40 mph club

[wasp]

new top speed set with 150lb rider...76.8kph

 

[dogman dan]

47 mph for us yanks. Nice!

Start saving for a trip to Tucson next spring. Bring all the Canadians with you in one vehicle. You won't mind a trip to 90F weather. That's faster than the winner of this years death race claims. Can you go from 18 kph to top speed in 700 feet? If so you could podium.

 

[icecube57]

I love my LOW MED HI switch. It not only helps me with consumption but it helps me get finer control on my throttle. It really extends your throttle range by breaking it up into three ranges.

 

[Hyena]

I've clocked my modded GM 1000w hub on 18S lipo (75v hot) doing 45mph. As soon as I get these casts off my broken wrists I'll do another run with 120% timing in delta mode

So yeah, just dropping in to the 40 mph club to say high on my way through

 

[icecube57]

Hyena how does the plastic on your stator teeth look. Mines looking all deformed.

 

[Hyena]

I'm not sure what you're referring to. Have you got a picture ?
This is how the inside of my hub looks at the moment :lol:

 

[icecube57]

You see that yellow piece of plastic that was behind the windings that sorta insulates the wire from the stator along with the sleeves that go in the teeth. Look bottom right on the stator. Most of mines is still intact like 50-60% intact. You can see where the heat cause mine to curl up and deform. Your wires look very dark. And you know I was pushing 4kw through mine for a short period. Kinda gives me some security that i can push mine a little bit more if you have been butchering yours and it has survived i like to stay between 160-180F. I guess you are the canary now.

 

[cell_man]

Yeah, get enough volts and the bike is likely to be a switch that goes from off to 20 mph. Mine's going to be front hub, but I better start laying in a supply of the tire I like.

I just need a few more details to complete the build on my low speed bike, using the 6x10. At 48v it climbs a hill at 10 mph great, and on more moderate grade, seems able to chug along at 5-10 mph all day without lugging till it roasts itself. It's turning out to be a great trials type ride for the dirt trails near my house. Perfect for riding the speed of a dogpack.

It's just really hard to have it all on one bike without going to the RC motor or other type of through the bike gears motor. It's ok with me though, no way do I want to corner on 2.5 inch wide knobbies on the street! I need to get more bikes, right now I have on FS commuter, one FS pedaler, one FS trials ride, one no suspension race practice bike building, and I still need one more for motor review testing. Hopefully some more wallbikes will appear at the flea soon.

I'd be worried about putting big power all to the front. My dual motor bike spins up the front on demand at speeds up to almost 20mph in the dry. Coming out of bends I can't power on too soon or it will wash out. Maybe the reduced torque of a DD may make this less of a problem than my geared hub. Ever though of dual motors?

 

[dogman dan]

If I had 48v 20 ah prismatic a123's, I'd be putting two motors on at least one bike! But not with just pings and nicads in the garage. Once I get a bigger lipo stash though, I'll have to try it.

Motors are not a problem, people send them to me to try to melt at stock wattage. I got the climate and the hill. Anybody can overvolt and melt a motor, but I have one of the worst commutes in the US in the summer. So I make a great tester for stock configurations.

Now that I have lipo coming, it's going to be interesting to see if 72v and 40 mph will be too much for front hub. I figure if I can drift a rear wheel, why not the front? I have done it in dirt. Feels fine to me. Better still though would be keeping the rubber fully grabbing road. Throttle going up entering the corner is the key. So I may enter the corner at 25 and leave it at 35. Panicking and backing down is a sure crash. Coasting a corner loses.

At racing speeds I won't have that much tourqe at 30 mph with dd motors, but I bet I have to ease into it on the start line.

 

[cell_man]

My setup pulls about 100A at 48V so yeah like I said, you need good batteries. It works for me as I have a fairly high capacity high C cell to play with and 24S of them just gets too big and bulky, so high volts is not so appealing. Even at 36V the dual motor works very well if you have the appropriate high rpm winding. Still not convinced about drifting the front wheel though, cars don't fall over, bikes do and I'm pretty sure that if I hit the throttle too early and too hard coming out of a tight bend on my bike as it is set up now, the only drifting would the front wheel straight from under me, quickly followed by my teeth, straight to the road

I'm sure you can handle it, just giving a word of warning, that's all. Try it and see how it works for you. With a no load speed of well over 50mph and the extra low down torque a geared motor gives you, it can be a bit twitchy at low speeds. The Fecher current based throttle would likely help a lot in that situation.

 

[dogman dan]

Yeah, I bet it's very different on peppy gearmotors. I've only experienced 1000 watts of front gearmotor. Even the 36v version of the fusin would spin the heck out of the wheel easily on a sandy spot. So the only front hub drifting I've done is on dirt. Hopefully I wont smear too much skin off on pavement when the lipo arrives. Ideally I won't do any drifting of the front wheel, but if I do keeping the throttle on and the front wheel pointed right is key to survival.

Again, the key thing is, if you are putting the throttle on while exiting the corner it's too late. Brake before the corner, and dive in with the throttle on, and just use enough power to grab pavement through the entire corner. Slowly accelerate all the way through and you wont break out of traction and be flying by the exit of the corner. Practice at very low speed at first of course, and build confidence slowly. Hanging out the inside knee really does make a difference too. After awhile coasting into a corner will start to feel suicidal compared to powering through.

When you coast into a corner, and make the transition from coasting to power while in the corner it's a sure way to wipe out. Get on the throttle just before you start leaning. The sudden change in the tire from coasting to pushing is breaking your traction. This is for either or both motors while cornering.

But yeah, the higher the power levels are the touchier it will get.

I just got back from riding that 6x10 all over the desert for an hour. Amazing how much skill it can take to ride 10 mph through cactus. But once I have a big enough pile of lipo, a gearmotor on the front hub and seperate throttles and controllers would be very nice for trials type riding.

 

[Hyena]

You see that yellow piece of plastic that was behind the windings that sorta insulates the wire from the stator along with the sleeves that go in the teeth. Look bottom right on the stator. Most of mines is still intact like 50-60% intact. You can see where the heat cause mine to curl up and deform. Your wires look very dark. And you know I was pushing 4kw through mine for a short period. Kinda gives me some security that i can push mine a little bit more if you have been butchering yours and it has survived i like to stay between 160-180F. I guess you are the canary now.

Yeah my windings are a little toasty - I ran about 4000w though it sealed for a while before I drilled holes. Now with the holes in place it's seen 5000w regularly and peaks of 7500w and I havent seen the temp go over 90 oC (194 F ). It regularly runs around 80oC on a daily basis on my commute (175 F) so I guess that's a reasonably safe temp to have them at.

I hadn't noticed the yellow plastic bits on mine, I guess they've withered up and are hiding between the coils :|
Mine often smells quite hot and has a slight burny smell to it after a hard ride - its probably that plastic melting giving off the smell.

 

[wasp]

can anyone confirm my speeds with their testing? the reason i ask is i haven't gps'ed mine yet but have run with a new ford and was told just over 80kph? someone else must be running at 20s 83.1v off the charger my settings are 50 amps phase current at 130amps & 120% throttle.
any other 9X7 9C folks running or testing at these volts and amp levels ?
any feedback would be great

 

[cell_man]

Yeah, I bet it's very different on peppy gearmotors. I've only experienced 1000 watts of front gearmotor. Even the 36v version of the fusin would spin the heck out of the wheel easily on a sandy spot. So the only front hub drifting I've done is on dirt. Hopefully I wont smear too much skin off on pavement when the lipo arrives. Ideally I won't do any drifting of the front wheel, but if I do keeping the throttle on and the front wheel pointed right is key to survival.

Again, the key thing is, if you are putting the throttle on while exiting the corner it's too late. Brake before the corner, and dive in with the throttle on, and just use enough power to grab pavement through the entire corner. Slowly accelerate all the way through and you wont break out of traction and be flying by the exit of the corner. Practice at very low speed at first of course, and build confidence slowly. Hanging out the inside knee really does make a difference too. After awhile coasting into a corner will start to feel suicidal compared to powering through.

When you coast into a corner, and make the transition from coasting to power while in the corner it's a sure way to wipe out. Get on the throttle just before you start leaning. The sudden change in the tire from coasting to pushing is breaking your traction. This is for either or both motors while cornering.

But yeah, the higher the power levels are the touchier it will get.

I just got back from riding that 6x10 all over the desert for an hour. Amazing how much skill it can take to ride 10 mph through cactus. But once I have a big enough pile of lipo, a gearmotor on the front hub and seperate throttles and controllers would be very nice for trials type riding.

Before I gave up my job and I had some spare cash and took holidays I used to do a few motorbike trackdays in Thailand and took a tour to the Pyrenees on my ZX6R with 121BHP at the back tyre, which is now sat in my garage a few thousand miles from me I agree I need to slowly ease the throttle on after apexing, but my god, the throttle on my ebike is more twitchy than my Crotch rocket. At low speeds it only takes a touch to go from almost nothing, to almost everything.... You put some power on, weight goes to the rear, unloads the front and it spins up real easy. Be interesting to see how running the same power on the front, without the power on the rear feels. I don't remember the front being quite so prone to spin up on the hardtail, running with the same motor in the front only, but i'm now running a higher current limit and have dual suspension (but fairly cheap).

I reckon that Fechters current limiting throttle circuit would be really useful on a high powered Ebike. The standard throttle when you've got a few KW of power with a torquey setup is really twitchy at low speeds.

I think I need to slow this bike down a little. I like the acceleration but the top speed is not so good for me, as I can't seem to use anything other than WOT. I've got no protective gear, brakes aren't as good as they should be and they are not known for their driving skills, road awareness and respect for the fellow road users in Shanghai.... Get lots of looks when I pull up to the lights and all the other cars and bikes catch up with me though, until the lights turn green 8)

 

[dogman dan]

Yeah, I forgot for a second, riding on the street is what you were talking about, while I was thinking on the track. Without curbs to hit, dump trucks to swerve around, and stop sign runners, sure you can power on in the corners.

Out in the street though, you are lots more likely to be tooling around the corner, and suddenly, EEK Better goose it and get out of this situation!

I should shut up for now, till my lipo arrives and I can speak from experience about a 2000 watt front hub. I just get my hot button pushed when people whine that the wheel spins so front hubs are no good. I just want to reply, learn to ride or stick to 300 watts. So far I have no problems at all with 1200 watts on a front hub on asphalt. In dirt, front hub is only a problem when the grades exceed 10%. Less than 10%, you wear out a tire fast, but otherwise the wheel spin is just something you adjust to.

Racing I expect the front hub to work fine though, since you will never slow below 25 mph on that particular track, and mostly will take the corners at 30 or more for non hairpins. So it's just all above wheel spinning speeds. On the start line, I may smoke some tire for a few feet for sure.

 

[cell_man]

For sure i wasn't trying to say a front hub running descent power is a bad thing, just giving my experiences which may well be very different from yours for various reasons. I reckon you should be hitting that bike with more than 2000W though. I reckon you should be looking at about 5000W. That would be more like it and would certainly give you a good top speed and good acceleration. 2000W is only gonna give you reasonably brisk acceleration.

Maybe you could even try a pair of the Mac motors, seeing as a pair would run to less than a single BMC and I'm sure I could help in some way to the cause, they might work out cheaper than you think

 

[dogman dan]

Be hard enough for me to afford 2000 watts. Unless some battery vendor is my sponsor..... By 5000 watts, I'd most likely be exploring dual hub drive, or just going straight to the etek motors.

 

[AussieJester]

or just going straight to the etek motors.

Far better choices than an etek on a bicycle Dogmanz too big and too heavy. RC motor setup is the better option mate, light with bundles of power 5900watts im pushing with a 44v 15ah lipo setup needs me a bigger speed controller to max out the motor to 6500watt My motor/reduction drive and battery pack weighs less than an etek(28lbs) alone, 11lbs for my pack and less for the motor for 8hp on tap Would give even the fastest ICE bike a run at the Spooky Tooth race mate

KiM

 

[dogman dan]

Yeah, clearly I'd need to have you build me a bike and ship it here, I'm so clueless about anything but the hubs. We'll see how much I shit my britches with just 2000 watts for now anyway. But really, unless you go to really heavy motors, I think 2000 watts is getting close to the practical limits of the hubmotors. So for more at that point dual hubs, or a hub and a RC motor starts to make some sense. The real issue is carrying the battery to blow all that wattage for a solid 10 miles. Then the way it's carried gets to be really an issue.

At some point, it's a motorcycle and will definitely need heavier rims, tires, frames, etc than even the DH bikes I think. Of course for a race, we'll gladly double any kind of practical limit.

 

[wasp]

i am regularly running 4000+watts through my 9C and sofar it's all good...

 

[AussieJester]

Your frock motors should be quick enough to dispatch the ICE bikes Dogman just need the controller and lipos
to do it I would look nto building yourself up a frame mate, good excuse to break out the welder and start practising anywayz?
Your a tradesman so i'm sure you will have no problems building a frame once you have had some time with the tools involved.

KiM

 

[dogman dan]

Long wheelbase would be nice, with decent suspension , and a nice fairing up front. That's for sure. Trouble is, I'm old and slowing down a lot, come home and flop every day.

 

[tycreek]

The 40mph number was sort of nagging me... I roughly calculated that it would hit about that number... but never held the throttle open long enough to find out until this morning. Previously I hit 38mph and backed off and before that 36mph two times, once each of my last 2 controllers. Since I sometimes reference 40mph as what I think the top speed of the bike is when people ask but haven't actually hit that number, I rolled down to a section of flat smooth street to find out if that number was a valid reference. I went easy up to about 27 until all clear as far as I could see and then held the throttle open until the CA speedo hit 41mph.

I know my CA speed is pretty accurate because I dialed it in from the chart numbers with a good GPS over the course of a few days. Anyway ... I feel better now using the 40mph reference when answering the "how fast can it go question". Still not sure what actual top speed might be but I did notice that mph ticker ramp up seemed to slow down as it approached that 40 mark. It was a pretty steady +2 each time I repeatedly glanced at the display at first and when I watched the last few increments they were about +1. I didn't pay much attention to the watts other than the CA was reporting something over 2.5kw.

Stock wires were hot at the axle exit, motor warm and I couldn't feel any heat difference when touching the controller. I would guess I was pretty close to melting the stock BMC wires and top speed! I'm sure speeds or loads above 35 mph or amps will cause failure sooner than later but figured since my new eparts were here that if something blew/melted I wouldn't be down for any longer than it takes me to get bike 2 ready to ride. And it was just a beautiful morning without a timeline!

IMO 40mph is just too fast for my ebike1. YMMV ...

 

[wasp]

i'm getting very close to cracking 50 and haven't even tried 25s yet...if i pick up a 150v controller i could try 30s and 35s muhaha hello 60

 

[Metallover]

Well I've hit 38mph with no major winds or hills.

With a tailwind the other day I got 39.9mph.

Down a hill today I got 42.3mph.

Can I join yer club?? :|

:lol: