cal3thousand said:
30 - 40 is just outside of the recommended operating envelope for geared hub motors, even larger ones like the MACs. So I would say go with a Direct Drive, especially since there aren't hills in Florida.
Some easy choices that will be able to do what you need are: Crystalyte (HS3540 will get you those speeds without crazy voltages; with HT3525, you'll need 100V for those speeds) or 9C.
Then there's even larger motors meant for more speed / longer durations, like the Cromotor. I'm seeing lots of room for batteries and mid-drive possibilities if you are so inclined. (except that bb width will be a challenge for some mid-drive kits)
How far are you planning to go at a time?
I spoke with LightningRods/Michael Backus and he has a new 3000w mid-drive kit which looks like a monster. http://www.lightningrodev.com
But I would have to check how far the threading goes into my 120mm BB, and cut 20mm off (10mm from each side presumeably) for it to even fit. He said he would consider making a custom sheet for the GNG Gen 2 that I own, which would be able to take advantage of my 3 speed internal gear hub. But then I'd have to figure out the custom freewheel situation that comes with the GNG Gen2 and everything. I simply don't have the time and theres too much to go wrong.
I've looked at the crystalyte and watched a video over @ http://www.ebikessf.com/node/199 and I don't see an option for disc brakes on it. As far as 9c's go people keep telling me to watch out for overheating. I don't have a clue how to change phase wires.
I'm not planning to go far, this will be a show bike that I take to car shows to drum up business. The whole reason I got the bike is for it to take the place of the pretty girl in-front of my booth. Same reason with my Super 32 Cruiser, one's mean the other looks lean. I'd be happy if this bike had a 15-20 mile range.
Regardless the bike does need to work and have some performance capabilities to it.
spinningmagnets said:
DD hubs also respond well to oil-cooling, it's where you add about 1/3rd of the interior volume with Automatic Transmission Fluid (ATF).
There needs to be a vent near the axle, because when the oil heats up, cools down, Justin proved that the motor will 'breathe" through the wire insulation when all else is sealed with silicone. If you give up on oil-cooling, just disassemble and clean, and then you are back where you started.
If you could be happy with 30-MPH being your max speed, you might consider dual BPM geared motors. One BPM would struggle at 30-MPH, but two of them easily have enough copper mass. If each motor/controller is using 20A peaks, then the battery must be capable of 40A peaks.
Ben was getting 37-MPH from twin 8T MACs at 57-ish volts, and since they weren't struggling he swapped in twin 6T MACs and got 43-MPH on flat land (being aware he used a lower amp-limit when climbing long uphills to avoid overheating). Be aware the MAC has a 25% wider stator and roughly 25% more copper mass, so the BPMs would need temp sensors added, phase wires doubled (easy), and they might work. The wider fork of the fat bike would require two REAR BPMs to get the axle width.
http://www.electricbike.com/custom-build-gallery-duty-cycle-awd/
If you are set on a single DD hub, the 9C/MXUS/Yescomusa/etc have a
28mm wide stator, the Crystalyte H35XX has a
35mm wide stator, and the almost identical Crystalyte 4080 has a
40mm wide stator.
DD hubs have the option of regen braking, so Kool-Stop Salmon rim-brake pads might be an option for the rear, with a disc on the front. For flat land, a 9C might be right on the edge of adequate for 30-MPH. If you could go to 60V, you could lower the amps a bit, and it is the heat from amps that will hurt the motor/controller.
Calculate the component costs for several different mixes. I would suggest starting with the highest voltage you can afford. 60V is better, and 72V would guarantee success. Since the Kv of a motor is fixed in a hub system (non-hubs can change sprockets), it is much harder to change the system voltage than to change to a different motor. The more copper mass a motor has, the cooler it will run when given a set load. On flat land with high volts, a 9C should be OK (especially if oil-cooled). Add a temp sensor so that if it is struggling, you don't fry the motor...at least then you can sell it for $100 to put that money towards a motor with a fatter stator.
I have looked into different cooling methods, but many take more expertise than I may have at my fingertips. Installing a temp sensor is something that I think I could do as is oil cooling, but I would have to do my research on these methods. I know that either route I take the waterproof seal needs to remain in-tact as I'll be splashing through puddles and mud. I have no idea how I would mount rim brakes to a fat bike but regenerative braking does seem pretty cool.
It would be nice if my system was a pedelec/grip twist mix where I could pedal, throttle, both, or coast. But I can settle for a grip twist and some active pedaling on my part.
Right now I'm not sure any of my bike shops nearby could even properly lace a motor to a fat tire so that it offsets the motor enough for a disc brake to be properly mounted/aligned. I think that I'm leaning toward more offroad performance than top street speeds so torque seems to be more desirable for sand and dirt and the few small but fun hills we have around here.
I spoke with Steve @ Volt Bicycles and he has a Fat Sand Bike like mine that he can lace and hang a 1000w 37v system with good torque and a 7 speed gear cluster with derailer on the rear for about $800 less a battery. I could upgrade and go to 2000w 52v if I wanted too but that would mean can't use my Ping Pack and the price gets up into the $1500ish range, outside the budget.
I could assist the motor by pedaling and would have no problem doing so with the gear cluster and derailer but I'm not sure how much stress this would alleviate from my system.
http://twowheelelectric.com/electric-fat-tire-bikes/
He sent me a photo and it would look something like this:
Drunkskunk said:
48 volts and a standard 2807 9C motor or any of the clones should get you to a peak speed of 30mph, on flat ground with no wind, but it's not going to be able to sustain it on hills or headwinds. Faster windings will get higher speeds, but overheat trying to maintain them with those huge tires, and will very quickly overheat off road.
The kit you linked is a bit misleading. Its a 1000 watt peak kit. The 20.83 amp controller is the give away. 20.83a X 48v = 1000w
That looks to be a 500 watt MXUS. A clone of the 9C, and a good motor. To hit 30 with a 26" normal bike tire, that will be one of the high RPM motors. likely a 2806. Not a good choice off road. Your 4.8" tires will have a rolling circumference larger than a 29er, so they're going to run faster than a normal 26" by a fair amount, but also be harder on the motor.
Thats one of the reasons I went with a fat bike is the overall diameter of the tires equates to a higher top speed in the end while it still has the benefit that comes with a fat bike of gliding over almost any terrain.
I'm thinking if I do it right I can ride along the surface tension over top of a small lake to the other side/bank
(not ever gonna happen)
wesnewell said:
Neiler106 said:
Think that http://www.ebay.com/itm/26-Electric-Bike-Bicycle-Motor-Conversion-Kit-eBike-Rear-Wheel-48V-1000W-/370934929537 48v/1000w could handle the fat bike? Lot more mass to move than a regular 26er wheel.
I'm also looking for an engine that has disc brake mounts which is some of the trouble that is plaguing my engine search.
Well, it's about the same as the motor I have and mine moves my 270 lbs just fine and this one has disc brake mounts. But you'll probably want to swap rims for a wide tire. If your current rim is 36H you could just use it. Oh, btw, the amp rating for the kit is wrong in the ad. One person that got one said it was either 26 or 28A max. Don't recall which. And it is a 1000W motor, not a 500W MXUS. And if you have a problem, it's from a company in the US, so you do have legal recourse. I'd put the 3000W kit with a motorcycle rim on it myself.
So you are saying that the http://www.ebay.com/itm/26-Electric-Bike-Bicycle-Motor-Conversion-Kit-eBike-Rear-Wheel-48V-1000W-/370934929537 can not only handle the fat but but its a 3000w kit for approx $300 with disc mounts? If that is the case then I'm on-board but can you verify any of this?
K nevermind, I understand that you were reffering to here http://www.ebay.com/itm/3000W-100KM-Hour-Electric-Motorcycle-Motor-Extreme-power-and-Extreme-speed-/390799423711 when you said 3000watt kit.
dogman said:
I think you are getting some good advice about high speed with the fat tires. On 2" tires, I've worn out a bike tire in 40 min, by cornering hard on a racetrack. The tire cooked itself. Later on when removing the tires, they had all the cord hanging loose inside.
But I think keeping it to 25-30 mph makes sense. 7 turn 9c or muxus would do it on 48v. 40 amps controller, so it still pops off the line fun.
But if you plan to ride beaches in deep sugar, you need a 10t and 72v. Hard to find now, Cellman doesn't stock them anymore. For a bike to ride slow in sand, the 12t mac might be real good. But it won't go 30 mph on 48v.
For crawling through the deep sand, I'd like to try the new bafang bb drive. But again, no speed if you have a single speed rear gear.
I don't plan to take this bike anywhere near salt-water and the very thought makes me shudder a bit. I do plan on riding through muddy trails and some deep puddles (I play in puddles
) so the torque, aka the ability to keep going against resistance, is more important to me.
By 10t and 12t you are reffering to sprocket teeth correct? I wasn't aware that sproket teeth played any role in a DD motor setup, only aware of their role in mid-drive setups.
I would like to try a BB drive/mid-drive but the bafang can only mount up to 73mm and I have a 120mm BB and I am not a fabricator by any means. But the bike currently does have a 3 speed IGH and I could utilize a mid-drive and low gear to achieve this, albiet slowly which turns my electric smile into an electric smirk.
dogman said:
But you want speed. Have you considered moped tires and rims on a fatbike?
I havn't considered switching to moped tires and rims because the same issue remains, getting DD engine laced and installed for less than 1100 and buying new rims puts me over budget.
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It might be easier for a pro to do this kind of work.
or hopefully by a professional 
The stock setup has a 3 speed IGH so a low/middle powered mid-drive is certainly in the realm of possibilities as long as shifting under power is kept to a minimum as not to damage the gears. The electric version is a front 500watt hubbie & bottle type battery so with a little pedal input gives a solid two wheel drive feel. 
