In previous articles, I was excited about the new ECVT systems announced by both Avinox and Gobao at Eurobike 2027. I learned from statements by Gobao, not from Avinox (who were being mysterious), that the system is based on a concept used in the automotive industry for several decades (since 1997):
We found out how to achieve automatic CVT transmission on an e-bike: with two electric motors!
Unlike Avinox, which presented functional frames from several well-known major manufacturers (Canyon, Commencal, Forbidden, Mondraker):
but no functional bikes, Gobao brought a functional bike with the new functional X1P system installed on it, available to journalists and influencers for testing during the exhibition.
At that time, they had not presented the system on their website, but it is now available, so we will take a look to see what we discover.
I was talking about the technological limitations of traditional batteries made up of 40-60 traditional 21700 cells, mounted in series and parallel to provide the necessary voltage - 36V but also the current of 42A - to deliver the 1500W power claimed by Avinox for the M2S systems. I noticed that bikes with Avinox M2S, except for the Amflow PX which contains a revolutionary Tabless battery, similar to those found in Tesla electric cars for the first time but also adopted in electric bike systems for the first time by Avinox.
With these new types of cells from Ampace, 50480, the number of cells has been reduced from 40-60 to only 10, and the current provided by them is much higher without dropping the voltage, allowing for the achievement of the 1500W power.
Let me remind you how these new cells look compared to traditional ones:
Only 10 cells in the Amflow PX frame:
Similarly, in the cylindrical frame of the Atherton, where traditional batteries with 40-60 elements in series and parallel would not fit:
Why aren't other bike manufacturers adopting this new type of batteries? Are there not enough available? Would the bikes become too expensive (we've seen how much an Amflow PX costs...)? Who and when will they do it?
Let's return to Gobao, which declares two systems:
So far, nothing unusual, just like Avinox, two systems, 1500 and 1200W, 150, 120 Nm, somewhat heavier compared to the classic Avinox M2S at 2.65 Kg and Avinox M2 at 2.52 Kg. Since X1 and X1P have the same weight, it's clear that only the electronics differ (smaller current transistors) or just the software?
At Avinox, we see a difference of 130 grams between the two systems, so something has changed inside - materials for sprockets, differential, pins, rotor, electric motor stator, it's not just software.
So + 1.33 Kg compared to M2 and +1.2 Kg compared to M2S.
We are told that we will save weight from the derailleur and sprockets and that we gain the advantage of shifting weight from the back to the center, a benefit for the rider. But let's calculate!
The chain remains with the Commencal system, I see. Probably being a single speed, a stiffer, more durable one can be used compared to an XT, but let's take an XT chain as a reference, from Shimano's website, it weighs 252 grams.
I found a belt on bikeinn, it weighs 93 grams.
So the advantage of the belt vs chain: 252g - 93g = 159 grams saved with the belt vs chain
Even though those with CVT do not have a rear derailleur, there is a chain/belt tensioner, which does not seem small at all, but rather massive, they look heavy from what I've seen in pictures.
Shimano XT derailleur: 284 grams
Pinion CT2 chain tensioner: 141 grams
CVT advantage with chain compared to chain derailleur: 143 grams
Belt tensioner Pinion BT1: 190 grams.
So far with belt vs chain we have 190 + 159 = 349
And we still have to calculate the sprocket set versus a sprocket for the belt
Shimano XT sprocket set: 12 speed MTB: 470 grams
Belt rear sprocket set: 90 - 100 grams
Belt advantage versus chain in sprockets: 370 grams
Belt advantage versus chain and sprockets in total: 370 +349 = 719 grams
So basically we bring 719 grams from the back to the front (the chain isn't all piled up in the back....) but the CVT box, weighing 1.33 Kg, adds another 611 grams which is reasonable for such functionality. So it's more than what we save in weight from the parts that disappear in the back as the marketing team said at the event...
We also notice the 45 Km/h version, Speed Pedelec, which are considered mopeds, registered at the city hall with a yellow plate, and you need an AM or B license.
We see a very powerful charger that charges 80% of a 750 Wh battery in 20 minutes with 30A compared to the 12A offered by Avinox, considered high current compared to other systems that offer 2-4, you have to wait a night to charge them.
But what do we see here?
At the charger: Applicable battery voltage: 52 V
At the batteries: Rated voltage: 50.4 V
52V from the charger / 4.2 V (cut-off voltage for a Lithium cell, meaning the charging voltage in constant voltage mode) = 12.38?! - Why isn't it a whole number? We have an arithmetico-electronico-chemical problem here with Gobao...
Let's now move on to the declared nominal voltages (rated voltage as they call it).
But 50.4V from the batteries / 3.6V results in exactly 14 Lithium cells in series (the nominal voltage of 3.6V - remember the convention from the article What are Nm, Wh, W, what do the numbers mean and what manufacturers don't want you to know about power in electric bikes - part I - about batteries).
So we have 14 cells in series and I don't know how many in parallel, we won't calculate them or only 14 in series if we adopt cells like Ampace 50480 as Avinox; but I don't really believe that because the shape of the batteries is rectangular, not cylindrical.
By increasing the voltage, adding another 4 groups in series, we can achieve a lower current at the maximum power of 1500W, so we will manage technologically with the classic 21700 cells, far too widespread, well-known, tested, and probably far too convenient for the manufacturer.
The current thus drops from 42A to 30A, a much more reasonable thermal regime, with much lower voltage drop, we won't repeat the calculations and graphs from the article What are Nm, Wh, W, what do the numbers mean and what manufacturers don't want you to know about power in electric bikes - part I - about batteries).
Current that is close to that in the Gobao brochure: Pulse discharge current: 34 A (how did they calculate that?!)
There could have been a bit more consistency from them, so our calculations would come out right too, not for nothing.
I won't check the charging times with the beautiful 30A charger! Kudos to them for achieving such a thing, probably with GaN - tough, small, and good.
We are waiting for the announcement of the models with Gobao from the bike manufacturers. When can we expect a response from the Germans at Bosch, the Japanese at Shimano, Yamaha, Panasonic?
Until then, if we want a powerful e-bike with Avinox, we settle for the models with derailleurs that work very well, we know how to maintain them, they are very well integrated, and we even find certain models in stock, you order today and receive it tomorrow, see the article Do you want to have a bike with Avinox M2S tomorrow? Order it today at bikeverse.ro/shop!
