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Scraping speed bumps

Discussion in 'Model S: Driving Dynamics' started by Vad42, Aug 22, 2016.

  1. Vad42

    Vad42 Member

    Joined:
    Jul 1, 2016
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    Location:
    New Jersey
    This is my first little scare with my 2 day (150 mile) old S. I have a base model with no 'smart air suspension' and default 19' wheels. Figured I don't need smart suspesion since it's all mostly flat around here and no inclined driveways. (May have been a mistake in retrospect)

    Decided to take my first "trip" on Sunday to visit my father. (~100 mile round trip, so no Supercharging yet.) Entering his enclosed gated community I arrive at the first of what's going to be 4 speed bumps. I've went over them 100s of times in previous cars without ever having any trouble. These are permanent out of asphalt type. I don't know how high they are.

    This being my first time over bump in S, I decided to take it slow. maybe 7mph. and then the noise of scraping.... My heart sunk, and there were 3 more bumps to go. I went even slower over the others <5mph and scraped one more. On the way out, managed to only scrape 1 out 4. but I was going like 1-2mph and trying to go at angle.

    Is this unusual? Are these some super bumps or is my S really that low? There's actually a speed bump near my house too, which I think is similar, but i didn't try it yet -- now I'm scared. If I do scrape it, how dangerous is it? The first time I scraped, immediately the image of French fire popped into my head. I knew it was silly, but it just wouldn't go away...

    I didn't take a picture of bumps, but I can do that next time I go there. probably in my non-tesla :(
     
  2. habanero69

    habanero69 I Dont Need Cialis. I Drive an EV.

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    I would assume the battery is protected by its enclosure and unless you were to actually dent the enclosure, you are probably alright. Hoverer, repeated scraping could potentially wear down the enclosure exposing portions of the pack that best not be. I don't have my MS60 yet, but maybe the frame area surrounding the battery is lower thus it is nearly impossible to scrape the battery enclosure itself. If it's the bodywork, i.e. bumper/nose, that's hitting, that will certainly be a problem...

    I would take the speed bumps as slow as the car could go. Then if you are still scrapping, you would either have to avoid, or have your father complain about them to his association or whomever is responsible. I HATE THOSE BUMPS. They tend to knock out alignments over time. Surely there is some height restrictions on them? You could also take them on the diagonal a bit to see if that prevents a scrape, but usually head on is best. Good luck. I had one of those POS in my neighborhood, but luckily when they resurfaced the road they removed.
     
  3. LastGas

    LastGas Member

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    The ground clearance with coil suspension is 5.65 inches. The maximum height setting for the smart air suspension is just 6.4.
     
  4. Vad42

    Vad42 Member

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    Location:
    New Jersey
    Thanks for that useful information that I didn't bother to lookup. I just checked and my current sedan (Camry 2013) that has no problems with those particular speed bumps has clearance (according to specs) of 6.1 inches. But I wonder if perhaps there's also a distance between the front/back wheels that matters here. I.e. for shorter distance if the back wheel starts going up before the front is all the way off the bump?

    Does anyone know if the speed bumps have a "standard" height? How would I measure a particular bump height? Maybe they are higher then allowed, and I can complain. Although even if that's true, knowing the management of that place - it will fall on deaf ears...

    PS. I'm definitely getting air suspension next time. I didn't think this would cause me any worry but it does now :(
     
  5. sorka

    sorka Active Member

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    I doubt your did any real damage. The battery casing underneath is designed to serious puncture abuse at speed. You could probably scrape over those speed bumps thousands of times without doing any real damage. Did you look underneath to assess the damage?
     
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  6. wilheldp

    wilheldp Member

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    Location:
    Louisville, KY
    On my second test drive, Tesla brought me a 90D with air suspension, but they set it on "normal" which they said is 1/2" lower than the ride height on the coil suspension. I have a curb at the end of my steep driveway, so I wanted to find out if the S would be able to clear that without scraping. I took the test drive car up and down my driveway with no issues. We were later driving through a neighborhood that has speed bumps. I got by the first 2 fine, but the 3rd one scraped pretty hard. The Tesla guy looks at me and says "did we just bottom out?" I just grinned sheepishly and said "yep!" I haven't taken my S through that neighborhood since I got it. I'd rather learn about those issues with a test drive car than my own.
     
  7. Zextraterrestrial

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    on speed bumps like this you will just be scraping the rails on the sides of the battery case, should be totally fine
     
  8. mrjedistud

    mrjedistud Member

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    Agree with this comment. Unless you are hitting an unusual bump, you are most likely scraping the side rails.
     
  9. scottm

    scottm Active Member

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    You could request to the condo / association for that parking lot, they press the bumps down next time doing road maintenance.

    A local grocery store had bumps that were too high and many many gouge marks in them... they must have hat a lot of complaints and actually lowered their bumps.. and made them wider more like a platform. Which solved the issue.

    I dialed up my air suspension (geo location memory) to prevent scrapes but now don't need to. Doesn't help you, I know.

    These cars are lower riding than usual. With or without air suspension.

    Another tactic that helps is if there is a way to drive over the bump so that only one side of the car's wheels rides over the bump while the other side's wheels sneak through a break in the bump as they often have a gap in the middle - do that. Target the gap with one side of the car. Then there's less "rebound / bounce" coming down off the bump and less chance of hitting.

    Also, crawl at low speed. Like really crawl.

    You may want to use Creep Mode .. just for this purpose.
     
  10. BobinBoulder

    BobinBoulder Member

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    I've done this in a couple of parking garages and have found that if you take the bumps at an angle, you lessen the "bounce" that you get, and reduces the chance of actually hitting the underside of the car and bottoming out.
     

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