Short test: ... if it's easy? With the Opal Esprit+, Diamant shows how the blessings of the additional drive can be used to breathe even more operating and seating comfort into bicycles - and at the same time make them simpler and require less maintenance.
Bicycles fascinate us with the freedom they give us and with the technology that makes this possible. In terms of comfort and operation, current models are well advanced - without suspension and gears with eleven or twelve gears, it's hardly possible anymore. So it's interesting to see that the additional electric drive in particular offers the potential for technical reduction without sacrificing functionality.
A good example of this is the Diamant Opal Esprit+. The plus sign stands for the drive, in this case a powerful Bosch Performance CX – anyway, the East German bicycle factory has completely switched to the motors from the electronics specialist. Anyone who takes this propellant for a walk no longer has to be afraid of climbs, headwinds and traffic light starts - even in medium support mode there is plenty of torque, paired with sensitive power development that responds to all pedaling frequencies.
In view of such a wealth of performance, you can confidently make compromises here and there - maximum efficiency is not necessary with an electric bike. And that means that the manufacturers can also break new ground. For example, when it comes to comfort: Why specify a heavy, complex suspension fork when you can mount extremely large-volume tires that dampen vibrations with slightly reduced air pressure and smooth out bumps in the road? Especially since the product managers at Diamant have thought it through carefully: 27,5-inch rims are installed on the Opal, so that despite the bulky tires, the rolling circumference and handling remain the same as with 28-inch wheels. And the fact that the rolling resistance increases with reduced air pressure is easy to get over given the strong drive support.
The manufacturer proceeds in a similar way with the gears – not an easy topic, especially with e-bikes. How many gears are necessary in view of the motor support? And should the gear ratio be as large as possible, as is the case with conventional bicycles? Diamant chooses a different path on the Opal: With the stepless Enviolo gear hub, they offer a full 380% large transmission range. For comparison: This corresponds to a derailleur system with an 11-42 sprocket cassette and mono chain ring at the front. In contrast to this, with the US hub you can switch any desired gear ratio under load and seamlessly - the gearing is, as I said, stepless. The only disadvantage is the lower level of efficiency compared to derailleur gears, which would make itself felt on a normal bicycle through greater effort on the part of the rider; with the e-bike, on the other hand, only the range is slightly reduced. Which isn't a problem with the Diamant Opal: the frame houses the "biggest" battery from Bosch with 625 watt hours, which should be good for well over 100 kilometers with medium support.
Combined with a belt drive that requires no maintenance (provided the belt tension is correct), maximum comfort is guaranteed; no circuit can be operated as easily and intuitively as the Enviolo. The only drawback is that you can't switch from the smallest to the largest gear ratio without changing your grip on the twist grip - but you only have to do that very rarely.
The Gates timing belt has another advantage: Since it does not need to be lubricated, it is extremely clean; a chain guard is therefore superfluous - one less component that can start to rattle. The solid mudguards and the elegantly mounted luggage rack contribute to the tidy look, which is objective but not devoid of emotion - the appeal of the Opal lies in its functionality, which is also given in the sitting position. The rider is positioned in a very balanced way, with the handlebars being significantly higher than the saddle; the pleasantly shaped handlebars with high-quality ergonomic grips could be placed higher/closer/further away by simply changing the Ahead stem. There is also plenty of room for maneuver when it comes to saddle height thanks to the rather short seat tube; But millimeters don't matter anyway: When it comes to ergonomics, too, the motor support ensures that you don't have to pay attention to maximum pedaling efficiency - the main thing is that the comfort is right.
The price, of course, too - and with this bike it's more in the upper range. However, some lifestyle manufacturers offer technically and functionally inferior products for the same sum, which may appear "cooler" at first glance, but cannot do much. And that makes them the exact opposite of the Diamant Opal Esprit+.
Conclusion: Diamond Opal Esprit+
The Diamant is simply styled, but behind the factual facade there is technology that proves: In Hartmannsdorf, the chances and possibilities of the electric drive have been intensively dealt with. No wonder - after all, Diamant is one of the pioneers when it comes to e-bikes with a lot of experience...