I expect that I am speaking for the rest of this forum with the following analysis:
I bought the '19 EXR. I have ridden Honda's for my whole life. While I can't comment anymore on Alta performance under full MX race conditions (read my profile), what I can say is that with the exception of the rear foot brake, it is the best dirt bike I have owned - hands down. BTW, I am in the process of fixing the rear brake with the left hand rear brake kit -also cool.
The first thing you notice is that the electric power is super controllable and it has crazy strong torque -smoother and more powerful than any bike at it's weight class. You are always in the right gear for everything -especially climbing technical single track or hitting the face of a jump. You can hear the rear tire start to spin which helps you back off the throttle to maximize traction up hills. The quietness enables you to see wildlife what would normally flee with 4 stroke bikes. The ability to wheely is unsurpassed. I am an average rider but the bike makes me shine like an expert on hill climbs and steep single track -super easy. You can literally stop anywhere on the climb and slowly crawl at 1 MPH up the hill. If you want faster, just twist more. Crazy good. Makes me look like a better rider than I really am.
The range is more than sufficient. On hilly rides, if I use setting 1 and I don't use the brakes and only regen for down hills or to stop, I have gotten 50 miles with perhaps 5% battery state of charge left. I typically don't use this mode because I like more torque offered mode 2 or 3. If I continually hammer the bike with wheel spinning acceleration in mode 3, brake hard as necessary, on the same hilly rides, I have gotten as low as 20 miles in range. I can tell you that after 20 miles in this mode, I was ready to sit and recharge. In an hour and a half the bike is good to go again -but generally the bike is more ready than I am. Power in mode 4 (overclocked) is simply crazy and for all practical purposes it not usable because your rear wheel simply spins any time you hammer the throttle -no matter what speed.
Torque-Consider this: A new 2019 Honda CRF450R comes out of the box with 53HP and 32 foot pounds of torque. The Alta EXR has 50 HP but 42 foot pounds of torque. That is 32% more torque AND that torque is always instantly available at any speed. There is no comparison. This is why the rear wheel has much thicker spokes than your average dirt bike. I raced my neighbor's 120 pound 28 year old son who is a good rider on his new Yamaha YZ450R with an obnoxious pipe on it on a paved country road. The YZ jumped the rolling start. I hammered the bike (mode 4) and the front wheel came up forcing me to back down the power. I was now 15 feet behind the loud exhaust belching throaty 450. I then leaned in my 6'5" slightly marbled 230 pound body over the front and hammered the throttle again. The Alta wheel came up again (only briefly) and I blew by the 450 like it was standing still. I had him by 25 feet by the time I hit 65 MPH and let off the juice to let the 450 ass me. While the Alta will do 75 MPH top speed, the 450cc ICE bikes have faster acceleration past 55 MPH or so (hope the wife doesn't' read this).
Oh yea, don't forget the lack of maintenance. No oil changes for the first 1000 hours, no air filters no matter how dusty the conditions, no valve adjustments, no clutch to change, no breaks to wear out -The Alta is a rider's dream come true. You want to ride, buy an Alta. You want to spend your time having to work on the bikes, go old school. From my experience, even the chain is lasting longer than on my ICE bikes. The reason is simple - 4-strokes continually pulse the chain with brief violent pulses of power. Electric is smooth torque. The Alta runs as good at 10,000 feet elevation as it does at sea level. Tip it over and there is no flooding of the carb or oil spitting on the ground. No wheel spin when you drop it. No burning exhaust to mar your pants burn your skin. No buying separate gas can or spilling gas on your hands when you fuel up. No smell of gas in your enclosed trailer or van.
"Oh but the battery will wear out" say the smelly gas covered idiots. Sure -their right -But do the math. Lithium Ion batteries are generally good for holding 80% after 2000-6000 of deep cycles depending on how fast they are charged, the temperature they are used at and how fast they are discharged. The Alta BMS (battery management system) is responsible for equalizing the charge of each cell and prolonging life. Most battery packs are designed to only use a portion of the available charge to extend battery life further than the 2000-6000 cycles. While the Alta BMS battery pack may not be proven by millions of units sold, the battery design considerations are well known for all electrical engineers and I am confident they built a solid battery pack. What is well known is that the core battery cells Alta used are top quality. While the amount of discharge cycles is unknown, I will be willing to bet that it will be at least deep 2000 cycles or better. I'd also be willing to bet that 80% of us have never ridden a dirt bike more than 1000 times in our lifetime let alone one dirt bike. That is effectively every weekend for 20 years. Name one serious ICE off road MX or Trail motorcycle that has been ridden 30-40,000 miles -no chance. In my 4-stroke MX years, a MX bike was maxed out at 300 hours and needed at least a partial rebuild. Serious MX racers rebuild at 50 hours. The Alta motor will be good for 100k miles. For interest, the Tesla Model S has a million-mile motor because electric motors have an order of magnitude more reliability over and ICE motor
Look, I love all motorcycles. I see each bike as a work of art, but for me, form follows function. While some of the new ICE bikes are truly beautiful and sophisticated, simply said, they're just not as good as the electric Alta. Thank you goes to Alta management and engineers for delivering on the first real viable off-road electric motorcycle. What they did with $70M in funds is remarkable. Eventually all motorcycles, cars, planes, tractors and long haul trucks will be electric. I've experienced the benefits of Alta -so for me there's no going backwards to an ICE dirt bike.