Last winter I had the pleasure of reviewing a Christini Fat-E BBSHD AWD ebike for about 2 weeks. For those of you who know me, you know I rarely review anything I don’t throw my leg over and thrash in the woods with. I fell in love with the Christini AWD system and told Steve that if he came up with an ebike that would hold 2XL Snow Shoes and my Ludicrous Ultra Max that I would buy it. Steve is the kind of guy who listens to his customers so he reworked the front fork to support the 2XL and then designed a new frame from the ground up to support the Bafang Ultra Max motor. I decided to plunk down my own hardly-earned cash to have him build the biggest frame that he could possibly imagine ever building to lug my lanky ass around in a foot of powder. The end result exceeded my every expectation for what was possible out of his AWD setup as well as the Ultra Max motor. Riding this build in the woods in 6-8″ of snow is the closest I’m probably ever going to get to pedal pushing Nirvana while still I’m inhabiting this body.
At Christini bikes, they custom build the entire AWD system from scratch. The gears for both the front and rear hubs are machined out of aluminum or steel (buyers choice). For my build, I opted for steel because I wanted them to last through serious abuse. On their website you can order bikes with electric motors (Fat-E) or without. Starting this spring they are even building 29er/27.5 bikes with hardtails or full suspension. There are fat bikes with 4 or 5 inch tires in a GX or X01 groupset, but I would only go with the 5 inch tire version and make sure you get it with the 5.05″ Snowshoe 2XL PSC which I believe is the best snow tire currently on the market. The bikes are not cheap, but Steve is great to work with throughout the build process and keeps you updated with pictures on a weekly basis or so. Expect several weeks from the time you place the order till when you get your bike. My only regret about this bike is that I didn’t order it sooner. I would have loved to have it all winter to thrash around in rather than just the last week of February.
Normally when riding in the snow with a rear wheel drive fat bike my weight and body position is about as far back as I can get it. Since the front tire doesn’t do much of anything but slow me down I try to ride with as little weight on the front wheel as possible. There are a couple of tricks to doing that, using a Thudbuster LT helps keep your weight back on the frame a couple of inches as it compresses. During large climbs through deep snow, I will pull my feet off the pedals and put them behind me almost as if I’m doing a ‘superman’ and flying along on the bike with the throttle pegged. It looks ridiculous but it gives more weight to the rear wheel thus increasing your traction.
With the Christini AWD system you actually want weight on the front tire because it actually is turning at the exact same rate as the rear tire. When riding my Christini AWD ebike I find myself standing up on the pedals and shifting my weight forward as much as I can. It’s nice having a very large frame because the long wheelbase helps cut down on the accidental wheelies and makes the bike feel more controlled.
You immediately notice that the front wheel on the AWD doesn’t just drift all over the place, but actually tracks extremely well in the snow. When riding my normal rear wheel drive ebikes I’m constantly having to put my foot down as the front wheel spits out on turns in the deep powder and the bike starts to fall. With the Christini AWD ebike I still have to put my foot down in extreme situations, but the number of times I have to save the bike with my foot is a small fraction of what I have to do when compared with rear wheel drive ebikes. The AWD system on ebikes is a total game changer in deep snow and in icy conditions.
I’ve experimented with several AWD systems that used 2 different electric motors, one for the front and one for the rear. My conclusion with these systems is that unless the front wheel and the rear wheel are spinning at almost exactly the same rate, you end up having even more problems with traction than without an AWD system. The problem is that the front wheel has a lot less weight than the rear wheel, so if you apply the same amount of power to both wheels, even if they both have the exact same motors, the front wheel is going to spin out first because it has much less weight on it than the rear wheel does. Unless someone figures out how to add electronic traction control to the motors, a 2 motor electric AWD ebike is never going to outperform the Christini mechanical AWD system. On top of that, I’m a firm believer that hub motors absolutely suck for trail riding although they are decent for commuting.
I had my build made with GX components because I am poor and the X01 gearset is too pricy. I love that the bike comes with the XD driver rear hub and an all steel 11 Speed 42T-10T cassette that has so many steel pins tying all the cogs together. Although I prefer the X9 derailleur, the GX 11 speed system is decent and with the short cage setup, I really like the way it works with the cassette. Everything feels solid and the gears don’t jump once it is adjusted properly. Since the Christini system does not come with a spoke guard on the cassette you’ll want to make sure that the Low gear stop adjustment is correct or your chain can get stuck behind your cassette and wreak all kinds of havoc with your spokes.
The Christini frame has 4 mounting screws for frame packs that look way beefier than your normal water bottle mounting systems. They have also designed a custom bracket to hold your frame packs in place and to keep them from wobbling. Since I always ride with a backpack battery and I preferred to have a 2000W+ Ludicrous Ultra Max instead of the stock 1500W peak Ultra Max I sent the drive unit off my crappy full suspension Rebel Scum II build to their factory in PA to be installed professionally on the frame. They did an amazing job routing the cables through the frame and making everything look pretty. I tend to be more of a duct tape and zip tie kind of guy, but it’s nice having a build that looks a little more professional.
There is a pop-lock style release for the AWD system so you can turn the AWD system on and off on the fly. I always just leave it in AWD mode unless riding on pavement without snow and ice on it. The AWD system makes a bit more noise than the Ultra Max motor alone. It sounds about as loud as a cellphone on vibrate mode. You hear it and notice it, but someone 20 feet away from you probably won’t. When compared to anything with a gas motor on it, the bike is darn near silent. The BBSHD has a nylon gear and it is much quieter than the Ultra Max which all have 3 steel gears in it and no nylon gears. The BBSHD you can ride right past someone with it in PAS mode and unless they see a battery or look at the motor then they probably won’t notice you have a motor. If you ride right by someone with an Ultra Max and the Christini AWD system they will probably notice something is up.
One of my biggest complaints about the AWD system is that it increases your level of confidence in what is essentially marginal conditions. The bike tracks much better so you tend to go much faster. This puts you even more at risk of taking a bad fall or hitting a tree because you really have to exercise restraint when riding these bikes. The faster you go, the more fun you’re having so you end up in this fun addiction loop where you’re going faster and faster and having more fun until you have a close call or dump the bike, then you slow way down again and the process repeats itself.
The torque sensing system is nice in the woods, and it allows you to actually get some exercise instead of just going in the woods and pegging the throttle the entire time. One of the dangers of the torque sensing system is when you dump the bike a lot of time there will be pressure on the pedals and the bike will spin the tires a couple of times. This is not a big deal if you can separate yourself from the bike, but it is something to be aware of. You also MUST turn off the drive unit anytime you touch the chain or the derailleur at all. If you treat your mid drive like a chainsaw then you probably won’t lose any fingers. The Endless Sphere Facebook page is littered with pictures of people with giant scars on their hands who got them stuck in a mid drive while playing with the chain while the system was powered. Torque sensing makes this problem even worse because if you tug on the chain or press on a pedal accidently then your fingers can get stuck in the gear before you can say “What the fu…”
There are 2 distinctly different ways to ride the Christini AWD ebike in the woods. The first way is to ride it like I usually ride my BBSHD builds which is to put it in the lowest granny and just ride the throttle the entire time. Since you are in such a low gear the motor is under the least amount of stress and there really is no way to keep up with pedaling since the crank is spinning so fast you just can’t keep up. You spend all your time trying to keep yourself upright on the bike while the trail and the snow try to knock you off. This is the most fun but also the most dangerous and you get very little exercise.
With the Ultra Max and the AWD Christini system, you can also set the gear to a comfortable pedaling RPM and then use the torque sensing system to pedal around. This is more of a dance where you try to set your assist level high enough that it overcomes the resistance of the snow, but not so high that it’s too easy to get around and doesn’t feel right. This is the way of riding that most sane people will probably opt for and with the right programming on the Ultra Max it works incredibly well. I’m a firm believer that the Ultra Max is an evolutionary step beyond the BBSHD, but has failed to gain market traction due to the lack of frames and commercially available ebikes on the market. What ebike dealer wants to deal with the liability of selling a bike that has peak power of double the legal limit in the US? Not many, apparently.
I bought my Bafang Ultra Max from Lunacycle when it first came out because it came with the extra $250 Ludicrous controller (the listing on their website no longer includes this option). This Ludicrous controller has been hacked to produce a lot more power than the stock Ultra unit and the Ultra Max units that Lunacycle stocks are also made out of magnesium so they are about 3 lbs lighter than the normal Ultra Max units that you buy from anyone else. They aren’t cheap, but I’ve ridden the stock Ultra Max and the Ludicrous Ultra Max and the Ludicrous one produces around 50% more peak power. I tested the Christini AWD system with the Ludicrous BBSHD so I knew the AWD system could handle the power, even with aluminum gears. As a side note, it is important to keep the AWD gears lubed, but the rear gear is located inside the rear brake rotor so be careful not to get any lube on the rotor. If you do, then wipe it off carefully before you ride so you don’t destroy the brake pads.
Christini sells a lubricant that is all natural and non-toxic called “Earth Oil”. I’ve been testing it for about a year now and may write an article on it. This lube seems to work well for the AWD gears and not only lubes them but keeps dirt, mud, and grime from building up on them as well. If you’re not concerned about dirt and mud buildup you could use grease, but I wouldn’t recommend it. My experience is that grease tends to attract everything that is bad in the world and holds onto it.
The AWD system goes through the handlebars and down the fork which causes a slight pull when the system is under full load. This can make the handlebars pull slightly to one side, but the sideways pull is easily overcome. It might be unsettling for people the first time they ride the AWD bike, but you quickly grow accustomed to it and compensate accordingly.
My only complaint about the Ultra Max system is that the BCD130 front chainring is just too large. It turns out that Bafang is releasing a BCD104 adapter for the Ultra Max that will be steel and will be way too heavy. Steve Christini is also going to machine an aluminum chainring adapter for BCD104 that will probably be much lighter and will work just as well if not better. Bafang’s continued insistence of making chainrings and adapters out of steel instead of aluminum will continue to be one of their biggest mistakes. The 5 hole BCD130 adapter is just too big, and although it works well with a 42T granny, if you use it with anything smaller you won’t be plowing through deep snow with it, you just won’t have the torque. The larger chainrings work well for 40mph commuter bikes, but suck for low-speed snow sloggers.
- Traction is insane, nothing else compares
- Torque sensing with 2-3 hp of power with full power available at zero RPMs
- AWD gears can be made of steel or aluminum
- Snowshoe 2XL do not rub the frame or the fork, plenty of clearance
- Custom frame built from scratch just the way you want it
- Steel 42T-10T XD drive cassette and GX derailleur/shifter
- Good hydraulic brakes without ebrake cutoffs which I absolutely hate
- Glued magnet on rim instead of spoke magnet setup
- All steel gears means it will probably be more reliable than the BBSHD nylon gears (I’ve melted 2 this season already)
- Expensive, but not when compared to a custom fat bike like a Carver
- The Ultra Max drive unit is heavy which makes for a heavy bike
- Most frame packs are only going to get you about an hour of riding in deep snow, I use a home-built 25Ah 52v backpack battery
- You cannot use just the front brake or you will thrash on the AWD system, rear brake only or if you use both you MUST use more pressure on the rear brake than the front brake
- Torque sensing system is dangerous, fingers, pants and shoelaces beware
- A slight pull on steering wheel under severe load of AWD system
- Have to lube the AWD gears occasionally to prevent excessive wear
- BCD130 chainring is too big for riding in deep powder
- If you want to shift gears in the deep snow from a standstill you have to pick up the whole bike a couple inches with one hand and spin the throttle with the other so both wheels can spin freely
I have about 12 ebikes kicking around the house in various states or repair. Now that I’ve gotten and rode the Christini AWD system I feel completely unmotivated to ride anything but the Christini. The feeling you get when you ride something that you built with your own two hands is something really special. Steve has that kind of pride and love with every single AWD drive system that leaves his factory. There is a level of attention to detail that you just don’t see with Chinese products, you can feel the passion that went into the design of this bike every time you ride it. This idea of a mechanical AWD bike was just an idea in Steve’s head, and with lots of time and effort and money, he has created a viable product that completely blows away anything else out there right now on the snow and ice. If Steve can just get this bike into people’s hands to try out who actually ride in the woods in the winter, there will be no end to the potential sales. The Fat-E 5 Ultra is available for purchase on their website here for $5895 with the stock 1500W Bafang Ultra drive unit and a frame pack.
He sold me, and all it took was a 2-week loan of one of his bikes, and I’ve never bought a factory custom-built ebike in my life.
The Christini AWD drive system completely changes the rules of the fat bike game.