metal. The 'gate terminal' could be something equivalent to a bimetallic strip which reacts to a temperature threshold and opens/closes (or diminishes/enhances) the heat flow between the two metals, creating opportunity to maintain both tyre temp and brake temp separately as required.


Edit : just came to know from Redbull thread that someone called B sport has posted a video in social media, calling out the same idea. Trust me, it's a coincidence, I haven't watched that video. Secretly I am glad that the same idea occured to someone else, kind of allowing me a 'not that stupid afterall' notion about my thoughts.

That side probably start to come under movable aero device I would imagine - similar to the blown wheel nuts Mercedes had a few years ago that were eventually banned for being movable aero, I guess depends how much they can keep this quite from the FIA. describe it well enough without going into full detail. But if discovered would I think almost certainly come under protest.

[FittingMechanics]

That side probably start to come under movable aero device I would imagine - similar to the blown wheel nuts Mercedes had a few years ago that were eventually banned for being movable aero, I guess depends how much they can keep this quite from the FIA. describe it well enough without going into full detail. But if discovered would I think almost certainly come under protest.

Not sure if there is a loophole around that, but let's imagine that the bimetallic strip is not exposed to the air stream, it is fully enclosed and only serves to improve or reduce conductivity of heat toward the rim. So if the rim is too cold, it "connects" to the hot brakes and conducts heat, if it is colder it disconnects. All fully enclosed and air sealed. This wouldn't be moveable aero.

But it wouldn't fit the theory that McLaren has more drag because of it, if that is accurate.

[Watto]

That side probably start to come under movable aero device I would imagine - similar to the blown wheel nuts Mercedes had a few years ago that were eventually banned for being movable aero, I guess depends how much they can keep this quite from the FIA. describe it well enough without going into full detail. But if discovered would I think almost certainly come under protest.

Not sure if there is a loophole around that, but let's imagine that the bimetallic strip is not exposed to the air stream, it is fully enclosed and only serves to improve or reduce conductivity of heat toward the rim. So if the rim is too cold, it "connects" to the hot brakes and conducts heat, if it is colder it disconnects. All fully enclosed and air sealed. This wouldn't be moveable aero.

But it wouldn't fit the theory that McLaren has more drag because of it, if that is accurate.

Ah that could work but would imagine it would come under protest if nothing else just to clarify do we do down this path.



The phase change materials that was mentioned in the B Sports video sounds a lot more black and white - if it could work and he did do some work for McLaren with batteries cooling some time. back so its an area he seems to understand well enough.

[Xero]

That side probably start to come under movable aero device I would imagine - similar to the blown wheel nuts Mercedes had a few years ago that were eventually banned for being movable aero, I guess depends how much they can keep this quite from the FIA. describe it well enough without going into full detail. But if discovered would I think almost certainly come under protest.

The one thing to support it's legality is that unlike the wheelnut, active brake cooling is allowed, including systems to adjust airflow. F1 teams have been using bio-metallic strips to reverse airflow for years. McLaren are just taking that to a new level with the brakedrum/tyre inteaction, and have clearly nailed what must be a incredibly hard thing to achieve.

[atanatizante]

Changing phase theory regarding how MCL39 is managing the tyres:

[.poz]

Changing phase theory regarding how MCL39 is managing the tyres:

i have some doubt
it' s a closed loop (as an heatpipe) or is something that evaporate and is lost ?
the volume required for a race can be fitted in a tyre drum ?

also they need something that sublimate because of rule 11.5 Liquid cooling of the brakes is forbidden

[atanatizante]

Changing phase theory regarding how MCL39 is managing the tyres:

i have some doubt
it' s a closed loop (as an heatpipe) or is something that evaporate and is lost ?
the volume required for a race can be fitted in a tyre drum ?

also they need something that sublimate because of rule 11.5 Liquid cooling of the brakes is forbidden

On this thread, there is a deep analysis of this matter: viewtopic.php?p=1284208&f=1#p1284208