Puma power..

[deecanio]

j3nks,

does the batt not fit in the frame?
would give you a better c of g and you wouldn't need the rack either?
if you could clamp it to the top tube above the controller would be good, more stealth better weight distribution?


cheers

D

 

[j3nks]

well it's all up and running

the bike feels super light..
but not got it on the scales yet..

a bit dissapointed with the top speed.. 21mph !!

but the torque is awesome

you can feel the front end lifting when you open the throttle.. haha!!

great for dodging through the alleys and pathways..

but could do with a better top speed for the cycle paths..

so maybe more voltage needed ?

battery is un-noticable where it is, bike handles like a dream :lol:

i'll post pics tomorrow..

 

[xyster]

well it's all up and running

the bike feels super light..
but not got it on the scales yet..

a bit dissapointed with the top speed.. 21mph !!

but the torque is awesome
...
so maybe more voltage needed ?

So that's 21mph at 36 volts? If so, then 72 volts will be good for 42mph IF the Puma can take sufficient amperage without overheating. Knoxie -- a dedicated Puma tester -- wrote in other threads that the Puma is good for 72v25a before overheating becomes an issue. That ~1500 watts to the ground (72v X 25A X 80% efficiency), should get you to 37mph on an upright bike in a regular seated position:
http://www.kreuzotter.de/english/espeed.htm

 

[j3nks]

thanks xyster..

think i'd be happy with 30mph..

so how many volts do i need for that ?

and can i add another battery to the li-po without upsetting the bms ?

now it's working I NEED MORE POWER .haha!!

 

[xyster]

thanks xyster..

think i'd be happy with 30mph..

so how many volts do i need for that ?

and can i add another battery to the li-po without upsetting the bms ?

now it's working I NEED MORE POWER .haha!!

So long as there are sufficient amps to cut through the increased wind resistance, speed is always proportionate to voltage.

21mph/36 Volts = 30mph/X Volts

X = 30 mph/21 mph X 36 volts = 51.4 volts

I don't know if your BMS can handle the extra voltage or not.

 

[deecanio]

Hi j3nks,xy,

i think you have the same pack as me, a point one lipo - if so your bms in the pack will be ~55v, you could add a 12v giving you 48v but you would be near the bms limit and you may need the modded controller to be on the safe side.i think you would get a 25% increase all round performance, voltage drop and other things i dont understand not calculated

cheers


D

 

[dirty_d]

i don't know what your motor specs are but i guess its around 350W on the bike power/speed calculator 350W gives me 22 mph for a mountain bike, to go 30 you need about 850W. since you're stuck with one gear ratio because its a hubmotor the faster you want to go the less efficient your motor will be running and you have to find the needed voltage by looking at torque not power, i guess you have a 26" wheel, so at 21 mph the motor is running 271 rpm to go 30 mph it has to run 388 rpm, at 21 mph there is X torque on the rear wheel to overcome friction at that speed, air resistance increases with the square of speed so 21^2 = 441.0, 30^2 = 900, those numbers dont mean anything without a coefficient of air resistance but the ratio between them does, 900 / 441 = 2.04, you need 2.04 times as much torque as you have at 21mph to go 30 mph. so what you need to do is graph your motors performance for different voltages and find at which voltage X * 2.04 torque is produced at 388 rpm.

 

[j3nks]

Thanks for your help guys

 

[ChopperMan]

Hi j3nks,

How is your bike, have you had any problems with your setup?

Cheers,

Ian

 

[j3nks]

hi guys..
been away for a while
licking my wounds and nursing my bruises..

bike lasted less than a week before a b*@tch in a 4x4 ran me down...
on a cycle path

but about the bike
everyone that jumped on came back with a grin on their face..
most couldnt believe the acceleration of it..

after all the years of abuse the bike has taken off road
its hard to face that it didnt even last a week as a commuter..

with the 4x4 parked on top of it the rear triangle had no choice
but to bend along with the front wheel, snapped brake etc, etc.. sob

but hey there was some good news
ALL the electrics survived.. yeehaarrr!!!

so it was on to build number 2..
but more of that later..
but must say it's 48v now :lol:
and it's fantastic..

 

[BiGH]

im sorry to hear it - hope ur ok though. at least part of it is salvageable.

 

[knoxie]

Damn

Sorry to hear that!! what a pain, hope you are ok? is the motor damaged? can you get some damages from the woman? grr, i get this all the time, the other day a guy side swiped me whilst I was cycling in the cycle lane, he just missed me! I gave the airzound horn for 3 seconds, he didnt like that! at the next set of lights he stopped, He was all aggressive as he drove passed, he shut up when I stood up! I calmly told him the reason I beeped him was he was driving in a cycle lane??? he said oh and looked rather sorry! ha ha.

Car drivers do it all the time, I wasnt going quick or using the motor, are we supposed to sit and go with the traffic when in a cycle lane? I thought they were there to provide a safe and free channel for bikes?

Oh well, hope you get back up and running soon, I always assume that people are going to do stupid stuff, most of the time they never fail my assumptions.

Cheers

Knoxie

 

[xyster]

I always assume that people are going to do stupid stuff, most of the time they never fail my assumptions.

Well said. The great majority of vehicular "accidents" are not accidents at all, but the predictable consequence of carelessness coupled with power, and a sense of isolation from the costs and the consequences. Sorry to hear you got runover, j3nks.

 

[j3nks]

Thanks guys..

Knoxie i've got to blame you in part..
it was watching your vids that got me into building a puma power fun mobile in the first place

this accident though was'nt in a cycle lane but on a cycle/foot path..
we do have some cycle lanes around here but they do seem pretty narrow..
i'd rather jump onto the footpath..

the police got the womans details for me ..
so when i was allowed out the back of the ambulance..
i checked the bike over to find the back wheel and all electrics intact

you can be sure that the next day the first thing i did was make a phone call..
a no win no fee solicitor..
the wheels are in motion, well legally anyway..

i walked away with no broken bones..
so thats the most important thing..

i also ride a 180mph kawasaki so i'm used to looking out for
cars that are about to do stupid things..
goes to show that there is always an accident waiting to happen when
the 4x4 is doing the school run

 

[deecanio]

hear hear.
Glad your ok j3nks, as long as your not badly hurt you can always get another bike!!
this is why i only ride off road, i think same as a motorcycle it's only a matter of time before some asswipe knocks you off.
It doesn't really surprise me that cyclists get knocked down a lot due to the stupidness of car drivers but.......... i'm tempted not to say this because of the backlash .......... i think all cyclists who use the road should be insured.
i'll give you a reason why....... a while ago i was travelling in a two lane road that has a sharp corner immediately followed by traffic lights - i was doing thirty as i approached the lights they went from red to green.
There was a car sitting in the right hand lane that had stopped at red and a cyclist in the left lane (who had amazingly also stopped at red). As i neared the changing lights the cyclist went to pedal away and somehow fell right in front of me!! the car in the right lane had not moved yet so i had nowhere to go, i jumped on the brakes and stopped just in time, and i mean just, i could see his frame and wheel over my bonnet and thats all.
Now the guy got up and dusted himself down and appologised to me but lets say i was going a bit quicker or even a bit nearer when this happened, my options would be:
1) jump the brake and hope i don't kill the poor guy.
2) swerve into the right lane to avoid killing him and smash my car and the other poor bugger at the lights.
3) swerve to the left to avoid killing him and just damage my own car

You see why i think cyclists should be insured the same as any other road user - if your on the road you should be insured,period.
Look at my options there...
1) dont want to kill him obviously but cant be sure by braking alone that i wont
2) save his life but screw my no claims and have the other guy claim on my insurance as i hit him (regardless of why)
3) smash my own car and claim off my own insurance coz the cyclist doesn't fookin have any!!!

i have decided that if i face this scenario again i will have to hope i can brake in time!!!!!

ok im ready for the insults now :lol:

you guys know im more in favour of bikes than cars but i really think this point should be addressed, here's a few others for instance
1) cyclist runs brake lever down door
2) cyclist causes accident between cars
3) cyclists don't obey traffic signs,red lights,
4) cyclists don't stay on the road but hop from pavement to raod and back again.
5) if ever caught (never) cyclists don't have a licence to endorse/ impose ban.

i'm not bitching as i love my bike and as a previous motorcycle rider i know what asswipes car drivers can be, but from the view of a car driver i think these points are valid.

abuse away.
:lol:

cheers


D

 

[xyster]

abuse away.

OK.

Insurance is a great way to kill the sport, stop ebiking dead in its tracks as an appealing alternative, and further separate the usually at-fault driver from the consequences of their carelessness, killing and injuring more bikers in the long run. After all, the great majority of these incidents we are talking about are not "accidents", but the predictable consequences of negligence. Leave the insurance for the uncommon and unpredictable accidents or incidents.

Just having insurance is no guarantee the insurance will pay, but is a guarantee of long term headaches trying to get the insurance to pay, as well more money lost to insurance premiums.

Just like with healthcare, as the money in the pot is diverted to insurance company operations and profit, the costs of doing any X that occurs with sufficient frequency (getting health care, riding a bike, whatever) continues to increase, necessitating more insurance in a vicious, unsustainable cycle. Is this really what you want?

Take whatever you'd pay to an insurance company in premiums, and put it aside to pay for the costs of the "accident", and/or suing the accident-doer (if there is one) for damages, thereby holding the accident-doer accountable, while keeping the sport appealing and a relatively inexpensive transportation alternative.

Same goes for the biker when the biker is at fault for negligently or willfully causing significant damages to a driver.

 

[deecanio]

HEHEHE i knew you'd want a piece of me brother xy ;p
expected tyler to beat you to it though!!!

i was saying insurance for all bikes not just ebikes that use the road.
i agree with some of your points but there's no disputing that a cyclist powered or unpowered can cause an accident costing thousands of pounds just as likely as the car drivers themselves.
policies could be set rather cheaply lets say as much as a motorbike is cheaper to insure than a car then a bike could be as cheap again compared to the motorcycle?
There are upsides to being insured to theft/fire/and the fact that your insurance would persue your claim (if not your fault) for you.
this is probably a whole new thread on it's own but the main point i was trying to make is if a cyclist causes a major accident they pay no penalty for their recklesness whereas an insured/licenced vehicle does.
lets not get into a tit for tat about car drivers and bike riders as im sure all would agree that there are assholes in each camp, neither is better than the other, my point is that only the motorist is able to be slapped with fines/higher premiums/endorsements etc.


cheers


D

 

[xyster]

im sure all would agree that there are assholes in each camp

I agree with that, D. I've never met a camp that didn't contain its fair share of total assholes. :?

 

[Lowell]

hear hear.
i'll give you a reason why....... a while ago i was travelling in a two lane road that has a sharp corner immediately followed by traffic lights - i was doing thirty as i approached the As i neared the changing lights the cyclist went to pedal away and somehow fell right in front of me!! the car in the right lane had not moved yet so i had nowhere to go, i jumped on the brakes and stopped just in time, and i mean just, i could see his frame and wheel over my bonnet and thats all.

cheers


D

A great example of why I like having the best brakes and sticky tires.

 

[vanilla ice]

The way automotive tires are marketed, extreme mileage is the #1 feature. For example they will say a tire is a 50,000 mile tire, and not mention a word about braking or handling. I guess thats what sells eh. Single most important component of a car as far as braking performance and handling.

 

[ChopperMan]

In the UK, if you join the Cyclists' Touring Club, from £12 per year for a student, £35 for an adult, you get £5m third party insurance and legal aid, free to all members.

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=4088

This seems very affordable, only far to sensible for me to do. :lol:

 

[knoxie]

Hi

A good point raised there by D, yes I agree somewhat, insurance would be great but it puts you back in the loop, which is why e-biking is so attractive, being out of the loop, not being able to be corralled like a yearly sheep in to tax and mot and the like, Liability insurance is a good idea though, this doesn't tie you in to a motor vehicle as such and you can get a good policy that covers you whether you are out on your e-bike or just fall in a crowded street and hit someone and kill them!!

The thing that seems to annoy car drivers is their inability to overtake you, this in my experience is what gets under their nose the most, all my bikes can reach over the 30mph limit here in the UK, (not saying I do this of course) but whilst peddling I can reach over 30mph, car drivers dont like it, I still feel a lot safer being hardly ever passed by cars, than I do when I am on an underpowered bike.

Anyway I hope the man gets his bike fixed quick, sorry If i gave you the bug!! ha ha I am sure a lot of people have gotten that! I sadly cant teach car drivers how to look and act responsibly as most of them don't, the best car drivers are also motorcyclists and cyclists! period!

Knoxie

 

[BiGH]

In the UK, if you join the Cyclists' Touring Club, from £12 per year for a student, £35 for an adult, you get £5m third party insurance and legal aid, free to all members.

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=4088

This seems very affordable, only far to sensible for me to do. :lol:

Thats very good - i'm not sure that there is anything like that in australia, I know that you can get roadside assistance for the pushbike though for a small extra fee per year through the RACV. I would definatly joing a touring club if it gave me insurance too.

not sure how they'd like an illegal ebike though :S

 

[Mark_A_W]

Yes, I'd be interested too - I nearly had a prang last night when some dick turned left (same as right for US/Canada/Euro/etc) right in front of me with no indicator...grr.

 

[BiGH]

yep same - on the road bike when i was doing 45kph merged in front with no indicators - doesn't make u happy when u've ridden 90k already.