LEGO Duplo cargo train - traction problem on bridge

Question

I bought my son a 10875 cargo train. The train is great for playing, but I have a problem with crossing the bridge. I saw that this is common problem with 10875 and 10874 LEGO Duplo trains, so I would like to ask if there is any solution to improve traction. I regularly clean the train and wagons, but it still happens that the axle slips from the wheel when I have to cross the bridge. Did this option of adding rubber to the wheels improve traction?

I've tried changing the batteries.

Edit to add:

I don't think it's the pinion on the motor. I checked and cleaned all the gears and there is no damage to anything. I just didn't know how to remove and disassemble the rear wheels in order to check the part between the axle and the wheels, but I saw in other posts that when it breaks, the wheels should be free to spin.

It seems to me that they designed the wheels to slip badly. I would try to somehow improve that part for better traction between the axle and the wheels.

The train starts to climb the bridge piece and you can see that it has power, but it happens that you hear a screeching sound, and then the train stops, at that moment the wheel does not slip between the rail and the wheel, but just between the axle and the wheel.

That piece is used for slipping and was installed probably for the safety of small kids and children, but it lacks traction to cross the bridge track. If it was completely fixed, it would probably damage the tracks if the train gets stuck somewhere.

I think it slips on this part of the picture. It is between the wheel and the drive axle.

We have two bridges in the set, so that's quite a problem.

Answer 1

In a very similar question the following alternatives have been suggested:

• Use non-rechargeable batteries due to their higher voltage and thus power
• Replace the pinion with a metal one

Your idea of using a rubber band is not mentioned, but can be useful in one specific scenario - if the wheels are slipping on the tracks. In your question you write that "the axle slips from the wheel" - is it really so though? If so, then the clutch between the axle and the wheel needs to be improved, for example by coating the end of the axle with cling wrap or nail polish to slightly increase its diameter or just straight away gluing it to the wheel itself.

But if the wheels are slipping on the tracks, you should indeed try the "rubber band around the wheel" idea, or some variation of it - e.g. duct tape, which similarly increases the traction but doesn't increase the wheel diameter too much (which would make the climbing more difficult by requiring more power from the motor).

In the last scenario, if the motor is stalled when going upwards with the wheels and the axle standing still due to insufficient power you still have a few possibilities:

• You could try using stronger batteries (with more voltage)
• You could experiment with changing the slope of the track (perhaps by slanting the whole track, or adding some padding under the lower sections to reduce the angle of incline)
• You could remove some weight from the engine or the attached cars
• You could add another engine and use both simultaneously