i_r_beej
Well-Known Member
- Messages
- 993
Recently I've been really frustrated with the shoulder screws falling out of the caster blocks. I've been running the RPM replacements for the stock ECX parts, and while they are nicer and "stronger" they still suffer from the fundamental ECX design flaw of very shallow holes for the shoulder screws to thread into.
In looking for an alternative (I'm not crazy about aluminum parts in my steering assemblies) I discovered that some Associated B4 (specifically B4.2/T4.2) steering components are compatible with the 2WD ECX vehicles (Boost, Circuit, AMP for sure; maybe Ruckus and Torment). The Associated design uses a kingpin that slides completely through the spindle block and caster block and appears to be a much more reliable, stronger design. (I hope!)
I found a complete set of caster blocks, spindle blocks, bearings, ball studs--everything--on Ebay so I decided to give it a try. The parts arrived early so I decided to test one side. (I'll perform the complete the installation later.)
It looks like this modification will be a success! The Associated parts fit right in with NO problem! The Associated design uses a narrower caster block so that you can tweak the wheelbase of the car a few millimeters by inserting a spacer in front or behind the caster block. The stock Associated spacer is about 6mm and the ECX A-arm is not wide enough to accommodate it but I did have 3mm nylon spacers on hand (or I would have just sanded down the Associated spacer).
Here's the stock ECX steering components (left) compared to the Associated B4.2 components. Geometries appear to be identical with the exception of the position of the spindle in the spindle block. The ECX is "in-line" whereas the Associated is off-set or "trailing." (Apparently a trailing steering arrangement makes for easier handling at speed and is better for high-grip conditions. This is the stock, out-of-the-box configuration for the Associated B4.2/T4.2)
Here's the Associated B4.2 caster and spindle blocks installed in the ECX A-arm. Everything fits snugly, with no binding. Like they were made for each other! Interestingly the camber link ballstud is locked in place with a nut, instead of just threading into the plastic.
And here's the underside, showing the white nylon spacer in place. In the Associated B4.2 documentation it's recommended to put the spacer behind the off-set/trailing spindle block. Even with the space in place it looks like I will be shortening my ECX Boost's wheelbase by a few millimeters. This will probably not affect in any appreciable way. (And look at that! The steering link ballstud is anchored with a nut! Nice.)
I DO have a few minor hurdles to clear before I can get rolling on these new Associate parts. The spindle is not a metric diameter so I will need to get Associated hexes. The hex pin is a different, smaller diameter so none of the pins i have on-hand will fit. I will also need new axle nuts. I plan on taking my car to the LHS and checking out what they have. And finally I'll need a new hex key to remove/install the small screw that captures the kingpin.
I'll update this post with additional information and photos when I perform the complete installation.
In looking for an alternative (I'm not crazy about aluminum parts in my steering assemblies) I discovered that some Associated B4 (specifically B4.2/T4.2) steering components are compatible with the 2WD ECX vehicles (Boost, Circuit, AMP for sure; maybe Ruckus and Torment). The Associated design uses a kingpin that slides completely through the spindle block and caster block and appears to be a much more reliable, stronger design. (I hope!)
I found a complete set of caster blocks, spindle blocks, bearings, ball studs--everything--on Ebay so I decided to give it a try. The parts arrived early so I decided to test one side. (I'll perform the complete the installation later.)
It looks like this modification will be a success! The Associated parts fit right in with NO problem! The Associated design uses a narrower caster block so that you can tweak the wheelbase of the car a few millimeters by inserting a spacer in front or behind the caster block. The stock Associated spacer is about 6mm and the ECX A-arm is not wide enough to accommodate it but I did have 3mm nylon spacers on hand (or I would have just sanded down the Associated spacer).
Here's the stock ECX steering components (left) compared to the Associated B4.2 components. Geometries appear to be identical with the exception of the position of the spindle in the spindle block. The ECX is "in-line" whereas the Associated is off-set or "trailing." (Apparently a trailing steering arrangement makes for easier handling at speed and is better for high-grip conditions. This is the stock, out-of-the-box configuration for the Associated B4.2/T4.2)
Here's the Associated B4.2 caster and spindle blocks installed in the ECX A-arm. Everything fits snugly, with no binding. Like they were made for each other! Interestingly the camber link ballstud is locked in place with a nut, instead of just threading into the plastic.
And here's the underside, showing the white nylon spacer in place. In the Associated B4.2 documentation it's recommended to put the spacer behind the off-set/trailing spindle block. Even with the space in place it looks like I will be shortening my ECX Boost's wheelbase by a few millimeters. This will probably not affect in any appreciable way. (And look at that! The steering link ballstud is anchored with a nut! Nice.)
I DO have a few minor hurdles to clear before I can get rolling on these new Associate parts. The spindle is not a metric diameter so I will need to get Associated hexes. The hex pin is a different, smaller diameter so none of the pins i have on-hand will fit. I will also need new axle nuts. I plan on taking my car to the LHS and checking out what they have. And finally I'll need a new hex key to remove/install the small screw that captures the kingpin.
I'll update this post with additional information and photos when I perform the complete installation.
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