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torque from curt hitch/bike rack

Discussion in 'Gen 3 Prius Accessories and Modifications' started by PortlandHiker, Aug 17, 2015.

  1. PortlandHiker

    PortlandHiker Junior Member

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    I installed a Curt hitch to carry my Swagman XC 2-bike rack. I took it with my mountain bikes on a short overnight trip last weekend and it seemed to hold up fine. Based on the advice in this forum, I limited the weight to just the two bikes. However, I was a little worried when I hit a few hard bumps on the highway. Since the bike rack sticks out from the back of the car, there is quite a bit of torque delivered to the undercarriage. Has anyone had experience with damage to the undercarriage of the car due to the bike racks? I'm fine if the hitch itself breaks (that's cheap and easy to replace). Damage to the undercarriage of the car is another matter and is probably a much more expensive fix.
     
  2. ChapmanF

    ChapmanF Senior Member

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    I added a hitch right after I bought my car several years ago and, like you, I drove around always with a nagging worry ... what about too much weight? What about hard bumps? What about neighborhood kids using it as a jungle gym when I'm not looking?

    The weird thing about hitches is they always rust, waaay faster than any other part of a car, so I finally reached the point a couple years ago where I said, all right, time to take that hitch off and get it powdercoated. And while I was doing that anyway, the brainstorm struck me, to take it to a hitch fabricator and have him locate a couple more usable holes in my frame channels about half a meter forward of the ones the hitch used. He welded a pair of extensions onto the sides of the hitch, to reach forward to that other pair of holes, so the hitch now has a four-point attachment, with a front-rear distance of half a meter to resist torque. Then I took the newly-modified hitch to the powdercoating shop, and put it back on the car.

    Maybe that was overkill, but I can say I just don't worry about torque on my hitch any more, and life felt too short to worry about it the way I was before.

    -Chap
     
  3. PortlandHiker

    PortlandHiker Junior Member

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    Wow, came across this post when looking up something. I have also come to the same conclusion as you. Drive and stop worrying. The hitch has proven to be very solid over the past 6 years and carried my bikes many places.
     
    bisco likes this.
  4. ChapmanF

    ChapmanF Senior Member

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    From your post, I'm not sure, it sounds like maybe my point didn't quite come across. My conclusion was to extend the hitch attachment to additional points half a meter further forward, turning my former torque worries into non-worries, and then stop worrying about them.

    It might be worth mentioning that what I had in my hitch was a platform-style carrier, which might even have had a larger moment of torque than a typical bike rack, so it was something I worried about, before doing the mod to make it a non-issue.
     
    Tande likes this.