- A rigid electric fat bike with provisions for front and rear racks, available in two frame sizes for improved fit, designed with a steep top tube for comfortable stand over and steadying
- Beautifully integrated Bosch Performance Line CX motor and battery pack, downtube is cut away and left crank arm is spaced out to align the chain, fun digital-camo accents
- Robust 180 mm hydraulic disc brakes with four-piston calipers for cool stopping power, stiff thru-axles support the heavier tires, punched out rims reduce wheel weight
- Solid 10 speed Shimano SLX drivetrain with wide 11-42T gear range, chainring offers narrow wide tooth pattern to reduce slip, may experience some chain suck if muddy due to smaller chainring and lack of pulley wheel or independent guide
The 2017 IZIP E3 Sumo is a complete upgrade from prior year models. Instead of using the mid-tier TranzX motor system, IZIP has opted for the top-tier Bosch Performance Line CX motor system. This thing offers 75 Newton meters of peak torque output, shift-sensing and shift recommendation, as well as a compact design. Electric bike shops that I visit regularly praise Bosch motors as being the most reliable… but they do produce a bit more noise than Brose due to higher RPM operation. The chainring is much smaller than you’d normally see and is rotated at roughly 2.5x your pedal cadence making it very responsive. In short, the motor generates a lot of power but whines a bit at high speed and can be vulnerable to chain suck if coated with mud. On some other Bosch powered ebikes that have rear suspension, pulley wheels and chain guides have been added to reduce chain slap, slip and kickback. The E3 Sumo does not have any of this additional hardware because it has a solid rear end but the chain suck thing could still be an issue. Notice how close the yolk and right chainstay are to the chain when riding in high gears… I saw the chain possibly bouncing into the joint where the yolk meets the stay in the video I shot and this gave me pause. Given the smaller chainring, narrow-wide teeth (that grip the chain) and tight chainring guard, would chain suck be an issue? I’m only theorizing here but it is an issue that has been brought up in the EBR forums before and fat bikes are designed for snow, sand and muddy riding. Depending on the type of terrain you intend to explore, I’d approach with these considerations in mind and possibly bring a cleaning tool. In the future, if this does present itself as an issue, maybe a lower guide will be added to the bike?
The frame on this thing is purpose built with internal cable routing and a custom battery motor interface. In order to fit a standard Bosch motor and align the chain properly, the motor has been seated to the right edge of the bottom bracket mount and a spacer has been added to the left crank arm. It has an alloy skid plate below but is otherwise much more compact than Bosh systems from a year or two ago which had bulky plastic covers and were mounted flat vs. at an angle. It’s an impressive design to be sure and the paint job looks great with digital camo stickers on the frame and battery and accents on the saddle. With two sizes to choose from, this bike becomes much more accessible and gives you the option of riding a bit small to bring in reach and make handling quicker. I love how steep the top tube is because this makes mounting and stabilizing the bike easier which is a huge deal if you’ve added racks and lots of gear. One thing it does not have is a kickstand or mounting bracket to add one. That sucks if you want to go bikepacking and are trying to put gear onto racks without having the already heavy 53 lb bike tip over. Again, I’m extrapolating here but the ample rack bosses suggest that this ebike is meant to carry a load.
Powering the bike is a standard Bosch Powerpack 400 rated at 36 volts and 11 amp hours. I say standard because Bosch now has a 500 watt hour pack that would take you further and be welcome for the rigors of soft surface riding with lower tire pressure or long steady climbs. Of course, those packs cost a bit more and the IZIP E3 Sumo is impressively priced at just over $3k. The battery interface remained the same from the Powerpack 400 to the 500 so you could always get one of the larger batteries later if you wanted. The battery case is thoughtfully designed with a handle loop at the top and an LED charge level indicator on the left. You can charge it on or off the bike and the charger is relatively lightweight at ~1.7 lbs and compact enough to toss into a bag. Rated at 4 Amps, it fills the battery faster than many other electric bike chargers which are only rated at 2 Amps. Charging the battery whilst on the bike requires the removal of a large rubber plug… which I love. It seats firmly and has several rows of ridges to keep water and debris out of the charging socket. The only downside here is if you set the plug down and forget it. There’s not leash or attachment to keep this plug with the bike and I feel like that’s a big tradeoff. Most of the other charge port covers on Bosch ebikes have a thinner rubber cover which do have attachments. It doesn’t get in the way and keeps the cover from getting lost… but those covers don’t always seat as well.
Operating the bike is intuitive and fast. Once the battery is charged and mounted you just press the power button near the lower left corner of the LCD display panel. This display is large, making it easy to read, and faintly backlit so it can be used at night. Unfortunately, you can’t turn the backlight off, it’s always there and in some ways that’s distracting. The bike doesn’t come with lights but some shops can wire them in and then you can use the Intuvia display panel to turn them on and off… Running lights off the main battery is favorable to charging and mounting them separately in my opinion but you could also charge a clip-on light with the Micro-USB port built into the right edge of the display panel. It feels like this display does everything. You can tilt it forward and back to reduce glare, remove it completely to keep it safe and deter tampering and you can even replace the display with the COBI system which uses your smartphone and offers even more features like GPS. Navigating the stock display is easy once it has been powered on. You can press the up or down key on the remote button pad which is mounted within reach of the left grip. Being able to add or reduce power while riding without taking your hands off is a great thing, especially for off-road riding. There are four levels of assist and the highest one will easily accelerate the bike to the top speed of 20 mph when on flat smooth surfaces. And while you only get five ticks to estimate charge level on the battery and display panel, there is another menu called range which dynamically estimates how far you can go and interprets it based on battery level, assist level and the last three miles of acutal ride performance. You can access this and other menus like average speed, max speed, clock and odometer by pressing the i button on the display or button pad.
The motor, battery and display panel on this electric bicycle aren’t as seamless and hidden as some others… partially because of their color and partially because they are larger and tacked on vs. built into the frame. But, they are a vast improvement over earlier designs and in many ways match the black tires, handlebar, and seat. Aside from the chain suck concerns I raised earlier, I feel like this is a really great bike. The price is impressive, the weight distribution is perfect and you’re getting high-quality braking and pedaling systems from leading brands. IZIP now sells online through their official website and fulfills using a mobile bike service called Beeline but it’s preferable to test ride in shops, especially to compare sizes, and they do have a solid network of dealers in the USA. I could see myself and friends riding these on long daytrips and possibly camping. It has the capacity to work with racks but does not include them stock like the Felt Outfitter. Hopefully, seeing that bike will give you some idea of what the Sumo could be with a little customization… The $2k price difference gives you a lot of wiggle room for customizing the bike and I think the Sumo has a much nicer motor and battery integration (though it is much newer). Apparently Felt used Old Man Mountain racks for their bike. Lots to consider, it’s a cool platform to say the least and I’m excited to see what people do with it. Big thanks to IZIP for partnering with me on this review and inviting me out to their headquarts in Simi Valley California to do some riding.
- Significant motor and drivetrain upgrades from prior model year, you get a wide-range 11-42 tooth cassette with Shimano SLX derailleur and a high torque Bosch Performance Line CX motor
- Very few mid drive motors offer shift sensing technology but Bosch is one of them and it will reduce stress on the drivetrain, especially relevant for climbing and moving heavier wheels like the E3 Sumo has
- The motor is tilted up and integrated into the frame more than some other electric fat bikes that use Bosch (or similar mid-drive systems), it has sleek casing on the sides and a metal skid guard on the bottom for protection
- The battery pack is also neatly integrated into the bike frame with a flattened downtube and cup-shaped bottom… it looks great and frees up the triangle for lifting the bike and putting the battery on easier (since it snaps in from the top)
- Lots of attachment option, there are five bosses on each side of the fork and two bosses on each side of the seat stays which could be used for outfitting this with heavy duty racks for bikepacking, hunting or other adventures
- Deep angle on the top tube makes mounting and steadying the bike easier, it comes in two frame sizes for improved fit and handling for a range of rider body types
- Impressive stock pedals, they offer space, stiffness, and traction beyond what I usually see and look great on the bike
- Incredible price point given the level of components and Bosch drive system, it costs a lot to produce niche models like this and to see it in multiple sizes with such a cool aesthetic and quality hardware got me excited
- Sturdy thru-axles keep the wheels stiff and can handle longer hubs (the rear is 190 mm long), punched-out Alexrims reduce weight and offer a bit more cushion on bumpy terrain
- Narrow to wide tooth pattern on the chainring improves grab and reduces slipping,
this is great for off-road riding
- At this time, Bosch does not make a fat bike specific motor so IZIP had to really customize the frame with a narrower yolk that’s welded to the chainstays and an offset spacer on the left crank arm, it’s excellent engineering work and keeps the chainring aligned with the drivetrain
- Large 180 mm hydraulic disc brakes with four-piston calipers deliver the stopping power you need for mountain riding and hauling heavy gear, the levers offer adjustable reach so you can bring them in if you’re wearing gloves
- Both the battery pack and display panel are removable so you can reduce the weight of the bike for transport and store the sensitive expensive bits separately (inside) if you have to leave the bike somewhere else
- Despite having so many rack mounting points they were not able to squeeze in water bottle cage bosses, it appears that there just wasn’t room in the center triangle given the lowered top tube and on-frame battery pack
- The four inch tires offer good comfort but we’re starting to see fat bikes with suspension forks and even full suspension, this isn’t so much a con as a consideration… the rigid alloy fork and solid frame won’t be as forgiving without suspension, consider swapping the seat post with a 31.6 mm suspension post like the Suntour NCX but note that it will raise the minimum seat height by a few inches
- Keep an eye on the left crank arm and left chainstay because they pass very close and the Bosch speed sensor wire is run along the top of the tubing, if you’re riding in muddy terrain I feel like this area could get bumped around more easily (especially if you pedal backwards and aren’t careful)
- I love the big rubber plug that covers the battery charging port on the left side of the bike but noticed that it does not have a leash to keep it with the bike when pulled off, it would be easy to set down while charging and forget… and lose
- Watching the frame-mounted camera towards the end of the video review above, it looks like the chain may be sucked up after rotating through the chainring, I’ve heard this can be an issue when chains get really muddy but perhaps the NW teeth are causing it on this brand new demo bike?