Kyosho Pro-X & Pro-XRT

[Dangeruss]

In 1994 Kyosho released the Pro-X and Pro-XRT 2wd electric off-road racing buggy and stadium truck. Created as electric counterparts to the gas-powered Rampage Pro and Outlaw Rampage Pro the Pro-X and Pro-XRT were Kyosho's top tier electric off-road racing platforms and shared all the same suspension components with their nitro brethren:

Pro-X: Kelron II injection molded nylon chassis with a bolt on 30 degree kickup plate. Seperate bulkhead located front suspensions with long white composite plastic lower a-arms and titanium turnbuckles retaining matching white composite inline hubs and knuckles sporting inclined kingpins and larger 6mm axles. Twin bellcrank steering system with built-in spring-loaded servo saver, ball bearing mounts and titanium turnbuckles tied to the front bulkhead by a Kelron II top plate. Hard anodized and teflon coated oil-filled aluminum Ultimate shocks with clip in spring adjusters in medium length were placed up front while long versions used in the rear, affixed to black fiberglass shock towers at both ends. Out back was Kyosho's new slipper clutch equipped three gear Super Sprint Transmission with a center mounted ball differential inside a white composite plastic case. A pair of Kelron II floating ball suspension mounting blocks retained the long white composite plastic rear suspension arms with titanium turnbuckles retaining the matching composite rear hubs through which steel universal axles would pass. Shallow offset single piece 2.2 buggy wheels with clear lexan dirt shields were wrapped inside W-5641 Pin Spike rear tires and W-5621 Ribbed front tires. A new clear lexan body, front mini bumper and a full set of bearings were included with the unassembled Team kit which was sold less radio. Also offered in a Sport version with plastic shocks, steel camber/tie rods, and bushings, less radio.

Pro-XRT: Kelron II injection molded nylon chassis with a bolt on 30 degree kickup plate. Seperate bulkhead located front suspensions with extra-long white composite plastic lower a-arms and titanium turnbuckles retaining matching white composite inline hubs and knuckles sporting inclined kingpins and larger 6mm axles. Twin bellcrank steering system with built-in spring-loaded servo saver, ball bearing mounts and titanium turnbuckles tied to the front bulkhead by a Kelron II top plate. Long hard anodized and teflon coated oil-filled aluminum Ultimate shocks with clip in spring adjusters were affixed to black fiberglass shock towers at both ends. Out back was Kyosho's new slipper clutch equipped three gear Super Sprint Transmission with a center mounted ball differential inside a white composite plastic case. A pair of Kelron II floating ball suspension mounting blocks retained the extra-long white composite plastic rear suspension arms with titanium turnbuckles retaining the matching composite rear hubs through which steel universal axles would pass. Shallow offset single piece 2.2 truck wheels with clear lexan dirt shields were wrapped inside 540/100/62 Pin Spike rear tires and 510/100/62 Ribbed front tires. An aggressive new clear lexan body, front mini bumper and a full set of bearings were included with the unassembled Team kit which was sold less radio. Also offered in a Sport version with plastic shocks, steel camber/tie rods, and bushings, less radio.

[mark]

Would be nice to see a rerelease of these.

[Lavigna]

These are 2 of my favorite. Both are great looking, iconic cars. They had high potential but let down by a very hit or miss transmission. I think there was an issue with the molds for the transmission cases. If you got correct cases, the transmission was decent. If you received cases that were out of spec, you had to deal with a transmission that bound up and destroyed itself pretty quickly.

I think Kyosho expected the platform to be a great success, however that never happened.

[stickboy007]

I'm a big fan of this platform. Having raced them multiple times, I would say it's a more robust and generally more tunable platform than most other chassis from their time. The Pro-XRT in particular is a rocket ship. Really, really great truck to drive. Each of the Pro-X and Pro-XRT have a few weaknesses, though:

Pro-XRT: the rear motor guard has a tendency to get pulled/bent back on hard landings. The bottom portion of the motor guard is sandwiched between the chassis and rear arm mount, with a little nub coming up from the chassis and slotting through a hole in the motor guard to hold it in place. That isn't quite enough, though. If you drill a hole through that sandwiched assembly and thread a screw, with a locknut (or serrated nut), it will hold in place just fine.

Pro-X: the main point of breakage I've experienced on this buggy is the rear wheel axle. The hole in the wheel axle where the drive pin slots through apparently doesn't leave enough material around it. If you land enough jumps unevenly, the axle will snap. I've had this happen twice. You can resolve this with a RB5/6-style 62.5mm CVA, which has a much stronger wheel axle. This will require you to shave a bit of the arm to allow the CVA joint to fit, but it's the same deal with the MIP CVDs which were once offered for these as well. Doing that does tend to affect the rear hub tunability, since you'll have to leave it in the center position for maximum joint clearance. Not a big deal if you don't need to move the hub forward or backward, but if you do, then you'll want to use the stock universals.

One common weak spot is the steering rack. Overall, it's pretty tough, but they can crack around the ball stud holes over time and so you'll want spares.

A common complaint for both is the SST gearbox. I made a few videos on how to deal with this, as well as a few posts here. In my experience, each one you get is a little different and so what works well to reduce bind on one may not work on another. Generally, though, the bind tends to come from the top gear not meshing well with the center diff gear, which appears to be rooted in the bearing placement being a little bit off, and/or the gearbox housing being too narrow. One thing that helps most of the time is actually leaving a small gap between the gearbox halves. Then just put some electrical tape or something over the gap to seal out the dirt. Then just be sure to use some threadlock for the screws which go through and mount to the motor mount/guard, and it will all hold in place.

Generally, I've had a much easier time with the Pro-XRT than the Pro-X. I can get the truck to run really nicely across many types of layouts and surfaces, but the buggy tends to be pickier. It's not as forgiving on landings as other 2wd buggies, in particular if you land a bit sideways, and generally I'm not as consistent with it as with other buggies like the TRX3 or Rampage Pro-E (electric conversion of the nitro version of the Pro-X, which is AWESOME). Maybe that's because I use modern rims which have a flatter tire profile. A more rounded rear tire profile will likely address this problem. There could be other issues related to my base tune with it, but I chalk that up to a lack of adequate track time. I wish I had more track time with the Pro-X, so I can really get it properly tuned, but even with limited tuning time, it's a very good buggy.

Another thing to point out about the Pro-XRT is that you can swap in RT6-style quick-release units as a direct fit. In the rear, the RT6 universals with the quick release wheel hubs fit perfectly. In the front, you just need to swap out the steering knuckle (no need to change the caster block), which does change the steering geometry slightly but is otherwise a direct fit. Same exact track width and it makes changing tires super convenient. Love love love that truck, which makes it hard for me to drive other trucks which I know are also very good, such as the T2 and XXT.

[R6cowboy]

Definitely one of my two favorite trucks. Also have the Pro-X boxed away awaiting a rebuild. This was 'the' truck I wanted so badly as a young teen but just wasn't obtainable at the time.

[juicedcoupe]

Definitely one of my two favorite trucks. Also have the Pro-X boxed away awaiting a rebuild. This was 'the' truck I wanted so badly as a young teen but just wasn't obtainable at the time.


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Those Schumacher tires give it a completely different attitude.

[R6cowboy]

Those Schumacher tires give it a completely different attitude.

Indeed, that was my thinking to use them. It's an already aggressive looking truck and those tires just add to it.

It sucks the silver looks gray in the pictures. It's metallicy in person.