Electric Earth
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I assumed as much based on my research. I was just replying to the grin motor sim that was linked, which was with a 52v battery.
35+mph Motor And Controller/Build Advice, Please?
- Thread starter Electric Earth
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If that's the case then the power to weight to cost champion hub motor is either a 30mm wide leafmotor or a Grin RH212.
Pair it with a VESC, either motor will do 35-40mph for your couple miles w/o overheating.
Add ferrofuid for a little more thermal endurance for that hill and hot weather.
If you wanted 30mph then i would recommend a MAC. A MAC will do 30mph continuous with some bursts in the 35mph range.
Pair it with a VESC, either motor will do 35-40mph for your couple miles w/o overheating.
Add ferrofuid for a little more thermal endurance for that hill and hot weather.
If you wanted 30mph then i would recommend a MAC. A MAC will do 30mph continuous with some bursts in the 35mph range.
Freehub bodies are weak and expensive and don't allow for regen. But whether it will work depends on whether there is a clear straight chainline forward from the top of the brake rotor to wherever you can mount the motor. Most modern frames can't accomodate that for the whole suspension stroke.
because with a disc brake sprocket we can hook up a much wider gear ( strong enough to handle the torque continuously ) and therefore not have the disposable drivetrain problem that high power mid drives have.
Electric Earth
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Well for f*ck's sake, I'm not going to be trying hard turns on it at top speed. It's a DIY ebike build, not a sportbike. If it's a 40mph top speed, that's not the comfortable corning speed. You also wouldn't try a tight turn on a sportbike at 150mph...
When you get up to 40mph speeds it's a good idea to have a very slack angle and long wheelbase, the closer you can get to that the better for handling, which becomes very important for safety at those speeds.
Not understanding the requirements. You can’t pedal at anything over 30mph unless you’re part hamster, so torque sensing PAS won’t provide any assist. Cadence PAS will provide assist, but you won’t be contributing anything, just moving your legs around. Most mountain bike frames won’t have clearance for a 52T+ chainring.
2Phast2Delirious
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I have a semi-street legal Stealth Bomber clone that I downgraded to 52 volts / 50 amps and it can achieve 35 mph or 40 mph downhill. It does have a beefy 72v 8KW motor, which helps with torque, hills/terrains, and overheating. 52v 20ah-30ah replacement battery is around $300-$500 compared to 72v 20ah-40ah $700-$1300.
Cheat sheets. Feel free to correct, add or officialize!
Post GPS MPH only!
Edited:
52v @ 50a = 35mph @2Phast (215lbs rider)
72v @ 20a = 37mph @bengxe
72v @ 40a = 47mph @bengxe
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I did a little math there, if you're paying 3-500 for 14s, you should be paying 430-720 for the same cells in 20s. FWTW.
My phone gps recorded 37mph when my CA was set to 20a and 47mph @ 40A, but I don't need to go over 30A anymore.
If you have a motor that can draw 50A @ 52V, you can go 35mph on 52V. But by your own numbers the equivalent 72v system will have 60% less heat.
Electric Earth
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Well I don't wanna get too deep into this and off track, but as you bring it up again - As mentioned, I'm a bike mechanic. Not like I tinker at home, but like I was a head mechanic in a reputable shop in a major cycling town before changing careers. I also am into all sorts of biking, including MTBing, and am fairly familiar with the capabilities of the bike. I've never had my hands on a Banshee, but if you're having stability issues at 40mph, I'd look to things like your wheels or the tires you're using as a first step. Check all of your suspension bushings and bearings to make sure they're tight. I assume this is a through axle bike, so if your axles are tight, you shouldn't have issues with flex there. You'll want something like a Fox 36 or beefier for no flex at those speeds and weight. Your frame shouldn't have a lot of flex to it. I'm not saying it'll be like it's made of solid marble type stiff, but it shouldn't have enough flex to give concern. I'd really start with looking at wheels/tires, though. Are your rims wide enough for those speeds? If you have a "light bulb" shape to your tires, they aren't. If you take a wheel off and put it on a work bench, axle on the bench, and push hard on either side of the rim, with your hands and 3 and 9 oclock, does it flex at all? It should be stiff with zero flex. Are you using quality street tires with a low, stable tread pattern? I've bombed a long mountain road on a loaded touring bike at 40mph and it felt solid. Just gotta make sure the bike is stiff, set up well, and everything is tight and in good condition.
Electric Earth
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The more I'm looking into it, the more the Grin All-Axle Fast Wind is looking like it might be the best option. The simulator on the Grin site says it's just under my 35mph goal, but it's close. What controller would you recommend for it? Ideally I'd like a basic display for speed and battery level, ability to go throttle only is a must, and regen braking would be cool. The Phaserunner that bengxe mentioned gets mentioned a lot as being fantastic, but as bengxe said, it's very expensive. I need to learn a lot more about controllers, but where should I start? I think something mid-tier would meet my needs?
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2Phast2Delirious
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My math aint mathing? lol jk I failed to mention the different vendors and cells. For 48-52v projects, I'm fine using decent generic 18650 cells, but for 72v setups, I will only use LifeP04. My main 52v 50A battery contains Samsung cells.
Yea, I guess I should've taken it to a professional when I was having all those issues. You sound like a real expert.
Electric Earth
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Just trying to help. 
Popstar
100 mW
With your skills at bike tuning/balancing/thinking you've shown in thread (ability to lace a true wheel yourself?!, likely good access to quality used parts) , you should for sure go for full power, quality and customization of Grin's All-axle + Phaserunner. It gives you such the options and If you are a "bike person" even if you say pedaling isn't important it is unlikely you want a motorcycle. You can do back pedal regen to give you coaster brake nostalgia, add a a torque sensor to feel like superman. I'm also not an expert, but I believe you can increase max speed with some FOC magic sauce
72V All Axle Phaserunner and 72V battery slightly max's your budget at $2.1K. You could zip at 40mph with 26mile range and never overheat. The more fun it is, the more it will replace they car.
The phase runner is certainly mid-tier. You can spend a lot more or a lot less on a controller, and it'll do everything on your list. I called it expensive because you had listed a budget that it didn't really fit under and because my own bike has a $60 amazon controller that's been tripling its power rating for the past 2 years (link). KT and Sabvoton both have cheaper options that would fit your needs. VESCs are generally very cheap for their level of performance and versatility, but the learning curve to tune them and set them up is significantly steeper than the alternatives.
Electric Earth
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The budget isn't so firm that I can't go over a bit, but thank you for considering it. And thanks for the other suggestions. I have a lot to learn when it comes to controllers, but this gives me options to look into.
Electric Earth
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One thing I did notice is that you selected the Fat version of the motor, which does have performance benefits due to the larger motor, but the fast wind version of the regular motor is still pretty fantastic results with the rest of the parameters you put in. And ultimately you're right, I will be happier and should go with a 72v Grin All Axle build rather than something cheaper. Yeah, I'll build the wheels myself. The current V3 All Axle says it has a torque sensor built into the motor. Would I be correct to assume the Phaserunner would accommodate that, and I wouldn't need anything else for torque sensing pedaling? My old ebike build with an amazon kit was PAS and it always felt like pushing against a wall. The nicer ebikes that I've ridden through my previous job with Bosch torque sensors, etc, felt fantastic. No comparison there. They were also mid-drives. I've never ridden a torque sensor hub motor. Any idea if it's the same feeling as mid-drive?
