Any downside to using the maximum regenerative setting?

[HJP1]

I am 100% high regen 100% of the time and a Rivian service guy told me I can expect close to 100 K on the brakes (my truck is not in Illinois during winter so no snow, ice and salt), I assume brakes & rotors are more $$ than a new set of tires.

Sponsored

 

[Forager]

I notice that High Regen is smoother when driving with ACC, the Standard regen has a more noticeable surge as the system modulates speed. However, I notice a distinct notchiness in the accelerator pedal when using High Regen that is less noticeable with Standard Regen. The notchiness is kind of a clicking that presents at various levels of pedal travel, especially when the vehicle is changing between feeding power to the motors and regenerative braking.

 

[SANZC02]

Last month at the Chelsea MA service center I was told that Rivians in NH, Vermont and Maine were at higher risk of accelerated brake pad wear and that premature brake pad wear was no longer "under the warrantee". I am planning on having the pads looked at by my mobile tech crew in the autumn when I change the tires. Maybe we have more sand on our roads? Just a heads up for norther new englanders

I would really like to have them explain this more. I’m thinking about what they are saying and cannot make any sense of it.

Anyone else have any idea why brake pads in northern New England would wear prematurely? Has anyone in the northwest or Colorado experienced any premature brake pad wear?

Just as a side, the brake pads on my Model S looks like they will never need replacing and it has much less regen than my R1S.

 

[jeeden]

I would really like to have them explain this more. I’m thinking about what they are saying and cannot make any sense of it.

Anyone else have any idea why brake pads in northern New England would wear prematurely? Has anyone in the northwest or Colorado experienced any premature brake pad wear?

Just as a side, the brake pads on my Model S looks like they will never need replacing and it has much less regen than my R1S.

I heard this from my BIL who is a mechanic in NH and isn't sold on EVs....

I think the premise is that under normal operation brake rotors get surface rust on them from water, humidity, and in northern (or even Mid Atlantic where I am) states, salt and salt derivatives they put on the roads. You may have experienced this if you ever let a vehicle sit for a few days and looked at the rotors and they looked rusted or you got into a car, started to drive, and it didn't brake very well for the first couple of tries or there was a real grinding noise when braking. This is usually not an issue because the braking will clear the surface rust... and anything that caused it off the rotor. With regen, if the brake pads are not used, then the salt just sits on the pads and rotors and continues to corrode into the material deeper and deeper. I imagine it is then pitted and likely to have more corrosive elements pushed into those pits next time.

I guess a solution might be to use the brake the first couple of stops each time you drive the vehicle after it has been sitting in those conditions.

I used to work putting military sensors on railroad cars for a project and I remember they had the same problem. Actually worse since the freight railroads refuse to acknowledge 20th century tech and their brakes still just leverage giant blocks of hard carbon steel directly against harder steel wheels. They coat the new pads when new, but once they are applied the first time and it all burns off the wheel and the pad looks machined and then they let it sit in a rail yard forever and rust

 

[SANZC02]

I heard this from my BIL who is a mechanic in NH and isn't sold on EVs....

I think the premise is that under normal operation brake rotors get surface rust on them from water, humidity, and in northern (or even Mid Atlantic where I am) states, salt and salt derivatives they put on the roads. You may have experienced this if you ever let a vehicle sit for a few days and looked at the rotors and they looked rusted or you got into a car, started to drive, and it didn't brake very well for the first couple of tries or there was a real grinding noise when braking. This is usually not an issue because the braking will clear the surface rust... and anything that caused it off the rotor. With regen, if the brake pads are not used, then the salt just sits on the pads and rotors and continues to corrode into the material deeper and deeper. I imagine it is then pitted and likely to have more corrosive elements pushed into those pits next time.

I guess a solution might be to use the brake the first couple of stops each time you drive the vehicle after it has been sitting in those conditions.

I used to work putting military sensors on railroad cars for a project and I remember they had the same problem. Actually worse since the freight railroads refuse to acknowledge 20th century tech and their brakes still just leverage giant blocks of hard carbon steel directly against harder steel wheels. They coat the new pads when new, but once they are applied the first time and it all burns off the wheel and the pad looks machined and then they let it sit in a rail yard forever and rust

Thanks.

It will be interesting to see how this plays out. Seems like Rivian does engage brakes at the end of the one pedal driving for the hold feature, might not use enough brake to generate heat to dry out moisture.

 

[SoCal Rob]

I would really like to have them explain this more. I’m thinking about what they are saying and cannot make any sense of it.

Anyone else have any idea why brake pads in northern New England would wear prematurely? Has anyone in the northwest or Colorado experienced any premature brake pad wear?

Just as a side, the brake pads on my Model S looks like they will never need replacing and it has much less regen than my R1S.

Maybe the salt-covered roads (and salt air near the coast) lead to more rust with infrequent brake use which results in more corrosion and deeper pitting of the rotors. The more deeply pitted rotors on pads may act like a grater on a potato: shaving more material off than a smooth surface would.

 

[SANZC02]

Maybe the salt-covered roads (and salt air near the coast) lead to more rust with infrequent brake use which results in more corrosion and deeper pitting of the rotors. The more deeply pitted rotors on pads may act like a grater on a potato: shaving more material off than a smooth surface would.

From what I read the bigger issue is brake pads do not get hot enough to get rid of excess moisture and cause rust that breaks up the pad material. A lot of manufacturers are using galvanized pads to counter this but was not able to see what pads Rivian uses.

Just seems odd they would mention Northern New England states and not other areas with similar climates/snowfall.

 

[SoCal Rob]

From what I read the bigger issue is brake pads do not get hot enough to get rid of excess moisture and cause rust that breaks up the pad material. A lot of manufacturers are using galvanized pads to counter this but was not able to see what pads Rivian uses.

Just seems odd they would mention Northern New England states and not other areas with similar climates/snowfall.

The excess moisture causing rust in the pad material makes sense. The Northern New England part does seem very specific. Maybe they’ll expand this after a second full winter of data.

 

[R1Tom]

Typically brake pads aren't covered at all anyway. What am I missing?

 

[usofrob]

Having researched this for another of my vehicles, there are at least a few different types of pads and different technologies for the mounting plate. It seems like an EV company could select pads that are less likely to rust and need clearing from being used. I haven't researched this for my Tesla, but I assume they've selected a reasonable compound because I haven't had an issue on my 5 y.o. model 3 performance in SE Michigan.

 

[SASSquatch]

Folks, having driven EV's now since 2015 I will tell you from experience that when you are using regen exclusively, you will build up moisture, road debris, salt, etc. and your rotors will develop layers of rust.

I have had to have the rotors resurfaced on my first EV because I almost never applied mechanical brakes. We get some snow in DC but not that much so it is not because of snow/salt.

Tesla recommends that owners clean and lubricate brake calipers every 12 months if you live in a cold weather part of the country.

Trust me - it's not a bad idea. On the other hand, it is also not a bad idea for you to 1 day a month turn regen off and use the mechanical brakes for your daily driving that day. You will probably have enough friction to keep things clean.

 

[dleepnw]

ive wondered this myself. everyone seems to think theres no downside to the motors. i hope thats true but can't help but think theres got to be some level of increased physical wear on them working harder.

i think its definitely true the tires will wear faster, especially in conserve mode.

 

[dleepnw]

Folks, having driven EV's now since 2015 I will tell you from experience that when you are using regen exclusively, you will build up moisture, road debris, salt, etc. and your rotors will develop layers of rust.

I have had to have the rotors resurfaced on my first EV because I almost never applied mechanical brakes. We get some snow in DC but not that much so it is not because of snow/salt.

Tesla recommends that owners clean and lubricate brake calipers every 12 months if you live in a cold weather part of the country.

Trust me - it's not a bad idea. On the other hand, it is also not a bad idea for you to 1 day a month turn regen off and use the mechanical brakes for your daily driving that day. You will probably have enough friction to keep things clean.

unfortunately, theres no way to turn off regen on the R1

 

[SASSquatch]

unfortunately, theres no way to turn off regen on the R1

Ah - I missed that during my test drive and Turo Rental.

In that case, I would set the regen to the lowest setting and consciously brake as much as you can 1 day a month.

 

[HJP1]

I've had a 2019 Model 3 performance prior to my R1T and in 3 years of ownership the only maintenance performed was a couple of tire rotations by Tesla and each time was told the brakes looked brand new and I did spend 2 winters with the vehicle in Illinois.

Sponsored