What is it with aluminum arms?

[DavidB1126]

I see alot of people on the 2wd Slash only FB group I am in. Alot of people are getting aluminum arms. I always comment that you'll regret it in the future.

Here is my understanding of aluminum arms and other components such as shock towers:

Aluminum bends and not break.

If you crash the energy will either bend the aluminum arms or transfer the energy to another plastic part and that plastic part will break.

And then you upgrade to all aluminum. After that where would all of the energy go? Will it just bounce around in the arms and make them bend?

My no go's for aluminum pieces are arms, shock towers, and turnbuckles. For shock towers and arms I would keep the OEM parts or if RPM makes them for the car. For turnbuckles I usually stay with titanium or steel. I had the traxxas aluminum turnbuckles and I snapped 3 of them before. It is traxxas and they do lie about their aluminum strength and other stuff. I heard that the amazon aluminum turnbuckles either pull out of the plastic rod ends (if they are plastic) or snap, or bend. Technically you could bend a steel turnbuckle (it happened before with my uncles xb4)

I just want to get a more understanding of aluminum arms and other aluminum pieces.

 

[WickedFog]

There needs to be some give in areas that will take a hit. If not, damage will occur. Aluminum bulkheads, , knuckles and uprights, chassis braces, motor plate, diff and trans housings, and chassis are all good places for aluminum. Shock towers are ok, depending on the design. Just know that aluminum adds weight. It will rob power from the motor to push that weight around. The vehicle will also perfom differently.

Shock towers bolted into plastic trans or diff housings add weight, so any front or rear collision can create more energy that pulls the shock towers away from whatever they are bolted to. But as long as the design has a sturdy mount for the tower, aluminum shock towers are just fine. But, like on buggies, where the shock towers are exposed, you definitely want 7075 T6 aluminum towers, as they will not bend (permanently).

I don't ever just go out and buy aluminum until something breaks. On smaller scale buggies and such, like our Dromida DB4.18, I added every aluminum part I could get because the buggy is so light, it doesn't really matter. It does 40mph cartwheels and lands unscathed. It made it pretty near indestructible. But anything bigger than that, I stay plastic til it breaks. The bigger cars just have too much weight, and go too fast for stuff not to break or bend. So you have to choose your aluminum upgrades based on that, and how you drive them.

Like on track cars, aluminum adds stability. Less flex, and more predictable performance. Bashers are used completely differently, and plastic lets things flex more on hard impacts.

You should never use aluminum arms on anything you plan to bash, unless like I said, it is a small scale, lightweight vehicle.

 

[TRAT]

Well I deal with a lot aluminum so guess I’m one those dumb dumbs
On thing I can say my Baja Bug all aluminum every bit of it. Aluminum adds a lot weight and that’s why that’s a 8s buggy. Rest my builds like my black rail mild steel tubing and yes some aluminum but way it handles is priceless.

 

[bill_delong]

In terms of racing there are many brands which offer various hardness of plastic ranging from soft-medium-hard where the stiffer the arm the more responsive the car will handle... in fact many brands offer carbon inserts as arm stiffeners as well. The key here is to adjust the amount of flexibility where there is no flexibility with aluminum which will not absorb the impact and will transfer the force to break more expensive parts.

Nothing wrong with running aluminum arms if you have the budget to replace the more expensive parts and absolutely need that extra level of responsiveness to get faster corner speed.

I suspect many people just want to dump as much money on "upgrades" with the belief that they are improving the quality of their car

 

[Bogda89]

Other factors that people don't mention is fit and finish. Many aftermarket aluminum parts don't fit properly and have to much slop or change steering geometry. And also additional weight especially if it is unsprung.

 

[DavidB1126]

Other factors that people don't mention is fit and finish. Many aftermarket aluminum parts don't fit properly and have to much slop or change steering geometry. And also additional weight especially if it is unsprung.

Yea I had Integy castor blocks and they fit. But for the steering blocks it didn't because the hole for the pin was too small and I stripped the screw pin into the castor block. Those integy aluminum ones were 20 dollars too. :| What a waste of money.

In terms of racing there are many brands which offer various hardness of plastic ranging from soft-medium-hard where the stiffer the arm the more responsive the car will handle... in fact many brands offer carbon inserts as arm stiffeners as well. The key here is to adjust the amount of flexibility where there is no flexibility with aluminum which will not absorb the impact and will transfer the force to break more expensive parts.

Nothing wrong with running aluminum arms if you have the budget to replace the more expensive parts and absolutely need that extra level of responsiveness to get faster corner speed.

I suspect many people just want to dump as much money on "upgrades" with the belief that they are improving the quality of their car

View attachment 161513

I put more into my slash and it still looks like a slash. I seen people do like a back slash custom thing where they use a 1/8 buggy body and wing on a slash with 17mm hexes and 1/8 wheels/tires and it looks awesome.

 

[WickedFog]

Our Slash doesn't look much like a Slash anymore.

 

[DavidB1126]

Our Slash doesn't look much like a Slash anymore.
View attachment 161518

Maybe I should do a drag build. But heres the thing, i gotta get on FB to find some local drag clubs/groups.

 

[Lukedavis]

Maybe I should do a drag build. But heres the thing, i gotta get on FB to find some local drag clubs/groups.

Or, a more fun thing to do is do it on the street as I do

 

[Addict Rc]

aluminum can be good and bad, you need some lean way (give) to parts that will break to save the rest of the car, if you get the aluminum a-arms and happen to land on them there’s a good chance you’ll break something else because of the stress it’s putting on the other parts

 

[RustyUs]

Well, people must be buying them (aluminum aftermarket parts), 'cause there is a crap ton out there being made. And sorry if you are the owner, or you know the owner, but this just blew my mind...

 

[Greywolf74]

 

[Bogda89]

Well, people must be buying them (aluminum aftermarket parts), 'cause there is a crap ton out there being made. And sorry if you are the owner, or you know the owner, but this just blew my mind...
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View attachment 161705

This guy is probably asking 800$ for a used aluminum slash

 

[cbaker65]

I use aluminum in certain area's ,like chassy brace's hubs an shock towers on certain rig's
but never for A-arms!
I look at all aluminum rig's as eye candy & shelf queen's an the occasional little show &
tell stuff!..

 

[JCsRCcar]

I learned my lesson the hard way with aluminum. Its heavy and expensive and like others said either bends or transfers the energy to something else that is harder to fix like the bulkhead or chassis. I stay stock or RPM now with a few exceptions like the steering linkages, diff covers, or motor plates.

 

[turbo27]

Sounds to me. To each their own. I will figure it out, see what happens. God bless America. Its all about choices, and fun.

 

[BarnFabRC]

I run aluminum arms on my Slash but that only ever gets used for pavement racing. My Rustler does all the bashing and jumping. That has RPMs all the way around.

 

[turbo27]

I won't do the A arm thing. But anything goes after that.