Denzel is a company that is making carbon fiber ebikes, and this last year they have really grown, so…here is a look at the newest models from their web-catalog.
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Alex Guliyants
Alex is the owner and chief designer for Denzel ebikes. I recently had the pleasure of having an email-chat with him, in order to find out more information. He grew up in the beautiful region around the city of Kislovodsk, near the southern border of Russia, between the Black sea and the Caspian sea, and on the north slope of the Caucasus mountains.
I found Alex to be a pleasant and humble man, so I had to ask to find out his background, which he has every reason to be proud of. He graduated from the Institute in Kiev, and then worked at the Institute of Applied Geophysics, doing research on the sun, and also radiolocation. That led to a job at the Institute of Atmospheric Physics.
As impressive as his fascinating background is, the Soviet/Russian economy has had many changes over his lifetime, and at some point…we are fortunate that he decided to change careers and focus his many skills on building an electric bicycle company. He named it East GEM, and it is located in the shipping port city of Weihai, in Shandong, N. E. China.
He first began marketing his new ebikes in Russia, and he has expanded into Poland, and the UK. He is currently in negotiations to add dealers in France and Switzerland.
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The Battery Box
One of the most eye-catching features of the Escort and Boxon models is the removable battery box that Denzel developed. There is nothing unusual about having a rectangular battery box in the frame, but Denzel made several interesting choices. One decision they made (that I like), is the remote on/off key fob, and…it also actuates an anti-theft motion alarm. The interesting part is that the motion alarm is on the battery box.
You can charge the battery while it’s in the frame (of course), and in keeping with current trends in ebike design, you can remove the battery box to store it inside. This has an appeal to many buyers for several reasons, one of which is security…since the battery is quite often the most expensive part of an ebike.
The Denzel battery box. The skeletonized frame allows the rider to see the voltage readout on the box. This 48V battery has been charged to 90%
The pack retention components on the frame allow it to be very secure, but also make it easy for the owner to remove the battery if they wish.
The optional voltage and capacities are:
48V 20Ah,
48V 28Ah,
60V 23Ah,
60V 28Ah
Another interesting feature is the Kelly controllers that Denzel uses, which have a bluetooth option, so you can access some very interesting features from your smart-phone.
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Sparta
The Sparta the first ebike that I recall seeing under the Denzel name, roughly about three years ago. In the pic below, this one has the optional carbon-fiber 3-spoke wheels. Large portions of the frame also make use of carbon-fiber, so it is lighter than it looks.
The Denzel Sparta
The body panels hide any wiring clutter, and Denzel has chosen bold colors for customers to choose from.
Three Sparta ebikes, with the more affordable spoke wheels.
The base-model rear shock is the DNM AV-22. There are several suspension forks that a customer can specify.
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Escort
This model is one of the reasons I decided to write about Denzel. The motor is mounted on the swingarm instead of the center of the rear wheel. Hubmotors clearly do work, but…engineering-wise, if there is any way that you can move the weight of the motor out of the wheel, and as far forward as possible?…it makes the entire bike more nimble. This has a beneficial effect on the feel of the ride, especially for off-roaders.
If you were to move the motor into the frame, or attached to the bottom bracket (like many mid drives), that would be more optimum from a weight-distribution perspective. However, doing that also adds a great deal of mechanical complexity to the system. I am looking forward to seeing more examples of a non-hub motor mounted to the swingarm, where-ever I can find them.
The Denzel Escort
There is a second reason that using a non-hub motor can be very beneficial, and that is to increase the magnet speed of the motor. In a large direct drive hubmotor, the motor spins at exactly the same RPMs as the wheel. A 26-inch wheel at 28-MPH (45 km/h), would be spinning at only 360-RPMs. The Escort has a #219 chain connecting the motor to the rear wheel, and their sprocket tooth-counts of 100T to 15T equals a ratio of 6.6:1, meaning that for every turn of the rear wheel, the motor spins 6.6 times. At 28-MPH (the US street speed limit for pedelecs), the motor is spinning 2,376-RPM’s…MUCH better for efficiency and system power.
I realize that the Escort is not a bicycle, it is a light off-road vehicle with pegs instead of pedals (pegs that fold for storage and transportation). But, this interesting example has some rarely seen features that I feel need more exposure. If you like the Escort, but would like fatter tires than the stock 3.0-inch, they just recently added a fat-tire version with 20 X 4.0 tires, in February of 2017.
The original development motor was the Cyclone 3000W, but since then Denzel has secured a different supplier for a very similar motor. By removing the geared reduction and specifying a lower Kv (the RPM’s per volt), this motor can be narrower and quieter. The front driving sprocket is a 15T, and the freewheeling large sprocket on the rear wheel has a 100T, 90T, and 80T option.
The Escort uses hydraulic calipers on the brakes, and 203mm rotors from Brakco in Taiwan.
Fully-loaded, the Escort has a weight of 77-lb (35-kg), and this is a full-sized vehicle suitable for riders up to a height of 6-ft 3-inch (195 cm). The carbon-fiber construction plays a major role in keeping the weight down, while still maintaining strength where its needed.
The key distinguishing feature of the Escort frame is the integrated “moto” style of seat. This frame can be purchased with a bicycle pedal-drivetrain, and outfitted for a rear hubmotor, but…I have shown it here with the “Escort Mid” option because I suspect that is probably the most appropriate configuration that customers would select for this frame.
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Boxon
This model is a true bicycle, with a fully functioning pedal-system. There are many similarities between this and the Escort frame, but…the key distinguishing feature of the Boxon is that it uses a conventional bicycle seat-post.
It uses the brilliant Denzel battery box, and their carbon-fiber frame, but the motor system is most often a large rear hubmotor. The swingarm is a shape that I have liked for quite some time. it is called an “elevated stay”, and doing this means that you don’t have to break the chain in order to install or remove a chain. It also makes it easy to swap-in a belt-drive , such as the famous Gates Carbon belt, however…you must make certain that the wheels and crank-set that you prefer have an option to mount the Gates pulleys.
The Denzel Boxon
In the pic below, this red version has mounted the Popular Bafang BBSHD, as you can see from the stock “frisbee of death” steel sprocket it comes with. Although the Boxon frame does allow the BBSHD to be rotated forward (in it’s common mounting position), the elevated stay combined with the rear-wheel set-back…it permits a BBSHD to be rotated around to behind the bottom bracket (BB).
The stock BBSHD when operated at 48V X 30A will equal 1,440W (the stock controller will also accept 14S / 52V). However, there have been several recent experiments with garage builders using an external controller at either 72V X 33A = 2400W, or 48V X 50A =2400W. Be aware that these power levels are at the upper limit of what the BBSHD is mechanically capable of. Between those two scenarios, the 72V system will run cooler (most heat comes from the amps), but a 72V battery will be much more expensive and difficult to source. If you attempt to use 50A on a BBSHD, add a temp sensor, and make sure to keep your ebike in the proper gear.
Denzel does have a 60V option, so 2400W at 60V would be 40A.
The Denzel Boxon with a BBSHD. The black item the rider is touching is a folded bike lock.
The wheel rims are a heavy-duty 24-inch, and with 24 X 3.0 tires, and the tire outside diameter (OD) is very close to 26-inches. Tires that are 2.8-3.5 inches wide have become popular recently, and are sometimes called “mid-fat”. The sideways flex on street-riding is not as squishy as full 4.0+ fat tires, but the traction on snow and sand is still much better than the common 2.2-inch MTB tires. Having a full-suspension frame with 3.0 tires should provide a lot of cushion to the ride.
The stock fork is the DNM USD-8, and the shock is a DNM RCP-3.
Although the Boxon is shown here with a rear hubmotor, and also a BBSHD mid-drive…it can be purchased with the swingarm-mounted 3000W motor option. Be aware that doing that negates the ability to have a standard bicycle crank, so that option includes foot-pegs.
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Denzel Alta, and the Haoshida company
Alex learned how to make molds and form carbon fiber bicycle frames for making his initial Denzel prototypes. However, if he wanted to expand, he decided it would be best to form a partnership with an existing company. Alex formed a joint-venture with a large Chinese carbon-fiber parts company, called “Haoshida”.
The Alta, a joint venture from Denzel and Haoshida
The first product from this joint venture is the “Alta” ebike. It incorporates a light and slim removable shark-pack battery on the downtube, which powers a 48V Bofeili mid drive. Although the Bofeili drive is typically adjusted to meet EU specifications, it is capable of 48V X 16A = 750W, should anyone want to import it to the USA. It is also ideal for 500W markets, such as Switzerland, Austria, and Canada.
Instead of paint, the Alta uses a clear epoxy to highlight the carbon fiber inside, and I really like this look.
Here is a promotional video for the Alta, to show how easily it can climb stairs, and how light it is to lift by hand. This bike only weighs 18-kg (40-lb).
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Solar Charging
Many of Denzel’s customers have asked about a solar panel system that can be unfolded and set in the sun to charge their ebike when it’s not being ridden. To be fair, it does take a very long time for a one-square-meter panel to provide a small amount of charge, but…if this interests you, Denzel has developed a system that is as good as it can be.
The Denzel solar-charging system
This two-minute video on the Denzel solar-charging system shows a large cargo-bag set for a road-trip. The panels fold flat, and the charge controller is actually very compact, so be aware the large bags (in the video) are not needed for the solar charging system. Again, you must adjust your expectations about how many actual watt-hours of charge you can get from a panel this size, but…on a road trip, every little bit helps.
If you want to see any one of the other 89 Denzel videos on Alex’s Vimeo channel, you can get to the index here.
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Written by Ron/spinningmagnets, February 2017
