Thread: tyre to tray clearance

  1. #1
    Join Date
    May 2016
    Location
    pomona qld australia
    Posts
    55

    Default tyre to tray clearance

    hope you all had a good christmas, i am starting to make my tray for the nps single cab and looking for advice on the tyre to wheel arch distance when unloaded. i have spent some time searching on here and have found nothing yet. vehicle is a 2007 nps single cab with 37 inch super singles and will be probable permanantly loaded at close to its 6000kg gvm

  2. #2
    Join Date
    Sep 2017
    Location
    South Australia
    Posts
    78
    Measure bump stop clearance and add 25% of bumpstop height for bump stop squish. Estimate cross axle deflection using straight edge to simulate max droop one side max compression the other. Add all together and you’ll be pretty close.

  3. #3
    Join Date
    Sep 2017
    Location
    South Australia
    Posts
    78
    My tray run 75mm chassis rails and 50mm floor joists

  4. #4
    Join Date
    Aug 2009
    Location
    Brisbane, Qld, Australia
    Posts
    615
    Mitsubishi have a rear axle bump diagram. I don't know about Isuzu.

    Simplistically, one side on squashed bump stop, the other side fully extended.

    The narrow chassis and dynamic forces mean the movement can be a lot more than one may imagine at first glance.

    Then allow for tyre size.

  5. #5
    Join Date
    Oct 2017
    Location
    Sydney
    Posts
    18
    Quote Originally Posted by trackadda View Post
    hope you all had a good christmas, i am starting to make my tray for the nps single cab and looking for advice on the tyre to wheel arch distance when unloaded. i have spent some time searching on here and have found nothing yet. vehicle is a 2007 nps single cab with 37 inch super singles and will be probable permanantly loaded at close to its 6000kg gvm
    G'day i have an NPS crew with singles , from the top of the tyre to the under side of the wheel arch i have close to 300mm . With all this flex it only came within 180mm of the tray ,
    hope that helps. I guess you need to take into account the extra weight .





  6. #6
    Join Date
    Aug 2009
    Location
    Brisbane, Qld, Australia
    Posts
    615
    maybe a second forklift on the opposite side, lifting the frame, so one side is fully compressed, the other side fully expanded.

    also things "bend" under dynamic loads in ways that don't show with static loading.

    but 180mm from that position "should" be ok. I have 250mm from flat on the Canter.

  7. #7
    Join Date
    Mar 2016
    Location
    Darwin NT Aust
    Posts
    54
    Hi Trakka, I posted the same question here a couple of years ago, there is a diagram in the Isuzu body builder manual but not much use if you have changed wheels etc, I got all sorts of answers, some as low as 50mm clearance, as I've had the ATW springs and alloys done I asked them and they said aim for 200mm, I have 190mm unladen. Hope that helps.

  8. #8
    Join Date
    May 2016
    Location
    pomona qld australia
    Posts
    55
    thanks for the replies every one, i have aimed at 200 unloaded and i can't see this being a problem

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •