vacuum cleaning tires - how to get the dirt out?

[Unusual RC]

After a year of use without any problem, we did some bashing with my Mojave.
Normally we only race, where RPM and speed are lower in order to make the vehicles go as fast as possible over the track.

I use Medial-Pro tires, which really do well on loose dirt.

Suddenly my battery was empty a lot faster.
Are my batteries old and need to be replaced?

A closer inspection showed a huge out of balance of the rear wheels.
A huge hump filled with dirt is visible. Basically not drive-able in this condition.

Check these pictures. There are two holes to let air in and out. Due to the ballooning at full throttle (2S) these holes need to be there.

I can feel the hump of sand through the soft rubber.
With a lot of effort I can move it a bit, and some dirt comes out of the hole.

Anybody had this before?
And anybody a simple solution to get it out?

 

[TheJoker]

I asked a friend and he knows the problem to.
He pluggs the holes in the rims and made 4 holes in the tires.
This makes sure a lot less soil or dirt is coming in he says.
But for get lots of dirt out of the car he searched the whole internet he said, without succes. Its a very common and known problem he said...sadly without a solution.
Good luck to you man!

 

[mrbelloso]

A simple solution is to get low profile belted tires.

 

[Unusual RC]

A simple solution is to get low profile belted tires.

I heard about the concept.
Can you give me some directions where to find these tires?

 

[Dustin Mustangs]

I had the same issue. It got progressively worse over time which made it hard to notice until it was really bad. My wheels were pretty out of balance out of the box but I used a prop balancer to get them close so I knew something was wrong.

I tore the tires off the wheels to investigate and found around 3 tablespoons of sand in one of the rears and 1 in the other along with waterlogged and torn liners. The fronts were both clean and dry (this is on a 2wd granite).

I don't see how this could happen to this extent in dry soil given where the holes are. My theory is that a slurry of water and soil gets sucked in when ballooning a submerged tire. I commonly do (did) that to roost through mud puddles and while chasing waves at the beach. It was a pain to fix so now I lift and coast through water or at least try not to accelerate.

There is s YouTube video of a guy 'waterproofing' his tires by covering those holes with tape. I am a bit reluctant to do it but maybe it is worth a try. Seems like a ballooning tire is going to suck air/water regardless, it would just be from somewhere else.

 

[Unusual RC]

I ....I don't see how this could happen to this extent in dry soil given where the holes are. ...

I have footage of the moment this happened, since my son was driving.
I will try to upload it.
There was no water anywhere where this happened.
And I check these wheels regularly, and this is the first time.

When I squeeze in them very dry sand/soil is falling out of the hole.

I am a bit reluctant to drill small holes in the tire.
But maybe I should get one off the rim > clean out > glue back on the rim > cover the holes with waterproof tape.

 

[Walter]

Perhaps the foams are worn/compressed and thus they are not making solid contact against the rim like when they were new. That might account for why dirt is getting in now and not previously. Also if the dirt is on the inside of the foam then a hole in the tire may not let it out... again it depends on the condition of the foam and whether it will allow the dirt to get around it from the rim side to the tire side.

I hate to think about un-gluing and re-gluing tires/rims... but perhaps some investigation inside the tire is needed.

Let us know how it progresses. Perhaps you can at least save some others from this fate.

 

[Unusual RC]

Thanks @Walter
I think you are right.

I just cut open the inside of the rim with a sharp knife.
This way I am not damaging the rubber, but it comes loose of the inner edge of the rim.

My hope is to not having to cut the front edge of the rim too, just fold it over.
The rubber is very flexible, so this should work.

For now I made a cut 1/4 of the total rim edge length.
A lot of rough (!) sand is visible already.

And my son's Fury uses the same wheels for the rear.
Closer inspection showed one wheel was clean, the other also featured a huge bump and out of balance.

I will try to fixed this in the weekend.
I guess I have to buy some special tire CA glue.

To be continued!
Thanks for all the support!

 

[RC fan]

Thanks @Walter
I think you are right.

I just cut open the inside of the rim with a sharp knife.
This way I am not damaging the rubber, but it comes loose of the inner edge of the rim.

My hope is to not having to cut the front edge of the rim too, just fold it over.
The rubber is very flexible, so this should work.

For now I made a cut 1/4 of the total rim edge length.
A lot of rough (!) sand is visible already.

And my son's Fury uses the same wheels for the rear.
Closer inspection showed one wheel was clean, the other also featured a huge bump and out of balance.

I will try to fixed this in the weekend.
I guess I have to buy some special tire CA glue.

To be continued!
Thanks for all the support!

I've had this problem too. My question is will the bouncing wheel cause problems with the differintial gearing causing the diff to go out. So far I've continued to run the vehicle with sand in the tire. Will this cost me big bucks in the near future?

 

[Basco]

I had lots of water in my tires caused by driving in a deep pool. I've tried to solve this by drying the tires on the heating for several days but they stayed out of balance a lot. In a while I will change the stock types for Pro-lines so I've decided to drill a 3mm hole in them, this solved the balance issue. Know I will see how the tires will hold up with these holes added.

 

[Unusual RC]

As happens when a forum gets a lot of activity, a sort of double post with a good solution was added:
https://arrmaforum.com/threads/venting-tires.1939/#post-25060

I've had this problem too. My question is will the bouncing wheel cause problems with the differintial gearing causing the diff to go out. So far I've continued to run the vehicle with sand in the tire. Will this cost me big bucks in the near future?

An unbalanced wheel is giving a lot of strain to a drive system.
Especially dog-bones, drive-cups, differential, bearings, and last but not least, the motor/ESC.
Vibrations will eventually destroy anything on your RC.

For me the unbalance resulted in run-times of less than 10 minutes, where 15-20 minutes going flat out all the time were the bare minimum.
That is why I noticed this issue.

Luckily I was just in time to take measurements.

 

[chargh]

I am a total newb with RC anything that is meant to stay on the ground (helis and airplanes are what I am use to).
Would it be possible to put a screen with very small holes over the hole to prevent the dirt from getting in?

 

[Unusual RC]

That mesh should be so small...dirt gets into anything.
I come from RC airplanes and fast boats, so I have been where you are now just a couple of years ago, @chargh
Cars looked liked the "easiest" RC option at the time...and I was so wrong!

 

[Hye]

There are a few good videos on YouTube about poking holes 180 degrees from each other on tire. Run wheels until they balloon and water/sand will come out through holes. Sorry I'm not sure how to post link yet or I would.

 

[lonee]

But also closing the holes into the rim in the same time!
I have don that before the first outside run.
I have made four (all 90°) holes in the tire with a small tip solder iron (maybe 1,5mm) and closed the rim holes with small homemade rubber plugs which are glued in with tire glue. Till yet no issues with water inside the wheels.

 

[soko]

Hey guys,
Any (new) suggestions how to get the dirt out of th tires?
My Kraton tires are like a rattle
thx
Soko

 

[Jerry-rigged]

If you already have dirt in the tires, add the holes / vents to the rubber - I do 4 holes, 90 deg apart, but don't plug the rim holes yet. Get the tires wet - let them fill with water (slow driving in water works) - then drive out of the water, and do WOT donuts till all the water is out of the tires - the water will wash the dirt / sand out of the tires.. Do this a few times, till the tires look mostly balanced again.

When you are done, give a good WOT spin in the air to get as much water as possible out of the tires, then plug the rim holes. If there is any sand / dirt left in the tire, the rubber side vents will let it escape over the next few runs.

 

[soko]

Perfect, thx. Only 1 dumb question left for me as a newbie: What is a WOT?

 

[Jeremy in WI]

Perfect, thx. Only 1 dumb question left for me as a newbie: What is a WOT?

Wide Open Throttle

 

[WTF MIKE]

You need to unmount the tires from the rim. I find boiling them is the best and fastest method. Usually for about 45mins flipping them a couple of times.