Expert Built Beetle Rally “Required” Upgrades?

[Andreas W 3147]

I see what you mean by slow . But it's surprisingly stable. I thought it would waggle more on the high chassis. 

 

Besides a larger pinion, as suggested, you could also think about upgrading to a Torque Tuned motor. Ihave ran that in my M-05 and M-08 (20t and 23t pinion respectively) and it's zippy enough for that little car and has enough revs to give a little more challenge while running. It's fast enough so you need to practice throtle control,  but still controllable on NiHm and Tamiya tyres. 

[Gratuit 182]

I'd first go for a bigger pinion, but certainly also for bearings. They will reduces losses in the drivetrain and make the car go faster

[Andreas W 3147]

21 hours ago, Gratuit said:

I'd first go for a bigger pinion, but certainly also for bearings. They will reduces losses in the drivetrain and make the car go faster

I fully agree with you. I read earlier in the thread that the OP did not want to dismantle the car (quite understandable when buying an expert built in the first place), so I did not suggest that. At some point he'll do it anyway - possibly after building the second car . 

[OnTheTrail 1417]

On 2/4/2025 at 8:40 PM, Burned_out_motor said:

 

Here’s a clip - sorry for the poor camera angle in the first link.

Car in action.

Car in action - better angle.

I'm guessing it's the camera angle but to me, the car looks noticeably quicker in the first video than the second one.

[Burned_out_motor 21]

Quick Parking Lot Test Run 3

I don’t think the car is getting slower.  I have noticed that a very fresh battery pack gives the car a boost of quickness for the first few minutes.  I think in one of those clips I’d been running it for a while so could’ve been batteries.   Hey, if it gets much slower, it’ll be going backwards, lol!!

Its just the way this model was designed.  High torque, best suited for skidding across a flat dirt surface like a dirt road, baseball diamond, or some other mild off-road surface.  Like a real rally car, I suppose.  
 

I’m considering bigger wheels, a pinion with more teeth, & faster motor as suggested.  No rush.  I’m going to drive it around the parking lot some more for now.  I don’t think anything’s in danger of breaking or wearing out like I was originally worried about.

[Burned_out_motor 21]

I bought a Torque Tuned 540 motor, and a set of pinions (22t, 23t).  It looks like an easy swap.  I have Tamiya Cerra Grease and the tools.

Now all I need is the time and energy to work on the car!  

 I also intend to change the wheels and tires.  Those stock rally block tires are excessively soft.  It’s as if the car is riding on 4 flat tires.  I bet just new harder tires would make the RC faster.

 

Stay tuned. 

[Andreas W 3147]

May I suggest M-grips in 60D 50684 with inserts 50686. I am weak for the 50569 wheel,  which also looks superb under a Beetle. For the first attempt I would go for a simple single tone paint in a solid color, sort of like this by our own @Willy iine.

 

 

 

Good luck. Next up is bearings. You can start with the easy accessible ones in the hubs.

[Burned_out_motor 21]

As much as I wanted to keep it stock, there’s no way.  It’s really boring as is.  Yes, I’m going to have to take a screwdriver and upgrade bearings as well, eventually.

I bought four 53215 tires and four 51666 wheels with foam inserts before I even unboxed the car.  I’m going to try those since I already have them.  

It’s kind of sad that the “Expert Built” 100% stock version is so lame.  Ridiculously, laughably lame.  I can foresee my building another MF01X chassis rally beetle from a kit.  This time, doing it right, with the right parts, from the start.  Maybe even going brushless.

[alvinlwh 8001]

5 hours ago, Burned_out_motor said:

It’s kind of sad that the “Expert Built” 100% stock version is so lame.

The only "expert" is the cheap labour on a production line building the same thing day in day out. Most of us will know to take a (A)RTR car apart immediately and rebuild it. I once opened up a gearbox to find it full of what looks like caramel. Cleaned it all out and reapplied proper grease. 

[Andreas W 3147]

When you decide to build a kit I would go for different car, just to get a different driving experience. The M-05 is still around and well proved. Just keep the hop ups on a minimum (bearings,  pinion and shocks). Wit a Torque Tuned and 20t pinion it goes well enough on the rock hard kit slicks. It's good for learning throtle and brake control and getting used to givenone input at the time.

 

 

[Burned_out_motor 21]

On 2/14/2025 at 9:41 AM, alvinlwh said:

The only "expert" is the cheap labour on a production line building the same thing day in day out. Most of us will know to take a (A)RTR car apart immediately and rebuild it. I once opened up a gearbox to find it full of what looks like caramel. Cleaned it all out and reapplied proper grease. 

Well - that actually makes me feel better!  The only “Expert Built” machine I’m ever going to own, is the one I build myself.  I confess, I was being lazy when I ordered an RTR RC.   I should’ve gone with a kit.  Live and learn.

On 2/14/2025 at 2:42 PM, Andreas W said:

When you decide to build a kit I would go for different car, just to get a different driving experience. The M-05 is still around and well proved. Just keep the hop ups on a minimum (bearings,  pinion and shocks). Wit a Torque Tuned and 20t pinion it goes well enough on the rock hard kit slicks. It's good for learning throtle and brake control and getting used to givenone input at the time.

 

 

Oh yeah, I already have one or two RC vehicles I want to build.  First up after upgrading the Rally Beetle is the Fast Attack Vehicle rerelease!!

I’ll send some videos of the Beetle once I get it up to par.  I am happy with the appearance of this RC.    Thanks everybody for the replies!  More to come…

 

[Burned_out_motor 21]

Just an update on my Rally Beetle newbie experience.

1.  I added a torque tuned motor and a 23T pinion at the same time.  The car is faster and has good acceleration..  It seems to be a good combination.  It’s still barely faster than some of the toy RCs I’ve got.

2.  None of the official Tamiya tires for an M chassis seem big enough.

3.  One bump into a curb and the plastic bumper is done.

4.  I drove it on wet pavement this weekend and just like a real car - better go slow!  I had one finale impact and did something to the drivetrain.  It’s not the pinion or spur gear.  Today was a disaster.  I’m gonna take a break for a while and will eventually take the car apart and see what I did to it.  The motor spins but some gears in there aren’t meshing anymore.  100% my fault.  

5.  FYI - Don’t adjust the steering trim while going fast on wet pavement!!!  That’s what caused the accident.

Minutes before disaster!

Wet Pavement

Just wondering if any of you guys know what I did.  I’m going to disassemble the car and find out but just wondering.  I obviously knocked some gear out of place!

[Andreas W 3147]

The M and/or S grips I suggested earlier are 60D- the same as the rallyblocks I assume you are running now. I have the best experience with the grippiest tyres rear, but that's personal preference. In my experience the car is less prone to spin with that combo (based on my Carten M210R and M-08). Others like it with S grips all round. 

 

Despite you saying it's not the pinion or the spur I think you have a loose pinion. Check if the grub screw is on the flat area of the motor axle and if the grub screw is tightened. 

[Burned_out_motor 21]

18 hours ago, Andreas W said:

The M and/or S grips I suggested earlier are 60D- the same as the rallyblocks I assume you are running now. I have the best experience with the grippiest tyres rear, but that's personal preference. In my experience the car is less prone to spin with that combo (based on my Carten M210R and M-08). Others like it with S grips all round. 

 

Despite you saying it's not the pinion or the spur I think you have a loose pinion. Check if the grub screw is on the flat area of the motor axle and if the grub screw is tightened. 

I bet you’re right.  This weekend, I’ll re-examine the grub screw.  When I took it apart after the crash, it looked like it was still affixed securely but it probably wasn’t.  
 

Man, if that’s all it is, I’m gonna drive the heck out of it this weekend!  
 

And - I need a solution to the fragile plastic front bumper.  I saw somebody made a front bumper out of foam for the MF01x chassis which I believe fit under the body shell.  If the brittle front plastic bumper outside the shell were made of rubber, the car would look good and more durable.  
 

I’ll have to ponder this some more…

[Burned_out_motor 21]

UPDATE:

Ok.  If you run one of these into a curb, there’s a good chance the “counter gear” (and I suspect other gears) will get knocked out of place.  

I took the motor off, put that gear back in place by wedging a screwdriver in there (it wasn’t pretty), reassembled, ran it while holding it and noted it sounded bad, then it disengaged again.  
 

I knocked he whole gearbox apart so the only solution is a complete rebuild.  I’m thinking about starting this project over with the exact kit, building a new one, then I’ll be able to upgrade and repair this one.  
 

I gotta take the whole thing apart.  Sounds like fun.  I’m gonna do it eventually.
 

Lesson learned:

PAY ATTENTION WHILE DRIVING!!!  

[Burned_out_motor 21]

Here’s another photo of the problem.

Ah, I might just get the screwdriver out and go for it.  I can’t admit defeat, yet!!!

[Nikko85 4404]

You need to open it up. Add bearings and then you can enjoy working out how it works.

I would say the benefit of the expert build cars are the paint job being done for you, everything else is just Lego.

I love my MF01x cars, but they do need bigger pinions and tires to get much performance from them. I know that Tamiya wanted a low gear rally car but really the gearing is so low the speed is just not exciting. With a 20T pinion and Toque tuned it gets more fun.

 

[alvinlwh 8001]

Hang on, it's a MF-01X. They are well known for the motor screws slipping causing the pinion to disengage from the counter gear. Check this is not the case before you start stabbing the screwdriver everywhere. 

[Burned_out_motor 21]

9 hours ago, Nikko85 said:

You need to open it up. Add bearings and then you can enjoy working out how it works.

I would say the benefit of the expert build cars are the paint job being done for you, everything else is just Lego.

I love my MF01x cars, but they do need bigger pinions and tires to get much performance from them. I know that Tamiya wanted a low gear rally car but really the gearing is so low the speed is just not exciting. With a 20T pinion and Toque tuned it gets more fun.

 

100% agree with the above.  I’m pretty good with model building and modifying RC toy grade vehicles.  So - I’m kind of ashamed of myself for not building it from a kit in the first place.  
 

I think my “bump into the curb” did more damage than I thought.  I believe it deformed the plastic in the gearbox where the bearings and axles fit.  At the very least, I think need to order another gearbox and the proper bearings before I get the screwdriver out.  
 

And - yes, I was hoping it was just the pinion or motor mounts but, nope.  I’d just tightened all that up when I installed the torque tuned motor.  Pinion is on there good and tight.  It’s the gears in the gearbox.  When the 4WD and strong torque tuned motor went to a sudden stop, I believe it ruined the gearbox housing.  The gears themselves are probably ok but they won’t likely stay in place.

 

 

I’ll fix it….

[Nikko85 4404]

If you have modified toy grades then getting a proper kit to work will be a walk in the park.

One thing the MF01X suffers from is that the motor can shift in the gearbox, causing mesh issues. I got some anti rotation washers and hex screws to really be able to tighten down.

Mine are now a short course truck

An off road racer

And a land rover.

At some point I also had the MF01x Pumpkin as shown! Lovely versatile chassis with a few quirks.

 

[Burned_out_motor 21]

Beautiful vehicles, Nikko85!  I like the drivers!

I’m going to get tthe MF-01X back out there, eventually.  I dropped a Tamiya torque tuned 130 motor into the toy Batmobile and repainted the Ripsaw tank toy.  
 

Awesome hobby, guys.  Thanks.

[alvinlwh 8001]

On 3/2/2025 at 3:45 AM, Burned_out_motor said:

I believe it deformed the plastic in the gearbox where the bearings and axles fit.  At the very least, I think need to order another gearbox

This is what you need.