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  1. #1
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    the science behind the rim holes

    I'm new to r/c, so perhaps I'm asking stuff that's already been discussed. But I couldn't find the science behind a lot of messages saying to punch holes in tires en drill them in rims.

    Why do we need holes in rims and tires?

    If tires balloon, the answer is easy, yes we need air inlets and outlets.

    But I taped my Big Joe's and they don't balloon any more. So the only airflow through the holes occurs when I hit something were the tire is pushed in. And that happens very fast where the hole in the rim is way too small the let the air out in those situations.

    If I close the rim holes and try to push in the tire, I don't get the feeling that the tire will explode or anything.

    any thoughts? any experiments? any tries?

    cheers
    emiel
    e-revo on Big Joe's.

  2. #2
    RC Turnbuckle Jr. Cameron's Avatar
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    the holes in the Tire are purely for water evacuation IMO. The hole in the wheel was to take some of the spring or bounce out of the tire as opposed to being completely sealed off. Holes do not do anything to minimize or increase with balloning. That is strictly interia.
    (RAH) (AH) + [ROMA (1+MA)] + (GA) + (OOH)(LA)

  3. #3
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    Have you ever watched the spin cycle of your washing machine? You'll have to override the door safety but, as the drum(tire) spins up to speed the clothes(tire foam) are pressed against the outside wall(tire) that has holes in it. The clothes(tire foams) are to big to fit through the small holes but the water is not, so it is pushed out of the clothes and into and through the(tire) outer holes.

    Now plug those outer holes(tire) and drill a hole in the top of your washing machine lid(inside wheel). Spin it up to speed then pour water and dirt into your new drill hole. Where does it the dirt and water go? Nowhere but into your tire foam(clothes).

    Holes in the tread are great for track racers that never balloon a tire. IMO A hole in your tread will rip asap when you start ballooning tires bashing.
    Last edited by BL-Bob; 09-02-2011 at 03:58 PM.
    Stop busting my canards!

  4. #4
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    Quote Originally Posted by BL-Bob View Post
    Holes in the tread are great for track racers that never balloon a tire. IMO A hole in your tread will rip asap when you start ballooning tires bashing.
    Hes talking RIM holes, I dont think anyone is a proponent of holes in your tires...
    The hole is made to let water and air out. But the hole also lets water in... I good glue job would be better keeping the insides dry.
    It does made for a slightly softer ride if the hole is big enough to allow air in/out on bumps, but only marginally.
    Bashers; Seal the hole. Tape the tires. Glue your tires well and be done with it.
    Racers; May see a slight benefit due to added "suspension"

  5. #5
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    If you'd have a perfectly sealed tire without rim holes, especially on wheels as big as the Revo ones, you'd end up with a rubber ball effect every time you come over a bump. The air in the wheel couldn't escape and the car would bounce, which would seriously mess up handling. Also, sooner or later the air being compressed on a landing would pop off the glue on the rim, and the air would then escape through there when needed, resulting in the glue coming off more and more.

  6. #6
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    my goal is to close all holes (or not punch them at all) so nothing can go in.

    If the holes in the rims are there because air needs to go out when the tires are pushed in, isn't that hole way too small? A tiny hole can never let the air fast enough out in case of bump.

    cheers
    emiel

  7. #7
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    Even if you think you've sealed your tires properly debris and moisture will eventually find it's way into the tire and start eating away at the insert. A sealed tire will balloon and deform and it will be really really slow at getting it's original shape back.

    Make two small ROUND holes in the tire opposite to each other to let water/moist and debris out. Use a glowing nail, leather punch or something similar to make the holes. Don't use a knife or scissors. The tire won't rip unless it's made out of the same rubber as the Talons

    Oh yeah, I'm no racer. Pure basher!
    E-Revo Xerun 150A/Leopard 4282//MBX6-Te MMM/CC1518

  8. #8
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    I always put holes in my tyres even the talons and have never had a ripped tyre, even on 6s. I use a drill bit or a soldering iron. The talons will tear everywhere else before the drill holes cause a problem.
    Signature removed due to excess awesomeness.

  9. #9
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    Quote Originally Posted by j.f.s View Post
    Even if you think you've sealed your tires properly debris and moisture will eventually find it's way into the tire and start eating away at the insert. A sealed tire will balloon and deform and it will be really really slow at getting it's original shape back.
    just trying to understand the 'why' .

    why does a sealed tire balloon and an unsealed tire not???? ballooning doesn't occur when the tire is taped.

    cheers
    emiel

  10. #10
    RC Turnbuckle Jr.
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    Quote Originally Posted by Emielstroeve View Post
    If the holes in the rims are there because air needs to go out when the tires are pushed in, isn't that hole way too small? A tiny hole can never let the air fast enough out in case of bump.
    sorta... how big of a hole do you think it would need to be? The small holes in the rim are to reduce bounce, if you get a fully sealed setup, you'll see what I mean by bounce. My Ofna Pirate 10.21 came sealed, and the tires would literally bounce along.

    You don't need a zero resistance hole, its just for a damping effect.

    Quote Originally Posted by revomikey View Post
    I always put holes in my tyres even the talons and have never had a ripped tyre, even on 6s. I use a drill bit or a soldering iron. The talons will tear everywhere else before the drill holes cause a problem.
    Yep... holes in the tires themselves, along the centerline. I use my soldering iron to melt a hole. I don't have any on the revo right now, but the SC10 has holes in the tires.

    It seems strange, but holes in the tires are way more effective. I'd even say go ahead and seal the rims once the tires are punched.

  11. #11
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    Quote Originally Posted by Emielstroeve View Post
    just trying to understand the 'why' .

    why does a sealed tire balloon and an unsealed tire not???? ballooning doesn't occur when the tire is taped.

    cheers
    emiel
    Any tire will balloon, sealed or not. The rubber itself isn't able to withstand the centrifugal force. Taping is necessary with most tires.

    There's air inside the tire even when they're sealed and as stated by others you'll be running your car with something similar to a ball instead of tires.

    Try both ways and see for yourself, that's a good way of learning

    Sent from my Desire HD using Tapatalk
    E-Revo Xerun 150A/Leopard 4282//MBX6-Te MMM/CC1518

  12. #12
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    A small counterpoint:
    I run rather large HPI Terra Pins on Maximizer beadlock wheels as my main tire of choice. They are airtight. The rubber ball analogy is good, but is only valid to a point. Rubber balls bounce. Rubber balls with a couple pounds strapped to them... not so much. I would NEVER recommend "pneumatic" tires for racing, and neither would I recommend the heavy beadlock wheels for that application, but for bashing a Revo I have found sealed tires make little difference in performance and enjoyment.

    If water in the tires is a concern, there are only 2 options:
    1.) Unmount the tires and dry the foams
    2.) Air the tires with a couple diametrically opposed holes.

    I know which option I'd choose.
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  13. #13
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    just got back from the first test-drive with no holes at all. no ballooning (off course, they're taped).

    bouncing also doesn't occur more than with holes. it's like ksb51rl mentions, a bal only bounces because there's pressure inside. in rc tires the pressure is the same as outside, so they don't bounce more than usual.

    cheers
    emiel

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