If I had a cool given name like Ivars I’d probably make sure everyone called me by it, while they followed me into battle to do my bidding. Maybe I’d use ‘Storm’ as my super-hero alias on the weekends while fighting crime, but Ivars is such an awesome name I’d want all my mortal enemies to repeat it to themselves in their sleep as they had their lucid nightmares about me and wet their beds.
This build I did for one of my closest friends who bought a Sondors Ebike way back when before the Sondors ebike campaign went viral. He had already written off the $694 he had donated after he learned about the Ivars\Storm lawsuits, but was surprised when a year later when I told him everyone else had gotten their bikes (except him). Due to some mixup he never got his bike even though he has paid for the shipping and the Sondors folks pretty much ignored him till he threatened legal action. They quickly perked up and his bike showed up not too much later with a sincere apology from the folks at Sondors … and everyone lived happily ever after.
The bike showed up and I put it together for him and he knew before he even started riding it that it was going to need to be seriously upgraded. Since he lived at the top of a 14-degree grade with about 3/4 of a mile climb, the tiny wound-for-speed 300W setup on the Sondors ebike was going to be pretty much useless. Eric from Luna had done a build with a Sondors and a 3000W Cyclone kit which easily went 35mph but even his build was still going to choke on any real steep hills because his 3000W cyclone was geared up way too high. I wanted to build something a little different. I decided that a wound-for-torque 12T Mac motor with a 25Amp controller paired with an upgraded 25Amp controller for the rear Bafang geared hub motor and a decent 52v battery was the way to go. In the end, we hit the nail right on the head and the build we came up with was top-notch, looked very professional and I think is better than any commercial ebike you’re ever going to find in that price range (not that it’s saying much as most commercial ebikes seem to royally suck). This article is about how we reached that end.
Love it or hate it, Ivars Sondors has singlehandedly put 12 million dollars worth of electric fatbikes on the streets of the world with their crowdfunding campaigns and completely turned the commercial ebike industry on its head. Although the original Sondors ebike was grossly underpowered for hills, it was actually a really nice commuter platform for upgrades. I talked to Eric at Lunacycle over 6 months ago and got him pointed in the right direction to start catering to the thousands of new ebike users who wanted cheap upgrades for their new favorite toy. Eric has set up a separate Sondors Upgrades section on his website which has been extremely successful. The ironic part is pretty much any battery he puts in this section almost immediately sells out, although many of his batteries listed in the other sections will easily fit into the Sondors plastic box.
How do I feel about the Sondors ebikes? Honestly it puts a knot in my stomach to think about them, as there was a lot of conflict with the Sondors ebike fans right before I completely stopped writing about it. I don’t like dealing with the cultish behavior of the Sondors fans, but I do think the Sondors ebike is really nice. For $499 + $194 shipping the Sondors ebike is the cheapest complete ebike on the market that is not a total piece of crap. Ivars did not cheap out on any of the components that I can tell. I’m not crazy about the brakes, and the steel frame is way too heavy for trail riding, but if you want to mount a 1300W front hub motor on a bike, it had better have a steel front fork or it’s going to break the dropouts at speed and you’re going to get hurt. The yellow color really jumps out and the anodized rims are just beautiful. I like that many of the smaller parts are also anodized and the plastic triangle box keeps all the wires hidden and makes your build look top-notch. My only real complaint about the original Sondors ebike is the total lack of power. A 10 Amp nominal 15 Amp peak controller on a 36v pack with a motor wound for speed gives you a bike that feels as anemic as a baby calf being prepared for a veal meal (Don’t worry I’m a vegetarian who only eats animals I kill with my own bare hands).
Replacing the crappy underpowered controller
The stock Sondors controller runs 10Amps nominal and 15Amps peak (yawn) for a max output of 540Watts at 36 volts. The first upgrades we purchased were the 25Amp peak/15Amp nominal controller (here for $50) and display (here for $55) for the Sondors ebike that I believe is a must have for every Sondors ebike owner. There is also a 20 Amp controller for the same price, but I would go for the higher power controller if you plan on doing an AWD conversion. Be aware that if you use the 25Amp controller with the stock 36V battery and lean on the throttle that you’re going to seriously stress the BMS. Your 36v water bottle battery cannot produce those power levels for any length of time without issues. Also be aware that the rear hub motor will not be able to run forever on a hill at full throttle without melting the phase wires, frying the windings or the hall sensors. That hub motor is likely a 500W nominal motor that can probably take 750W for extended periods. At 1300W it’s going to overheat in just a few minutes. By setting up the bike as an AWD setup you add a lot of help to the rear motor and allow you to use a lot more power on BOTH motors for longer periods as they help each other out. My feeling is that a controller upgrade is mandatory for the Sondors ebike no matter what you decide to do. It is the best $50 you will likely spend on your ebike.
Deciding on a motor for the front wheel
There are a lot of options out there for highish powered hub motors. I wanted to put a motor that would do 1000W all day long on the flats without burning out and climb hills like a billy goat so I settled on the 12T Mac motor. This motor produces a lot of torque but tops out at about 18mph with those giant 5″ fat tires. The idea behind this build is we wanted a motor that would cause the bike to jump off the line and accelerate very quickly, could easily take 1300W of power for extended periods of time and also was relatively lightweight (around 8lbs). The upgraded Mac motor puts a check in all of those areas and it only costs about $270 or so (not including the shipping). Building up the motor to a rim is a royal PITA that everyone should do before they die. You can also mount that motor to the pretty anodized rim that comes with the Sondors as it is a 36H version 80mm fat bike rim which is nearly impossible to find anywhere. We used a Weinmann double wall 80mm black rim because it was already built up from my Reaper build I did last year and abandoned. The reality is that any hub motor you can find that takes 130mm dropouts (most REAR hub motors are that size) will work perfectly in the front fork of the Sondors ebike which is also 130mm wide. I strongly recommend a geared hub motor as I find that they produce a lot more kick at lower power levels than Direct Drive motors do. For a brief article describing this differences between direct drive & geared hubs click here.
Don’t forget the Torque arm
Because I was putting 1300 Watts into a front fork I decided that it was prudent to install a torque arm on the inside of the front fork. The torque arms that I find don’t make your bike look like crap with giant hose clamps are the ones custom-made by Dr Bass on Endless Sphere. You basically just grind the paint off the inside of the dropout and epoxy it in place and you’re done. The whole process takes about 30 minutes, but you have to wait 24 hours for it to dry. Once you glue it on, it’s never coming off again as it has a shear strength of 4500 PSI so be sure it’s what you want before you do it.
Picking a tiny 25 Amp controller that won’t die for the 12T Mac
To drive the front motor I wanted a tiny 25Amp controller that was incredibly reliable. I settled on the Lyen Mini Monster which is ridiculously overpriced for a 6 FET controller at $79 and available here. I can say that I have had no issues with any of the Lyen controllers I’ve used once I got past actually forcing myself to spend the money to buy one. The MosFETs are upgraded as is the solder on the traces making the controllers work much better than most cheap Chinese ebike controllers on the market. I’m still hoping that someone produces a decent ebike controller that doesn’t LOOK like a cheap crappy Chinese controller, but as of yet no one has. Too bad, so sad.
Deciding on a battery
We wanted to get a 50Amp cont 18650 pack that would not get hot under a constant 50 amp load and could survive years of abuse. In the end, we settled on the 52v 12.5 Ah 25R triangle pack from Luna for $540 located here because it was in stock (stuff sells out wicked fast). This pack is a 5P which means that it is a total overkill for this application as the pack could produce 100Amp continuous all day long (although the BMS only supports 50Amp Cont). If I were you I’d wait for the new GA triangle packs that are arriving very soon and should not be too mauch more than the 25R packs. I have very high hopes for the GA cells and I think they are going to completely dominate the ebike market within a year. They can produce over 10 Amps all day long without getting hot and have 3500Mah of storage capacity per cell vs the measly 25Mah of the 25R. Bye, bye 25R the honeymoon is over. Be aware that if you buy a larger pack (like my 7P 20Ah 48v 26F Luna triangle pack) you can cram the battery pack in the triangle, but there is not going to be any room for the controller, so you’ll have to mount that on the outside the plastic box. If you are in doubt about whether a battery will fit in the Sondors case then check the measurements and do a best guesstimate. Remember that you should have about 1/2″ around the battery on all sides for padding (I use Thermarest pads) and you will also need to squeeze the controller in there somewhere.
Cramming the controllers in the box
We decided that the controllers should be above the downtube of the Sondors bike because there was a huge slit cut out of the box on that side which is going to help with cooling. During the test runs of this ebike one of the problems I was having was after several miles the controllers were getting incredibly hot and there was no air flow around them. In the end, we put both controllers on the bottom with a thin layer of Thermarest between the controllers and the battery. The bike was designed so that the battery would stay in the bike and the charger would just be hooked up in the garage directly to it. This arrangement worked very well and kept the battery from moving at all, which is what you want.
The test drive
The ebike with dual motors running at 2600W was really awesome. With both motors powered up it was incredibly fast and torquey and it felt the way that an ebike should feel. Although the bike in its final form was the heaviest ebike I’ve ever built by a far margin, it still felt just fine on the road or even riding around on my gopher hole filled lawn at high speeds. Those giant 5″ tires seem to completely absorb everything they hit. The ebike would scream up steep hills at over 15 mph with both motors on full blast and the ebike has the added redundancy of a separate AWD system with 2 different controllers. The left thumb throttle was for the front wheel and the right thumb throttle was for the rear wheel. The top speed of the bike went from around 20 mph to about 23 mph, but the biggest improvements were in acceleration and hill climbing ability. This 2600W bike climbed steep hills ever bit as well as a BBSHD 30 Amp mid drive (my current favourite ebike motor).
The best part was the feeling of acceleration you get when you peg both motors at full power.
Cost break down
Here is our cost breakdown
- Sondors Ebike $499
- Shipping for ebike $194
- Upgraded Fat Mac 12T from em3ev $270
- Lyen 6fet controller $79
- Weinmann 36H 80mm double wall rim $55 (you can save $55 by using the Sondors rim)
- Dr Bass Torque arm $25
- Epoxy DP 420 $10
- Ebike Throttle $15
- 25R 12Ah 52v Triangle pack from Luna $540
- Luna Charger 52v $79
- 25Amp Bafang controller for Sondors rear motor $50 (Get the 20Amp version if you’re afraid you’ll roast your motor)
- Display for Sondors ebike $55
For a grand total of (drum roll) $1871 *ding* *ding* *ding*. If I was to do this build again I would skip the front motor and just do the upgraded Sondors controller $50 and display $55 and a 52v NCRb Shark battery for $475 located here. That would keep the total cost closer to about $1273 and although you would have to be careful to use only about 1/2 throttle or PAS level 2 or 3 on hills, it would still make an ebike that would beat anything else in that price range even if you couldn’t sucker anyone into buying your old Sondors 36v water bottle pack. That setup would also take about 60 minutes to do instead of the 10+ hours I spent on this build.
But at least it was fun, and that’s why we’re all here isn’t it?