I can spin my clyte 409 on 100v with rim, tire, tube, spokes and freewheel ratcheting full throttle on less than 200w
SoCal Grange Race Roll Call!!!! Congrats PaulD!!!
- Thread starter etard
- Start date
Kurt
10 kW
The funny thing I do notice when you compare them to a hub motor. The turning the rc motor over wot no load might use 300-500w but when you put a load on it the Amps - watts don't shoot up like they do with a hub motor. So in the end my rc drive is way more energy efficient than my any hub drive I have owned.Even with what looks to be a lot of wastage for no load rpm.
Kurt
Kurt
Thud
1 MW
The stock wind on the CA120 is usless for E-bike application.
I will say, it pulls like a train.
(re-wound in a 6turn double 15g wire with a kv of 54 volted to 5krpms
)
I will say, it pulls like a train.
(re-wound in a 6turn double 15g wire with a kv of 54 volted to 5krpms
)John in CR
100 TW
MotorBicycleRacing said:
zombiess
10 MW
MotorBicycleRacing said:
I hope that's a joke because ebike hub motors are almost all over 6" If that was a rule you'd have a heart attack if someone shows up with a magic pie hub motor which is 12" in diameter and basically bans all ebikes.
Alan B
100 GW
It does seem funny that he banned almost all the ebikes except the one that won.
zombiess said:
i think that's his point, 8"+ only so magpie=aok.
thanx motorbyecycleracing, for being so predicticable which we all saw this inevitable reaction heading our way down main street from a mile away.
let it be recorded in the ES timeline that it was on this date (well the race date actually) that the torch was passed.
the date the gassers admitted defeat & bowed to the superiority of electric drive acknowledging their slo fade out to history.
dogman dan
1 PW
As the sport grows, we can eventually draw numbers that allow ogranizing an official ES bike race.
Thud
1 MW
I am pretty certain MBR is refering to non-hub motors in this instance. (or at least i hope so)
(that only leaves the 5" advanced motor if your looking to go crazy LOL)
http://www.cloudelectric.com/product_p/mo-140-01-4005.htm
I will say that Motoredbicycleracing is "the man" untill some one steps up & promotes another event in competition with his..then we'll have consumer buying power to support our favorite promoter.....till then any bitching or guffawing is babble. especialy from anyone who has never attended an event or intends to.
There is the impresion over the internet we are a bunch of geeks who are full of ourselves & think OSDS.
(i think statments like this are fuel for that point of view)
This race really settled one thing...PaulD has a beutiful set up & can run it into a corner much faster than Luke or Adin or anyone else on this particular track.....sounded like the unlimited AGK bike/rider combo was still untouchable (untill it broke that is) on the race track.
Be certain the gas powerd guys are getting as much or more enjoyment from the racing activity than the e-crowd's seeming inferiority complex.
Personaly, the whole us vs them thing is wearing thin on me...especialy when spoken by non-particpants in the gatherings
E-bikers have won nothing untill some one considers an e-bike over a gasser for recreation...(I am not 100% ellectric powerd to this day & would really enjoy racing my 50cc 2-stroke china girl on the track some day or even build me a 4-stroke thunder bike for grins)
I haven't met any A-holes in the motored bike pits yet.....Ellectric or gasoline powerd...but on the forum's there is a lot of yak yak that don't help anyone in any camp.
(that only leaves the 5" advanced motor if your looking to go crazy LOL)
http://www.cloudelectric.com/product_p/mo-140-01-4005.htm
I will say that Motoredbicycleracing is "the man" untill some one steps up & promotes another event in competition with his..then we'll have consumer buying power to support our favorite promoter.....till then any bitching or guffawing is babble. especialy from anyone who has never attended an event or intends to.
LMAO,
There is the impresion over the internet we are a bunch of geeks who are full of ourselves & think OSDS.
(i think statments like this are fuel for that point of view)
This race really settled one thing...PaulD has a beutiful set up & can run it into a corner much faster than Luke or Adin or anyone else on this particular track.....sounded like the unlimited AGK bike/rider combo was still untouchable (untill it broke that is) on the race track.
Be certain the gas powerd guys are getting as much or more enjoyment from the racing activity than the e-crowd's seeming inferiority complex.
Personaly, the whole us vs them thing is wearing thin on me...especialy when spoken by non-particpants in the gatherings
E-bikers have won nothing untill some one considers an e-bike over a gasser for recreation...(I am not 100% ellectric powerd to this day & would really enjoy racing my 50cc 2-stroke china girl on the track some day or even build me a 4-stroke thunder bike for grins)
I haven't met any A-holes in the motored bike pits yet.....Ellectric or gasoline powerd...but on the forum's there is a lot of yak yak that don't help anyone in any camp.
auraslip
10 MW
- Joined
- Mar 5, 2010
- Messages
- 3,535
Sounds like you are talking about me, so let me clarify; it's great that everyone is having fun. But at a certain point electrics are going to be cheaper and out perform gas. Considering that I spent only $1k on my latest build that does 0-30mph in seconds and wheelies all the way there, it's going to be hard for amateur motorized gassers to compete vs. amateur electrics. Especially when the level of difficulty of builds is so low on an electric.
It should be interesting to watch ICE and electrics push their bikes to the limits to try to out compete each other. In the end it's just a friendly competition, and anyone taking it too seriously is missing the point. This is all in good fun, and the competition between the two just makes it more fun. That being said, the officials probably should make an effort to even the playing field. It's easier to strap a giant electric motor to a bicycle frame than it is to strap a giant gas engine.
It should be interesting to watch ICE and electrics push their bikes to the limits to try to out compete each other. In the end it's just a friendly competition, and anyone taking it too seriously is missing the point. This is all in good fun, and the competition between the two just makes it more fun. That being said, the officials probably should make an effort to even the playing field. It's easier to strap a giant electric motor to a bicycle frame than it is to strap a giant gas engine.
Thud, fully agreed... 8)
Thud said:
zombiess
10 MW
Toorbough ULL-Zeveigh said:zombiess said:
i think that's his point, 8"+ only so magpie=aok.
thanx motorbyecycleracing, for being so predicticable which we all saw this inevitable reaction heading our way down main street from a mile away.
let it be recorded in the ES timeline that it was on this date (well the race date actually) that the torch was passed.
the date the gassers admitted defeat & bowed to the superiority of electric drive acknowledging their slo fade out to history.
Just chill out mate. MotorBicycleRacing probably made that comment without realizing what he was saying so cut him some slack. He does go out of his way and invests his own time into putting on these events. I don't think attacking him is correct approach. No need to create any kind of divide, this is about having fun and he fully proved that to me by letting me run with the gassers when I didn't make the 2nd ebike race. I also didn't really see much racing, just people having fun going around a track. It's more of a track day event than a race. If it was real racing I'd never go, too many assholes and attitudes in real racing.
Luke's bike should be the last thing anyone worries about, he breaks pretty often, only worry about it being unfair when it actually runs correctly, has paul driving it and it laps the AGK bike twice in a 12 lap heat, until then relax and have fun. Not like there are a ton of ebikes. Everyone I met at the event was great, lots of fun and I will go again.
Thud
1 MW
Auraslip,
Actualy no, it was a gentle "shut up" to John & thoorbough's antagonizing one of only 2 guy's activly promoting the cheapest form of motorsport racing on the planet. They can spout all the reteric in the world....but a few of us actually go to the track & represent the e-bike scene to the world....this continuous flack does nothing to promote any cause.
For the record, $1k is about triple the budget for most motored bike builds on the track.(my china 2-stroke cost $100 & initial out of pocket is as far as the average consumer looks)
We are getting Zero converts from the gas bike scene. But you are spot on regarding the fun.
I like the rilvalry between gas & e-bikes also, but name calling,constant verbal aggresion & general lack of "class"on the open forums will sour folks from even attempting to attend an event (that goes dubbley to the promoter) I have seen a few guys not bother attending because they didn't want to be in the drama.
After meeting Neil at the track, I can assure you he is a stand up guy (who apears socialy awkward & abrasive on the forums) and genuinly loves bikes & seeing a group of guys come together & have a great time.
THAT is what its all about.
Well spoken Thud, Zombeiss, Y-pedal, some talk on this thread comes off as insecure. Occassionally some of it pops up on the 'MotorizedBike' forum but other members redirect it pretty quick such as you 3 are doing here.
Ha, ha Have 'em pedal the 1st lap! Go crazy with a Cloud electric motor! "Annoying evangelistic e-bikers!" Love it.
Now, to discuss Kurt's quality question.
The context of whether it's commute use, race testing, on a dyno, or a separate reality (theory) matters. Though I've probably read many of the threads discussing the voltage/amp trade offs, plus excellent references, such as this one by Miles. A wide variety of conditions and remarks surrounding those can send one down the 'garden path' so to speak.
http://books.google.co.uk/books?id=...&resnum=1&ved=0CDMQ6AEwAA#v=onepage&q&f=false
I've memorized the above chapter1 and scrutinized ES for several years. I'm just now starting to grasp the voltage/amp concept. Sure, trading the 2 results in theory, in similiar power levels, ect . . ect. . . Yet playing with the volt/amp with varied windings at fixed volt limitations trackside is still an expensive proposition (understatement). What hasn't been addressed often enough, is the 12S 50V ceiling, often dictated by sensorless RC motors, in conjunction with various windings.
Somewhere, Recumpence, a respected contributor here, makes the point that lower windings, say a 5 wind vs a 10 wind, tolerates more amps. Good, in the mix rpms increase and more efficient power is developed. However, inductance is low in the 5 wind which is suspect in being problematic to controllers. As well, generally an additional reduction stage is needed before the rear wheel gets driven, thus negating some of the efficiency gains. Some of us have tried to find a way around the extra reduction by useing lo-Kv motors. Example, my 84Kv 8turn Astro3220. (and in the realm of possibility due to a new 16S Fighter Cat ESC)
Now the Astro3220 8turn wind is rated for (and can handle) 63burst amps @ 94V but I haven't gotten involved with installing halls so had to use the CC HV160 limiting myself to half the volts using 12S/48V. Whether my lack of hi-voltage was compensated by higher amps than an 8turn could tolerate or somethingelse, such as not up to the job epoxy, I don't know. The 5turn Astro is rated for 100burst amps. Maybe it could've handled the higher amps better @48V, but then again, RWP's 5turn fried and died at the Willow Springs race.
This might fill in a few gaps, but really, the experts need to chime in. Best to 'ya
Gotta step in for MBR, he invites us e-bikes to piggy-back his motoredbicycle races, loses dollars on the event, and takes abuse from some on forums, and yes generally the ES forum, from guys who don't attend.
(PS Thud, is "wonky" akin to "wack-a-do?" )
Ha, ha Have 'em pedal the 1st lap! Go crazy with a Cloud electric motor! "Annoying evangelistic e-bikers!" Love it.
Now, to discuss Kurt's quality question.
Yes.
The context of whether it's commute use, race testing, on a dyno, or a separate reality (theory) matters. Though I've probably read many of the threads discussing the voltage/amp trade offs, plus excellent references, such as this one by Miles. A wide variety of conditions and remarks surrounding those can send one down the 'garden path' so to speak.
http://books.google.co.uk/books?id=...&resnum=1&ved=0CDMQ6AEwAA#v=onepage&q&f=false
I've memorized the above chapter1 and scrutinized ES for several years. I'm just now starting to grasp the voltage/amp concept. Sure, trading the 2 results in theory, in similiar power levels, ect . . ect. . . Yet playing with the volt/amp with varied windings at fixed volt limitations trackside is still an expensive proposition (understatement). What hasn't been addressed often enough, is the 12S 50V ceiling, often dictated by sensorless RC motors, in conjunction with various windings.
Somewhere, Recumpence, a respected contributor here, makes the point that lower windings, say a 5 wind vs a 10 wind, tolerates more amps. Good, in the mix rpms increase and more efficient power is developed. However, inductance is low in the 5 wind which is suspect in being problematic to controllers. As well, generally an additional reduction stage is needed before the rear wheel gets driven, thus negating some of the efficiency gains. Some of us have tried to find a way around the extra reduction by useing lo-Kv motors. Example, my 84Kv 8turn Astro3220. (and in the realm of possibility due to a new 16S Fighter Cat ESC)
Now the Astro3220 8turn wind is rated for (and can handle) 63burst amps @ 94V but I haven't gotten involved with installing halls so had to use the CC HV160 limiting myself to half the volts using 12S/48V. Whether my lack of hi-voltage was compensated by higher amps than an 8turn could tolerate or somethingelse, such as not up to the job epoxy, I don't know. The 5turn Astro is rated for 100burst amps. Maybe it could've handled the higher amps better @48V, but then again, RWP's 5turn fried and died at the Willow Springs race.
This might fill in a few gaps, but really, the experts need to chime in. Best to 'ya
Gotta step in for MBR, he invites us e-bikes to piggy-back his motoredbicycle races, loses dollars on the event, and takes abuse from some on forums, and yes generally the ES forum, from guys who don't attend.
(PS Thud, is "wonky" akin to "wack-a-do?"
)
Seeing as MBR is the only game in town, I'll keep my mouth shut.
If you know me at all, you'll know how hard it was to type that sentence. :|
If you know me at all, you'll know how hard it was to type that sentence. :|
Thud
1 MW
I'll chime in on this one also:
but it is important to know your particular set up to reailze its maximum threashold regarding input.
look over the astroflight chart for the 3220:
View attachment 3220.pdf
interesing how the different winds all add up the the same amount of power outputs.
Any time your putting more than 4500 watts of energy into that motor you are producing heat the motor cannot disapate.... you will have to lower the input for a time, or add active cooling we can raise the output #s by a bit...but as John in cr has said a few times....watts are watts. any time you can maximize your power density with voltage & never overlaod with amps....your doing it right (imho)
Lets do the math. Sosauty running 12s x 165 amps=7326 watts (nearly a 60% overload) which can be tollerated for a short burst easy enough, but needs to be addressed for the time/load average that happens on the race track to keep the thermal limits in the safe zone
the lower wind motors don't "tolerate" higher amps, they absolutly require it to deliver the same performance as a higher wind on higher voltage & lower amperage. Once resistance if calculated, the math is exactly the same for the thermal limits for any 2 identical motors.
Since we are allways overloading these small motors on e-bike applications we need to be more mindfull of higher voltages. especialy with smaller motor wire required for a high turn count high voltage motor. Thermal runaway seems to happen faster on the light wire even though the math is the same....
simple isn't it LOL!
Agian, Yes.
but it is important to know your particular set up to reailze its maximum threashold regarding input.
look over the astroflight chart for the 3220:
View attachment 3220.pdf
interesing how the different winds all add up the the same amount of power outputs.
Any time your putting more than 4500 watts of energy into that motor you are producing heat the motor cannot disapate.... you will have to lower the input for a time, or add active cooling we can raise the output #s by a bit...but as John in cr has said a few times....watts are watts. any time you can maximize your power density with voltage & never overlaod with amps....your doing it right (imho)
Lets do the math. Sosauty running 12s x 165 amps=7326 watts (nearly a 60% overload) which can be tollerated for a short burst easy enough, but needs to be addressed for the time/load average that happens on the race track to keep the thermal limits in the safe zone
the lower wind motors don't "tolerate" higher amps, they absolutly require it to deliver the same performance as a higher wind on higher voltage & lower amperage. Once resistance if calculated, the math is exactly the same for the thermal limits for any 2 identical motors.
Since we are allways overloading these small motors on e-bike applications we need to be more mindfull of higher voltages. especialy with smaller motor wire required for a high turn count high voltage motor. Thermal runaway seems to happen faster on the light wire even though the math is the same....
simple isn't it LOL!
Hey Thud,
I had that Astro geared so low it never pulled 140+ amps except for brief spikes; see the radar speed for #105 (31mph). In practice the CA settled at 120amp up the straight. Your example still holds true as my voltage was up close to 48V and pulled near 7K.
What I have yet to come across, is at a fixed lo 12S/44-48 voltage, does the lower wind maintain its' cool, thus continous power level, at say at a fixed amp level
The question can be restated as; Does the higher wind when fed lower volts, still have the same amp ceiling as if fed double the volts
Let's pin down this fickle question:
Would have selecting a 5turn to run 12S "maximised my power density?" or can the higher wind run higher amps to compensate for the lower voltage? (the Astro folks I talked to, generally very helpful, sidestepped this, "We'd have to put it on a dyno."
It's a $700 question :wink:
There you go again MBR, getting everyone frocked off. You should try teaching 7th grade math to a bunch of pre-teen girls. I've retired but it was fun for 25 years 8)
I had that Astro geared so low it never pulled 140+ amps except for brief spikes; see the radar speed for #105 (31mph). In practice the CA settled at 120amp up the straight. Your example still holds true as my voltage was up close to 48V and pulled near 7K.
What I have yet to come across, is at a fixed lo 12S/44-48 voltage, does the lower wind maintain its' cool, thus continous power level, at say at a fixed amp level
The question can be restated as; Does the higher wind when fed lower volts, still have the same amp ceiling as if fed double the volts Let's pin down this fickle question:
Would have selecting a 5turn to run 12S "maximised my power density?" or can the higher wind run higher amps to compensate for the lower voltage? (the Astro folks I talked to, generally very helpful, sidestepped this, "We'd have to put it on a dyno."
It's a $700 question :wink:
There you go again MBR, getting everyone frocked off. You should try teaching 7th grade math to a bunch of pre-teen girls. I've retired but it was fun for 25 years 8)
MotorBicycleRacing
100 W
- Joined
- Aug 21, 2011
- Messages
- 150
Sorry to get everyone so frocked offzombiess said:
I already said that any hub motor was OK if you were paying attention.
Just talking about the external motors like what Luke and PaulD were running.
PaulD's bike is fine and was a blast to briefly ride at the track.
Farfles bike was fine and his hub motor is way bigger than 8"
Only bike affected is Lukes and I hope he runs it in the Unlimited class next race
and doesn't break it for the 3rd? time running.
I mean come on, Lukes bike went 67 mph down the front straight and probably
could have gone faster.
I already made the fast 20 hp gas bike Unlimited so there is no difference in the
way I am treating gas or ebikes.
The fast 20 hp gas bike being in the Ultimate race was a mistake and when I saw
that AGK was on his fast bike I just went with it.
If he had of finished and won he would not have counted just like the very fast
#50 Moped that I let run with the 4 strokes.
PaulD would have still won.
What was I supposed to do? Black flag him? Not going to do it.
It's a fun race first and foremost and that will decide how a lot of decisions are made.
Fantastic turn out by all you ebike guys.
Everyone had a frocking good time from what I saw so please come back to
the next race on Saturday April 7th 2012
Just taking it one race at a time and refining the direction as we go.
Please email me any suggestions to improve the next race.
PS: There are people coming at me from every angle with all kinds of crap.
One prominent motorbike guy only wants me to only run "legal" 50 cc and under
bikes and called me a pimp. Was accused of ruining the motored bike scene by
including the big fast bikes.
Some of the competitive faster riders want me to limit and exclude the slower
"fun" riders because they are in their way.
Some of you ebike forum guys are annoyingly evangelistic and take yourselves
way too seriously.
A few people mad at me for not doing it their way.........
Arizona guys are pissed off because the CA race competes with the Death race.
Dave31 said very clearly both at the Willow Springs race and later that there
wasn't going to be a Death race this year.
I will say it again for all you guys who didn't quite hear me.
Dave31 said very clearly both at the Willow Springs race and later that there
wasn't going to be a Death race this year.
How do you compete with a race that you were told wasn't going to happen????
A lot of crap, almost enough to say frock all of you but WTF I will try it one more
time on Saturday April 7th 2012.
You gots 5 months advance notice. That enough for everyone?
etard
100 kW
I think many would agree that Luke's bike is borderline motorcycle, you gotta give the guy props, he beats the living snot out of components and WHEN they fail (not if :lol: ), he pedals around with a smile on his face in full race leathers. That's the kind of guy you want representing this forum. if you watch the videos of him disappear from the other riders down the straight, you will notice how different this bike is than the others. However, Luke remained within the constraints of an electric Bicycle by limiting the output and strapping bicycle tires and components on. It may be easier and and more forthright to say you can have unlimited power but you have to have bicycle tires, brakes, etc... That's in the distant future though, I keep seeing angry and off-hand comments by people who have never attended an event toward Motorbicycleracing. If you want to support the cause IN A POSITIVE MANNER, either sponsor a guy that is going, or send some money to SoSauty for prizes and such. If more people would join in the fun, than we might actually have enough riders to make seperate classes, until then STFU!
LEt's see more racing footage!! Cmon, I saw Lyen holding a camera from the stands, lets more videos and pictures posted.
LEt's see more racing footage!! Cmon, I saw Lyen holding a camera from the stands, lets more videos and pictures posted.
Thud
1 MW
SoSauty,
at the risk of further thread derailment I'll give you my take on your motor failure this time out.
EDIT: i did the math for a 5 turn astro.....will add the corrections for an 8 turn will actually was running.
All of the Astro's are rated for 4.5kw of continuous power output.....which is ironicly close to the maximums i measure on the simular sized outrunners.
your 5 turn motor is optomised to spin 8100 rpms at 60v. To arive at these performance #s, Lets assume Astro sent them through empirical tesing & not lucky guesses & over optomistic assumptions.
At 44.4 volts (i use nominal, as batterys sag to that some time in the race I am sure) your motor is already behinde the max efficancy range targeted by astro spinning at only 5994 rpm's. almost 25% below ideal rpms for the 93% efficancys astro advertises.....(warning flag #1) this motor is not producing data sheet power levels.
8 turn optomised to operate on 96v. you were spinning it at 3729 rpms, less than 50% of its design intent.
The motor is also constrained by wire gage & maximum amps...burst & continuous. It is stated to accept a continuous 75 amps @60v (4.5kw of power) assuming again (a dangerous trap door I know) Astro optomises wire gage for the different winds, we should pay carfull attention to their recomendations. running at an unloaded straight away draw of 120 amps calculates to 5328 watts of input...that figures out as a 16% overload on the only section of track it had to recover. (this is the back breaker )
8 turns require smaller wire diameter=less amperage carrying capacity before thermal limits are reached- at 120amps you are roughly 2.5x over the continuous ampreage ratting for that wind based on the astro chart)
overveiw:
Over feeding wattage into a motor running well below its optimal efficancy range.....bad for motors,pets & spouses. even with your monster cooling fins you were set up for failure.
What was your gearing again?
By my calculations you should have been running a minimum of 9.3 to 1 gear reduction for 30mph on the track. if you were geared higher I suspect your motor was running even worse regarding efficancy & was lacking the hp to beat the wind resistance wall that occurse near 30mph (its a real barrier for the pedal guys as well as us powerd guys. efficancys plummet after the 30mph mark. (refigure for optomised set up & a 24" wheel lands us at 16.5-1 for 35mph)
If you are constrained by voltage I would set up thusley:
a 4 turn motor with a kv of 169 wound with wire that will sustain 94 amps at the 12cells in your pack....now you need to gear so that your not drawing more heat generating power than the motor can disapate.
Astro can tell you the max burst for that wind for 1 minute.....idealy you will only be in that range for a few seconds during accelration & be in the max efficancy range for a majority of the lap. & have at least a short section for some recovery at least once a lap. Speed be dammed.....this is the beauty of the slipper clutch...the ability to never load a motor into the suicidal zone of wasted watts.
I know its easy to show a burst of 10kw on an CCHV160 logging graph....it means nothing on the race track...in touscon I was drawing less than 60 amps off the battery on the main straight with twin motors....& almost 4 times that off the starting line (that was the demise on the controller. I should have pedaled more!)
I hope i have all that right LOL....I am the dumbest controller wrecker on the internet! (but the only motor I ever burned was the single turnigy 180 that was suddenly over geared when a controller failed in tuscon)
at the risk of further thread derailment I'll give you my take on your motor failure this time out.
EDIT: i did the math for a 5 turn astro.....will add the corrections for an 8 turn will actually was running.
All of the Astro's are rated for 4.5kw of continuous power output.....which is ironicly close to the maximums i measure on the simular sized outrunners.
your 5 turn motor is optomised to spin 8100 rpms at 60v. To arive at these performance #s, Lets assume Astro sent them through empirical tesing & not lucky guesses & over optomistic assumptions.
At 44.4 volts (i use nominal, as batterys sag to that some time in the race I am sure) your motor is already behinde the max efficancy range targeted by astro spinning at only 5994 rpm's. almost 25% below ideal rpms for the 93% efficancys astro advertises.....(warning flag #1) this motor is not producing data sheet power levels.
8 turn optomised to operate on 96v. you were spinning it at 3729 rpms, less than 50% of its design intent.
The motor is also constrained by wire gage & maximum amps...burst & continuous. It is stated to accept a continuous 75 amps @60v (4.5kw of power) assuming again (a dangerous trap door I know) Astro optomises wire gage for the different winds, we should pay carfull attention to their recomendations. running at an unloaded straight away draw of 120 amps calculates to 5328 watts of input...that figures out as a 16% overload on the only section of track it had to recover. (this is the back breaker
)8 turns require smaller wire diameter=less amperage carrying capacity before thermal limits are reached- at 120amps you are roughly 2.5x over the continuous ampreage ratting for that wind based on the astro chart)
overveiw:
Over feeding wattage into a motor running well below its optimal efficancy range.....bad for motors,pets & spouses. even with your monster cooling fins you were set up for failure.
What was your gearing again? By my calculations you should have been running a minimum of 9.3 to 1 gear reduction for 30mph on the track. if you were geared higher I suspect your motor was running even worse regarding efficancy & was lacking the hp to beat the wind resistance wall that occurse near 30mph (its a real barrier for the pedal guys as well as us powerd guys. efficancys plummet after the 30mph mark. (refigure for optomised set up & a 24" wheel lands us at 16.5-1 for 35mph)
If you are constrained by voltage I would set up thusley:
a 4 turn motor with a kv of 169 wound with wire that will sustain 94 amps at the 12cells in your pack....now you need to gear so that your not drawing more heat generating power than the motor can disapate.
Astro can tell you the max burst for that wind for 1 minute.....idealy you will only be in that range for a few seconds during accelration & be in the max efficancy range for a majority of the lap. & have at least a short section for some recovery at least once a lap. Speed be dammed.....this is the beauty of the slipper clutch...the ability to never load a motor into the suicidal zone of wasted watts.
I know its easy to show a burst of 10kw on an CCHV160 logging graph....it means nothing on the race track...in touscon I was drawing less than 60 amps off the battery on the main straight with twin motors....& almost 4 times that off the starting line (that was the demise on the controller. I should have pedaled more!)
I hope i have all that right LOL....I am the dumbest controller wrecker on the internet! (but the only motor I ever burned was the single turnigy 180 that was suddenly over geared when a controller failed in tuscon)
liveforphysics
100 TW
Thud said:
This simply is not correct my friend. For our power levels <10kw, staying sub 50v has a lot of advantages. If you look at a Zero or a Brammo or a Gem car or a Think EV, or a forklift, or an electric Kart, or many many other examples, they run lower voltages than most of us do on our Ebikes.
It's really simply a matter of trading larger wire sizes to the motor for additional battery management complexity.
An exception would be if you're using a controller fitted with parts for higher voltages that would be at a severe resistance penalty to operate at lower voltages. This goes along with choosing your parts to work together as a system though, which is the key to a good performing system regardless of the voltage or anything else.
My next race bike will likely be under 60v. I think I can actually get better performance with the pieces I'm thinking of using by setting up a system there.
Thud
1 MW
Derailment continues:liveforphysics said:Thud said:
This simply is not correct my friend. For our power levels <10kw, staying sub 50v has a lot of advantages. If you look at a Zero or a Brammo or a Gem car or a Think EV, or a forklift, or an electric Kart, or many many other examples, they run lower voltages than most of us do on our Ebikes. (& not one of them utilise an Astro flight or an HV160...)
It's really simply a matter of trading larger wire sizes to the motor for additional battery management complexity. (
An exception would be if you're using a controller fitted with parts for higher voltages that would be at a severe resistance penalty to operate at lower voltages. This goes along with choosing your parts to work together as a system though, which is the key to a good performing system regardless of the voltage or anything else.
My next race bike will likely be under 60v. I think I can actually get better performance with the pieces I'm thinking of using by setting up a system there.
Luke,
Glad you dropped in on this as you can enlighten & articulate the sublties of these senario's far better than i can.
taking your statment literly, are you saying the motor was alright running below its optomised voltage at higher amperages that it was rated for, for such an extended length of time(rhetorical)
lets stay within the constraints of the Astro Flight motor set up the conversation was focusing on....& using controllers that any joe blow wannabe can attain. (the hv160) what would the ideal senario be? in your opinion....remember we are constrianed to 12cells here.
given my preferance for wye terminated motors & the astro can only reasonably maintian 4.5kw of output.....I would select a wind to spin in the sweet spot at max throttle & gear acorodingly..loaded so that I reach maximum safe operating temprature as i crossed the finish line. all things being equill what else is there to factor in?
Hillhater
100 TW
i hesitate to comment since i am not involved, but ...MotorBicycleRacing said:
Have you considered a " Bracket Racing" format. ??
That would allow any form of motor /bike /power etc, whilst separating the slow guys out from the fast ones, and allow everone to race against similar paced bikes .
JMHO. :?
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