X12 Inline Chassis Conversion

Building off the success of the original inline X12 we did almost 3 years ago its now time to release our Gen2 of the Chassis conversion. Back in 2021 after the release of the newly designed X12 we worked with a few drivers to make an inline kit. Sending 3 of them off and hearing positive feedback we put it to production. The kit was a success for us but like everything else they slowed down so we turned them into cut on orders. Messages were still coming in over the last couple years asking for them and overall we sold a couple hundred.

In that time we did work on a Gen2 of it with some small but improved changes. Some testing but we never pushed it much. Now with the release of the 24 coming this was the time to revisit the project.

Pulling our notes and designs out of our hard drive we didn’t need much to tweak. Our main goal on this Gen2 was versatility. How do we make one kit fit the 21,22,23 and 24 year kits? Well thankfully the main and important pieces haven’t changed for any of those models.

The rear pivot, side links, front axles and front plate mounting hardware have all remained the same. Add the rear pod assembly of the kit you have and we have it done.

So what is different? What do you need? Lets start with something that you will need additional to your donor car. In 23 they came out with some nice aluminum threaded inserts. We chose not to use these for 2 reasons. First they dont stay in place and we felt can cause a tweak issue after hitting something. Second is they are expensive to replace. We chose to go with the Schumacher pressed inserts. They stay in place and are much more budget friendly. You will need 2 packages of U7689 Brass OR 3 packs of U8065 Black Alloy ones. They come 10 to a pack for brass and 8 to a pack for Alloy and range from 4$ for the brass or 14$ for the Alloy ones. You will need 17 total per car and we will note through this write up how many and locations.

**Do Not Press these into the carbon with pliers. You Will Split the layers. Schumacher Has a very simple way of doing this and it has worked well on all our models of cars. Simply take a 3mm motor screw and 4/5 plain steel washers, stack the washers onto the screw and place through the hole for the insert. Now thread the insert on with knurls towards the hole. Tighten the screw until the insert is pulled into the carbon and seats against its shoulder. If you’re a little shy about doing this you can always CA the edge of the carbon pieces prior for that extra layer of security.

So onto the car itself.

You will use all the rear pod pieces from your donor car, including the lower pivot assembly. The first cross over parts are the two rear standoff posts for the cross brace. You will need to use the ones matching the year pod you have, but not the actual brace. The 21 and 22 models use the same two brace mounts but in 23 they changed it. The earlier two years were taller so they could interfere with a pod from 23.

*Builders Tip: You ‘could’ use the brace mounts from a 23 with a pod from 21/22 and run your dampers under the pod top plate. In 23 they lowered their pod top but make you run the dampers on top, raising some CG points. We dont recommend trying the opposite, this may cause the damper tubes to bind.

Next in our kit is the center shock mounting. We left you with 3 options for tuning. Included are two 20mm alloy posts. These are for the shock bridge. The shock bridge has two holes for inserts. The shallow hole, almost inline with the two mounting holes on the end, will put your shock in the stock kit location. If you wanted to use the forward hole you would need a threaded piece roughly 8mm long to extend your shock. We dont provide this but again Schumacher (U4849) does make something we recommend for it.

*Builders Tip: For the shock bridge you will need a short threaded ball stud. Stock ball studs for these kits are 4.2mm and we recommend one with 4mm of threads at most. For our prototype we cut one down and used a 2mm shim to keep the shock from touching the battery. We do know though Xray makes a short one you could use, its the #372649 ball end. After installing verify the threads will not touch your lipo, this could cause tweak problems or worse.

Next are the side links. In our kit there are two side link wings as we call them. These wings will need 3 threaded inserts each. **Be aware when installing them to the link orientation, they will go in opposite sides of the wings for left and right locations. We will include six 4mm spacers to mount these up from the chassis. This will help bring the side links to their correct height with about .5mm of rear steer in them. If you want to flatten the links out just add .5mm shim between the link and wing when mounting.

**Builders Tip: The wings we include will have the standard 2* of link sweep your donor car has when using the outer holes. We do offer an optional 4* link sweep set as a tuning option and are noted by 1dot milled onto their surface. These will match the inner hole on your donor chassis and can give an increased in-corner steering.

Lets roll onto the rear cross brace. This will need 4 of the threaded inserts, two for the dampers and two for your tweak screws. All four will get mounted through the same side and want them to be on the bottom, no different then the 23 kit inserts. This is also used for keeping your lipo inline and secure with an included smaller o-ring.

**Builders Tip: Test fit your lipos before mounting. Be sure they fit in the rearward section secure. They should be a little loose for float but not have to be pushed in. If they seem a bit tight you can use a small file (recommended under running water) to sand each side. Carbon dust is bad therefor the water will help keep it out of the air.

So in 23 the kit was optimized by lowering the side braces down .5mm to help with the CG. We took our kit and dropped the side braces directly on the chassis. You will need 2 threaded inserts on each rail, again paying attention to orientation. These will install top down so when attaching the screws they will pull them against the lower chassis. These can still be used as a tuning tool for flex. The very front of the brace will mount under your front axle plate. The two inserts after that can help stiffen of loosen the chassis up depending how many you use. The rear of these side braces will go around the rear cross brace mounts helping to keep a tweak free setup.

The Front plate will use the same pivot balls and mounting hardware from your donor car. As said before, these are all the same pieces for each year. When installing these be sure they fit snug but should not require any use of pliers. Tooling wear does make some a bit tight just as the factory ones can be. We recommend a snug finger push in feel to them. This, we felt, still lets the front flex a small amount and also not damage the plastic. If yours feels like they wont seat all the way in with out excessive pressure then stop. You can use a small file or some sand paper, again under water, and sand the holes open a little more. Just enough that you can push them in and they dont fall out.

Our front plate also keeps the stock width and also allows you to use the steel lower arm braces #372109. These can help with flex and protection during impacts.

**Builders Note: When figuring out castor here is some helpful info. Our side braces are 2.5mm thick. Per the instructional manual if you use 2mmF and 0mmR shims you get 3* of caster. With our kit and the math you would need to add a .5mm shim to each of the rear mounts to equal the kit 3*.

• 1.5* caster = 0mmF – 1mmR
• 3* caster = 0mmF – .5mmR
• 4.5* caster = .5mmF – .5mmR
• 6* caster = 1.5mmF – .5mmR

The kit ride height shims will not work on our kit. Be aware that caster changes can/will effect ride heights. You will need to alter shims separately from the caster ones to alter ride heights. Another way is to use the shims under the steering blocks. Be mindful with these also. What ever you add or remove you will need to add or remove from above the steering block. These shims also effect droop in the front ends.

Being orientated how it is you will reverse your servo and run it forward. Theres no way around this to gain the real estate needed for electronics. Our kit was designed around the popular Sanwa SXR servo but has been fitted for testing with the MKS HV50P. We honestly do not know about the PowerHD many use but we left 3 options for drivers to mount. There are slots on the chassis for direct servo mounting, or you can use your kit servo mounts. There are also slots on the upper front plate brace. These will align directly with the chassis slots.

**Builders Tip: When using the front plate brace to mount your servo be aware of two things. First – Be sure to use the two brace screw holes closest inline with the king pins. This will help with flex not effecting the steering. Second – Your servo will stay at the same angle as your caster. Be mindful of this when making Ackerman or bump steer changes. We also recommend no matter what servo you choose to use the Sagami RC Fab XR-007 Alloy servo horn. This will give you the best tuning for adjustments. We also milled in small notches on center for you to use with servo alignment.

Front plate bracing, we did this more for stiffness tuning. Just like used on your stock kits we made sure this brace can alter front plate flex for different track conditions. No brace would give you the most flex. The two forward most screws would give a medium amount of flex. And all four mounting screws would give you the stiffest feeling and responsive front end.

If you are using a 21/22 donor car you can use the extra 10.5mm side brace mounts for yours. If you are using a 23 donor car then you will need to use #373075 (2 packs) for the front brace to clear the servo.

The front bumper will use the last 2 of the 17 inserts needed. Using the inserts to mount this way allows us to make bumper changes easier. Also with no contact to the front plate it can help crashes from effecting tweak. We also kept the body mounts in their kit locations. We did this for all 4 body mounts. Depending on your wheelbase of the donor car this should allow for you to drop a body right on. This will help make bumper fitting/trimming easier as well, or mounting any of the TPU printed ones out there.

And last but not least, our chassis. A lot went into this Gen2 for the X12. Driver input from conversions we sold and even from drivers on different cars. First was how to make it work for 3 years worth of kits.

Knowing how important CG is with these cars we added a milled Lipo pocket thats .5mm lower then the top of the chassis. Biggest piece of weight in the car down a bit more. This also leaves it open to adding those .5mm weight plates that drivers use to meet minimum when needed.

We tackled the front corner dip and rubs from running such small tires as well. Angling the corners back helps keep the chassis at minimum ride height and not rubbing during cornering. Helping keep those speeds up instead of in the carpet. All plates are of course made from quality 7075-T6 Alloy. Hand cleaned and deburred we do like the brushed aluminum look they have. Unfortunately Anodizing isnt something we have access to so all our chassis have always had that brushed look. But it does leave it raw for drivers to have them done or as many, some nice polishing work for that shine.

Our Official web site launch is November 26th – all orders will be available directly on our site. Listings and prices have already been loaded if you want to browse over for a look. No pictures yet, we’ll let the teaser pics sit here until then.

As always – Thank you to every single person supporting us and our products. This has always been a business goal of making things that work and not just sell. Almost 10 years of parts in the 30+ years of being in the hobby. It really is a sport of competition among friends.

Hope you enjoy the pictures.