Diamondback Union 1 Hands-on Review (2022)

Profile of the Diamondback Union 1 from the drive side

This supercharged commuter ebike is the Diamondback Union 1 and it’s a pretty good deal to get a class 3 Bosch motor on a solidly built frame with 2.4” tires that can do some off-road as well as pavement. It also comes stock with metal fenders and a rear rack.

The Diamondback Union 1 – At A Glance

* Price – $3500 * Weight – XL 53lbs * Sizes – small, medium, large, extra large * Class 3 mid-drive

Range Test

I weigh 220lbs and can get 17-35 miles on this ebike in real-world testing. Depending on which assist mode I’m in, how many hills there are, and how windy it is. Lighter riders will get more range.

Of course, the bike can be ridden if the battery runs out, just without any motor assistance. 

This bike has been a great commuter and around-town bike for many of my customers and they have nothing but praise for it. It’s fast, fun, and capable.


  • Bosch motor system 
  • Shimano Deore 10 speed drivetrain 
  • Intube battery
  • Includes fenders (metal ones btw) and a rear rack
  • 2.4” tires


  • 400wh battery
  • Basic Bosch Purion display
  • No lights (but they can be added)

Who’s It For?

Are you sick of the bus? 

Do you want to save money on gas by riding to work? 

Do you want an ebike that can rip around town and still be able to take some curbs on occasion or cut across a field?

If you want all that and more with a top-tier motor and battery then this ebike is for you!

Some Backstory

Diamondback just started making electric bikes in 2021 and like all the Diamondback electric bikes, the Union 1 for 2022 will be the same as the 2021 model. Diamondback is carrying over its 2021 ebike line to 2022.

Diamondback also offers a Union 2 with more bells and whistles, you can check out the review for that here.

Form & Function

When you buy an electric bike or any bike for that matter, what you are really buying is the ride. You could have the prettiest bike in the world and unless it rides well, then it’s just a piece of artwork.

This bike is sleek and fast! The Union 1 rides like a dream and with the built-in fenders and rear rack, it’ll keep the road yuck off of you and carry all your stuff. It has a class 3 Bosch motor, bigger tires at 2.4” and is built like a tank. The big tires help smooth out the ride, considering this bike has no suspension.

The Diamondback logo is just raised letters on the downtube the same color as the frame, very stealthy! It’s a good-looking bike. Unfortunately, for now, it only comes in a kind of dull matte grey color.

The handlebars are a little far out front and narrow, so this puts you in a more aggressive riding position. Personally, I would change them to be more upright, but that’s just me.

Nuts & Bolts

Here’s a breakdown of what comes stock on the bike – 

The Motor, Battery, and Display

These are the parts you are really looking for when buying an electric bike.

The Diamondback Union 1 uses Bosch, which is the best there is!


  • Bosch Performance Line Speed gen4 mid-drive – 250w – 85nm max torque – up to 300% assist


  • Bosch 400wh in-tube vertical with Bosch compact charger (charges from 0-100% in about 7hrs)


  • Bosch Purion (basic display telling – speed, range, trip, odometer, assist level, battery level)

The Drive Train

If you are looking for a pedal-assist mid-drive ebike then the drive train is very important. This is the gearing and shifting part of the bike.


  • Shimano Deore M6000 10 speed

Rear Derailleur

  • Shimano Deore M6000 SGS 10 speed (can go to a 36 tooth cog)


  • 11-32t, 10 speed (can be expanded to 11-36t)

Now the tooth count on the cassette is where you can tell how low the gearing is, the higher the tooth count on the biggest cog, the lower the gear is. 

You’ll notice that the Union 1 comes with an 11-32 cassette, which when paired with the beast of a motor that is the Bosch Performance Speed, is more than enough for most. 

But, you can buy a 10 speed 11-36 cassette and put it on there if you need lower gears. The rear derailleur is rated to go to a 36 tooth.

The Brakes

The brakes on an ebike can often get overlooked, but when you are able to cruise at speeds above 20mph it is good to know you have brakes that stop you fast if needed.

The Union 1 comes with the Tektro Orion brakes, a 4 piston front caliper with 180mm rotor, and a 2 piston rear caliper with a 160mm rotor. 

These were the brakes on my first ebike at a time when I weighed 290lbs and they worked wonderfully!

The Fork

Close up of the fork on the Diamondback Union 1 2022

Nothing too special here. 

The Union 1 has an aluminum rigid front fork with a 12x100mm thru-axle. It does have mid-fork eyelets that the fender stays are mounted to and these can also be used to mount a front rack.

The Wheels and Tires

Front wheel of the Diamondback Union 1 2022

Wheels – 

The Union 1 comes with double-walled, 32 spoke, non-tubeless-ready rims laced to thru-axle sealed bearing hubs. 12x100mm front, 12x142mm rear.

This means that they are tough enough for most terrain but they are not tubeless-ready. So tubes only on this one.

Tires – 

The tires are Schwalbe Moto-X – size 27.5″ x 2.4” – These are some of my favorite tires for riding just about any terrain. 

For off-road just lower your tire pressure a little and these tires grip very well even though they are semi-smooth. I have ridden these exact tires on just about every surface and they rock. Just be cautious when turning in sandy areas.

Before you buy – 

Even though this bike does not come with lights, lights can be wired into the Bosch system pretty easily by your local dealer. Also, the handlebars can be changed if want to be more upright.

You can find the Diamondback Union 1 here!

Handlebars from the top on the Diamondback Union 1 2022

At the End of the Day

If I wanted an ebike to mainly commute to work or school or to get where I need to go fast, then this would be it. 

If after reading this far and you think you may be interested in the Union 1, check out my review of the Union 2. It is basically the same bike but comes with a bigger battery, better display, and integrated lights. It also costs more, though 🙂

This ebike is another great bike in the Diamondback lineup. A commuter-inspired ebike that can also do some dirt and gravel roads.

You can never go wrong getting an ebike with a Bosch Performance motor.

In the past, they have been available online, but that may not be the case this year due to the lack of supply. So check with your local Diamondback dealer and see if they have a waitlist going for these.

Supply on this ebike has been a bit better than most. Currently in stock at Bend Velo Bike Shop!