Soldato
Does the ID4 have drum brakes on the rear like the ID3 does?
New VW ID 4 Reveal
- Thread starter nam
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Yep, with Silicon Carbide or Carbon Ceramic discs on the option list
Soldato
wut, drum brakes?
Caporegime
It's like some sort of steam punk scenario. Past, meet the future.
If you look at a list of Pros / Cons for Drums...
Drum brake advantages
Brake shoes today are still being used. Here are some advantages that drum brakes have over disc brakes:
...EVs actually remove quite a few of the disadvantages because so much braking effort is transferred to the regen process instead of the braking system. All the issues with excessive heating, thermal expansion etc. are unlikely to present. You can see why'd they use them again to try and shave some cost off the vehicle.
edit - VW threw some other reasons for their use out there too:
Drum brake advantages
Brake shoes today are still being used. Here are some advantages that drum brakes have over disc brakes:
- Drum brakes can provide more braking force than an equal diameter disc brake.
- Drum brakes last longer because drum brakes have increased friction contact area than a disc.
- Drum brakes are cheaper to manufacture than disc brakes.
- Rear drum brakes generate lower heat.
- Drum brakes have a built-in self energizing effect that requires less input force (such as hydraulic pressure
- Wheel cylinders are simpler to recondition than with disc brake calipers.
- Brake shoes can be remanufactured for future use.
- Drums have slightly lower frequency of maintenance due to better corrosion resistance.
- Excessive heating can happen due to heavy braking, which then can cause the drum to distort, and thus cause vibration under braking.
- Under hard braking, the diameter of the drum increases slightly due to thermal expansion, the driver must press the brake pedal farther.
- Brake shoes can overheat to the point where they become glazed.
- Excessive brake drum heating can cause the brake fluid to vaporize.
- Grab is the opposite of fade: when the pad friction goes up, the self-assisting nature of the brakes causes application force to go up. If the pad friction is enough, the brake will stay engaged due to self-application, even when the external application force is released.
- Another disadvantage of drum brakes is their relative complexity.
- Maintenance of drum brakes is more time-consuming, compared to disc brakes.
...EVs actually remove quite a few of the disadvantages because so much braking effort is transferred to the regen process instead of the braking system. All the issues with excessive heating, thermal expansion etc. are unlikely to present. You can see why'd they use them again to try and shave some cost off the vehicle.
edit - VW threw some other reasons for their use out there too:
Soldato
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I was once in a mini with drum brakes all round and we nearly bust through a farmers gate a-team style.
Soldato
It’s almost like they know what they are doing?
Maybe VW are ahead of BMW and have discovered Google in their engineering department, so they've progressed beyond imagining.
Soldato
The disadvantages suggest they are looking at front brakes not rears where you will not really get overheating because they only provide 25% of the car's total braking anyway. We have rear drums on our fiesta, the brakes are fine, no issues and no dirty wheels either..
The advantage/disadvantage list wasn't ID4 specific, just a list regarding drum brakes in general that I copied in. As you say, this is also why drums are used on smaller cheaper cars rear brakes too - they're good enough for what they need to do.
Yep, they are pretty hairy once they get hot lol. You really wouldn't want them on the front or on something high performance.
It's what the ridiculously long stopping distances in the highway code are based on
Soldato
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I remember looking at my mate going why didn’t you brake?! and he was like I was!
The augmented reality platform that'll be in the higher end ID3/ID4s looks quite impressive. Certainly better than the new S Class' anyway with all its technological might.
Meanwhile musk is still hooked on promising the world full av autopilot (despite all the amounting problems or incoming nhtsa regulations) and seems to be completely forgetting about the in cabin experience as a result.
No doubt the next five years will be the most interesting and rapidly accelerating period in the industry ever.
Meanwhile musk is still hooked on promising the world full av autopilot (despite all the amounting problems or incoming nhtsa regulations) and seems to be completely forgetting about the in cabin experience as a result.
No doubt the next five years will be the most interesting and rapidly accelerating period in the industry ever.