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Discussion Starter · #1 ·
Why old-fashioned drum brakes may be the way of the future for EVs
June 17, 2021
A. Tarantola

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Drum brakes are an OG technology that have been around almost as long as cars have. First developed in 1899, this style of brake can be found on some of the very first automotive prototypes built by the likes of Wilhelm Maybach and Louis Renault. Drum brakes were long the standard means of slowing a vehicle given their decent performance and inexpensive cost to produce. But they began falling out of favor with automakers in the mid-1960s when shorter-stopping disc brake systems became widespread. Most commonly found today in medium- to heavy-duty trucks and buses, drum brakes are poised to make a resurgence due to the growing popularity of electric vehicles.

Drums and discs operate very differently, and each system has its advantages. Disc brakes have a pair of pads attached to a caliper that squeezes down to generate friction and slow the wheel’s rotation. Disc systems are more powerful and faster stopping than drums, quite necessary as the front brakes will carry 60-80% of a slowing vehicle’s momentum compared to the rear, which is why you’ll never find a new car with front drums anymore. Discs are also self-adjusting, which leads to less grabbing or pulling, and self-cleaning, which makes them quieter. They’re also less prone to warping from extended exposure to heat and do not fade in heavy braking situations.

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All I saw was a rudimentary splain yourself Lucy! description of two braking systems. I didn't see the reasoning as to why drums would be better for lektriks. Like many here, I've had boo coo experience with drums and discs. There is no comparison.
 

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Discussion Starter · #5 ·
All I saw was a rudimentary splain yourself Lucy! description of two braking systems. I didn't see the reasoning as to why drums would be better for lektriks. Like many here, I've had boo coo experience with drums and discs. There is no comparison.
they said in the article that due to regenerative braking, rear brakes won't be used as much. In that case, they explained discs are subject to deterioration if not used where drums are more robust in such an environment. And they can exert more stopping force to counteract the added weight of batteries.

Other stuff too, I posted only part of the article.
 

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Nuthin' wrong with drums in the back. They also double for the E-brake, whereas rear discs often have internal rotor shoes for the E-brake adding complexity.
 
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Big Rigs still roll with drum brakes. I wonder why if discs are supposedly superior?
 

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All I saw was a rudimentary splain yourself Lucy! description of two braking systems. I didn't see the reasoning as to why drums would be better for lektriks. Like many here, I've had boo coo experience with drums and discs. There is no comparison.
the main advantage is that if a drum isn't used much it doesn't deteriorate like a disc brake does (rust). Also it provides a mechanical parking brake.
 

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Interesting to see people be willing to question conventional wisdom with the transitions to a new platforms with different needs. That's all goodness... as long as we don't go back to leaf springs.
 

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I have heard many complaints about rear brakes getting rusty, especially on EV. I had troubles with my Grand Caravan brakes because they don't work enough.

If that move can some money and trouble, why not ?
 

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they said in the article that due to regenerative braking, rear brakes won't be used as much. In that case, they explained discs are subject to deterioration if not used where drums are more robust in such an environment. And they can exert more stopping force to counteract the added weight of batteries.

Other stuff too, I posted only part of the article.
That was my first thought. The regenerative part. Interesting going back to old tech because it holds up better.
 

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I've never had issues with discs, not with the rear not anywhere. When I traded up from a '67 Catalina to a '66 Rover 2000, 4Wdrums to 4Wdiscs, I became a True Believer. I'd be leery of drums, but then I'm not in the market for advanced technology anyway.
 

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I've never had issues with discs, not with the rear not anywhere. When I traded up from a '67 Catalina to a '66 Rover 2000, 4Wdrums to 4Wdiscs, I became a True Believer. I'd be leery of drums, but then I'm not in the market for advanced technology anyway.
Only issues I've ever had were warped rotors on a GMC Yukon and a Chevy Blazer.
 

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Disc brakes are a lot more expensive to maintain- parts are more expensive generally-speaking and rotors don't last as long as drums.

The biggest complaint against the average drum system was brake fade under very hard use and higher unsprung weight... but there were 4W drum systems that were excellently engineered and had no fade (oversized aluminum finned drums). Given modern engineer scrutiny, they absolutely could be improved beyond previous top results.

But try telling people that. Some folks still believe drilled/slotted rotors are better performing than undrilled rotors.
 

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But try telling people that. Some folks still believe drilled/slotted rotors are better performing than undrilled rotors.
Umm...someone should tell Mclaren:

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Now who should I believe...Mclaren engineers or some guy on gminsidenews...hmm that's a toughie.

Or perhaps they're doing it wrong...maybe they should have some drums on all 4 corners of this beast.
 

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My main beef with drums was uneven stopping.. Modern tech presumably fixes that.
I know some of the '60s big Buicks had big alfin drums, 12" I believe. Alfas and other Euros also had aluminum finned drums that were pretty effective, but couldn't equal discs for truly hard driving.
 

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Discussion Starter · #19 ·
I've never had issues with discs, not with the rear not anywhere. When I traded up from a '67 Catalina to a '66 Rover 2000, 4Wdrums to 4Wdiscs, I became a True Believer. I'd be leery of drums, but then I'm not in the market for advanced technology anyway.
Warping was a big problem for me on my '94 Grand Prix GTP, when it was all the rage for GM to use under-sized disc brakes. I don't think I could make it 5k miles without them warping.
 

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Drums are better for load carrying vehicles as they can apply more braking force per area than a disc brake

Thats why you see them in commercial vehicles
Plus they are cheaper. Cost per mile directly impacts your profitability in a Commercial Logistics Fleet.
 
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