Upgrade time! 40mph max speed target. Help

electr0n

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Mar 29, 2009
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I want 40mph / 65kph top speed and I'd like fast acceleration. I use my bike for commuting, errands and just plain fun. Right now I've got a front 407 running at 66.6v and 20 amp controller, 26" wheels. I can get up to about 50kph top speed give or take but I'd like more. I find myself wanting more power particularly when I'm commuting on busy roads with no bicycle lanes.

I'm debating between a 9C 2806, 2807, Crystalyte HS3540.

Using ebikes.ca simulator:

2807 26" wheel, 40 amp controller 88.8v top speed is almost 64kph, but overheat in 9.6 minutes!
2806 26" wheel 40 amp controller 66.6v top speed is 58kph, over heat in 18 minutes.
HS3540 26" wheel 40 amp controller 66.6v top speed is 61.5kph overheat in 18 minutes.

I'm concerned about overheating. Keep in mind I'm a light weight ride less than 150lbs and I live in a mostly flat area and I'm in Canada where the temperatures don't get too high most of the time. What are you experiences with these motors running at this kind of wattage?

Are those simulated speeds accurate with users experience here? I'd prefer not to modify my motor and just run it stock. I do like to ride wide open throttle sometimes. Which motor at which voltage amperage combination will get me closest to 40mph, 65kph without too much risk of melting things?
 
Hm, i'd think that the Crystalyte HS would deal with the heat better. Maybe the simulator is off a little. The 9C does have less magnet and copper in it after all.

I am seeing that cruise speed on 66v requires amps much higher than 40A, more like 50A. ( you have to go into the custom controller mode ). A HT on 100v / 90A controller seems to fare better.

40mph does ask a lot of power from a motor. Definitely in the 2000-2500w zone, and that's on completely flat ground.
If you want to do this speed constant, and have it be reliable, you do need a bigger and badder motor. Short spurts of a few miles on a lesser motor is OK.
 
or go mid-drive where you can more easily cool the motor, and also put it thru a shiftable transmission so you can use a smaller motor and raise teh voltage and gear it down.
 
The standard recipe for just getting into the 40 mph club in 26" wheel is......

9 c 2807, 72v 40 amp controller (lyens 12 fet my fave), 20s lipo. Unlikely to overheat by the time you drain 20s 10 ah. That will take about 20-30 min. Garanteed to be fried or close to it if you try to make runs with 72v 15 ah at full speed, or up steep hills. So by about 10 miles of 40 mph, you are about to melt, carry 15 ah and go 15 miles and you will melt.

Nobody giving me a clyte to melt, so I have no data on how quick I can ruin one. Supposed to take a bit more time. Definitely the cheaper route to go 9c. If you keep it short, a 9c will really run nice on 26s.

Thermometer on the motor required. I just monitor the axle temp, and guess the inside temp good enough to stay out of trouble. To really flog one, drill out the covers, either motor. Mostly it's just so the motor temp cools faster after you stop though.
 
On 20S lipo ( 76v nominal ) x 56a, my 8x8 MXUS ( basically a clone of the 9C ) would hit about 45mph, and be breakfast cookin' hot in 15 mins on a flat :(

Would get pretty damn hot running 35-38mph power ( 15S / 57v ) for over 30 mins as well.
Performance would gradually drop down as the heating started within the first couple minutes.

It's just not a powerful motor. I'm surprised that people have got out of it.... then i realize the rides were very short ;)
 
Yup, in general the gearmotors shed heat a bit slower, so they can cook off a bit easier when getting really flogged. Harder to ventilate one too. You'd let dirt into the gears.

The other generality is a heavier dd motor can absorb heat a few minuites longer, simply due to it's greater mass. The 5304 was great for that. I'm not convinced the HT or HS motor is the equal of the 5304 for soaking up heat, but it seems to have a decent heat soak time.

Again, till I go give one the melt test on Augustine pass in 110 F weather, I couldn't say how it compares to the 9c. I just know It's taken me at least 20 min to melt one 9c, and the other took closer to 40 min. Not many have suceeded in melting one down on an 800wh or less battery.

Personally, I find it much cheaper to melt 9c motors than clytes.
 
So just looking at the weight of these motors from ebikes.ca the weight of the 9C is 6kg and the HS3540 is 7.5kg So there is 20% more mass on the Crystalyte to soak up the heat generated in the windings. Not a real big difference. Maybe I'd be better off to try to get a hold an X5.
 
No current geared motor can handle this duty.. unfortunately.

There are a couple used 53xx's for sale on here, and soon there will be more, because the cromotor and 54xx are coming out.. :) keep your eye out for stuff in the 'used' section.
 
Too easy. Go from 18s on your battery to 24s and 30-35A on the controller. Check with Ypedal regarding the safe max current for a 407. Maybe with your light load and flat terrain it's no problem going to 40A. Include a programmable controller in the mix for future flexibility, and eek out a bit more top end with the 110 or 120% max limit on the speed limit settings. You could go even further on the acceleration part with even more current if you learn the limits of your motor, so you know intuitively when you've ridden it hard, and ease on and off the throttle a bit shortly afterward.

Also, those X series motors have a cooling advantage over other motors if you go ventilated. That's because the overlapping winding strategy that creates the low cogging torque for pedal only results in a lot of extra copper on the end windings, so the cooling air flow comes in contact much more copper than all of the other more common type motors. Justin's testing showed that there's really no way to keep water out of the motor if you ride in the rain, so there's really no reason not to ventilate, and it might even enable you to go to 50A or higher, which at your weight should be high in fun quotient.

In doing so, please use a well thought out ventilation approach, and no just swiss cheese the side covers. The air inside our hubbies spins due to the side covers. This spinning creates a centrifugal force pushing the air to the perimeter, so intake should be as near the axle as practical and exhaust as close to the perimeter as possible. The splayed stator laminations of the X series motors creates an angled channel at each tooth that stimulated some air flow through the magnetic gap naturally. On my X4 motor that flow is from the right to the left side, so I believe the best passive ventilation strategy for that motor is to intake air near the axle only on the right side with exhaust holes at the perimeter of both covers. Smaller holes permits you to get closer to the lip on each cover that locks the magnet backing ring in place, and angling the holes so the air exits rearward at the top of the rotation (the creates a left and right cover so be careful of correct orientation) stimulates a freer flow. This is all much easier than my usual detailed explanation makes it sound, and only very basic tools are needed, a center punch to mark nice evenly spaced places to drill so the drill bit doesn't "walk" on that curved surface, a hammer, a drill, a 1/4" or 5/16" drill bit, and a marker.

Be sure to replace those bearings while you're doing the upgrade to make your motor good for many more trouble free years.

Also, spend some time and a few bucks addressing aerodynamics. The cycling calculator here http://www.kreuzotter.de/english/espeed.htm shows the power requirement increases by over 1000 watts going up from 30mph to 40mph. Since you're looking at about 2kw, small differences pay huge dividends. eg at 40mph on a racing bike simply going from hands on the tops to hands on the drops saves 500W. Even just the type of tire can save 100W or more.

If you're itching for a new rig and get new everything so you can just power through it, I completely understand, though I would suggest modifying your target to 50-55mph as an absolute top speed in a tucked position. That's even if you never intend on going that fast. That will give you nice zippy acceleration in the 30-40mph range where you need it the most to mix safely with traffic. If your bike tops out at 40 on the flats, then accelerating from 35 up to 40 will suck. Also, any slight incline or headwind will force you below 40. My main bike will go 60 but I've only done it twice just to see. Typically I ride between 30 and 40 mph, and sometimes 45 or 50 on some good roads that warrant it. That puts my peak power rpm around 30ish, so when I get behind some idiot driving too slow, I just zip right past. Just like I'd never own a car that I needed to drive around at WOT, I wouldn't own an ebike that needed WOT either.

That said, if you're looking for much better performance with a cheap price tag, some extra batts in series and a new controller is a cheap way to get there. Then if you still have some extra dough, spend it on more batts, not for more range (though riding conservatively you'd have more range), but to get the same range but quicker and a whole lot more fun. EBikes at 20A are for old people and children. :mrgreen:

Sorry for the long-winded post with no pics or videos, but at least it's solid info.

John
 
ebikes.ca simulator says it will overheat in 6.5 minutes under those conditions. That's on flat ground. efficiency would be low at 74%.

I have not ventilated a hub motor before, but i think we would be talking more about liquid nitrogen than open air here.

For cheaper options, the crystalyte HT and BMC/MAC "torque" motor ( 10 turn ) seem to do pretty well, tho you might have to ventilate the HT or pedal quite a bit to save it. On flat land, it could be OK. If you have hills, then you really need one of the jumbo size motors.
 
I'd suggest looking into Ypedal's real world results with X4's before making recommendations based on a simulation, especially when the person who designed the simulation program said the overheat times were overly conservative. Also, why bother to comment about ventilation if you have no experience with it? Done correctly it works very well. With my ventilation strategy I have no doubt I could run that motor at 40 or 50A pushing fat me, much less the 100lb lighter load OP.
 
You mean his 409 in a 20" wheel on 72-100v? that's a whole different ball game and you should know that. That's probably the best possible setup for that little motor. On his setup, i can't see how he was going faster than 30mph.

I see how it could have had good acceleration, but poor top speed.

( ebikes.ca simulator says that the 408 will run up to 33mph on 92v nominal, the 409 is going to run at an even slower speed. )

Regardless of how well the ventilation would work, even if you could shed a good fraction of that 800-900 watts of waste heat ( on a flat... ), you'd still be running at 73% efficiency, far below the peak efficiency zone of 84%

Maybe the overheat times are a little pessimistic.. run the bike in the middle of summer and they may not be :)

Always good to build some headroom into your motor selection.

Since i am going off a simulator, and not real world experience ( even though the simulator data does come from real world experience, so it's a matter of faith if you don't believe it :lol: ), electr0n, send YPedal a PM and ask his opinion.
 
I wouldn't hesitate for a second to put 20s at 40 amps on a 407 in 26" rim. But it wouldn't be able to shed the heat quite as good as a 9c or other larger dirameter motor cover. Definitely no reason not to haul ass around on the 407 for awhile. I can't see why it would overheat that fast, if you just did most of your cruising between 30 and 35 mph. Just use full blast for breif periods when you need it.

Again, with a thermometer on board, it's a simple matter to just stop when you see it's time. Really easy to insert a temp sensor to the 407, and have the temp reading right on the windings. Not as hard as stuffing two more wires into a 9c axle.
 
I was also looking carefully at the geared motors, particularly the mac. The acceleration, torque and top speeds are impressive watt for watt, within limits. But a couple things I don't like, the gears and clutch at higher wattage seem to be vulnerable and introduce more points of failure. At the end of the day to get 40mph+ with strong acceleration even approaching top speed I think will require more watts than the mac will tolerate which is why most of the higher power setups are running direct drive hubs. I saw a video on youtube of an mac or maybe it was a bmc out accelerating an X5, or an HS can't remember details but they were at the same wattage I believe and it impressed me, but when the watts are increased to a certain point the mac can no longer compete due to heat and the gears etc.

I was considering if my 407 could be pushed up to 88.8v at say 30 amps that would give me a nice performance boost for low cost but not sure about how hard I could push the motor. I do know that at 66.6v 20amps my motor only gets warm to the touch after a hard run so there is definitely room for more power there. The thing with my 407 is that it's a front motor too so there's the safety factor there. Will pm ypedal to get his thoughts. Thanks John, neptronix and dogman!

With regard to the cooling mods with our Canadian winters here with all the salt and slush and snow and ice and road grit won't having gaping holes on my side covers eventually lead to issues inside the motor? I know there's just about no way to 100% water proof these motors but I imagine there is a difference between the tiny amount of water that gets into my sealed motor vs having larger ventilation holes. I guess the biggest issue might be the hall sensors when its really pouring hard out. I ride in all weather conditions since this is my sole transportation.

One way or another I plan on getting a 2nd setup both as a backup and so my wife has something to ride with me.
 
HS3540 26" wheel 40 amp controller 66.6v top speed is 61.5kph overheat in 18 minutes.

I run a HS3540, totally stock, on 20S, at 50amps. I ride WOT everywhere, and I never ever pedal (I am 95kg). I find that my HS3540 pulls around 3000W through a large part of its curve (2800-3500), and I find that after a WOT ride - my only mode, (which on a flat is about 60-70kph) the motor starts to get a bit too toasty after 15 minutes. I usually stop after that and let it have a rest, but by that I mean I take it easy. My commute is 12-14km, and I can make that WOT with no problem, but I probably wouldn't want to turn straight around and go home WOT. But sometimes that has happened (ie, gotten to work then wanted to turn around and come straight back - actually every time I get to work I want to turn around and go straight back :D ), and I have just waited 10 or 15 minutes then WOT home. 15 minutes of total WOT riding (with literally no stopping on the throttle, which for most of my commute I can do), is a lot of hard riding (I get to work about 8 minutes faster than driving my car).

You haven't said how much WOT you want to get without overheating. Overheating is always a problem. The only way you can not worry about overheating on your voltage (to reach those speeds) is to get an X5303, and a controller to take the rape. Otherwise, I back John's suggestion of ventilating your hub and knocking up your amps and volts. I know nothing about the 4 series, but ventilating makes the world of difference. Your hub motor is basically an oven unmodded.

But if you are looking for the 20km or so range (WOT the whole way), then I think the HS3540 is the cheapest upgrade for you on the volts you have to get your goal.
 
electr0n said:
I know there's just about no way to 100% water proof these motors but I imagine there is a difference between the tiny amount of water that gets into my sealed motor vs having larger ventilation holes.
it's not necessarily a tiny amount. ;) go watch justin's last video about hubmotors. :lol:
 
I have hs3540 72v 40a 26" it does close to 70 kmh all the time, i have it drilled and it does not heat beyond 60 celsius even after a long rough ride. I don't know if that motorhub can smoke without the holes using it like that.
 
Well for starters, if you are riding through cold water or slush, your motor is now pretty nicely water cooled and won't need vents on that day. When I say vent a motor, really I'm talking about vent it for a motor smoking run on a Tuscon racetrack on a 90F day.

As I've said before, and it was said again just above, let er rip for a short time. What's a short time? It is untill your motor thermometer tells you when to stop.

Slap a bargian price 9c or muxus dd motor on the rear, and let er rip. Just keep the 40 mph part down to 10-15 min, and you are good to go. Ventilate the motor only if your thermometer is telling you to do it. If you need summer vents, tape em over for winter with metal high temp duct tape.
 
Philistine said:
My commute is 12-14km, and I can make that WOT with no problem, but I probably wouldn't want to turn straight around and go home WOT. But sometimes that has happened (ie, gotten to work then wanted to turn around and come straight back - actually every time I get to work I want to turn around and go straight back :D ), and I have just waited 10 or 15 minutes then WOT home.

:lol: That's funny and I can completely relate to that! That was really helpful too. It's nice to get some real world performance info rather than just going by simulation. So you're around 200lbs running at 50 amps 74 volts and start to get too hot after about 15 minutes of full throttle. Realistically right now I've only got 8 amp hours of batteries at 66v. I'd like to double my amp hours on my next battery purchase and might go up to 88.8v as well so I'll probably be close to the same wattage as you, maybe a little less cuz I weigh a bit less than you.

So let's say I end up with 88.8v 16ah of batteries. That'll give me 1420 watt hours. At full throttle HS3540 88.8v at 40 amps should put me around 48 watt hours a kilometer. Let's say I could squeeze about 25km at full throttle from that size battery pack at 65kph. I should run out of watt hours within about 23 minutes probably around the same time heat buildup is becoming an issue.

So just like dogman was pointing out battery capacity vs overheat time is another issue.... hoping others will chime in with their experiences on their motors with overheating.

Thanks for that rojitor. I'm beginning to lean towards the HS3540. Makes good sense dogman. Maybe the 9C could handle what I'm asking for it too and it's really just a toss up between the two motors. Maybe a slightly higher overheating tolerance with the HS vs the 9C. Actually overheating shouldn't be much of an issue for me for most of the year here in Southern Ontario. Today it's -1C.
 
amberwolf said:
electr0n said:
I know there's just about no way to 100% water proof these motors but I imagine there is a difference between the tiny amount of water that gets into my sealed motor vs having larger ventilation holes.
it's not necessarily a tiny amount. ;) go watch justin's last video about hubmotors. :lol:
link?
 
nomad85 said:
amberwolf said:
electr0n said:
I know there's just about no way to 100% water proof these motors but I imagine there is a difference between the tiny amount of water that gets into my sealed motor vs having larger ventilation holes.
it's not necessarily a tiny amount. ;) go watch justin's last video about hubmotors. :lol:
link?

I'd like to check that out too. Maybe I've been lucky but water hasn't caused much of an issue aside from my hub motor freezing in the mornings a couple times. Now I take my motor off and bring it inside once or twice a month and put anti rust and lubricant inside.
 
I've had similar experience where I had to chose between 9C and HS and in the end I got HS3540 from MethTek.
If you really are worried about over heating and all that, you could get your self 52T chainring and 11T-32T freewheel with these combo you can pedal at 35mph therefore you can pedal 30% and use motor 70% to save battery and over heating problem!
I would recommend getting HS from MethTek or someone who has already done upgrade to the motor so you wont need to worry about phase/hall wires getting cut by the axle.
what sort of bike you riding??
 
nomad85 said:
amberwolf said:
it's not necessarily a tiny amount. ;) go watch justin's last video about hubmotors. :lol:
link?
a quick google search on my exact phrase "justin's last video about hubmotors"
http://www.google.com/search?q=justin%27s+last+video+about+hubmotors
finds it as the very first item. ;)

(though google put a space between "hub" and "motors" when it displayed the search, so if it doesn't find it as first item for you, put the space there)
 
amberwolf said:
nomad85 said:
amberwolf said:
it's not necessarily a tiny amount. ;) go watch justin's last video about hubmotors. :lol:
link?
a quick google search on my exact phrase "justin's last video about hubmotors"
http://www.google.com/search?q=justin%27s+last+video+about+hubmotors
finds it as the very first item. ;)

(though google put a space between "hub" and "motors" when it displayed the search, so if it doesn't find it as first item for you, put the space there)
http://www.lmgtfy.com/?q=%22justin%27s+last+video+about+hubmotors%22 :mrgreen:
 
ok, now google has cached *this* thread and puts it first. :lol: so it's the second link now.

but the search your link does only shows this thread, and not any of the other results. :(
 
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