Question about adding weight to wheels

[Greywolf74]

I have a question that Id like to get expert opinions on about adding weight to wheels. Now Im a complete novice to crawlers as the only thing I own that even resembles a crawler is an SCX24 but Ive been in the RC hobby itself for somewhere around 12-14 years. Someone that I met recently tried to convince me that cutting your foams down to 3/4 of their original height and then sealing the wheels after filling the tires with water was the most amazing "mod" ever. We debated this quite heavily as I was convinced otherwise. My theory was sure it adds weight but it also would seemingly greatly reduce the tires ability to conform to what its trying to crawl over like it would normally with the air being able to escape the tire and allow the soft rubber compound to be much more pliable. Not to mention the water would ruin whats left of the foams after a period of time.



I tried to tell him that adding actual weights around the wheel itself would do the same thing and still leave the tire with the ability to function as intended. Its my understanding that this is a common practice for people to do to their crawlers and it makes sense to me. There were actually 4 of us that were trying to tell him he was mistaken but he said we were all idiots who dont know anything about crawlers. Well its true that I dont know to much about crawlers outside of what I read in forums and the other 3 guys have crawlers but arent experts so I figured Id come over here and see what seasoned veterans of crawling have to say about it.



Im completely open to the possibility that I might be completely wrong here and Im genuinely curious if theres something that I dont know preventing me from seeing the benefits in this persons "mod" Thoughts? Opinions?

[high plains drifter]

Don't use water. There's a lot of different types and choices regarding brass, steel, etc. You can do hubs, portal cover weights, weights inside the wheel ( which I'm not a big fan of but whatever). But regardless.. my opinion would be to get some legitimate weighted parts to add to the four corners. Water is going to be a mess, will degrade many types of foams, and won't add much weight overall. I don't like lead/ copper/ brass pellets either but I'd use that method over water too.

And I'd take zero advice to heart coming from someone that outright calls me an idiot. He sounds like a moron himself, or an asshole... prob both. Either way... I wouldn't waste my time with people that have that kind of attitude when it comes to "helping" others.

[Browneye]

I'm with you on this one.
For one thing, the water thing is too much hassle.

With proper two-stage foams you get good squish and contact patch, the the more rigid core assist with side-hilling. I'll usually put a slit between two tread blocks on polar opposites, so that heat or change in elevation vents the tires. I've had them blow up and shrink down/suck in from elevation changes.

I was happy with my Crawler-Innovations foams, but the outers tend to get too soft, they flat spot horribly (not putting my trucks on center stands) and even the center cores deformed horribly. I have a couple sets of the new 'lazer foams' coming from AMain, anxious to see how they do.

YMMV

[DRED805]

He's right, but you're gonna want to use liquid mercury instead of water. It's like 15x heavier.

[HumboldtEF]

Back in the old days people filled crawler tires with BB's, I think with no foams so they'd roll to the bottom. I might try that on a SCX24 but nothing else.

Water in the tires is a farmer trick I think, they do this with tractors and other farm equipment to keep them shiny side up.

I'm also not a fan of adding mass to rotating mass especially when theres typically a weighted knuckle option out there already.

Only item I agree with is an undersized foam (just no water afterwards), provided is not a heavy crawler.

[Greywolf74]

Thanks for the replies folks. Just wanted to check and make sure I wasnt crazy.

[themountain]

https://www.youtube.com/watch?v=pvwmu-WWFS4 all you want to know.

[Greatscott]

We back in the day, people in the comp crawler scene would put BBs in their tires to get the CG lower, some even experimented with different liquids. The whole mess actually worked fairly well for slow crawling, the tires oozed over the rocks, giving lots of traction, so it does work. They would play with the amount of foam in the tires to give a good balance between uphill crawling and side-hilling; with out foam in the tires, the tires would just fold if there were not going straight up a rock. Problems ensued when the driver wanted any kind of wheel speed, the BBs would pool in one spot and cause all kinds of control issues.

[Inspector86]

In general, I do not advocate adding weight to the wheels which becomes rotating mass. However, rotating mass in a slow speed crawler is not really a big deal. That said, I much prefer adding un-sprung weight to the axles in the form of C-hubs or any of the many brass axle parts available in the aftermarket.

[DirtBug]

I've got an old bottle of liquid mercury if anyone wants to give that one a shot

[DRED805]

Originally Posted by DirtBug

I've got an old bottle of liquid mercury if anyone wants to give that one a shot

[Gula]

BB gun bb's the .177 cal ones, is what the ogs used to put in their tires.

[ferp420]

Originally Posted by Gula

BB gun bb's the .177 cal ones, is what the ogs used to put in their tires.

my losi still has bbs in the tires i cant remeber the last time i ran it though

there werent alot of options at the time