When Veteran Sherman rose to the top of EUC, everybody was taken aback by its battery size. We made a real life range test back in autumn 2020 when Markus travelled from Tallinn (Estonia) to Parnu, a city located 140km away in a single day on a single charge.

The 140km challenge on Veteran Sherman. English captions available.

Soon after, Gotway introduced the Monster Pro, the biggest wheel by many different metrics – wheel diameter, battery size, power, weight, range, top speed etc.  Naturally, we were tempted to go for even a bigger challenge with Monsu (a nickname that is sometimes used for Monster Pro) – to cover the distance of appr 195km between the cities of Tallinn and Tartu.

When doing the planning, Markus was to take the Monsu to be accompanied by Mart on Sherman as long as Sherman’s battery holds up.  Unexpectedly, Markus caught cold just a day before the event. So it had to be Mart riding the Monster. Our friend and Voltride’s client Rocco, who has had Monster Pro for about half a year, lent us his Monster for the occasion. Big thanks go out to him!

However the big question was – will it be possible to reach Tartu at all? Will there be enough juice in the battery? It did not look too encouraging when we checked the data from our 140km ride on Sherman to Parnu: energy consumption 22Wh/km at speeds 25-30km/h as an average. However, the temperature back then was about 8 degrees, and riding was done in the standing position. To cover the distance to Tartu, with similar energy consumption we had to have the battery size of 4300Wh!!! Or cut the consumption down to 18Wh/km. Otherwise, no way!

Watch the video of the challenge at the end of the post ⬇️

Morning of the Gotway Monster Pro test-day

Wake-up at 6.30am, glancing out of the window – the roofs of neighboring houses were all wet. Not the best day for riding the hollow-bore motor wheel prone to water ingress. A quick call to the wheel owner confirmed our fears – “I would not go”, was the reply that delivered us the message. The ride should be called off. Oops!

When gathering at the starting location, we decided to check out the road for a few more kilometers away from the city. Turned out the road was mostly dry. We were good to go!

For the record, here are some data about the wheel and the rider. The wheel weighs 43.1kg, the rider with gear 84.9kg, total 128kg.  Prior mileage – wheel 7500km, rider 5000km (that included just 1km with Monster Pro). The tire: Michelin Pilot Street (24.2″) at 2.1bars. The weather was not the best one – temperature outside 14°C.  But the battery was full at 99.9 volts, and all of us were pretty excited.


The start was 8.55am at the east border of the city of Tallinn. Whoa!!! Riding seated for the first time with Monster Pro was a bit of a surprise. But given the sheer size of the wheel, the knees actually did not feel folded to the chest.  The seat was brought in from Gotway MSP as a last minute decision. We had concluded, that there was no way to reach Tartu while riding in standing position. The wind resistance is too much.

Riding a bike, wind resistance equals the rolling resistance at 15km/h. For unicycle we do not know for sure, but probably it is about the same if riding seated. Wind resistance gets even bigger when riding standing. At speeds 25-30km/h, wind resistance is already 80-85% of total resistance. We set the speed alert at 32km/h not to ride too fast and the goal for Mart was to keep the body position as aerodynamic as possible.

We had to take some small back roads out of the city to avoid motorways. Funny enough, no-one had actually checked, which roads. So the first thing was to open the Google maps on the phone and check out the route. Of course, no stopping, multitasking while riding 😉 And despite of the help from Google, we got ourselves lost for 2 times. The second time ended in a dirt road full of potholes and rocks – no way the battery would last to Tartu on these kinds of roads.

After the first 10 km, the battery was down at 89%. A quick math and the result did not cheer us up. What’s going on? For those who not just ride their wheels but also follow the battery voltage, this is nothing new. The initial voltage drop is a rule. But anyhow, if you have planned to go on for another 185 km, losing 11% on the first 10km was a bit discouraging.

Before our trip, we had studied some other EUC range tests on Monster Pro. Marty Backe in Southern California had been able to reach 101 miles or 167km. He used about 20Wh/km, riding in standing position. Wrongway in Poland had been riding seated. He reached 219km, spending about 16Wh/km. The average speeds were similar to ours, around 25-35km/h, averaging below 30km/h. Both of them had the range test done during 2 days with temperature higher than ours. So concluding from that, the only way for us to reach Tartu was to ride in seating position. And not to spend more than 17.5Wh/km, this was our goal.

On the road

After 20km everything started to feel under control. We had found our way to a country road with less traffic. The wheel was pretty comfortable and easy to control. The mass and the size of the wheel made the experience very stable. Catching up with an elderly man on a bike, he soon recovered from the first shock ,asking: Is it a cucumber cart? We’ve no idea what’s the resemblance, but it was good for starters ;). Riding a cucumber cart to Tartu. However he refused to believe that we are indeed on our way to Tartu.

The video team followed Mart on a safety car. This worked pretty well also during our previous trip to Parnu. A small inconvenience for cars overtaking us, but certainly a great help to our EUC-rider. When there was a bicycle road available next to the main road, we used that one of course. Of the total distance, the bicycle roads made up about 20km.

Still not sure, how the battery would hold up, we checked the app every now and then. At 30km, the battery was at 83%. So, with the last 20kms we had spent only 6% or 3% per 10km. That’s not bad.  The energy consumption seemed to be highly impacted by the quality of the road – yes, the road quality can be very different. It also seemed that Mart’s position on the wheel made some difference. When he tried to make himself as small as possible, almost make it look like a swimmer on the wheel, the energy spent on 1km dropped. At 52km passed, we had battery still at 72% with voltage at 93.8V. Looked like we had improved our odds to last until the happy end.

At 100km, halfway through the whole distance, we made a stop in a village Jarva-Jaani. There we found out that a huge area of that small village was dedicated to firefighting museum and utility vehicles display. A nice crazy place for shooting a video. Then it was the time for lunch. Not the wheel, just us. The battery stood at 49%. What would you say – would we make it, or rather not? The consensus of our Facebook fans seemed to be that we would probably make it, or just a few kilometers short.

Leaving Jarva-Jaani, Mart was texting again. And he almost hit a hen walking on the main road. So never lose you focus while on EUC, as you never know what you could hit. At 120km the battery stood at 39%.  The road got less even. More like a dirt road that was covered by a thin layer of asphalt. The power consumption was up immediately.

Take the detour?

Totally unanticipated, we found a mandatory detour of 15km in front of us. The bridge on the main road seemed to be under reconstruction and the road was closed. As the reopening was due in 10 days, we had hopes that may be there is some part of the bridge already in place to cross the river.

Indeed, the concrete structure was ready. But there was a problem – it was just being covered with some sort of glue. No way the workers would allow us to cross it.  The bridge had some 30cm wide concrete border on both sides. The site manager offered that we use that border for crossing the river. The safety car should follow the detour.

Mart: Yep, the construction guys were really curious, what were we riding? And learning that we travel to Tartu with THAT THING, they became very excited. And they wanted to help us to continue the trip.  The boss even asked, isn’t that dangerous to ride it (what an unusual question about EUC :))? Honestly, the most dangerous moment was crossing that bridge along the very edge of it.

Will we last?

At 160km we had 24% battery left with 83.8volts. Not bad. The Polar tracker showed the distance of 149km. So the difference with wheel seemed to be some 7%. Comparing it to road signs, Polar seemed a bit more accurate, however underestimating the distance a bit. Spirits were high and we were rather hopeful. But we still had about 40km to go. We knew that the road would get a bit hilly when approaching Tartu. And this would consume some extra energy.

However we did not know that there will be another road construction ahead – the asphalt was being grinded off during 10km. Riding along the grinding lines made Mart almost lose balance. He later said it was the most difficult leg of the whole day. And it took a significant toll on the battery level. At 180km the battery was down at 8% and we still had some 20 km to go. Did not seem too realistic.

The final kilometers were pretty nervous. 3.5 km to go and 1% left.  The owner of the wheel told us that it is typical to Monster Pro, that even with 0% battery left, the wheel can still get you some extra distance, not sure how much, but some. At 198.8km, we had our battery at 0% with 79.9V. It was the last incline before Tartu that drained it. But our Monster Pro was still moving at speeds 25-28km/h. No beeping.


We arrived in Tartu at 18.10 – Yes, yes, yes! 201.1 km according to Monster’s odometer and 187km according to Polar tracker. Battery was stable 0% and voltage 78.4V. We had made the trip in total 9h15min with pure riding time about 7.5 hours.  The average energy consumption was 15Wh/km – better than expected. So the wheel had made it. But what about the rider?

Mart: Sitting 7.5 hours on this moving “cucumber cart” was not easy. It’s not as exhausting, as one could say about running a marathon.  The main difficulty came from being forced to a more or less fixed position. The MSP seat was a life-(ass)-saver. Still, from 150km on, sitting down on the wheel was not a welcome task.  Some pain emerged in unexpected places, like on the left side, and the feet up from the knees.  But you do not complain about this when you have just finished the long-distance ride successfully!


As the wheel was not as exhausted as we thought it would be, we decided to run it until it lasts. We had already passed the result by Marty Backe. So there was just one goal – surpass the top range achieved by Wrongway of 119.3km. 

The wheel performed pretty well up to 218km, then the beeping started.  Tilt-back came at 220km. The tilt-back was finally impossible when the single mileage stood at 221.3km. What a nice conclusion for this long day. 

When doing some adjustments in our math, the total usable capacity of the Monster Pro battery is 3258Wh (Gotway factory specs state nominal 3600Wh). Our calculation is based on 3.1V per cell when the low-voltage protection activates. The real useable capacity of Samsung 21700 50E cell is 4.65Ah (in between 3.1V-4.2V) according to the manufacturer data. The resulting net energy consumption was 14.7Wh/km. Not bad.

The wheel performed with no problems all through the trip. The temperature stayed low as expected. But for sure, this is not the way to ride Monster Pro on every-day basis. This wheel is made for speed. So we are already thinking of the next challenge. If you have any suggestion about what could be the next challenge, let us know.

PS. For anyone who plans to go for another range test, reducing the air resistance is the key. Lower speed helps, like 15-20km/h. Also try to minimize the area of your frontal projection. Try to be like a spade, not like the brick. The tire should be as narrow as possible with low rolling resistance and with pressure around 3 bars. Pick the roads with high quality asphalt, no hills and as small number of forced stops as possible. If you have weight around 50kg, you should be able to push the wheel beyond 300km.

Gotway Monster Pro can be purchased from our sitehttps://voltride.com/gotway-monster-pro/