Hi All,

A little while ago I bought a 9125 to start my kids with an off road truck.

https://uk.gearbest.com/rc-cars/pp_1522345.html

My kids love it but I don't think it is anywhere near the 45km speed that it is advertised at. Maybe 30-35km/h at most.

I briefly tested one of my 3S batteries from my brushless RC boat and I really don't think the two brushed motors can handle that power for any length of time. There was a huge difference in the sound of the motors (only ran for a few seconds).

Are there ANY upgrade routes for this truck?

It does seem like the truck has a bit too much torque as it will easily flip if you just floor the trigger so could I mess with the gearing?

The two motors are each side of the spur could that be problematic?

At the price point of this truck I don't think there is much point going brushless - So are there any 390 motor upgrades I could go with? It has a 60A ESC (apparently) so could I use a single much more powerful 390 motor?

Thanks for any help.

So my next idea would be to get a 540 motor and mount and then swap the two 390 motors out for it.

Any thoughts?

It's great that you have all helped so much...

After dismantling the motors and diffs, the motors are held in by a mount screwed in to the front of the 390 motors that are then held in by the outer housing.

So you can replace the motors and just screw in the new motors to the mount regardless of the length of them.

So if someone could help with a faster 380/390 motor then it should fit.

The diffs are all metal but are not sealed. They are grease filled.

I have just ordered this car for my kid (or should I say the kid in me). It seems like a great truck for the money ($70-ish).
Would it be a good idea to get oil filled shocks for the thing? It seems like that (and the small battery) are the main complaints I hear.

What kind of replacement shocks should I be looking for? Does most 1/10 shocks fit, or does it need to be exactly the same... A bit of a noob here, and the truck havent arrived yet either.

/J

OP if it already has enough power to flip over I'm not sure why you want even more power?

A single 540 motor probably isn't going to give much if any advantage over dual 390 motors.

If anything, you'd be better off with two brushless 390 motors but I have no idea if the gearing would hold up to such an abuse.

I'm not sure there's many brushed 390 motors out there that would give a big advantage, these Chinese cars usually have pretty fast motors as stock as far as 390 motors go. Perhaps the Traxxas 380 motors? Those are actually 390 motors despite being called 380. The only difference between a 380 and 390 is the length, all other aspects are the same so they are usually interchangeable.

The battery compartment is very small so you will need to modify the car to make any kind of bigger battery fit.

Although this car is advertised as 1/10th scale, I would say that 1/12th scale would be more accurate.

The shocks are a weak point but I have not yet looked in to replacing them.

I ve tried 3s battery 45 km/h with a gps trucker.
with 2s only 30 km/h
and with 4s 56 km/h

but I play a lot with the 3s battery it has no problem.
now ive ordered new oil shocks.for better handling.

Can someone please point me to upgrade shock absorbers (oil filled) that would fit the 9125 ?
Thank you.

I've seen a few people run it on 3s and it seems to manage ok, I guess because there are two motors they are sharing the load and not getting as hot as a single motor. I think 4s would kill it after a while though lol.

Does it already have bearings in all of the gearbox? If not, that would be a cheap upgrade to improve performance a little and longevity.

Originally Posted by hackra

Can someone please point me to upgrade shock absorbers (oil filled) that would fit the 9125 ?
Thank you.

A good way to start would be to measure the stock ones from eye to eye and the diameter too.

Originally Posted by nowinaminute

A good way to start would be to measure the stock ones from eye to eye and the diameter too.

That is true indeed, but I do not have it yet.... I just wanted to prepare some upgrades until it arrives...

Hey you said you run your xinlehong 9125 on 3s a lot and it does fine. What sort of batteries and what sort of run times do you get? I have one on the way and I would just like for it to last as long as possible but I'd like to use 3s batteries.

Originally Posted by PitterPatter

Hey you said you run your xinlehong 9125 on 3s a lot and it does fine. What sort of batteries and what sort of run times do you get? I have one on the way and I would just like for it to last as long as possible but I'd like to use 3s batteries.

Have the similar question. I just want a confirmation if the car will run on 3S completely stock, long term. I plan to not do runs more than 20 mins. Will the 2 motors balance the load and not fry? I live in a fairly hot country ambient is ~30C.

To those unfamiliar with the car, its got dual 390 brushed motors and a 60A rated ESC.

Any help on the above would be appreciated.

Has anyone found an upgrade to the steering box? Every time I hit something, it breaks due to the plastic gears. That is the only complaint I have, and the shocks need to be upgraded.