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Air Guide rubbing on DFW

Discussion in 'Ask The Pros' started by Revenge of 85, Apr 20, 2022.

  1. Revenge of 85

    Revenge of 85 Pack Champion

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    I have an air guide catching the DFW when I push the wheel in on the bent axle. The only way the wheel spins free if I set the wheel gap wider. It seems to steer without a wobble with a wider gap. Would you suggest sanding the outside of the guide to try and get a closer gap? Or, is it fine running a wide gap?
     
  2. T-Bone Racing

    T-Bone Racing Workshop Leader

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    Is this for a Mid America car? Just to clarify, you’re saying that the air shield is rubbing the inside of the wheel right? Basically the part you can’t see when it’s in the car?
     
  3. Revenge of 85

    Revenge of 85 Pack Champion

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    Yes, it’s for Mid America . My guess is the outer edge of the guide is touching the inside of the wheel where I can’t see it. If I move the axle out a bit it works fine but has a bigger gap than I like.
     
  4. T-Bone Racing

    T-Bone Racing Workshop Leader

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    Yeah, I’ve run into this problem countless times. I’d recommend trying to sand it. Sanding it allows you to run the gap where you want rather than where you need to. If sanding it doesn’t work, then you could try to reglue it and adjust the angle, or try to get a smaller air shield. The MA wheels are very small and angling the shield for the DFW can be tricky.
     
  5. DerbyDad4Hire

    DerbyDad4Hire Administrator Staff Member 25+ Pro Race Wins! National Champion

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    The underside of the tread needs to be lathed.
     
  6. HurriCrane Racing

    HurriCrane Racing PWD Royalty 25+ Pro Race Wins! Pro Racer National Champion

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    I normally don't run into this problem, especially with 2.0 gram and Mid Am wheels. They have quite a bit of material removed from the inside of the wheel. Are you using a stock BSA wheel? What type of air guide are you using? What is the diameter of the air guide?
     
  7. Revenge of 85

    Revenge of 85 Pack Champion

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    The wheels are DD4H Mid-America. The air guides are from Derby Evolution. I think the problem was that the axle bend caused the inside of the wheel to rub the air guide at the bottom outer edge. I ended up using a dremel to shave down the guide and had to glue two derlin washers together so the wheel didn’t rub the guide. It’s got a nice gap now and the wheel spins without rubbing. But, I’m wondering if the extra derlin washer on the DFW will cause issues.
     
  8. T-Bone Racing

    T-Bone Racing Workshop Leader

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    I’m not sure I’ve ever heard of using two washers. I don’t know if anyone has ever done this and I could be totally wrong about saying it, but when I’ve had the problem with the air shield rubbing the track, I cut off the bottom of it. I just don’t think that the speed of the bottom part of the air shield is worth the risk of it rubbing the track.

    It sounds like you may not have angled the air shield enough if it’s rubbing the wheel. But I’d probably just cut the bottom off rather than glue two washers together to push it out, but that’s just me.
     

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