Pikes Peak, Electric Mountain Climbers...

[comradegerry]

Thanks Remf for posting the link, it does seem like a great balance of man and machine effort, I am truly impressed with John's achievement.
The bar is indeed sat very high... Did I miss his finish time in the article?

[gtadmin]

...
I think: 1. speed 2. range 3. price are the 3 most important factors on an ebike followed by another big 3 : 1. reliability 2. aesthetics 3. Noise level (stealthiness)
...

I know I'm in the minority here, but this is almost my top 6, err ... in reverse

[veloman]

*not* if the race is strictly uphill with no or at least very little variation in slope which is the case here.
the multiple geared bike isn't gonna shift anyways.
those extra unused gears are nothing but dead weight.
you bet the lighter weight fixie's gonna win that race to the top.

FYI... on the PP run, the Opti's speed ranged from 14mph to 25 mph most of the time, but with periods over 30 mph and peak of 42mph.
That is a big range to cover EFFICIENTLY with only one gear.
A derailleur set, weighs what ?..1 lb ?
my money would be on the geared bike ! ... by a long way !

Hell yeah.

What race, even a hill climb is such a steady grade? There are not any! You will still vary speed by at least 50% over the course. Gears win hands down in 95% of events.

Tom Danlieson won Mt Washington on a geared road bike, not a single speed. When I rode that climb, even though it was quite steady at 12% average, I still varied from 5mph to 15mph, with peaks above 25mph . That's a HUGE range. I'd like to see an ebike do Mt Washington. 12% for 7.6 miles.

I don't hate on the Opti, other than it's price tag. I built a similar design bike, (see GT Ricochet in sig), but it only had a 450w motor. It still rallied up steep hills, AND cruised the flats efficently at 25-30mph with light assist. Mid drive crank designs are really fun to ride, in that you go through the gears, making it feel like a race machine moreso.

My 6 turn Mac is pretty damn efficient. Pulling 500 watts from the battery (400 to the tire), it gets about 26mph on flat ground with an aero tuck (zero pedaling). That's only about 50 watts more than me on my 18 lb road bike in spandex (low position, but not an aero tuck).

Even at 15-20mph, it still seems to be about 80% efficient, which is really impressive since it is designed to go 31mph.

[veloman]

I think i will get an opportunity to test ride this new optibike..and at that point i would like to continue my review. Because i think this new optibike is a "dream bike" even to a very skeptical and smart ES crowd.

You've shown a few times that you haven't a clue what ESers want in an ebike. So I'll go out on a limb and would say given the choice that most here would choose a Stealth bike over an Opti. Although I might choose the Opti if they throw in turn signal and brake lights.

Gary

Most here want power and speed, not efficiency. So I would agree.

When batteries cost 10 cents a watt hour, and weigh a couple pounds for a kilowatt hour, then I will lose interest in efficiency.

[neptronix]

Next year i want to do this. I live very close to pike's peak now, about 5 miles away. I want to make optibike cry. Any suggestions on what hub motor setup to use? am currently thinking 5305 or so...

[liveforphysics]

Next year i want to do this. I live very close to pike's peak now, about 5 miles away. I want to make optibike cry. Any suggestions on what hub motor setup to use? am currently thinking 5305 or so...

I think a hub is kinda the wrong path for this. Or, if you were to choose a hub, a magic pipe laced into the smallest diameter rim possible would be the best option.

This isn't a sprint, so thermal mass doesn't help you a bit, you need your heat production to match the rate of heat removal. Super heavily drilled vented Magic Pie, internal controller gutted and replaced with some internal cooling fans, and an 18fet controller turned down to maybe 50 battery amps on a 24s pack would be a very strong attempt at the peak if you wanted to go hub.

I smoked my X5 in 10mins of road racing, and it was well vented. You need something with a good design for this rather than something that relies on being a big pig boat anchor to survive bursts of high power.

[neptronix]

Now.... why would you chose a magic pie over the biggest crystalyte? any reason?
Would two MXUS/9C DD motors with a high turn count.. one on each wheel.. do the trick?

I wish i had the machining ability, space, or tools to put together something like your agni bmx. After a lot of searching, i have yet to find anyone into eBikes here either. For that reason.. hub motors make a lot of sense to me, if they work.

[gensem]

I think a hub is kinda the wrong path for this. Or, if you were to choose a hub, a magic pipe laced into the smallest diameter rim possible would be the best option.

This isn't a sprint, so thermal mass doesn't help you a bit, you need your heat production to match the rate of heat removal. Super heavily drilled vented Magic Pie, internal controller gutted and replaced with some internal cooling fans, and an 18fet controller turned down to maybe 50 battery amps on a 24s pack would be a very strong attempt at the peak if you wanted to go hub.

I smoked my X5 in 10mins of road racing, and it was well vented. You need something with a good design for this rather than something that relies on being a big pig boat anchor to survive bursts of high power.

Errm... wouldnt a dual MAC 200rpm running 80v 20amps each be way more efficient and have more torque? BTW they wont heat or break at under 2k. A little more weight than a single HS but with a hella lot more torque!

[neptronix]

That certainly is an option. However i am very concerned about braking; the regen braking is probably going to be critical on the way down, where some cyclists will hit 50mph or more. Imagine going down a 15%-7% grade on a bicycle for extended periods of time.

I am a big MAC fanboy but the lack of regen is an issue. I wonder if welding the clutch solid would be a proper workaround.

[liveforphysics]

Dude, riding down is the very least of your concerns. Rim brakes will be fine. Start with fresh pads, and you will maybe burn through most of the pad before reaching the bottom, but they will be fine and not fade.

Your #1 concern is getting rid of motor heat. It's 98% of the whole project. Followed by 1% in battery (big pile of LiPo), and 1% in mounting it on a bike.

[gensem]

If im not mistake regen ll generate more heat inside the hub, and if you dont trust that your disk pads ll last just add rim brakes too.

[veloman]

If im not mistake regen ll generate more heat inside the hub, and if you dont trust that your disk pads ll last just add rim brakes too.

Just drag a parachute.

I'm serious.

[MadRhino]

Imagine going down a 15%-7% grade on a bicycle for extended periods of time...

It stops to accelerate after a while, then you have a stable speed. If your bike is well tuned and there's no sharp turn, you can freeride most of the hill without touching the brakes.

[gensem]

I never went an offroad hill at 50mph but I did it on road without eletricity at over 50mph and I was fine without braking, granted there was no sharp turn.

[liveforphysics]

The downhill portion should not even be a spec on your thought horizon for focusing efforts at being successful at this event.

[gensem]

Dual MAC ftw

Dual 8t or 10t laced MAC with dual 9 fet controller 600-700 USD

32ah zippy 24s 4p = 1300 USD

2k budget and ready to kill!!! haha


*24amp hour should be more than enough just wanted to waste 2k on the motor+bat combo.

[veloman]

At what point does it become you are building a motorcycle and it's not a bicycle anymore?

This is an ebike class. I think there should be a weight limit, or power limit.

[liveforphysics]

I think this may be a bit out of the league of tiny geared hubs. I may be underestimating them, but if opti is running a solid gearing optimized 1800w setup (just a guess), I don't see any of the tiny hubs handling >~1.2kw input continuously. I know they are troopers about burst currents, but this isn't a burst current game.

For example, in the case of the x5, it's huge thermal mass protects it from bursts and lets you hotrod around safely in little 1-2min zips.
The moment you've got it up to temp, it's strictly a matter of waste heat (which means input power x 1-efficiency) and the ability to continuously shed heat into the air around you.

Something like a magic pie, featuring the robustness of direct drive, but a huge radius to keep the magnet speed up without gearing is going to be a big plus. It's also got a lot better ability to continuously shed heat, way more open design, big radius, lots of surface area of the critical places to cool. But most importantly, it's a really efficient motor design at lower speeds, more than any other direct drive hubmotor.

[amberwolf]

The 36V Fusin geared hub, run at 48V, can easily see 1200W hauling me and my trailer full of dog with DayGlo Avenger, even on the flats. It doesn't take very long to overheat to the point where it cuts out because the halls are too hot to work.

I imagine if I hadn't poured icewater over it and cooled it with the icegel bags I had with me, and then kept going, it'd've cooked it pretty well.

Maybe a ventilated and force-cooled MAC or BMC could do it; maybe even the Fusin if it was force-cooled the right way...but otherwise, no. There's just too many layers of stuff to try to get the heat out of the motor and magnets to the outside in a geared hub.


On the DD 9C motor, though, the same 1200W bursts don't overheat it, though it gets nice and hot, even unventilated it could probably take that power even continuously for quite some time, and properly ventilated (or force-cooled) it would easily do it and more.

[gensem]

I understand what you saying LFP, and I woulda be seeking for a DD if we were speaking about pikes peak 2010 race...
The major design flaw in geared motors a year ago were weak gears that would strip very easily.

But now the gears are way stronger, I hardly doubt anyone would be able to break the gears with anything under 3k input.
Now clutchs and axl are failing more because gears can handle alot more power, but im yet so many melteded MACs like we see with 9C and Clyt.
Lets pretend you ll be using 88v 20a in each hub, at that power level its nearly impossible to overheat the mac if you doing 20mph and up.

I do like the DD simplicity, and that why im trying to get a DD with 56mm magnets from Hal....
I wish MAC had the big geared ready too...


Is the Fusin much dif than a MAC?

[gensem]

I just tought that pike peaks would take 1h of continuos riding... hummm... my battery doesnt last much over 30m if im hauling ass with lots of hills. But im still always able to touch the motor even in very hot days. I was thinking about dual hubs, and not a single one...
I think the best would be an empirical test.

Since Neptronix now lives very close to Pikes he coulda test a dual MAC setup just for the fun of it.

[amberwolf]

Being able to touch the motor's *outside* doesn't tell you much about the inside, especially on a geared hub. It can be quie a lot hotter at the stator and magnets than it is on teh case. A DD hub is easier to tell, but still can be very different.

Is the Fusin much dif than a MAC?

Dunno. Most geared motors are very similar in basic design, but some details could be drastically different--enough to work in one application while another might not. Supposedly Fusin has improved their motors even more since mine was made (they offered a test/review unit of the new type to me but I can't afford the shipping).

The major design flaw in geared motors a year ago were weak gears that would strip very easily.

The major problem in a hill climb doesn't have a lot to do with the gears stripping, but with overheating because it can't conduct the heat out fast enough.

Gears can still strip if you apply enough power suddenly enough, or do that often enough, but unless they actually melt from the heat of the hillclimb, they probably won't break just because of the power itself, unless the hillclimb is really rough and requires lots of sudden bursts of power.

Lets pretend you ll be using 88v 20a in each hub, at that power level its nearly impossible to overheat the mac if you doing 20mph and up.

But you are not using 20A (battery current) if you are at 20MPH on the flats, probably not even 5-6A. 88V x 5A = only 440W, and it could probably take that all day.

However if you have a 20A battery current limit and do a hill climb, you will pull at least 20A *all the time*, probably, and that's 1760W at 88V (assuming no sag and full throttle). I doubt the motor will take that for the whole climb, *and* you will probably not be at 20MPH either--you'll be lugging slower, and the motor's phase currents will be a lot higher because it is unable to reach a good speed that it can keep them low.

[gensem]

Im aware that at low speeds all your watts goes to heat and that ll screw the geared hub even if its under 1kw of input power. But I find it really hard to believe watching some short youtube footage about the event that a dual geared hub setup eating 3,5kw of power(1760w x2) wouldnt be able to keep at least 20mph.



I vote for Neptronix and the real life test. eheh

[neptronix]

I will say this about the MAC. When i lived in Portland i would run it at 1500-2000 watts for long periods of time. I had a ~5 mile hill to climb quite often that took, hmm.. 10-15 minutes to get up, i think? 36 amps and either 38v nominal or 56v nominal were fed into the motor. It would get warm but not hot. I put the 9x7 MXUS DD through the same trial a few times and it got almost burn your hand hot from the trial. It also went at a slower speed. It's a hardy motor but i wasn't as impressed with it.

Temperature was hand-measured at the axle on the stator side.

I have never had to replace the original gears on the MAC despite severe and intentional abuse. Only problem so far is the freewheel side cover, which is probably the result of a wobbly freewheel + slightly bent cranks putting odd side-to-side loads on it.

The unfortunate thing is that you can't really ventilate the MAC motor and run it around all day. Junk will get into the grease. I guess it would be fine for a ~12.5 mile run though, just once.

That fusin geared hub does not match up to the MAC at all. It is about the size of a ebikekit or ampedbikes kit motor. The MAC is the same size as the BMC - right inbetween the MXUS/9C DD style and the small geared style. Looks like a mini crystalyte HS/HT.

[gensem]

LoL... i see the fusin problem... the mini geared motors are a joke compared to MAC, I had an ampedbikes one, so I know the diference.
Im mostly positive now that a dual mac would be able to get to the top and win.

Btw I was watching even more videos about the optibikes on pikes, and how in the name of christ could some hit the poor fella right at the start. Bikes were really slow... i was about to point fingers at opti, but I ll just let go because I wasnt the one being hit...