DEXPRESS Mettle – Cargo Electric Scooter : Test Report

What’s the secret? Both bikes use the same naked tubular steel design. We have seen a similar design in the Pure EV E trance as well – and I think there is some logic in standardising on this design for EVs.

It’s a minimalist design, and is in keeping with the low part count frugal mentality of EVs. The rattle factor is quite less thanks to the minimalism – though the Lite that I tested at the dealership had a very noisy front loader. 

The real killer for the Mettle is the Bosch BLDC drive. Bosch really does a great job in motor manufacturing – and I think their motors are going to save the company once their fuel pump business starts declining.

The motor is pure magic – and if I were to borrow a Thai Airways tagline – Smoooooth as Silk. It delivers an amazing torque.

At signals, the Mettle is always the first off the blocks – and remains there till it reaches its top speed of 25 kmph.

One does wish for a high speed version of the vehicle – that would leave all the Activas biting the dust. During my ride I came across two Chetaks on test – and daresay the Mettle did as well as them in the speed range that it exists in.

There are two modes to operate the vehicle. I liked the toggle switch – it is easy to use. The rocker switches that are used by most other e bikes are not as good – there is no default mode in rockers.

And no standardisation about whether the left rocker position is for high speed – or the right one. And yes, 2 levels of speed are good enough for low speed bikes.

I don’t think anyone ends up using the mid level in a 3 level switch. The torque in the Eco and Power mode is the same.

The only difference is in the speeds. I guess low speed saves energy simply because you accelerate and decelerate fewer times. And if you are climbing inclines the motor is drawing fewer amps – leading to lower I2R losses.

Talking of losses, the Mettle is again one of the rare two wheeler electrics that has regeneration.

I guess that will make more sense when the vehicle is fully loaded. Most of my use was with loads of between 15 and 25 kg – of course in addition to my own weight.

It is a single seater – though there is a provision of adding a rear seat.

Am sure it will not have any problems in doing 10% gradients, which the company claims in the specifications.

The regeneration is used to good effect in braking. The company claims that you can stop the vehicle with regen even if the brakes fail. 

Moving on to the battery. It runs a LFP battery on 60 V, 18 Ah. So you end up storing one unit, or 1 kWh of energy in the battery.

Being LFP, you don’t end up losing on speed as the battery discharges – a problem faced by the NMC chemistry.

The battery is in the shape of a conventional lead acid battery form factor, with the major difference that it is much lighter. I assume that it is about 10 kg – goldilocks territory for swapping solutions.

We have seen that the Revolt swapping is not picking up – a big reason is the 20 kg battery weight.

A self swappable battery cannot be more than 10 kg. You can split the battery into two if you want higher power – but the basic ergonomics principle puts that limit on the design.

One more thing that I liked about the battery is that the electrical connection fitting is automatic. You don’t need to remove or join any connectors during swapping.

The battery is a snug fit in its compartment – and there is a spring operated connector which ensures that the current remains flowing even when the vehicle bumps its way around. A very swap friendly feature indeed.

One disadvantage that we have seen with some of the cheaper LFP battery fitted vehicles is voltage based range indicators – which let you down without warning.

Happy to report that the Mettle works well here. We took delivery of the vehicle at 5 bars (there are a total of 6 bars). And when I put it for charging at night – there were 2 bars on the indicator.

I was a linear decrease, and we did a total of 40 km running on day 1. So the math says that the meter is calibrated at 12 km per bar. Extrapolating.

I expect the range to be about 72 km. Caveat is that the vehicle’s range will drop with load.

So I would expect a real life range of a loaded vehicle of around 60 km.

I discussed the BMS design with our battery expert, Abhay Patwardhan, who felt that there were no data cables in the connector – so the odometer is input being used as a surrogate for displaying range.

If so, then it is a very clever and frugal solution, though it has got Kamlesh worried. He feels that the SoC will not take into account gradients and weather in that case. 

A few words about the suspension. Takes the bumps quite Ok – but having a longer wheelbase, I could not use my cycling strategy of leaving the seat on a speedbreaker. You do have to slow down to 20 kmph then.

My first look at the vehicle made me apprehensive about the seating posture. The battery is on the floor board. But I realised that the floor board is actually load board.

Tucked away on the sides are two footrests – which ensure that the feet are resting at a better angle. Feels better than the pedals that the E Trance has. The seat is comfortable – though I would have appreciated a back rest.

Delivery boys spend more than 8 hours on the vehicle every day – and a back rest will go a long way in reducing fatigue.

Also, since you are not lifting your leg over the seat to sit in a moped type vehicle – the back rest does not come in the way. Another suggestion that I have to make is about storage.

I assume that even delivery boys would want a minimal lockable storage. This can be placed inside the tubes too, Half of my driving happened in the rain – and would have appreciated a small space where I could have kept my diary to save it from the downpour. 

(Note to self: in spite of the small tyres the vehicle seemed quite stable – you sit lower – like a cruiser – so that would help. I did slip a wee bit once, but that was it. The hydraulic disc brake on the front wheel helps.

Stopping distance is quite less.. Should be the case even with a loaded vehicle. Btw, it’s load capacity is 200 kg. Not bad for a 60 kg bike.

Took the Mettle out to do some heavy duty kirana shopping in Pune’s market yard. I assumed that a mundane looking bike like thus would hardly turn heads.

But I found two young shopkeepers, who were in the shopping line with me at the wholesaler, seeking me out to enquire. Gave them a test ride.. and they were blown away. The Mettle sure bites more than it barks..