10 years ago, we started the journey into the development of a belt driven 1:10 4wd offroad car, with the intent to revolutionize the market. The original SRX-4 was born, although it was a good car, it had its short comings. Since that time we have continued to develop, test, design and re-designed it behind the scenes in our secret lab. It had to be easier than any car of its kind to work on, handle with precision and ease, be maintenance friendly, and share more parts across the 1:10 categories we compete in. Aside from those targeted positives it also needed to be better than any 4wd car in performance we have created to date. Foresight was a key factor, when the SRX-2 Gen3 was being born, we already had a good understanding how to craft together from its DNA the ultimate 4wd version. The two cars had to be worked on in tandem to make sure it was possible to reach the goals we had set forth. The SRX-4 Gen 3 shares over 50% of its SRX-2 Gen3 relative, an accomplishment we are quite proud of. This was really important as we didn’t want customers to have to purchase a significant amount of new parts just to operate two cars. Lowering operational costs is always a positive thing, and there is no doubt we have managed to achieve this goal. The SRX-4 Gen3 is a belt driven masterpiece, when evolution becomes the revolution.
Part 1: The chassis on the all new SRX-4 Gen3 is 7075-T6 aluminum, its narrower in design for better flex characteristics, while it also incorporates a new packaging concept for the front pivots and diff position, too give greater ground clearance. Front ground clearance on most 4wd cars is an issue, this was an area for sure we wanted to improve. With the new improved ground clearance, it greatly improves jump takeoff and landing. Less scrubbing on jump faces and less lawn darts, improves your ability to run faster lap times lap after lap. Trust us when we say your local carpet track owner will appreciate the advancements in this area, especially if they have wooden carpeted jumps.
Part 2: Not only did we lighten the chassis where we felt we could to reduce weight for those that love to run their cars as light as possible, we also added locations to add weight. This adding of weight can be a great tuning option for low grip all the way up to high grip racing conditions. The ability to adjust your weight balance is a simple way to get those extra tenths of a second that often times separate you from winning or getting second.
Part 3: The side pods are molded from premium composite nylon and mounted to the chassis by way of a tongue and groove style fixture. This concept improves flex characteristics across the length of the chassis. Incorporated into the side pods are the 4 mounting pegs for your body. Whether you like using body clips or velcro, you can use these pegs to properly mount your body time after time. These pegs help ensure your body does not fall off when your car is being turn marshaled by the body. All these small positives simply enhance your hobby experience
The steering system on the SRX-4 Gen3 has also been updated to reduce maintenance time, increase drivability, reduce any unwanted bump steer, and create a smoother linear ackerman curve. To achieve this, many design demands had to be met.
Part 1: The multipurpose front/rear pivot blocks also double as steering post mounts and pivot insert holders. This design helps reduce the overall part count and simplifies the design. They are also removable without having to remove the front transmission.
Part 2: The entire steering system is now placed on the same angle/plane as the kickup angle. In doing this, it reduces the bump steer through the entire range of suspension travel. It also creates a more consistent ackerman curve through the entire range of steering throw and also through the suspension travel.
Part 3: The steering bellcranks and the length of steering crossbar have all be re-designed to give the optimal steering throw and ackerman curve. The steering rack posts are as short as possible to reduce twist and flex on the chassis and steering system itself. To reduce maintenance time, the system was designed for full access from the top down.
Part 5: The servo horn length and its relationship to the bellcrank have all been updated. This update will give you the most consistent feeling from radio input to the reaction of the car. The servo mount is floating and the mounting location is as close to the center line of the chassis as possible. By mounting it as close to the center of the chassis you gain the best flex characteristics in a larger array of conditions
The SRX-4 Gen3 , has a brand new, state of the art driveline configuration. Not only have we made it the absolute easiest belt drive car to ever be worked on, we have easy access differentials at both the front and rear. The new layout can be made to have perfect left to right weight distribution with a variety of batteries. This exceptional weight distribution improves handling in every condition. Let’s take a look at the masterpiece we have created.
Part 1: Included in the SRX-4 Gen 3 are 2 super light weight gear differentials. The differentials can be run with either 2 or 4 gears. Regardless of what configuration you choose, they will prove reliable in every condition you throw at them.
Part 2: The rear differential is accessible by 4 vertical screws and 2 horizontal screws and you will need to remove at least one shock nut. The greatest part of the removal process is not having to worry about the camber link mount dangling, disassembly of the rear suspension or having to take off the wing. The removal of any un-necessary parts has been completely avoided. This allows you to spend more time hanging out with your friends, and less time spent working on the car.
Part 3: The differential height can be adjusted in 9 different heights, by increments of 0.5mm. Winning and losing can be defined by the adjustments on your car, here we spare no expense. The inserts are blocked into position to make sure that the oval inserts can’t rotate slightly during operation causing damage to the internal gears. Sadly our competitors copied our previous design of the oval insert, but didn’t realize what we had learned about keying them into position. Shame on you..:)
Part 4: All rear drive gears have had the width increased to 10.5mm. With the increase in gear width, you can run on any surface and be rest assured you will not strip a gear. In addition to widening the standard gears, we also have Stock racing internal gears, which are a 6mm wide. This reduced width will give you massive gains in rotating mass, reduced friction as well as less power train loss. If I must say it, yes, we are here to win and prepared to keep it that way.
Part 5: If you have the differential out for maintenance, changing the diff height or swapping internal gears, the idler gear can be removed by a single button head screw. You will not have to remove the transmission case or slipper assembly from the chassis. This allows you to do any necessary work inside the gear box with the least amount of assembly related issues. Nothing competes with brilliance.
Part 6: Not only can you easily access the rear differential and idler gear. We didn’t forget about how important it might be to maintenance or replace the top shaft. To access and or replace the top shaft you will simply have to remove the slipper bolt, remove the slipper, then remove the 3 screws that holds the motor plate, and boom you can slide the top shaft out.
Part 7: The slipper assembly on the SRX-4 Gen3 is nothing short of class leading tech. Not only do we have a solid full time 4wd slipper assembly available as an option, we have a Limited Slip Differential (LSD) slipper assembly. This is a far more precise way to distribute power to the front wheels than oil driven differentials. In the case of a gear diff, the oil thins as you run, changing the performance of your car, in this case, it is held more consistent with spring tension. This allows you to run the same laps, lap after lap the entire race. Both slipper assemblies share the same top shaft, so you can change this in a very short amount of time without the removal of extra parts.
Part 8: The rear belt has never been easier to take off, put on, and do it all over again on a belt driven 4wd car. You can simply remove the rear belt with the removal of a single circlip. You wanted it easy, we answered the call. You don’t have to remove the slipper, so you won’t have to adjust that if you simply want to replace the belt between practice, qualifying or mains. These low friction belts will last and last and last, in fact we think you will be stunned by how long this belt lasts
Part 9: When it came to the front belt, we also wanted this to be super easy to maintenance and or replace. It can be done at the same time as a front differential adjustment or by itself. The process is basically the same and can be done with the remove of the 4 front upper bulkhead screws, removing one steering rack screw and popping off the servo link. This is actually even easier than changing the rear diff. Yes it really is that easy, hard to believe we know, you can thank us later..:)
10) To adjust the front belt tension, we also wanted this to be easy, but also very adjustable. Regardless of what front differential position you run, you can fine tune the belt tension mounts up by use of shims. You simply place any 3mm shim under the mounts. This way you can make it as tight as you want or free based on your tracks condition. If you run 13.5 this will be quite useful for you to reduce drag and increase efficiency
New Rear suspension Geometry
New Narrow Rear Pivots / Insert System:
When testing, we found that the pivot system from the SRX-2 Gen3 provided an astonishing amount of rear grip cornering and lap speed. This during testing provided the best overall traction, awesome forward bite and gave the best balance front to rear. Aside from the Narrow pivots, you will also be able to purchase, medium and wide pivot sets for even more adjustability as optional parts
The new system will allow us to go 2 degrees total in or out from 3 degrees which is standard. This system is adjustable 0.5 to 1 degree in almost any direction. We didn’t cheap out like many other makers, we actually made a complete set of inserts. This will help increase the adjustability in a much larger variety of conditions. We want to see this car excel in every condition, anytime, anywhere. In order to do that, you need to have all the tools to do so at your disposal. Oh, and I almost forgot to tell you how amazing they look anodized jet black with silver chamfered edges!!!!
New rear suspension geometry:
Fully adjustable new upright:
All New Track width, axle position, and Roll center adjustments.
A: The new rear uprights are part of our movement to make the most versatile buggy on the planet. With so many new features on this upright it will literally make your head spin off.
B: The upper camber link has an adjustable length, which is done by way of shims between the camber link mount and upright. The camber link mount is capable of being flipped so that there is a perfect overlap so that no length of link is missed.
C: The vertically mounted ball stud further enhances the setup, so you can adjust the Roll center in the absolute finest amount to perfect the setup.
D: The wheel axle can be adjusted in 1 and 2mm increments in or out. This will allow you to adjust the driveshaft length, but also the location of the outer driveshaft pivoting point. This adjustment has an influence on rear end grip and lean. We offer the original 65, 66 mm drive shafts as well as two new ones, 67mm and also 68mm.
E: You can adjust the roll center by way of 7 different positions in reference to the distance away from the axle. Those steps are 0.5mm different. You can then take the same inserts and adjust the offset of the upright by way of 1mm.
F: Finally, we developed a completely new set of hex adapters that make all these axle adjustments possible. The new set has an offset of 4, 5, 6, 7, 8, 9mm.
If you haven’t figured this out by now, we mean serious business. There is no doubt, winning is the first thing on our minds
New rear suspension geometry:
Part 3: New rear shock geometry utilizing the shocks mounted to the front side of the arm.
When we developed our first SRX-4 we had the shocks mounted to the rear side of the arm. Since that time we have developed, redefined the rear suspension geometry and moved the shocks to the front side of the rear arm. Moving the rear shocks to the front side of the arm, has proven to be beneficial in cornering, jumping as well as sheer speed. With that in mind, we went back, updated the height of the tower to maximize the down travel as well as up travel. We tested multiple towers and angles for maximum grip, cornering and stability. The end product was an easier to drive, yet significantly faster car. The first time you hit the track with this car, you will feel the lateral grip it generates. This is the same kind of grip, which gives confidence to overtake your competition in the toughest corners and tightest windows
Part 4: No 4wd car would be complete without a ball bearing raced rear Anti-Roll Bar. This fully integrated sway bar system is super easy to install and remove with only two button head screws. In the event you want to use a standard rear camber link mount, you can swap it out super easy. If you love your sway bars, then you will be excited to know you have a large variety of rear roll bars to choose from.
We have 1.0, 1.1, 1.2, 1.3, 1.4 and 1.5mm roll bars to choose from. No matter the track conditions, you will be more than able to dial in that rear suspension
New Front suspension Geometry
We have learned a lot having designed multiple 4wd offroad cars over the last decade. Here we really wanted to make sure we improved on our past designs and incorporated ideas that would allow us more freedom into the future. Naturally you need to start with the IFMAR legal offset wheel and then design from there. The main goal was balance; we needed a front end that mated well with the rear of the car. Precision, drivability and ease were all areas we focused heavily on. Let’s introduce the parts shall we.
Part 1: All new front pivot/insert system. Here we spared no expense on adjustability. You can change the kick-up angle from 6 to 10 degrees, change the arm sweep angle from -2 to +2, and adjust the track width narrower or wider. Let’s just say, the inner pivot system has more than enough adjustments to refine your front end for any track condition. You can do all this using the same exact pill system found at the rear of the car.
Part 2: The caster block, was completely redesigned to have a specific offset, caster range,and the position of the roll center has been adjusted to improve the handling in the racing conditions of today’s tracks. It needed to also be strong and we wanted it to be as adjustable as possible. With this in mind we gave it two upper link choices, where you can mount a vertical ballstud.
The standard caster block using the 0 deg insert is 10 total degrees of caster. From this point you can adjust it in increments of 2.5 and 5 degrees in more or less. This gives you a total range from 5 degrees all the way up to 15 degrees of total caster at the wheel.
Part 3: The steering spindle has also been re designed to improve scrub offset as well as mate the caster block in a way we could adjust the roll center by 3, 1mm shims. The ackerman arms are mounted to the underside of the spindle and the bump steer can be adjusted by shims on the top side under the ballstud. The outer bearing was increased to a 5x13x4 bearing, to improve the life and durability.
Part 4: These new Ackerman arms which are mounted to the steering spindles are made form 7075-T6 aluminum and are black anodized. These 3 choices, 0 notches, 1 notch (included in the kit) and 2 notches, these options will allow you to adjust the total ackerman of the SRX4 Gen3. 0 Ackerman will have the most Ackermann, while 2 will have the least Ackerman. You can use these to fine tune your car to most all conditions
Part 5: The front end would nothing without an Anti-roll bar. On the front end, we have a nicely packaged from roll bar system you can easily take on/off and adjust on the fly with the minimalist amount of effort. Here you can adjust the bar from 1.2mm, 1.3mm, 1.4mm, 1.6mm and 1.8mm options
One thing great about the SRX-4 Gen3 is the space. You have more than enough room for your electronics. You can use a full size or shorty servo, full size receiver and still fit your speed control. There is also space behind the electronics and in front of the motor for a fan if you choose to use one. This might be helpful in the 13.5 category
In the category of 4wd offroad, it’s tough to make a body look good. Generally they are blocky, big and bulky looking. We spent a lot of time trying to make it look sleek, stylish and aerodynamic. Aside from that we tried hard to match the stunning style of the 2wd, here on the 4wd. We wanted them to look as similar as possible so regardless of which one you were driving they felt similar to you. We think you will agree, the styling is fresh, sharp and tough to beat.
The 1/10 electric offroad market is an extremely challenging market with so much at stake, however we are confident this new SRX-4 Gen3 will drive the direction of this class to a place it has never been before. There are many good cars out there, but, here at Serpent our main goal was to create a game changing, game winning car, which would be an inspiration to anyone willing to wield one. Good was not acceptable, we wanted great. With long tiring hours at the track and behind the computer, we worked diligently as a company to provide the absolute best product we could. Our lead Designer Billy Easton, spear headed the program and had only one goal, to take the 4wd market to the next level and produce a new 4wd second to no other.
Here at Serpent we are very proud to introduce the brand new Serpent SRX-4 Gen 3.
Designed by Billy Easton, USA