20% Hill Climb at speed using a Hub motor

Hi

Had a mail from Steve Head with the Dirt monkey, he has been out and about in his home town, he has put up a very impressive hill climb on his brushless un geared hub motor! anyone who questions hub motors ability to climb need to check this out.

He tackles a steep 20% grade, it looks steep on the video which means it really is steep, he takes the chain off before the run so you can see he isnt peddling.

Again quality is better if you download it and watch it with the google video player, enjoy!

http://video.google.co.uk/videoplay?docid=6555036344853915426

Knoxie

That was an impressive climb.
nice vid too, the dirt monkey is a really nice bike, was one of the reasons i bought some kit and had a go myself to be honest, we need more on the bike from Seve, can you get him on the forum knoxie?
im surprised thats only 72v 25a good power, lol loving steves little wheelies throttle only,thats impressive. i think steve has got good torque having gone to 16's from 20's, a little too small for me but nonetheless a very impressive bike, loving the trails more than the road - ask steve to show us the off road capabilities

thx for posting it knoxie,if you speak to steve ask him if he minds if i mail him? just want to ask him about his dual crowns


cheers



D

Hi Andy

Just back in from a bit of BMX!! I use it to pop down to my local Tesco and recycle wine bottles, then went cruising through the park, a nice day for it as well and that little bike goes like a bomb, it feels fast as you are low down and even though its 28 deg outside the motor and controller were staying only luke warm maybe 35 deg or so! impressive considering I didnt peddle once!

I have asked Steve to Join but I think he is a little busy on some other forums and hasnt the time for both ( I can understand that ) also he hasnt really changed the bike in any way for a while so doesnt feel the need to post old stuff.

Those forks are nice, he got them off Ebay super cheap, 16 Inch wheels makes it a little twitchy at high speed but you get used to it, it does have impressive torque for a none geared motor and for its size and weight is a great option, Steve will have a Puma to play with as well shortly as we are keen to get him one to evaluate.

I was impressed with the torque of that Dirt Monkey and yes Steve is also the reason i got in to this as well, I used to watch in amazement at his vids in the early days, nobody was posting videos coz the bikes were so bad, I used to pile on the pressure for folks to do videos all the time, its nice now we have an easy medium in which to do so as before long videos required server space and bandwidth, now thanks to Google we have no excuse.

I am going to meet Steve in the summer taking the BMX and the KMX, going to stoke up the BMX with 72V just for him! and let him have a go on the KMX also at 72V.

Glad you enjoyed the video so did I great to see Steve getting the kids involved as well, Family Ebiking!
8)

Knoxie

hi mate,

yeh nice to see steve taking his girls with him and them all enjoying it together i bet soon his youngest will be saying "dad, i need some kit on mine!!!" lol
yeh i can understand he is a little busy - just nice to see the bikes and what steves been doing to make them better,controller mod etc.
im a bit bummed out as i dont have my bike running at the mo so no rides still busy looking at components and stuff for the next one though and passing the time as best i can untill i find the right setup for it.
ebay is a great place to get parts for the bike, ive been looking at new bikes then finding them second hand at a really good price off - sometimes it's a little difficult to know what goes with what but i want to find a frame that goes with some forks i've picked out which has the right dropouts and space for batteries tricky.


D

Awesome video! I'm definitely going the smaller tire route soon to get more thrust.

Hey Lowell.. should try and get Justin to lend you a 5302 in a 20" with your current battery setup.... i'd like to see a On-Road comparison from your current setup.

My Chaos is getting a 408/4012 instead of the current 406/409.. just have to make up my mind if i want it in a 20 or a 16... the smaller wheel will create clearance issues.. but solve some battery mounting problems at the same time... tough call.

Steve also got me started in all this, i found his videos on Evsolutions website a few years ago and have never let it go....... It's become an obsession. But a good one ! :wink:

I'd like to go to a 504 in a 20" or 24" rim. Ideally I'd like to run the 20" rim, but I need to test the high RPM ability of the 504 since I'd be spinning it around 1000rpm.

Hey Lowell.. should try and get Justin to lend you a 5302 in a 20" with your current battery setup.... i'd like to see a On-Road comparison from your current setup.

Click to expand...

Why try the 5302? At Lowell's ~90 volts 60 amps it's unlikely he could ride it to top speed well in excess of 105kph. And at 83 ft-lbs, he'd not gain any thrust compared to his present system, and lose 1/3 the thrust compared to the 5304 in a 20".
http://www.ebikes.ca/simulator/
The 5304 in a 20" should top out at 80kph with 125 ft-lbs of thrust.

I don't understand why many hubmotor users chose much faster windings than they can ride, paying the price in lost torque, thrust, and efficiency (since peak eff shifts far right of the speed they ride).

Wow that was impressive. Still can't get used to you guys riding on the wrong side of the street.....

Any idea what motor he was using there? Those were some really steep hills for sure.

Hi Fechter,

it was a 4 series dual speed crystalyte 408/413 (i think) it sais the spec right at the end of the video.


Cheers


D

xyster said:

I don't understand why many hubmotor users chose much faster windings than they can ride, paying the price in lost torque, thrust, and efficiency (since peak eff shifts far right of the speed they ride).

Click to expand...

Hi all, lost sheep returning.
My favourite formula is f=ma.
Work out the force at the tyre from all your Torque curves etc and try altering the wheel size to alter the value of 'f'.
Then check out how 'a' (the acceleration), which is a good way to 'feel' performance, rises rapidly with smaller wheels.

Xyster, your statement above is sooo true, why don't folks get it?
I guess wannabe Hubmotor owners are hypnotised by high motor rpm specs, then just hope that their little battery pack will get them there.

My achillies heel is my battery packs. They perform really well right now as England basks in 25 degrees heat. During the winter, they're 'pants' - which is the English impolite way of saying unsatisfactory.
One of my bikes is running a 4 year old set of Li-Ions, so I'll be looking to change them for Li-Po's a-la Knoxie at the end of this summer. To be frank, I'm more interested in the Li-Po's than the Puma as I'd like to shove 35 amps into my 4 series hubs and see what happens. Probably spend a lot of time looking at the sky!

Nice to see all the Vis4V dudes here, including illegal-bike-maui

Steve Head

hey Steve,

Great to see you here, been missing your knowledge and your bikes, i think quite a few of us here cite you as inspiration for our own efforts so very pleased here
i did wonder why you hadn't gone for more amps - do your li's have a lesser limit than 35?
i have the li-po's that paul uses and they are cracking, i only ran 36v but the peak amps were 42 ish, good stuff.
hope to see you around more, one more good guy helping us noobs is always welcome



cheers


D

illegal-bike-maui

Click to expand...

:lol:

also known as EbikeHooey ...

Hi

Yes great to see Steve on here! still blown away by that hill climb as well and Steve has got his cape coat on again!! Super Steve!!

Yes the 35A lipos would help a lot, you can try my ones Steve they have been modified for 100V series use so will be ok, it will be interesting to see what the difference is.

The Puma is a rocking motor for sure but so is your dual speed as well, see what you think after you have had a go on it!

Be great to see you chip in with some posts Steve!!

Knoxie

" I'd like to shove 35 amps into my 4 series hubs and see what happens. Probably spend a lot of time looking at the sky!"

Steve Head

So is it possible/ok to go to a 35A controller (and 72V) on a 4 series? Is this what Steve is referring to?

Greg

The motor will take it, within reason, using a small wheel gives the motor alot more mechanical advantage than a large 26 inch wheel !!!

But the batteries that can push that much power are what start to become a problem. :wink:

I'm a bit slow with all of this, but when I put the 406 in a 20" wheel and 72V with a 20A controller the ebike simulator seems pretty decent compared to the 408 at 72V in a 16" wheel that the Dirt Monkey is running. Or am I missing something?

The DM would have a lower top speed but better hill climbing ability, yes?

Gaston, I get that the batteries become the limiting factor, but over relatively short distances like I am looking at (approx. 9 miles round trip) is it a feasible compromise?

Two steps forward one back eh? :?

Greg

gwsaltspring said:

I'm a bit slow with all of this, but when I put the 406 in a 20" wheel and 72V with a 20A controller the ebike simulator seems pretty decent compared to the 408 at 72V in a 16" wheel that the Dirt Monkey is running. Or am I missing something?
Greg

Click to expand...

Well I would say that is a problem with simulators then. The 2 configurations above will be like chalk'n'cheese when you actually ride them. The 406 delivers a miserable thrust and spins like a dervish. This means that it will spend a lot of time trying to spin at the rpm you've dialled in with your throttle, but underachieving. This is the time when you make heat, not motion - not good.

On the aforementioned video, the entire 20% grade hillclimb is done in 408 mode. The 4013 mode is very useful in the 3mph to 10mph range under extreme load, not required in this case. This would simply not be possible with any other configuration of (gearless) Hub Motor, as the small wheel allows the motor to get into it's sweet spot very quickly and stay there.

I've noticed comments about problems with ground clearance when considering using a smaller wheel. This will not be a problem if you simply replace the existing rear shock with a longer one. The swinging arm will be forced further down, thus regaining your original pedal height.

deecanio said:

i did wonder why you hadn't gone for more amps - do your li's have a lesser limit than 35?
D

Click to expand...

Hi Deecanio,
My amp limit was determined by the specs of the (old) Thundersky Li-Ions I'm using. They are rated for 30A max (3C), so a 20A controller is being moderately kind to them.
I was suprised by how these Li-Ions die at the end of their useful life. I was expecting a gradual decline in performance to the point where the range was no longer acceptable. What actually happens is that now, in their 4th year, the pack suddenly becomes duff. Recently I clocked an 8 mile range on my oldest pack, but 10 charges ago it seemed fine.
What I will say is that I wouldn't have swapped the last 4 years of Lithium e-biking for anything, and all those bike builders nervously waiting for the battery technology to be 'sorted' have simply missed out on 4 years bloody great FUN!

About lithium, My God Man !!! ... after all the work i put into boxing and mounting my Nimh.. i'm strongly considering removing it all to strap on my Limn's !!.. 20ah at 72v will give me ass-hurting range ! still heavy but 20 amps for these cells are no problem ( might even bump it up to 25 lol.. )

About the ground clearance, my frame will not allow alot more up-travel, the way the pivot is made for the swingarm ( sealed cartridge bearings. instead of rubber bushings ) travel is limited to a set range, so i'm stuck with a 20" rim on this bike...

I'm going to start looking for a 16" rim friendly DH bike that can take one of the LI packs inside the diamond, with plenty of travel, disks front and back and i'm going hydraulic this time round !

Steve, you really need to get a meter on that bike.. i'd love to know what the amp load and voltage sag was going up that hill !!!

Ypedal said:

About the ground clearance, my frame will not allow alot more up-travel, the way the pivot is made for the swingarm ( sealed cartridge bearings. instead of rubber bushings ) travel is limited to a set range, so i'm stuck with a 20" rim on this bike...

Steve, you really need to get a meter on that bike.. i'd love to know what the amp load and voltage sag was going up that hill !!!

Click to expand...

Yeah, I had to hack my frame & swinging arm about quite a bit with a grinder and Mig Welder to get the extra movement I needed at the back. Aaah the versatility of steel.

Meters..... maybe one day. I'm not that interested until something doesn't do what it's supposed to do. If I can figure out a way - and it seems possible - of getting Knoxies Li-Po's into my fake exhaust battery boxes then it'll be time to get the probes out.

Hi Steve

We can put the Lipos in a rucksack for a test on your bike! they aint that heavy 20lbs total, I dont have a meter that can measure 72V the wattsup meters top out at 60V.

A123 Altairnano batteries will go in your pipes! Ill send you some I got boxes of them lying around! good for 80A! @ 72V!

Later

P

knoxie said:

Hi Steve

We can put the Lipos in a rucksack for a test on your bike! they aint that heavy 20lbs total, I dont have a meter that can measure 72V the wattsup meters top out at 60V.

A123 Altairnano batteries will go in your pipes! Ill send you some I got boxes of them lying around! good for 80A! @ 72V!

Later

P

Click to expand...

Just lying about! Aaah the luxury of it all Paul. Just put 'em in the pile over there eh?
Paul, do the A123's charge happily to 4.29v? I'd like to use my Li-Ion chargers with them, which top off at 4.29v.

hi guys,

wow, so many topics touched on here that im struggling with at the moment i'm not sure where to start.
Ypedal,
you hit the nail on the head with the difficulty in getting a small wheel dh bike - i am currently looking at dh dual crown forks (marzocchi juniors) but they have a 20mm "through axel" - i worked out that my frame headset will take the forks no problem, is a straight fit so not too much bother there.i intended to keep the original frame i have as it has large triangle to fit my lipo's, i think you will find that unless you have the ability to break/remake battery packs (which you do you lucky swine) you won't find a suitable dh frame to mount with. secondly on that front dh frames are heavy!! most have the 20m through axel on the forks too.im not sure what they have on the back but would be surprised if a hubmotor would drop straight in? dh frame and forks are a heavy combination - i think too heavy for a hub to power well, although that said you may get an xc frame with good travel (4") that would do the job "giant reign" bike for example.
Anyway after looking into it i thought that i would keep my limited travel frame and go with the marzocchi forks, however after speaking to a bike shop today they gave me good news and bad news.
good news was that they could build me a front 20" wheel with the rims i want (halo sas combat 36hole) and use a 20mm through axel hub allowing me to drop it straight on the marzocchi's and use my disk no problem. i had planned on getting a rim only again 36h and sending it to mark to lace in my puma.
Bad news is the guy at the bike shop told me that he thought although it could be done, really the marzocchi's need a 26" wheel (maybe 24") as if you run 20"s once under load it would be very hard work for the frame headset post not to snap once the fork travel kicked in
its difficult to marry parts from various bikes, thats even before you consider the electrics!!
Steve,
i see - i cannot wait to hear how your bike runs on knoxie's lipo's as i said they really can put out some power and seeing your hill climb at 20a 35a should be outstanding to the point of you struggling to keep the front end on the floor!!
wondered about your dual crowns also - are they 1 1/8" steerer tube?
my bike is currently in bits and although i want a similair setup to ypedals thoughts i'd really like to stick with 20's - i find that the clearence issue is totally gone with my shortened crank and im really happy with the way it pedals too so no problem there.Also the torque on the puma is also very acceptable so you may find that you are able to go back to 20's too with the extra power?
An exciting time - cannot wait to see how evryone's bikes turn out - im still looking for the dream bike like Ypedal so i'll get some pics up once it's built, then i'll be looking to you guys for some help in powering it right


Cheers


D