Pikes Peak, Electric Mountain Climbers...

[neptronix]

Hm...
Is it true that higher rpm = higher efficiency?
Which in turn = higher power per total volume of the motor.. ?

Seems like hub motors, never spinning too much faster than 1000rpm, seem to be at the lower edge of this efficiency spectrum... that's why stupidly high volts on a my little pony sized bike wheel wins.

 

[John in CR]

... so it's imperative that the bike is still pedalable though. At the very least, pretend to

I agree, they definitely need pedals on an ebike. They're for when you try to stretch the range too far and run out of go juice. FWIW, I have just enough pedal clearance on my ebike to comfortably pedal going straight, and my pedals go horizontal while riding. If I get tired of that position I just rotate them 180° for the other foot forward. That results in more clearance in turns than some motorcycles. A manly racing ebike has to slow down for the curves anyway, so pedal strike should never be an issue. If the switchbacks are sharp enough to require a significant speed reduction, then helping accelerate back up to speed is where pedal assist would be best used, because that's where the motor could best use help. We're pretty good in the torque department, but we suck in terms of continuous output, so gear accordingly and save your strength for those hardest sections. Without going full recumbent, the 50wh or so you could add during a 30min run is far less than what the wind will eat up with a position conducive to pedaling. That's why the rules about bike dimensions are so specific for race cycling, because they want to retain the typical upright bike shape. Without those rules, bikes would be totally different.

 

[LI-ghtcycle]

Pedal strike!? What's that!!

(Beard not included!) :wink:

 

[Whiplash]

For me it is all about the continuous torque capacity for the motor. If you can gear an RC such that it stays within the maximum continuos torque it is able to sustain you should be okay.

Nope.


If you need 1.5kw-2kw continuous output, and you've got a 93% efficient RC motor, you're never going to get up the mountain unless you've got water flowing into it or something similarly extreme to cool it.

Luke, I normally agree with everything you say, but this time I have to differ. I have a small motor and run at a max of 1500 watts for now. This combo has pushed me for several miles up the same grades at pikes without any active cooling of any kind while the motor barely got hot to the touch?? I do have gear selection that allows me to rev the motor instead of lugging it and I think that is partly the reason it works. I am confidnt with a heat sink/ cooling fan I can run at at least 25mph up that hill and use only about 12-1300 watts doing it but we will see, I am hoping to make the race next year..

 

[neptronix]

Hmm.. how many gears do you have? sounds like you're doing something similar to what optibike does;
keeping their motor well cooled and at peak efficiency is how they win.

Several miles is different from 25.. hehe.

I agree with luke here though, the small can motors produce a hell of a lot of power per square inch / weight but their cooling surface area is quite small.

I wonder what the peak efficiency for those motors is + how broad is the peak eff. area..

Do RC guys dyno these motors .. ?

 

[AussieJester]

Pedal strike!? What's that!!

(Beard not included!) :wink:

hehehe that is the exact type i picture when they say they are a 'bent' rider
a podgy unfit lookin' old guy in lycra with a bush beard and goggles teehehee (BiGMooSE do you own a recumbent? LoL)
... oh, that isn't actually you is it LI-ghtcycle? no offence intended if it is
your a good luookin fella if it is you

KiM

 

[amberwolf]

hehehe that is the exact type i picture when they say they are a 'bent' rider
a podgy unfit lookin' old guy in lycra with a bush beard and goggles teehehee (BiGMooSE do you own a recumbent? LoL)

Yes, he does. He even posted a pic of it (and him, I think) somewhere around here.

I almost qualify, but the beard's not bushy and all I've got is regular glasses instead of goggles. :lol:

 

[AussieJester]

I've got is regular glasses instead of goggles. :lol:

googles = glasses (of any kind) tiz what i call them
my ex-Dutch Missus started it off years ago, always called her glassess goggles
sort of stuck i guess... Good news AW, all ya need is some LYCRA and your
IN!!! we can excuse the non bush beard. least your making an effort buddy

KiM

 

[liveforphysics]

Pedal strike!? What's that!!

(Beard not included!) :wink:

Now that is the ultimate recumbent operator. OUTSTANDING BEARD! A beard of that magnitude enables operation of even streamlined recumbents.

 

[AussieJester]

I believe the bushy beard on Bent RiDeRs is an aerodynamic aid Luke when they are in their
reclined position, the beard lays between chin and chest creating a more aerodynamic
form :: nods confidentially :: that 'cavity' below the chin and chest effectively
removed from the equation, i think some wind tunnel test should be conducted
with bushy bearded and non-bushy bearded (if we can find any ) riders to see the 'EPiC' magnitude
of effectiveness the bushy beard really is in the aerodynamic make up of the e-bent bushy bearded rider!

KiM

 

[bigmoose]

hehehe that is the exact type i picture when they say they are a 'bent' rider
a podgy unfit lookin' old guy in lycra with a bush beard and goggles teehehee (BiGMooSE do you own a recumbent? LoL)KiM

I almost missed this! Here I am on my KMX... bushy beard, check; googles, check; podgy, sort of double check lycra.... not till I steal the michelin tire man's suit!!

 

[AussieJester]

LoL@ Michelin man suit :lol: ... You definately tick all the boxes other than the Lycra BiGMooSE! The side profile also shows exactly
what i was talking about with the bushy beard being an aero dynamic aid
cutting out the the space below chin and chest that would without a shadow of
a doubt act like a a reverse parachute! With this irrefutable proof bushy beared bent riders
for the sake of aero effiecency GROW YOUR BEARDS gentlemen

KiM

 

[docnjoj]

Hey AJ
I resemble that remark!
otherDoc

 

[AussieJester]

Hey AJ
I resemble that remark!
otherDoc

LoL why am I not surprised...

KiM

 

[Jay64]

So, is anyone interested in going up there for some pre-event testing?

 

[Alan B]

Is the road normally open to bicycles?

 

[neptronix]

I'll look into it and find out.
I've been told you can go up the back way however.

 

[Jay64]

When I go up to Colorado I'll have my race van with me. We can drive that up to a point and race up and back to the van and stash them in van before any cops show up. Download data on the drive back down.

 

[neptronix]

That's actually what i planned to do, minus the van, add a sedan..

There are plenty of mega hilly mountains around too even if you couldn't pull that one off.

 

[LI-ghtcycle]

Pedal strike!? What's that!!

(Beard not included!) :wink:

hehehe that is the exact type i picture when they say they are a 'bent' rider
a podgy unfit lookin' old guy in lycra with a bush beard and goggles teehehee (BiGMooSE do you own a recumbent? LoL)
... oh, that isn't actually you is it LI-ghtcycle? no offence intended if it is
your a good luookin fella if it is you

KiM

Hehe not me, just a quick pic of a bent rider with a 'tude looking rumble or something! (I don't wear lycra, but beards are kewl! Mine isn't bushy enough though for the aerodynamics yet! Workin' on that one! :wink: )

I couldn't find any pics of mine so I posted that one, but I'm sure I could get his phone number for ya AJ!


Oh and you gotta shush about the beard streamlining secrets or the bent police are gonna show up at your door!

 

[LI-ghtcycle]

So, is anyone interested in going up there for some pre-event testing?

Man, if I have the time, I would be down for some testing!\

I don't live too close, but once I get my ride sorted out it would certainly be a great test!

I dunno if I have enough juice for that many miles climb, might need to get a few more packs from HK first . :wink:

 

[neptronix]

I've calculated 30AH of 24S would be the absolute minimum....

$1200 + shipping..

 

[LI-ghtcycle]

I've calculated 30AH of 24S would be the absolute minimum....

$1200 + shipping..

YIKES!

Sounds like time for a mid-drive? :wink:

Can still be something way cheaper than a Opti, is that using a single geared hub motor?

 

[neptronix]

That's an optimistic case based on running two golden motor wheels in tandem.

I'd love to run a geared motor. A DD has ~5% better peak efficiency though,so a mid-drive DD would be better..
But that CVT would eat into the power somewhat.

We're only talkin' bout a few percent here and there..

 

[amberwolf]

How many Wh is that? (30 x 3.7 x 24 = 2664?) And what current draw peak and sustained does the setup you're thinking of require?


I'm wondering if large enough laptop-cell packs could manage it? Cuz those would be cheap to make, relative to RC LiPo. As long as you also have some sort of cell-group-level LVC (like the new Methods' units) it should be safe enough.