Thanks for the reply, that is good info. So hard to judge power usage. I’d say most of the time, 1/4 of the bikes power is all that’s necessary for riding in the woods at my level. Honestly I would be totally open minded to usable power numbers, if the range could be reliable.
I have no idea. The products appear on their website so they will probably be available soon: http://www.sur-ron.com/SDP180-?_l=en
Count me in for a group buy as well! The dual motor kit looks awesome...thoroughbred wrote: ↑Jun 20, 2018 1:19 pmI'm no expert and nobody has checked my math so keep doing your own research. I think the light bee has a 2.2kWh battery and i don't know off hand how much singletrack time that buys you. It might be in the surron thread post from the australians. The 2.2kWh battery is $1500 from Luna
Your bike will be 100 # more than the light bee so that will have an effect on range, etc.
The surron offerings are 5, 8 and 16kW motors with 2 x kW burst capability. The luna folks are getting huge output from the 5kW motor in the light bee so I bet the 5 or 8 motors could work in a 200# dirtbike.
I'm in for a group buy if it should come to pass.
Hmmm. People smarter than me have figured out that Alta’s estimate for four hours of “expert single track” riding assumes about 1.9 hp used on average over the four hours. I race locally in “B” class in our local enduro series, so I am most likely below the Alta estimate for a given ride. Which sort of surprises me, sort of not. I’ve always felt like I’m using about 1/10 of my bikes actual power, turns out it’s about 1/20.flat tire wrote: ↑Jun 20, 2018 4:22 pmDepends how fast you go, how hard you accelerate, and whether you carry momentum vs turn n burn (how frequently you accelerate). Those are the main factors. Terrain matters too, mostly how soft the ground is and whether there are inclines but riding style is the main thing.
Good info on the gas to kWh conversion. Somehow, the Alta’s “four hours of expert single track” is coming from a 5.8 kWh battery. I go through roughly 3 gallons of gas in a four hour ride, so something is not quite right.John in CR wrote: ↑Jun 21, 2018 11:07 pmHow much gasoline do you use for your 4 hours of trail riding? That's the best way to back into how much battery you need. A gallon of gas contains 33.7kwh of energy. An electric motor is roughly 3 times as efficient as an internal combustion engine, which turns gasoline mostly into waste heat. That means for similar performance you'd need about 11kwh of battery capacity per gallon of gas used with your gas bike. IOW unless you're talking about most of the time riding easy, 4 hours of riding isn't going to happen with current battery tech. Even the top electric bikes can't be ridden hard for 4 hours using state-of-the-art high efficiency motors and battery packs that you're unlikely to match DIY.
Interesting. My favorite terrain is gnarly technical woods, where average speeds are around 10 miles an hour. Even though I ride a 2 stroke, I am almost never “on the pipe”, and I use the “soft” setting for my bike’s power valve, to reduce wheelspin. That being said, my riding buddies would say I’m a pretty aggressive rider. Not sure that provides enough info to determine if any of those motors in the above link would work for a dirt bike conversion.John in CR wrote: ↑Jun 22, 2018 10:14 amHow you ride and the terrain and conditions (eg hard dirt or mud or sand or hills) make an extreme difference in how long your battery lasts. Even so Alta's claim sounds like absolute BS, and must be that the lightweight expert rider in ideal conditions on flat terrain trying to make the battery last as long as possible. I only ride on the street, and going for range I could make my battery last for 4 hours, 100 miles or so, however, I ride in a fun manner on my daily commute and use about half of my pack capacity each way in about 20min, and a bit more if I ride hard.
Exactly the same for me. I’ll post what sur Ron says as soon as I hear back.thoroughbred wrote: ↑Jun 22, 2018 3:55 pmI'm into the same ride through trees as fast and hard as you can and still only average 10 mph stuff. I think I could ride 95% of the terrain with the power of a 50cc motor in a full size chassis. It's the last 5% that defines the riding experience, though. Some stuff has to be attacked with 40 horsepower like abrupt hillclimbs with limited runup.
The videos of the light bee at 5kW show it to be pretty agile on the trails but it does struggle on sustained hillclimbs. Maybe the 8kW Surron motor will turn out to be the sweet spot but it will take some trial and error.
Lol right? It came up in my parts-accumulation thread (since I haven't really built anything aside from a pile of parts and boxes yet) because I'm using a dual motor setup on my motorcycle. I wish I was still at school to make a nice clean machined case for the primary reduction, instead of the aluminum L-channel and i-haven't-decided-on-chain-or-belt-yet nightmare I'm currently looking at.