What are the benefits of BTA?

[sim]

Like the title says, what are the advantages and disadvantages of BTA setups? I know you get a bit more clearance in front and (for most angled knuckles), you get more toe-outish ackermann. Are there other benefits?

Is BTA important in a comp rig?

[gunnar]

The obvious advantage of BTA is nothing to hang up on rocks except the axle itself. It does take some more work to get it right, as you are dealing with much less room to run tierods, etc. around shock and link locations. Ackermann has more to do with what knuckles you use, and how they are set up, as opposed to just running BTA. Toe-in or out are all adjustable, just depends on what you want to do with your steering to get the best result. I have seen several excellent front-of-axle steering setups, so BTA is not totally necessary, but it does help if tierods, etc. are as high up as you can get, at least near the top of the pumpkin. It's great to have on a comp rig, but it is not a must-have.

[sim]

Thanks again, Gunnar. I've been learning a lot just from reading up on your 3 builds.

[EeePee]

Yeah this gunnar guy is pretty helpful.

What he forgot to mention is that the behind the axle set up is for people who can't drive.

[gunnar]

Originally Posted by EeePee

Yeah this gunnar guy is pretty helpful.

What he forgot to mention is that the behind the axle set up is for people who can't drive.

Ha! yea, that's true, at least in my case.

[rc4x4crawler]

Pros:
It helps your approach angle
It gives you better steering ackreman
You can dig up hill easier

Cons:
It takes a lot of work to set up
It takes a lot of your suspension tunability away
Since the inside tire turns sharper you may rub on shocks

[gunnar]

Originally Posted by rc4x4crawler

Pros:
It helps your approach angle
It gives you better steering ackreman
You can dig up hill easier

Cons:
It takes a lot of work to set up
It takes a lot of your suspension tunability away
Since the inside tire turns sharper you may rub on shocks

I will have to disagree on a few things. In your Pros list, the first line is right. In the second line, Ackermann has nothing to do with where the steering rods are located, it is what type of knuckles you run, and the degree of toe-in or toe-out you have. Dig uphill easier? I would think that would depend on how much traction you have, and how much steering you have if you are turning.

Onto the Cons. It's not that hard to set up a BTA, but it does take some thought as to making room for everything, and steering capabitily of the knuckles. As long as nothing is rubbing too much, shock tuning should not really change.
Moving your shocks will get get you more steering angle, Ackermann knuckles or not. If you can't move the shocks, then that or hitting the links will determine your max steering angle in most cases.

[sim]

With the Ackermann, I think it doesn't make a difference if you're running 90-degree knuckles (0 ackermann). But for most knuckles (like the AX10 kit knuckles), with the normal (in front of axle) steering, the outer wheel turns more, while with BTA, the inner wheel turns more.

I think that's what he meant.

[phillyb]

For me it was getting the servo output behind the axle. Didn't like my servo hitting things. Been running plastic servo horn without problems, broke it several times when it was out front. It is a pain to get to work smoothly without rubbing anything. It can limit your link and shock options, but I have mine setup the way I like it. Also depends on what kit you get, or if you build your own.

[newtoy]

what does bta mean?

[JeepinOR]

Behind The Axle.