TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Speed bumps - how do you judge them?

Discussion in 'Roadster' started by asgard, Nov 17, 2013.

  1. asgard

    asgard Member

    Joined:
    Aug 17, 2013
    Messages:
    296
    Location:
    CA
    Went over a speed bump today and heard the awful crunch. Fortunately, survived with just a few scratches on the bottom of the panel just behind the front splash guard.
    The speed bump looked like it was 6 inches high.
    How do you folks judge whether you can make it or not?
     
  2. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    15,851
    Location:
    Ottawa, Canada
    Just go really slow if it looks like a big bump. Most speed bumps are too low to touch the bottom of the car unless you go over too fast. If you go over too fast the springs overshoot and you end up bumping the bump.
     
  3. caddieo

    caddieo Member

    Joined:
    Mar 21, 2013
    Messages:
    877
    Location:
    Palm Coast, FL
    Would it help to jack up the suspension to "high"? (assuming you have the active air suspension)/
     
  4. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

    Joined:
    Mar 8, 2012
    Messages:
    12,753
    Location:
    Texas
    Right. Going slow is the correct answer. Unfortunately, raising the suspension is awkward to get at and takes a long time to deploy once you get to the screen and push the button. Suspension raising should be on the bottom along with the climate control. An ideal place would be where the volume button is. I have yet to have a passenger use the volume button, and it's easy to get to without looking.
     
  5. jbadger

    jbadger Roadster #506

    Joined:
    Dec 28, 2012
    Messages:
    272
    Location:
    San Jose, California, United States
    caddieo / jerry33 this is the Roadster forum. We unfortunately do not have the ability to modify the suspension from inside the car like the Model S with air suspension, and I believe our car is lower to the ground.

    asgard, I just take it as slow as possible. If you've ever seen a lowered car, they generally try to take it at an angle, but i'm not sure how that helps.
     
  6. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

    Joined:
    Mar 8, 2012
    Messages:
    12,753
    Location:
    Texas
    Oops, sorry about that. My bad.
     
  7. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    15,851
    Location:
    Ottawa, Canada
    If the scrape is caused by a change in slope, that makes the slope shallower. I'm not sure it would help as much on a speed bump, except to spread out the bumpiness and perhaps reduce the suspension rebound.
     
  8. ElSupreme

    ElSupreme Model S 03182

    Joined:
    Jan 13, 2012
    Messages:
    4,279
    Location:
    Atlanta, GA
    #8 ElSupreme, Nov 18, 2013
    Last edited by a moderator: Mar 13, 2016
    I apologize for the music. You can mute this and get everything you need.



    Notice the wrong way driving bypass maneuver in the first 30 seconds.
     
  9. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    @ElSupreme video: Stupid human tricks. I hope they don't reproduce.
     
  10. adiggs

    adiggs Active Member

    Joined:
    Sep 25, 2012
    Messages:
    1,347
    Location:
    Portland, OR
    I've learned to take bumps in the road (railroad tracks, driveway ridges - that sort of thing) at an angle in my Roadster. As best I can tell, it is as Doug says - the bump is spread out instead of being taken straight on and evenly by the tire. My theory, at least with railroad tracks, is that the tires are wide enough that if I get enough of an angle, then some part of the tire is always on the road surface, and the tire as a whole never gets a chance to drop down into the track / depression.

    For speed bumps, I've tried taking them slowly at an angle, but I find slowly and straight on is better. I haven't yet encountered a speed bump that was tall enough to scrape the car when I had wheels on either side of the bump (and I'll be pretty unhappy if I ever do find such a thing). Slowly and straight on lets the entire front of the car rise up as one unit and then come back down, followed by the back going up and down.
     
  11. wiztecy

    wiztecy Active Member

    Joined:
    Apr 29, 2012
    Messages:
    2,720
    Location:
    Santa Cruz, California, United States
    I've always been cautious going over speedbumps, at least the 1st pass, as if they're landmines. If one appears to be tall I do my attack on an angle and sometimes open the door to visually see that the Roadster clears. Its not the speedbumps that've been the issue but rather roads that are perpendicular to each other, such as entering from a side-road to a main road where there's a good dive/dip/transition angle while entering. At first I slightly scraped the paint on the far front right corners of the ABS nose, nothing major and surprised me it scraped there. I've learned the car since then and only the nose will slightly scrape now which the nose has some give and the scratches are so fine you don't even know they're there so its fine for me. I have entered a road, felt the front black airdam scrape and I knew that I wasn't going to make it, had to back up and find a new way out of the parking lot. For my driveway I have to back in to charge as well as to avoid scrapes since there's a transition for the storm run-off there built into the neighborhood road. If its really bad you can back into higher areas easier without scraping than if you approached it going forward.
     
  12. wiztecy

    wiztecy Active Member

    Joined:
    Apr 29, 2012
    Messages:
    2,720
    Location:
    Santa Cruz, California, United States
    So I went out last light dialing in the headlight adjustment, finding old warehouses with garage doors that were level. I entered one warehouse driveway, didn't seem all that steep heading in, but heading out, my nose began scraping. I backed out then attacked it backwards, no scraping on the same line.
     
  13. asgard

    asgard Member

    Joined:
    Aug 17, 2013
    Messages:
    296
    Location:
    CA
    Was it the nose scraping or the front splash guards?
     
  14. wiztecy

    wiztecy Active Member

    Joined:
    Apr 29, 2012
    Messages:
    2,720
    Location:
    Santa Cruz, California, United States
    #14 wiztecy, Nov 24, 2013
    Last edited: Nov 24, 2013
    Didn't sound like it, the front had minor scratches. Just felt the front mud flaps, nothing rubbed off. The sound was more nose specific. Just beware the point of backing up, if you have a lip, say a concrete divider running parallel with your nose or anything like that which is raised, you have to use your best judgement to keep going forward or moving back. Like parking curbs, the brunt of the damage is backing up where the nose / air-dam locks and can't move... eventually ripping off.

    Give me a PM/Mail when you get your TRS HID lights in, I can give you a few pointers to aim them. Mostly showing you where the two low beam adjusters are, where their limits / breaking point is, and ideas on how/where to aim them. Truth is you need both a flat warehouse door with horizontal lines, a docking port where you can see your side angles of your lights. The HIDs will throw a straight line across the sides, so lining left and right is key. And your drive. You need a good stretch of open tarmac that goes up for some time as well as down. Then you can get the best coverage. During the 1st rain I have to say I really love these lights! I could see the yellow headlights of other cars next to me bleeding out. Even in the rain I had an intense white illumination in front of me, that alone gives me quicker response time to any unexpected situation on the road.
     

Share This Page