This bike has been purchased by a client as an off road bike. He chose this bike because of its mid mount motor and the ability to drive through the gears for higher torque at low speeds. He felt it was a more elegant solution than a mid drive kit like an Elation or Cyclone motor.
The bike has come in to EVLAB brand new for upgrades to make it more usable as an off-road machine.
Review of the standard bike.
The Tonaro Big hit is available in New Zealand for about $2000. One of the lower priced e bikes on the market.
The model purchased is the lowest spec in regards to componentry, suspension and gears. In Europe they produce much higher spec bikes. They claim the 200w mid drive motor to perform the same as a 500w hub motor. Hmmm.
First ride impressions.
The bike is set up with pedal assist. You have to pedal for the motor to cut in. Not good. Any mountain bike that has this already shoots its self in the foot. You need the motor to get started on a hill, and the fact that it take 2 pedal revolutions before it cuts in means you often find your self stalling and rolling backwards before the motor provides any assistance.
However, once the motor does cut in, its all on. One speed, full throttle. In low gear, the bike climbs superbly with no effort from you. A definite advantage over hub drive motors. For slow speed mountain trails with steep climbs, a mid drive geared system is the way to go. After 2nd gear however, I see no real advantage over the hub motor in performance.
Another big downfall of the pedal assist set up, is because the bike is always full throttle, you are making full throttle gear changes. SLAM!, SLAM!, SLAM! go the gears as you shift through them. Bike clusters were not designed for this. Any review that says the gear changing is smooth is rubbish. Other models of this bike use the Rolloff internal gear hub, that would be many times a better set up than a cluster. A fix to this issue is to fit a hand throttle, which we do in our upgrades.
The motor and gearbox appear of good design and robustness. The motor is very smooth and basically silent once at speed.
The controller is a tiny little 6fet controller, 15amp, with 50v capacitors, so limited to 36v batteries. It is possible to use a throttle with this controller. You could also up the current to 20amps and be ok.
The bike tops out at 32km/h with the restrictor removed on the stock 36v battery.
The battery is a Lithium Ion prismatic cell 10ah. It is a low cost, mid performance battery. Very light, but has considerable voltage sag and I would not expect more than about 500 recharges before the performance was unbearable. However, it works well for this low power set up.
The bike frame is Aluminium, and very basic. Reasonably good style frame but lacks any production finesse. No progressive linkages and the rear shock, is a shock absorber, rather than suspension. The front shocks are your low cost rock shocks, that work ok with various adjustments and fine for light off road use.
I think the term, light off-road use is appropriate for this bike. Trail riding, smooth tracks and 2" high jumps.
As a stock bike, the performance is usable and the bike would make a great weekend electric bike, or road commuter. An upgrade to a hand throttle and immediate start, rather than pedal start would make the world of difference to the usability of this bike.
The 3 core upgrades asked for to make this bike perform much better were, immediate start throttle, the ability to run a 48v battery, and cycle analyst computer.
We set out by removing the stock interface, pedal assist sensor, controller, basically everything but the motor.
I retained the wiring harness that goes through the frame, though put new plugs on it. Be aware, the colours going in on end are not necessarily the same colours coming out the other! The stock wiring of this bike was poor, with many wires pulling out of there crimps with little force.
A new infineon 48v 25amp controller was fitted with cruise control. A thumb throttle was fitted along with a large screen cycle analyst. Also we have fitted a temperature monitor to the motor to see how well it handles 48v.
The bike is a million times better with the thumb throttle. You can now start half way up a slope, hit the throttle and off you go. With the 48v battery the bike will pull a wheelie, how ever that is over pretty quick as the motor reaches its top speed in a second. Now with the throttle you can let the power off and make smooth motorcycle style gear changes.
Top speed with the 48v battery was 40km/h. The bike was climbing most hills on the road at about 30km/h, step hills at 20km/h. I rode up a track in the bush that all my hub motors stall and this kept going until I lost traction. At 48v I think it would climb almost anything, though 30 seconds full power climbing will get the motor quite hot.
On the standard 36v pack, now running more amps, I can manage to get the motor to stall going up the bush track.
In summary, at 48v about 20amps, this bike comes alive. The performance becomes usable and fun.
However, this bike, even with the upgrades has not won me over hub motors. I would still choose a Nine Continent 2808 at 48v 25amps for the sheer smoothness and acceleration. But for tight track work and slower riding, this bike would be great and will still be going up when the hub motors had stalled out.
Buy as a light use trail bike or commuter. Make the modification to hand throttle. Enjoy.