ID3 Drum Brakes

[OB1CCFC]

Do any other EV manufacturers, aside from VW, have rear drum brakes?
Clearly there are some cost savings in doing it but do you think it effects brake performance?
I assume drums last longer than disks which is a plus but the concern is more about stopping a very heavy car effectively under emergency heavy (physical) braking.
Do NCAP safety ratings cover braking performance??

[andrewparker]

Less rolling resistance, and better when combined with regen.

[monkeyhanger]

Have you done any emergency stops to see how effective the brakes are (I haven't, and I haven't had a really close call in the ID3). The vast majority of heavy braking in all cars is done via the front brakes, the rear brakes are mainly used for stability under braking. Don't forget that you have 0.25g.of stopping taken care of by the regen system. I do over 90% of my slowing and stopping via the regen system, if the green regen bar is accurate.

[Daveion]

I dont find the ID3 brakes confidence inspiring but I dont think its down to rear drums. Drum brakes are pretty efficient as the braking surface is a greater distance from the centre of the axle compared with discs. The problem with drum brakes is they heat and fade quickly compared with discs. That is why they are ok for the rear but for motorways and faster roads discs are better.
My concern is the amount of brake force I need to pull up quickly compared with my ICE that just needs a light touch to stop quickly.
I believe its the ID3's weight that I feel braking hard and the amount of force needed to be applied to the pedal but a little easier in B.

[monkeyhanger]

I dont find the ID3 brakes confidence inspiring but I dont think its down to rear drums. Drum brakes are pretty efficient as the braking surface is a greater distance from the centre of the axle compared with discs. That is why they are ok for the rear. The problem with drum brakes is they heat and fade quickly and for motorways and faster roads discs are better.
My concern is the amount of brake force I need to pull up quickly compared with my ICE that just needs a light touch to stop quickly.
I believe its the ID3's weight that I feel braking hard and the amount of force needed to be applied to the pedal but a little easier in B.

For me, that lack of confidence is in that initial 1/3 of brake pedal travel that is doing pretty much regen - it just doesn't feel solid compared to traditional ICE cars with decent brakes. I've had cars with very grabby brakes, needing only a light touch to brake relatively hard. That light touch on the ID3 is just doing regen. You just have to press harder/further on the brake pedal to start using those front discs effectively.

[Warminster id]

I had a car pull out across the road from a junction a couple of days ago, I was doing 35 (40 limit) and parallel with the junction. Stopped no problem

[G43FAN]

I dont find the ID3 brakes confidence inspiring but I dont think its down to rear drums. Drum brakes are pretty efficient as the braking surface is a greater distance from the centre of the axle compared with discs. That is why they are ok for the rear. The problem with drum brakes is they heat and fade quickly and for motorways and faster roads discs are better.
My concern is the amount of brake force I need to pull up quickly compared with my ICE that just needs a light touch to stop quickly.
I believe its the ID3's weight that I feel braking hard and the amount of force needed to be applied to the pedal but a little easier in B.

For me, that lack of confidence is in that initial 1/3 of brake pedal travel that is doing pretty much regen - it just doesn't feel solid compared to traditional ICE cars with decent brakes. I've had cars with very grabby brakes, needing only a light touch to brake relatively hard. That light touch on the ID3 is just doing regen. You just have to press harder/further on the brake pedal to start using those front discs effectively.

Indeed, it's effectively a two function pedal, initial travel is only regen braking, but if you press hard then the 'real' brakes kick in. There's definitely an odd lurch if the car is already slowing down for a junction or whatever and you decide to hit the pedal, but once you're trying to slow at greater then 0.25g it's all front discs anyway and so far I have found them effective.
I can't see the drums being a 'life of vehicle' item unless they are only there for handbrake functionality and minor stability correction. There have been reports from some people of a knocking from the rear brakes under extremely severe braking, I've experienced it once but to recreate it you need to be driving the car like a track car (which it isn't)

Daveion, I'm not sure what you mean by easier in B, there's no difference in the brake function or performance in D versus B, once your requesting greater than 0.25 (approx) it's a straight forward braking system?

[TheJimster]

I had a car dart out of a side road right in front of me a couple of weeks ago, it was a proper emergency braking job and the ID3 did a decent job on the anchors.

I don't have any issues with the brake performance, but I do agree that the pedal feel could be better, and it takes a while to get used to the blend of regenerative and mechanical braking.

I drove our A3 the other day, which now feels incredibly old-fashioned coming from the ID3, but the brakes definitely feel more reassuring, even if it's just perception.

[Daveion]

G43FAN
"Daveion, I'm not sure what you mean by easier in B, there's no difference in the brake function or performance in D versus B, once your requesting greater than 0.25 (approx) it's a straight forward braking system?"

Its just that instant deaccelleration once you lift the pedal before you even apply the brake. That brief period reduces speed which in turn can reduce the pedal pressure required to stop.

[G43FAN]

G43FAN
"Daveion, I'm not sure what you mean by easier in B, there's no difference in the brake function or performance in D versus B, once your requesting greater than 0.25 (approx) it's a straight forward braking system?"

Its just that instant deaccelleration once you lift the pedal before you even apply the brake. That brief period reduces speed which in turn can reduce the pedal pressure required to stop.

Oh.. Ah yes, as someone who hates B with a passion (precisely because, just because I lift off doesn't mean I want to Brake) I hadn't thought about that point, so in a 'Slam on' situation there's a split second of advance braking I guess.

[Daveion]

G43FAN
"Daveion, I'm not sure what you mean by easier in B, there's no difference in the brake function or performance in D versus B, once your requesting greater than 0.25 (approx) it's a straight forward braking system?"

Its just that instant deaccelleration once you lift the pedal before you even apply the brake. That brief period reduces speed which in turn can reduce the pedal pressure required to stop.

Oh.. Ah yes, as someone who hates B with a passion (precisely because, just because I lift off doesn't mean I want to Brake) I hadn't thought about that point, so in a 'Slam on' situation there's a split second of advance braking I guess.

Exactly that although its not just the slam-on its those occassions when circumstances change with traffic around you. If you dont use B its something that you avoid. If Im in B in these circumstances I end up braking later because B hasn't seen a hazard that I see unfolding. I then have to press the pedal much harder. Much harder than I ever need to do in my ICE and that difference in cars also doesn't help.

[Scratch]

Just had an emergency stop. Idiot in front of me (who was behind me earlier and driving like a pratt), stopped suddenly. He was about to write off a motorcyclist but decided not to. The brakes worked fine, although, I must admit, that in day to day driving, they don't instill a great amount of confidence. My previous Fiesta ST had discs all round and was amazing at how little pressure was needed to stop. Either normally or in an emergency.

[Uphamid3]

The braking characteristics of all cars are different, and one just has to adapt one's driving technique to match the performance of the particular vehicle being driven. I'm also lucky enough to own a 54 year old classic car. The car is fastidiously maintained, and is totally legal and is even subjected to an MOT test each year even though it is not legally required, yet the brakes feel alarmingly non-existent in comparison to a modern day car.

During my id3 test drives I found the brakes entirely adequate in a large range of traffic conditions and speeds, so much so, I didn't even give them a second thought.

If they were in any way dangerous, the vehicle wouldn't meet regulations and be given Type Approval.

[monkeyhanger]

I do have to wonder how progressive some of these brakes are when people say they literally have to tap them to stop - will they get any better with a harder press or are they just fully operating under a small range of travel?

When the new Polo MK6.came out in 2018, we got a Polo GTI+ just before VW mandated the implementation of GPFs. We were that impressed, we got another new one in 2019. They were the same car, except the 2019 one had aHPF and a much quieter exhaust note. The brakes though... both should have the same stopping capability, same components, but the 2018's were progressive and the 2019's were grabby. When I switched between the cars, I'd almost nut the windscreen for the first 2 brake presses on the 2019 one. So grabber brakes, but almost certainly no more capable. That regen zone of travel really does feel like the brakes are a bit crap to the uninitiated, but there's some very effective braking beyond the regen zone of travel.

[Daveion]

The braking characteristics of all cars are different, and one just has to adapt one's driving technique to match the performance of the particular vehicle being driven. I'm also lucky enough to own a 54 year old classic car. The car is fastidiously maintained, and is totally legal and is even subjected to an MOT test each year even though it is not legally required, yet the brakes feel alarmingly non-existent in comparison to a modern day car.

During my id3 test drives I found the brakes entirely adequate in a large range of traffic conditions and speeds, so much so, I didn't even give them a second thought.

If they were in any way dangerous, the vehicle wouldn't meet regulations and be given Type Approval.

All true but descibing brakes as adequate isnt a huge confidence vote. I dont think anyone has said they are dangerous, just not as sharp as would have expected given we have moved on from 54 year old classics.

[sidehaas]

I found the brake feel a bit weird for the first couple of weeks driving and there were a few times I didn't brake quite as much as intended in the early phase and then had to stop more abruptly than intended. That hasn't happened for a while though and now that I'm used to them I don't notice anything untoward. The transition from regen to mechanical brake forces per se isn't noticeable to me. I don't think comparing them to the brakes on old classics gives a remotely fair impression...

[Uphamid3]

Oh no, they are definitely much, much, much better than my old classic car. I thought the brakes on the id3 were very similar in efficiency to my present-day MINI Cooper - perfectly adequate!

[ItshardtobuyId3]

I do have to wonder how progressive some of these brakes are when people say they literally have to tap them to stop - will they get any better with a harder press or are they just fully operating under a small range of travel?

When the new Polo MK6.came out in 2018, we got a Polo GTI+ just before VW mandated the implementation of GPFs. We were that impressed, we got another new one in 2019. They were the same car, except the 2019 one had aHPF and a much quieter exhaust note. The brakes though... both should have the same stopping capability, same components, but the 2018's were progressive and the 2019's were grabby. When I switched between the cars, I'd almost nut the windscreen for the first 2 brake presses on the 2019 one. So grabber brakes, but almost certainly no more capable. That regen zone of travel really does feel like the brakes are a bit crap to the uninitiated, but there's some very effective braking beyond the regen zone of travel.

I’ve got a 2019 GTi plus (until tomorrow!!!) and I find it really difficult to stop gently in it. Like you say they are extremely grabby. When I took the ID3 for a test drive I wondered what the was going on when I got towards the end of the motorway off ramp. I thought nearly overshot the junction as the breaks seemed so weak. They nearly put me off the car but I figured I’d get used to it and at least there would be less chance of me smacking my face into the windscreen in traffic lol