Sport Front Weight

[Rocky Bar]

Okay, just got the TRX4 Sport. Looked at the front bumper for adding weight. Got some 1/2oz stick on tire weights to fit in the cavities . 3oz total slid right in, so will see if it works out on our rocks. More rain coming in tonight. Will post after testing. Anyone tried this? Cheers.

[Mailman19]

I just purchased the Sport and want to know if the brass differential covers are a good way of adding weight without sacrificing performance?

[Browneye]

A lot of fans for these...
Unsprung weight down low works the best. Anything else will just raise COG.

[stormridersp]

Originally Posted by Browneye

A lot of fans for these...
Unsprung weight down low works the best. Anything else will just raise COG.

That's a double edged sword argument. You're right to say that putting the weight down into some of the unsprung components is beneficial: that's particularly true for solid axles because they have their roll centers in the center of the axles and one wants to get the *weight as close as possible to the roll center. *In particular the sprung weight because that's where the momentum is.


It wont help if you put a lot of weight in the axles, but as soon as you move forward while in an incline, the sprung weight shifts around throwing away the balance. Most of rolls are caused not while static, but when accelerating or braking.


Also, tires and wheels are also unsprung components. While it can be beneficial to put some weight down, even in the rotating parts, one needs to learn how to do deal with the change in dynamics caused by the added inertia. This weights is rotating around the roll center and drawing vectors everywhere and stealing performance out of the suspension (geometry, dampers and springs).



IMO, the conclusion is that the weight is compromise between sprung weight balance or sprung weight momentum and CoG.

[Browneye]

Originally Posted by stormridersp

That's a double edged sword argument. You're right to say that putting the weight down into some of the unsprung components is beneficial: that's particularly true for solid axles because they have their roll centers in the center of the axles and one wants to get the *weight as close as possible to the roll center. *In particular the sprung weight because that's where the momentum is.


It wont help if you put a lot of weight in the axles, but as soon as you move forward while in an incline, the sprung weight shifts around throwing away the balance. Most of rolls are caused not while static, but when accelerating or braking.


Also, tires and wheels are also unsprung components. While it can be beneficial to put some weight down, even in the rotating parts, one needs to learn how to do deal with the change in dynamics caused by the added inertia. This weights is rotating around the roll center and drawing vectors everywhere and stealing performance out of the suspension (geometry, dampers and springs).


IMO, the conclusion is that the weight is compromise between sprung weight balance or sprung weight momentum and CoG.

While that all makes perfect sense for anything that goes fast, it's just not applicable for a crawler - most of the time it's barely even moving.


Weighting makes a HUGE difference - and you don't want it on the chassis.



The SSD portal covers is a very clean way to add 75g to each wheel, or almost 3 ounces, none of it rotating, so that's also a plus. LockedUp RC makes nice covers as well, I think they come in around 2oz.



I run wheel hub weights too, in conjunction with Beeftubes, on my Vaterras - comp level traction and balance, and no issue at crawling speeds.



If'n you like brushless speed and bashing then all bets are off.

[Natedog]

What Browneye said, but I prefer these portal covers as the fit, finish and quality is far better than any of the other brands.
https://metalfabbyreed.com/products/...nt=46563025364

LockedUpRC does some decent black steel covers, but fit is not as good as MFR (Metal Fab by Reed).
TRX-4 Black Steel Portal Covers

[JC3]

I think a few people have definitely tried it. It's a free upgrade that will help a little by increasing the weight distribution up front. As you move forward with your tuning you will want to take the advice given regarding the portal covers. My friend and I have crawled for probably 75 hours with our X4's. While that certainly doesn't make us experts it has helped us know the X4 better. Point is, you'll find that a 60f/40r weight distribution combined with a concerted effort to lower the trucks center of gravity as much as possible will get you a very capable crawler.

[Browneye]

Hey, nice link there Nate - have not seen that stuff before.
Those would be perfect for rears.
I really like the trx chassis, it seems to work well.
Much as I love the Vaterra the trx does everything just as well and some things better. Jury is out on the portal axles in the first place. These are surprisingly simple and well engineered. I liked how they fit together, very smooth running.

[Travis G]

I really like the Treal outer drive housings, they weigh in at a massive 93 grams and made a very noticeable difference compared to my second (100% stock) Sport.

[Tankinfrank]

I ran the stick on weights inside the front tires for awhile. (5 per wheel) I liked the way it help on climbs. Just recently removed those weights and went with the brass front portal covers. The portal covers gave me a little extra weight down low. I could defiantly tell the positive difference of my Sports vertical climbing ability after this change.