We test the GT Grade Bolt, an electric gravel bike for everyday use

Road 20/05/21 19:31 Migue A.

The Grade range is reserved for the Californian GT brand's gravel bikes, and in early 2021 it included a new series with electric motors fully integrated into the geometry and aesthetics of the conventional models. The result is a beautifully designed eBike that can be the perfect bike for city riding, gravel tours and bikepacking. We've been riding the GT Grade Bolt for a few weeks now and here are our impressions.


 GT Grade Bolt, a perfect eBike for everything

Since we took it out of the box there are a couple of comments that are repeated among most people who stop in front of the GT Grade Bolt, the first usually refers to its aesthetics; "how beautiful it is" and the second usually comes when you tell them that it has a motor; "ah, but is it electric? Undoubtedly its aesthetics with the triple GT triangle and its fully integrated electric assistance thanks to the Mahle X35 system are the two most outstanding features of this bike.

We haven't said it yet, but this is a 6061 aluminium bike with a carbon fork. We have been able to test the intermediate model of the series, but the truth is that among these Grade electrics there is none with a carbon frame. It would not be unusual to see it in the future.

The GT Grade is fitted with 700c wheels and although this Bolt comes with 40mm tyres it will accept up to 42mm.

The seat stays surround the seat tube without touching it.

But the most remarkable feature of the frame is the floating seat stays which, from the rear wheel, pass through the seat tube without touching it to connect to the top tube. In this way the bike has a very recognisable aesthetic thanks to the triple triangle that is formed and uses it as a mechanism to absorb rear vibrations. Previously, GT welded these braces to the down tube to stiffen the frame, but since 2020 it has evolved its concept to improve flex without compromising stiffness. A wise move, as we will see later.

Motor MAHLE ebikemotion X35

In order not to break the lines achieved in its conventional models, the GT Grade Bolt integrates the MAHLE ebikemotion 35 system. An assistance system that houses a 250 W motor in the rear hub and a 250 Wh battery inside the down tube. The aesthetic result is simply impeccable, the bikes that mount it do not look like electric bikes. It's not the most powerful motor, but that's not what we're looking for here either. Efficiency prevails.

Just one button is enough to control assistance

And to finish with the aesthetics, the welds are bold but well finished. The floating seat stay system and the GT Grade Bolt's destiny for tough gravel trails, even with a lot of weight on top of it, make the welds a sensitive part of the frame, so we think that their appearance, despite being the least of it, is very well done.

Flat Mount Brakes

The frame of this GT Grade Bolt, and the fork, has a multitude of attachment points for various bottle cages, bikepacking bags or saddlebags.

GT Grade Bolt: assembly

As we have already said, the Bolt model is the intermediate model of the Grade electric series. There is still one below it, with flat handlebars (Grade Current) and one above it (Grade AMP) that has a single chainring with the GRX 800 groupset and balloon tyres. But let's focus on the assembly of this Bolt.

This is a mid-range gravel eBike that aims to be very versatile, so the choice of components is completely directed in this direction and we have to highlight that the added value of this GT Grade Bolt lies in the concept of combining the new MAHLE ebikemotion X35 assistance system with its particular triple triangle design.

GT's own carbon fork offers a robust and rounded aesthetic that has already become a classic of this type of bike, but that combines well with the design and performance of this Grade Bolt. Aluminium will be the protagonist of the rest of the components, as in the wheels, seatpost or stem. The handlebars are also made of aluminium and its larger opening or flare gives this bike a marked gravel look. This allows for more control on bad terrain and offers more space for handlebar bags.

The tyres are WTB Nano Comp 700x40c Tubeless ready, and would definitely be the first change we would make to this bike to replace them with 42 tyres.

Open handlebars and a frame full of bottle and bag holders make a statement for bikepacking.

In the drivetrain and brakes we find Shimano's specific groupset for gravel, the Shimano GRX. In this case the entry-level groupset of the series, the GRX 400 with a 2x10 drivetrain with 11-34 cassette and 30 and 46T chainrings. The hydraulic disc brakes from the same series have 160mm discs front and rear. The good thing about this groupset is that you can make an infinite number of combinations with its components.

Fabric Scoop Shallow Sport Saddle

Finally, on the saddle we find the signature of Fabric, a brand that belongs to the same group that includes Cannondale, Mongoose and GT itself.

Riding with the GT Grade Bolt

In 2020 the GT Grade was one of the most exciting Gravel bikes in the discipline, and when we heard the news that it had been upgraded to integrate Mahle's X35 electric system, we made every effort to test it.

Out of the box, first impressions didn't disappoint. The GT Grade Bolt is a very attractive gravel bike with its triple triangle system and its dark turquoise colour with gloss finish. There is only one colour in each version and this one seems to us the most beautiful of the series. But after the first compliments and after checking that the Mahle X35 engine does indeed go unnoticed in the rear hub, the first thing we did was to put it on the scales.

The battery charging port is located on the bottom bracket.

Without pedals and in size M, the GT Grade Bolt weighs 14.7 kg, which is not at all unreasonable and can be ridden even without assistance. To put this in context, these types of e-bikes are in the 12-15kg range for aluminium models and vary depending on assembly.

But it was time to test it and although the brand invites us to use it as an urban bike, we didn't hesitate for a second to take it directly to the mountain.

Until we reached the first unpaved track, a long uphill awaited us, which on some occasions has been a stage finish in the Vuelta, and so we were able to begin to enjoy the benefits of the eBikemotion X35. A very simple system that, due to its efficiency, is becoming more and more popular on most road and gravel electric bikes. It is easy to learn the system of lights and actions offered by its single button located on the horizontal tube, next to the steering, and the assistance modes allow us to decide the degree of effort we are willing to endure. In addition, eBikemotion has an app that, when downloaded to the smartphone, pairs with the bicycle and multiplies the information, practically turning it into a cyclocomputer. Here, we have to say that by default the app sends audio notifications every time we change assistance mode, which can become annoying. Nothing that can't be fixed by deactivating them.

GT Grade Bolt, a gravel bike on its own terrain

With a torque of 40Nm, this system has an outstanding power delivery, and its range with the 250W Panasonic battery is 75km. This range can be extended with an external 250W battery which is housed in one of the bottle cages. It is not included.

After finishing the uphill, we had a long downhill with a combination of track and some trails ahead of us, and here we could see that the response of the floating stays was clearly noticeable. They really absorb vibrations and impacts. With this kind of geometry you expect the flex to translate into more comfort over the kilometres, but in our test we could feel it in bumpy and rocky areas.

In the picture you can almost see the bending of the stays.

We were also pleasantly surprised when riding downhill, but this time on asphalt. The poise of this bike and the comfortable riding position that can be adopted on it, makes going down big mountain passes on the road a real pleasure. Even with these tyres.

In terms of overall handling, we found everything to be well behaved. The brakes do not lack more power and the feel is precise and pleasant. The drivetrain also seems to be just right. The Shimano GRX responds very well and it seems that its resistance will be high, but in our case we would end up changing it for a single chainring with an 11-speed cassette.

The GT Grade Current model with flat handlebars is more city-oriented.

Away from the dusty, unpaved tracks, the Grade is one of the coolest and most comfortable urban bikes in town. Its unnoticeable battery and motor and the complete absence of manual locks, everything is bolted on, will make it go unnoticed by friends of strangers if we have to leave it parked.

All these sensations were corroborated as the days went by on the Grade BOLT, and the only downside we found to its assistance system is that of hub motors, which is why we won't be seeing them on MTB bikes for the time being. When we take the gravel terrain to the limit and enter areas of very slow pedalling, for example on very broken and steep slopes, this system ends up weighing us down due to its location and the weak response of the motor to almost no pedalling. Even so, we wouldn't trade it for a more powerful and heavier mid-mounted motor. A clear example is that the new Cannondale Topstone Neo SL, the latest in the brand's electric catalogue, has arrived with this same motor. 

Generally speaking, if we could only have one bike and we wanted it to be electric, the GT Grade Bolt would be a perfect choice.


  • Frame: All New Grade Alloy 700c Frame, Mahle Ebikemotion specific design, Internal Battery, Tapered Head Tube
  • Fork: GT Grade E-Carbon
  • Drive unit: MAHLE ebikemotion X35 250W
  • Battery: MAHLE ebikemotion X35 250Wh
  • Tires: WTB Resolute Comp, 700 x 42, Tubeless Ready
  • Rims: Shining, 32h
  • Drivetrain: Shimano GRX 400 with 46/36 chainrings and 11-34 cassette
  • Chain: KMC X10, 10-speed
  • Handlebar: GT Butted 6061 Alloy, 16° Flare Drop
  • Brakes: Shimano GRX 400 Hydro Disc, 160/160mmRT56 Rotors
  • Saddle: Fabric Scoop Shallow/ Sport, Steel Rails
  • Sizes: S, M, L
  • Colour: dark turquoise (only colour)
  • Price: 2799€




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Probamos la GT Grade Bolt, una gravel eléctrica para utilizar todos los días