The Giant Road E+ 1 Pro is a fun bike to ride, with a powerful motor and a big range. If you like to get out and about on the roads and are looking for some help – especially if you ride on your own a lot, or with slower groups – then there’s masses of help available here.

Some e-road bikes are very subtle: you’d barely notice if you didn’t know what you were looking for. The Giant’s at the opposite end of the spectrum. This is clearly an e-bike, with the cavernous downtube housing a 500Wh battery (that can swing out for recharging off the bike) and the bottom bracket replaced with a full-power SyncDrive motor from Yamaha. The full-power system promises plenty of oomph and a big range; the downside is a fair bit of extra weight to carry around.

I managed to run out eventually...

Let’s delve into range first. The longest ride I completed on the Giant was just under 120km. The battery ran out with about 200m of road to go, so overall it was pretty well judged. With 20% of the battery left an hour from home, and four decent climbs to complete, I had to be judicious with the power over the last bit, and I had the motor off a lot of the time. Having said that, the ride also included a 25km timed loop with 500m of climbing, that I went quite hard round with the motor turned right up. Those two things more or less cancel each other out, I reckon, so 120km with the motor on lower settings the whole time is not unreasonable. This was a long way from being a flat ride, too: three times over the Mendip hills and lots of smaller climbs too. A total of over 1,500m of climbing for the battery to cope with: that’s the equivalent of going up a really big alpine climb. And that’s with me on it, a 92kg rider. It’s a pretty impressive range.

Obviously the motor isn’t assisting you for every metre of that 120km. The assistance cuts out at a nominal 25km/h – in reality it’s a bit above that – so any time you’re going quicker than that you’re on your own. So that’s downhills of course, but on the flat I didn’t find it hard to clip along at 27-28km/h on the Giant. Okay it’s a heavy bike, and you’re not going to win any sprints on it, but once you’ve worked it up to speed (and the motor helps there) it’s not too hard to keep things moving. The position is reasonably relaxed for a road bike, but if you’re working into a headwind you can still make yourself reasonably aerodynamic with a bit of hunkering down. When it’s in anything above Eco mode (the lowest assistance) the motor is powerful enough that it’s a bit of a jolt when it cuts out, and the bike feels a bit leaden at that point, but working the bike up to speed from a standstill with the motor off isn’t that hard. It’s more a question or perception.

The bike is heavy and has a big range because unlike some other e-road bikes we’ve tested recently (the Pinarello Nytro and Wilier Cento1 Hybrid to name two) the Giant eschews the lightweight motor and small battery in favour of a full-fat system. In this case it’s the Giant SyncDrive Pro motor, which is based on the Yamaha PW-X unit. Giant uses its own firmware and controls, and the mid motor is capable of knocking out 80Nm of torque. Yamaha has tweaked the PW-X to respond better to higher cadences, which was a criticism of the predecessor, PW. The Road E+ Pro gets a centrally-mounted LCD display that’s easy to read, and a remote that sits on the tops on the left of the display. You can’t really access it from the drops but it’s fairly easy to use, with up and down arrows moving you through the five modes of assistance; six if you count Off as one.

No mincing words here: this motor is fierce. Not since the Bianchi Impulso e-Allroad have I tried a motor system quite as poky as this one. Set to maximum boost, and pointed at the 16% hairpin at the bottom of Cheddar Gorge, I was rocketing round a corner that normally has me gasping. Up the rest of the climb, which varies between about 4% and 8% gradient, I was having to back off to keep from going above the motor assistance limit.

A while ago I rode the Pinarello Nytro round a 25km Mendip loop as part of a video for road.cc and completed it in 54 minutes at an average of 28km/h. On the Giant I knocked three minutes off that going at a similar intensity. So clearly the gain to be made from having the more powerful motor far outweighs the penalty of the extra weight, if you’re just riding around on your own and can dictate your own pace.

On the flip side of that coin, if you’re riding with a group that regularly exceeds 25km/h on the flat – and more tellingly, on gentle uphill gradients – then that’s when you’ll really feel the weight of a bike like this. It’s perfectly rideable without motor assistance, sure, but trying to push on above the assistance limit on rolling terrain is pretty tiring, and if most of your riding is done in a group then weight is something to consider, especially when the weight of e-road bikes varies so wildly. The Giant is a nudge over 19kg. The Ribble SL-e we’ve just received in the office is over 7kg lighter at 11.6kg. That’s a big difference and one you can certainly feel on rolling terrain.

I have a couple of gripes with standard the levels of assistance. The first is that five is too many: When I was riding the bike I didn’t find much meaningful difference between the last three, so once you’re in Active mode (the middle one) there’s very little to be gained from going up to higher modes. At the other end the motor is sufficiently powerful that the Eco mode is often enough to smoke your riding buddies up a climb, or at least stay with them without really trying. That being the case it’d be good to have another level below Eco to eke out the range a bit more. I found I was finding the climbs too easy at times in Eco and using more of my battery than I’d like. Okay I’m a reasonably fit rider and a lower assistance mode might not suit everyone, but there’s plenty of other modes.

If you're not happy with the standard mode setup then you can download Giant's RideControl app to play about with them. I dialled the Eco mode right back and adjusted the next two modes down a bit so there was more of a gap between them all. That made the range of assistance feel much better, and the low-power Eco mode would give the bike an even more impressive range, if that's all you used. It's still enough assistance to make it easier than a standard road bike.

The Road E+ 1 Pro is a well-equipped bike. You get a Shimano Ultegra 11-speed groupset with hydraulic discs; the chainset is from FSA as a Shimano one won’t fit on the Yamaha motor. The bike uses a standard double chainset setup, but really it’s crying out for a single ring transmission. I barely ever took it out of the big ring, and a 50-tooth front ring with a wide-range cassette would be lighter and easier to use. Okay the gaps between the gears are bigger, but with an enormously powerful motor helping you out that’s a non-issue. Shimano don’t make a 1x road transmission yet and Giant mostly spec the Japanese manufacturer’s components, so that’s probably the main reason it’s still a double chainring bike. It’s not an issue from a performance point of view.

Shimano’s hydraulic disc brakes are excellent, giving masses of controlled stopping power in all conditions. That’s a good thing on a 19kg bike that’s actually quite fun to throw down a technical descent. The handling is pleasingly neutral, with all the weight in the centre of the bike, and the steering is fairly relaxed but still responsive to quick changes. Giant spec 32mm Maxxis tyres which feel about right for the bike in terms of size; they roll pretty well and the grip levels are decent. Both wheels and tyres are tubeless ready if you want to make the jump. There’s a bit room in the frame and fork for a bigger tyre if you fancy taking in a bit of gravel.

Overall I really enjoyed riding the Giant. It’s a better bike than its predecessor; back then it was a small field but the market has exploded in the two and a half years since we first rode the Giant. Everyone makes an e-road bike now.

And how does it stack up? Well, the heavy bikes have their merits and the light bikes have them too. If you’re a leisure road cyclist that likes exploring and the assistance is a must-have rather than something you’ll use occasionally, the Road E+ 1 Pro has a lot going for it. It’s a pleasant bike to ride, and it has masses of power on tap and a huge range. If you spend a lot of time trying to keep up with your mates then you’d blow them apart on the hills if you turned up on this, but across rolling terrain, at or above the assistance limit, the bulk of the bike starts to make itself felt. If you just need a gentle shove to stay in the pack then something lighter and less powerful will suit you better. There’s no one-size-fits-all solution, and for many people the Giant will be an enticing prospect. It’s decent value given the spec and it’s fun to ride.

https://www.giant-bicycles.com/gb/road-eplus-1-pro-electric-bike