First leak: LEGO 42129 C Model Ultra 4 Buggy with bigger tractor tires, soft sand trials (Introduced: Ultra 6 Buggy with 6x6 drivetrain)

[Kamil]

This is the Lego 42129 unofficial C model (by Victor Gyenes) modified by 107x44R tractor tires. The tires are mounted in the reverse direction to provide shovel effect on dry and loose sand:

 

Edited Sunday at 11:26 AM by Kamil

[gyenesvi]

Happy to see you are experimenting with my model :) I didn't think those large tractor tires would fit on it. I guess sand is kind of the most difficult terrain, as it lacks traction, so these kind of tires are really required, though maybe with this tire size it's a bit underpowered. Are you using 9V batteries or 7.2V rechargeable ones? Have fun with it!

[Kamil]

21 hours ago, gyenesvi said:

Happy to see you are experimenting with my model :) I didn't think those large tractor tires would fit on it. I guess sand is kind of the most difficult terrain, as it lacks traction, so these kind of tires are really required, though maybe with this tire size it's a bit underpowered. Are you using 9V batteries or 7.2V rechargeable ones? Have fun with it!

Thanks a lot ! 

It is well built, and I like its minimalist style. I think absence of a differential lock here did not seem to matter with this vehicle. Even if one wheel spins, the other three wheels provide traction. It is more energetic, more active, and far more easier to drive than official Zetros truck. 

Yes, this vehicle stalls with these 107x tires at the start of a hill at high gear in my video. Your observation is most likely correct. Although my batteries are 6 x 1.5V Duracell pack, they were also used in my last MB Zetros beast mode trials video before. So, these batteries may already have lost some of their power.  

It might be better to replace batteries, and take it to a faster riding outdoors terrain like you did before. 

All the best

 

 

Edited November 16 by Kamil

[Kamil]

I had another goal in mind when I did the above,

I have slightly modified the Ultra 4 Buggy (designed by Victor Gyenes) into the Ultra 6 Buggy

- The rear axle of the Ultra 4 Buggy is replicated and modified 

- A tandem style super flexible rear bogie is built

- Red touches are added

- Openable rear covers are added

- Designed for low gear ratio of the Ultra 4 Buggy. High gear is usable but not recommended (may break parts if used without caution)

- Oiling may be necessary for better performance

 

Edited November 21 by Kamil