- A tough, sporty looking, high-quality, kids electric bike that can reach ~15.5 mph with four levels of pedal assist, smaller wheels keep the frame low and approachable
- Premium accessories including tires from Schwalbe, a Shimano Altus 8-speed drivetrain, and Tektro hydraulic disc brakes that are easy to pull for small hands
- Excellent weight distribution for improved handling and balance, the motor and battery pack are well protected and come with a fantastic two year warranty
- Integrated lights can keep small riders seen by cars day or night but it would be nice if they automatically activated and stayed on, the top speed cannot be raised, it's expensive
$0 (0 €)$18,000 (16,920 €)
0 lbs (0 kg)220 lbs (100 kg)
0 mph (0.0 km/hr)50 mph (80.5 km/hr)
0 watt3,000 watt
0 in (0.00 cm)22 in (55.88 cm)
0 Newton meters250 Nm
For this review I got some extra help from a young lady named Carla who knew how to ride a bicycle but had never tried an electric bike before. You can see here, her older sister Paula, and her father Victor in the video review above. My big takeaway from this experience was that young kids can have a blast with electric bikes but it’s worth spending some time on the control systems and shifting before setting out. While Carla picked things up extremely quickly and had a blast riding with the lightweight, smoother operating, Bosch Active Plus line motor on the BULLS TWENTY4 E, her older sister required a bit more practice and support to master the Bosch Performance Line CX motor, which feels zippier and can “surge” depending on how you pedal because it’s made for trail and mountain riding. With the TWENTY4 E, a young person can hop on and click the + or – buttons to add and subtract power in order to climb easier, keep up with their older siblings and parents, and feel empowered. This is one of the more premium kid’s electric bikes, and as such, it comes with a higher price tag. For $2.9k, you get one of the highest quality motors, a well-protected battery, integrated lights for safety, and a frame that was custom built for a smaller rider, complete with smaller 24″ wheels vs. 26″+ on adult sized bikes. The stand over height of the frame is roughly 24″ and this is what you can try to match to the inseam of your child. Will they be able to stand over this ~45.3 lb ebike easily? Carla had no issue, and the saddle height is adjustable so as your kid grows, you can keep their leg extension comfortable, even if they start to be more upright vs. leaned forward. One thing you cannot change however, is the limited 15.5 mph top assisted speed. Most full sized adult e-bikes can hit and maintain 20 mph or even 28 mph for Class 3 speed pedelecs. I do wish that you or your dealer could raise the top speed because that could make it easier for young riders to keep up with the rest of the family once they and you feel comfortable. Still, in Europe, almost all electric bikes are limeted to 15.5 mph, so it’s not a big trade-off. And there are some competing youth-oriented models that can only reach ~12 mph such as the Haibike HardFour 4.0 priced at $2.6k.
Driving the BULLS TWENTY4 E is the brand new Bosch Active Line Plus mid-motor. Compared to the older Bosch Active Line, this new motor weighs ~1.5 lbs less, is more compact in size, and offers a full-sized chainring vs. a reduction gear that spins 2.5 times for each crank revolution. In short, there’s a touch less drag when pedaling but chain retention might be slightly lower and response time may also be just slightly slower. I noticed and appreciated the Aluminum alloy chainring guard, which will keep pant legs and dresses snag-free while simultaneously keeping the chain on track. The motor is smooth and quiet but responds near-instantly so there’s no problem with unexpected starts or delayed overpower when it’s time to slow down and stop. Stopping is handled very well on this bike because Bulls opted for 160 mm hydraulic disc brakes with smaller levers that kids can easily grab and pull. Carla seemed to have no issue stopping during our ride and was regularly leading the pack with a huge smile on her face. She also handled gear shifting extremely well, easily going from low gears to start up to the higher gears in order to keep up with the pack. This electric bike is outfitted with a Shimano Altus 8-speed drivetrain and traditional trigger shifters near the left grip. The big button shifts to easier gears (for slow riding or climbing) while the small button shifts to harder gears (for faster riding and descending). One thing that I have always appreciated about the Bosch mid-motors is that they have fancy control systems that can detect user shifting and tell the motor to ease off, which reduces wear on the drivetrain. Considering that many young riders are new at shifting, and may be paying attention to balance and stopping, it’s great that the Bosch system can sort of protect itself and keep the bike from getting worn out prematurely. The motor casing-surround is made from black plastic which blends in with the bike frame. In my opinion, the bike is a bit more masculine in color, but Carla didn’t seem bothered at all by this (never mentioning it) and the fluorescent blue and green accents keep young riders visible to cars. Again, the lights, bright frame color accents, and white accents on the Schwalbe tires are all designed for safety because kids tend to be shorter and more difficult to spot by automobiles.
Powering this “kids” bike is an adult sized battery pack. The Bosch Powerpack 500 offers 36 volts and 13.4 amp hours for a total of ~482.4 watt hours of capacity. It’s enough to go probably 40 to 70+ miles on a single charge depending on how the bike is ridden, how much the rider weighs, and what level of assist is used. This battery can be charged on or off the bike and is filled by a quick 4 Amp charger that weighs ~1.7 lbs. I appreciate that Bosch has stuck with the same battery design since 2013 in the US because it means that many parents might be able to share their own batteries with their kids’ bikes… same goes for the charger. The battery casing has a big open loop at the top, making it easier and safer to carry around. It has an LED charge level indicator built into the left side, so you can tell how full it is when unmounted. And, it uses an ABUS locking core to be secured to the bike frame. ABUS makes high-quality locks and sells a whole range of security locks like u-locks, folding locks, and chains which can be “keyed alike” by using the code printed on the card that comes with your ebike keys. Okay, so one of the few question marks or complaints I have about this electric bicycle is that it’s expensive, which could make it difficult for many parents to justify if they expect their kids to outgrow it. One area where BULLS might have been able to save a couple hundred dollars and also reduce weight by ~0.5 lbs is to utilize the older Bosch Powerpack 400 battery. I think that it would have offered enough range for kids to match parents due to the lower top speed and lighter weight of this bike.
Operating this bike requires a few memorized steps to turn on and adjust power levels using the Bosch Purion compact display panel. This display cannot be removed like it’s bigger brother, the Intuvia, and it doesn’t have a micro-USB charging port built in, but maybe that’s for the best? It means that it’s tougher and less likely to get lost. The four buttons on this display are the power button along the top edge, a plus and minus key on the front left side, and a walk-mode button on the bottom. When you press the power button, the display comes to life very quickly and is faintly backlit so as not to distract but also stay useful when it gets dark outside. Once it’s on, there’s a battery infographic with five bars to designate fill at the top, a speedometer in the middle, a listing of assist levels that change as you press + and – and a couple of sub menus that can be accessed by holding the minus key (trip distance, total distance, and range). The range menu is neat because it updates as you select different levels of power. Other secrets include holding minus and tapping the power button to switch from metric to standard units and light activation which is done by holding the plus key for a few seconds. Considering that this is a kids bike and they nerfed the top speed, I think it would have been cool to make the lights auto-on and constantly on… just to increase safety. The final lower-edge button is for walk mode and you have to tap it and then hold + in order for it to work. This can be a very useful feature for pushing up hills, through grass, or getting home with a flat tire. You can change gears to increase or decrease walk-mode speed. All things considered, once this electric bike has been charged and turned on, it’s easy to use the different levels of pedal assist and reaching the button pad isn’t too much of a stretch, even for small hands. I feel that the plus and minus buttons could be improved by Bosch, to be easier to click near the lower edge and center (because they pivot at an angle) but Carla figured it out and did just fine. For those who wish to upgrade to the larger Bosch Intuvia display, many authorized dealers do offer a replacement/upgrade option which would make the display removable and just bigger (easier to see) with more responsive buttons and more complex menu options to explore.
For families that love cycling together, or kids who are excited to explore town, ride to school, and gain some independence… the BULLS TWENTY4 E offers a balanced, high-quality design with premium components and drive system hardware that should hold up very well. My guess would be that this bike will outlive individual kids as they grow and would maintain resale value or could be passed along to siblings. It’s not quite as bright as the Haibike SDURO HardFour 4.0 model mentioned earlier but the integrated lights and bright accents aren’t bad. I have a preference for Bosch motor systems over Yamaha (which the Haibike uses) but the Active Line Plus is very similar in operation and performance, it just allows the bike to go a bit faster. I love the adjustable kickstand, puncture resistant tires, and simple flick-bell that come standard, and appreciate that Bulls sells through a wide network of dealers who could help with fitting and post-purchase maintenance as well as accessorizing (helmets are important!) I’d like to thank Bulls for partnering with me on this post and the family who agreed to share their experience realtime on camera. Carla and her sister Paula did an amazing job and really let their personalities shine through. It made me smile and I hope that this review and the accompanying specs can help guide you towards the right choice of e-bike or regular bicycle for your special young ones.
- One of the few ebikes available, that I have seen in the USA, designed specifically for kids… it uses smaller 24″ wheels that lower the stand-over height, and a gentler motor with limited 15.5 mph top speed for safety
- Higher quality components that won’t get worn out as easily, note the Schwalbe tires with puncture protection, Shimano Altus derailleur,
SR Suntour suspension fork, and Tektro hydraulic disc brakes
- Using hydraulic disc brakes vs. mechanical disc or linear-pull brakes means that kids don’t have to pull as hard to stop, the levers can also be adjusted to actuate closer to the grips so they are more comfortable if you have small hands
- Excellent weight distribution because of the mid-drive motor and mid-frame battery pack, this improves handling and stability compared to a hub motor design or rear-rack battery
- The battery pack and motor are well protected if the bike tips, Bosch is known for producing some of the most reliable electric bike systems on the market today and they offer a two-year comprehensive warranty with lots of dealers who can provide service
- I’m not sure a rear-rack would fit on this frame without some creative tweaking but there are bosses for attaching such a system on the chainstays, I like the kickstand choice and location, and I appreciate the sturdy chainring guard that will keep the chain from dropping easily while simultaneously protecting pants from getting greasy or snagged
- Very few mountain bikes have integrated lights but I think the reality of this bike is that it’s more of a “go anywhere and be cool” platform which utilizes some mountain design and hardware (such as the suspension fork and knobby tires), so the lights really improve safety and will help to keep smaller riders safe around automobiles
- The new Active Line Plus motor from Bosch is very compact and lightweight at ~7.05 lbs vs. 8.8 lbs for the Bosch Performance Line motors, this helps to keep the overall bike weight down at ~45.3 lbs, making it easier to maneuver and ride for young people who might not be as strong
- Normally, I complain about how the Bosch Purion display panel cannot be removed, but in this case that’s probably a good thing! It’s less likely to get lost by younger, possibly distracted, riders
- I like that the bike comes standard with a little bell and that they used shorter crank arms and a shorter handlebar to really fit the rider and make it feel comfortable
- Both wheels are connected using quick release and the battery is also easy to remove, this means you could store it without taking so much space, fix flats easily, or just break it into smaller lighter pieces for easier moving
- The Bosch centerdrive motor system offers shift detection and this helps to reduce mashing and wear on the chain, rear sprockets, and derailleur… which is going to be extra useful if the young person riding isn’t as experienced at riding bikes, basically, it’s designed to protect itself
- The locking core on the battery interface is from ABUS and it comes with a card which has a code you can use to purchase locks that will match and that way, you can use the same key for everything on your bike :)
- As much as I love the integrated lights, I feel like they should be programmed to turn on automatically and stay on because kids could easily forget how to activate them (hold the + symbol for a few seconds once the bike is on) or just get excited and ride off before taking that step
- The official Bulls stock image shows the headlight mounted up on the handlebar which means it won’t bounce as much as if it’s connected to the suspension fork bridge and it will be easier to see… but the demo model I actually reviewed did not have the light up there, instead, it was mounted to the suspension fork
- Very minor gripe here but the suspension fork isn’t very adjustable, you almost need pliers to twist the plastic caps to dial in rebound and both caps need to be adjusted in tandem to get it working perfectly… it’s more of a set it and forget it type of thing
- Priced at $2,899 USD, this is not the kind of toy that most kids could save up for and buy themselves, it’s a big investment (and will last) but the kids might outgrow it, compared to adult electric bikes with similar hardware it is priced on target, but kids just don’t have as much money and I can see how some parents might be reluctant to pay so much
- As kids grow up and become more comfortable on their electric bikes, it would be nice if parents or shops could adjust the maximum assisted speed from 15.5 mph to the full 20 mph that most adult Class 1 models can achieve, that way kids won’t be left behind
- it only comes in one frame size but the 250 mm seat post offers some good fit adjustment, there’s also only one color which leans towards masculine… but the fluorescent colors help it to stand out vs. being all-black, reflective tires and reflective frame stickers would be nice
- The Bosch Purion control panel uses big buttons that are easy to reach but I have found that they don’t click as reliably if you press near the lower edge or center because they pivot at an angle towards the screen, this could be confusing, distracting, or frustrating for a younger rider… press near the screen for best results
- As much as I love the high-capacity Bosch Powerpack 500, this pack does cost more, and it feels like they could have saved some money and just a bit of weight by going with the older Powerpack 400 battery