Target: 200W (ish) Aussie Stealth Bike - ideas

Hi All,

I have a Trek 4100 MTB w/26" wheels. I currently commute 15km (about 9 miles) one way to work on it a couple of times a week in Brisbane Australia. It's pretty hilly, and takes me about 45mins. The 15km trip home takes a bit longer, mainly because I'm still knackered from the trip in. An e-bike seems like it would help, and be a bit of fun.

I've been around motorcycles for over 30 years, so one of the 2000W monsters some of you guys have look really great, but the road laws here in Qld limit me to 200W, and I'd want it to be reliable enough to do the trip 4 or 5 days a week.

So, plan B is to build a bit of a stealth bike that gives me a boost on the hills, and stays (close-ish anyway) within the 200W limit here in Oz.

So my plan at the minute is to buy something like the cute motor posted here: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=13998 , as I think the 108 motor can fit my 26" wheel with 7 speed free-wheel and still fit my 135mm dropout.

Then i'd need a stealth battery, a bit like this one :http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=14129
Although I'd really prefer a LiFePO4 battery, as I reckon the wife would get really angry if I burnt the house down.
Anyone know of a stealthy LiFePO4 alternative ?

I quite happy pedalling, even on the hills - it'd just be nice to do the trip a little quicker and not feel quite so week at the knees when I get home. Then again, I bet most of you said that until you built your first e-bike. Then it was, it just needs a little more power...

Anyway, I found a GPS tracker type program for my phone, so I might record the trip one day next week so I can work out what sort of incline the hills have and how long they are etc.

I guess once I work that out, I can work out what size battery I need, and whether to get two chargers so I can charge it at work and at home (which might save a bit of wait and cost ?)

Any ideas/opinions/flames ?

Thanks
H

Our 200w laws are total bullshit
That motor is a good choice, it'd pretty much be hidden behind the freewheel and disc brake (if you have one). If you want stealth batteries lipo is the best way to go. If you're planning to keep pedalling I reckon a 12S 5ah pack would just get you there (you'd have to recharge at work) and would probably have you doing speeds of just over 30km/hr unassisted. That sort of speed wouldn't attract attention from the cops, especially if you're pedalling too and dressed in lycra (which I imagine you are if you're already pedalling that distance without a motor)

The battery and a 6 fet controller would fit in a small stealthy under saddle bag like this.


Alternatively you could carry the batteries (a larger pack if necessary) in a backpack if you're wearing one anyway (I assume you'd be taking a change of clothes if you're pedalling all that way now)

You might want to checkout Elation they sell a nice quality non :: cough :: 'hub' motor setup and are conveniently located in Queensland...As Hyena sdaid the 200watt law is booolshit, stick to the speed limit look like your peddling and get at least a 500watt setup...

KiM

Rear gearmotor like a bafang or cute would work fine. The internal gearing will help you get up the hills with less wattage. It won't zoom up the hills, but you'll get a nice assist. 15-20 amps controller, and a 15 ah lifepo4 battery will be a perfect matchup. A 10 ah would do it, but the 15 will last longer since your depth of discharge will be less, and allow some long route home type riding. The battery in that size will fit discreetly in a rear rack box or bag. 36v x 20 amps is 720 peak watts, but 90% of the riding will actually be at around 400-500 watts. 15 amps of 36v on a good gearmotor will climb 10% grades, but slowly. That's often called a 350 watt bike, though it's obviously a bit more peak watts.

The end result will look like a 250 watt bike. Just don't ride it like the 500 watt bike it is. Stick to speeds that look normal and you won't have a big problem. Terrorize the town and you will. Some controllers have a speed limiting jumper wire that you connect to have 250 watts, then you can ride with it unplugged if you wish, or keep it legal if you wish.

Also, put some vents in the bag where the controller goes if you choose to go really stealthy and hide the controller. They need to get some air to cool.

I've had some of the Cute 108 rear motors and they were very wide. If you want 7 speed and disk it will not fit in a standard dropout. Mine were like 155mm. If you can get it specced without the disk you might just squeeze it in.

OK. This is probably pushing the law a bit, but how about 2 * 200w motors with different windings & separate throttles/controllers. I'm sure this has been done before, but it would be difficult to prove you used both motors at the same time and the combination could improve reliability, speed and hill climbing, at the expense of an extra 2.5Kg?

HTH

Spike

hoontune said:

So my plan at the minute is to buy something like the cute motor posted here: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=13998 , as I think the 108 motor can fit my 26" wheel with 7 speed free-wheel and still fit my 135mm dropout.

Click to expand...

Yeah, 7 speed should fit fine as I was able to get an 8 speed to fit on my 108 cute motor.

One thing that may be a problem is that the axle shoulder to shoulder width is exactly 135mm on mine. And the axle shoulder is too small to safely go against the dropout without a washer. So you will have to spread the dropouts by the width of two washers.

I plan on doing a bit of machining on the axle shaft on mine on the side opposite the freewheel. I will remove some material so that the spacing is back to 135mm with washers or torque arm installed.

cell_man said:

I've had some of the Cute 108 rear motors and they were very wide. If you want 7 speed and disk it will not fit in a standard dropout. Mine were like 155mm. If you can get it specced without the disk you might just squeeze it in.

Click to expand...

I emailed back and forth to BMSbattery and always specified I needed disc brake and 135mm compatible motor and after only a month or so that is what I did get. Was not the most pleasant experience dealing with them but they did get my order 100% right.

I hope to finally get it on the road tomorrow barring any unforeseen problems. I just got the motors back from wheel building at the LBS and installed the tubes and tires on them. They look very cute. :wink:

Gary

GrayKard said:

hoontune said:

So my plan at the minute is to buy something like the cute motor posted here: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=13998 , as I think the 108 motor can fit my 26" wheel with 7 speed free-wheel and still fit my 135mm dropout.

Click to expand...

Yeah, 7 speed should fit fine as I was able to get an 8 speed to fit on my 108 cute motor.

One thing that may be a problem is that the axle shoulder to shoulder width is exactly 135mm on mine. And the axle shoulder is too small to safely go against the dropout without a washer. So you will have to spread the dropouts by the width of two washers.

I plan on doing a bit of machining on the axle shaft on mine on the side opposite the freewheel. I will remove some material so that the spacing is back to 135mm with washers or torque arm installed.

cell_man said:

I've had some of the Cute 108 rear motors and they were very wide. If you want 7 speed and disk it will not fit in a standard dropout. Mine were like 155mm. If you can get it specced without the disk you might just squeeze it in.

Click to expand...

I emailed back and forth to BMSbattery and always specified I needed disc brake and 135mm compatible motor and after only a month or so that is what I did get. Was not the most pleasant experience dealing with them but they did get my order 100% right.

I hope to finally get it on the road tomorrow barring any unforeseen problems. I just got the motors back from wheel building at the LBS and installed the tubes and tires on them. They look very cute. :wink:

Gary

Click to expand...

You must have got the QX85 motor in the rear with the disk threaded on? The 108 motor I had was the wider unit and with the threaded section for the disk mount and space for 7 gears it's very wide. Any pics?

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=14553

Gruber Assist!!!!


E

Thanks for the comments everyone.

Gruber Assist does sound good, until you see th US$2500 price tag !

I like the idea of the battery in a bag under the seat, is there anyway I could get a 5AH LiFePO4 battery and controller into one of those (still worried about burning the house down - you haven't seen my wife when she gets mad ! )? Is there a good site that lists different battery configurations with dimensions etc, or is everyone building there own ?

I don't currently have a disc brake, although I wouldn't mind converting to one if possible. Sounds like the fit would be better without it though. Look forward to seeing some pics Gary.

And yes, while I do take a change of clothes with me, I haven't yet subjected the world to me wearing lycra - I guess I could bring myself to do it for the stealth factor though

spike said:

. I'm sure this has been done before, but it would be difficult to prove you used both motors at the same time

Click to expand...

Difficult for the police on the side of the road to prove your usinga 1000watt motor too, they carry no equipment than can test your motor. I have asked Paco from Cyclone to send a 1500watt motor to me with 200watt stickers on it...he said no problem...ill put one on the controller too he said hahaa good lad...

KiM

hoontune said:

And yes, while I do take a change of clothes with me, I haven't yet subjected the world to me wearing lycra - I guess I could bring myself to do it for the stealth factor though

Click to expand...

I wear camo pants and a body armour jacket when riding mine and keep up with traffic and still have had no problems with the cops. Don't make youself look like a fag unnecessarily... :lol:

Alot of battery manufacturers will make a battery to your spec. Most of the 10ah packs use 2 5ah cells in parallel so you could largely just half what ever dimensions they list to get a rough idea. You're probably looking at roughly the size of a big tissue box for a 10ah pack, so about half that size (either a squarish block or a longer flatter pack) Most wouldn't make something as small as a 5ah pack though and as dogman said you'd be better off with a 10ah for the extra headroom. Also if you're going to use lifepo4 most packs are only rated to about 2-3C, so on a 5ah pack you'd be running it at the limit with a 15a controller. Lipo on the other hand will be fine but yeah it's not for noobs.


AJ, it sounds like there could be a good market here for those stickers!

Hyena said:

Don't make youself look like a fag unnecessarily... :lol:

Click to expand...

Sometimes you make it too damn easy Hyena ..

Hyena said:

AJ, it sounds like there could be a good market here for those stickers!

Click to expand...

Indeed...poor Paco missed out on a sale though, enoob has some halls sensors for my i just paid Lyen for a 12 fet controller so RC motor stays...i wonder if Paco will still send me the 200watt stickers for the 6500watt rc motor LOL..

KiM

Hyena said:

A lot of battery manufacturers will make a battery to your spec. Most of the 10ah packs use 2 5ah cells in parallel so you could largely just half what ever dimensions they list to get a rough idea. You're probably looking at roughly the size of a big tissue box for a 10ah pack, so about half that size (either a squarish block or a longer flatter pack) Most wouldn't make something as small as a 5ah pack though and as dogman said you'd be better off with a 10ah for the extra headroom. Also if you're going to use lifepo4 most packs are only rated to about 2-3C, so on a 5ah pack you'd be running it at the limit with a 15a controller. Lipo on the other hand will be fine but yeah it's not for noobs.

Click to expand...

OK, you're starting to convince me that Lipo might be an option, do you have some recommendations for places to go for them ? Is there a good thread for Lipo noobs ?

Thanks
H

hoontune said:

OK, you're starting to convince me that Lipo might be an option, do you have some recommendations for places to go for them ? Is there a good thread for Lipo noobs ?

Thanks
H

Click to expand...

HobbyCity Turnigy or Zippy packs is what the fellas are using and where they are getting them...

There is a sticky in the battery thread on the does and donts of Lithium polymer..

KiM

Someone on this forum had a 500w cyclone, and had a 200w sticker made at a sticker shop.
I would do that.

I agree with all that a 200W limit is a joke and at the moment i blatantly disregard it....

Unfortunately i have some possible bad news for Australians heading into the future.......your "200W" stickers may not save you for long....

I got a call the other week from an old school friend recently turned graduate engineer. He tells me he is working for the RTA in Sydney these days and he knows i'm right into eBikes so he tells me i might be able to give him some advice/help with his latest work project.

Get this - he tells me he's just been assigned the task to prototype the design for a BICYCLE DYNOMETER to check power output at the wheel of electric bicycles! The RTA wants to give powers to police to be able to submit eBikers to power output checks if they suspect the eBike in question may be over the 200W limit. Im not sure if there is intention to allow impounding of bikes on-the-spot so that there is no way the owner can 'adjust' things before fronting to the local RTA for their 'vechicle inspection'. Either way, Im thinking some sort of quickly adjustable current limiting device within handy reach may be a necessity if this thing takes off.... Oh, and he said that although NSW will be the first state to impliment the laws, the RTA expects most other states will quickly adopt the laws and necessary equipment if things "go well" in NSW. Not good news at all...

Needless to say, i "couldn't help him" with his project.

Wow, thats a bit troubling. Not only is the law utter rubbish but now they're going to try and enforce it
I dare say that most commercial ebikes supposedly sold legally would exceed 200w when actually tested.
You'd think ebikes would have to have been an issue for them to go to the effort of doing this, and I haven't heard any negative publicity, nor have I seen more than half a dozen ebikes on the streets of sydney in the last year...

Bugger making the power lower, time to increase it so they can't catch us :lol:

Use a controller with the euro limit jumper wire on it. Wire a switch to it and prominently label it ON OFF. Tell the cop it won't run unless you switch the thing on, and then submit to the test with the jumper connected. Then ride off happily switching to the off position for normal riding. Flick it to on if a cop starts to eye you.

Or even ride legal most of the time, but have the jumper ready to disconnect when you leave the pavement, or just come to a big hill.

I suspect it's not negative publicity or eBike related accidents driving the enforcement, moreso the thought of all those 'moped's' out there not paying registration fees/road tax that is irritating state governments :x . If they catch people over the limit, together with the revenue from the fine they could possibly insist that the bicycle be fitted with indicators, a license plate and of course the expensive rego sticker as they tell the rider they are safer being on the road IN the traffic than exceeding 25kph on the cycle/foot paths

I'll bet my left nut that governments will be looking for alternative revenue as more people start migrating from cars to alternative transport. You can't just have all that registration revenue decline by letting people freely ride eBikes around that are fast enough to compete with cars for transit time now can you?

My car can easily travel at 100-mph, but the speed limit where I live is 65-mph. So trying to limit the power instead of actions is just plain wrong. I think once they begine trying to enforce these power-limited laws, I would have to get a ped-elec, so that there is only power when I am pedaling, because otherwise I'd forget too often and a policemean would see me before I saw him.

How about a longtail cargo-bike with 4 bags of groceries and a child on-board that needs to climb up a hill. That is the person who most needs power-assist and 200W is terribly unsuited to the job.

Perhaps a 24V/48V switch that is activated by a hall-switch in the grip? Turned on by a magnetic ring. When the police try to hit the throttle they only get 24V. The switch could also activate a dual-amp controller.

Whatever you end up with, a BB-drive like Cyclone or a geared hub would be MUCH better than a direct-drive hub at low wattage.

i got a 250w rated motor and controller but it easily goes over 500w going up a steep incline and i'm still peddling!don't really get how these things get rated but if it only pumped out 200w it wouldn't be very useful.

the law is a bit of a joke - but seriously i have seen maybe 2 or 3 ebikes in the last year on my ride to work into sydney cbd. why would the police even bother to track us down there are so few of us! maybe its more targeted to those electric moped things. if its really true its time to go super stealth...

Boostjuice that sounds about right re: the govt and taxes
I wouldn't actually mind paying some sort of lesser registration for ebikes if it meant we could ride higher powered bikes (without actually going the whole hog with numberplates and insurance etc) and they put the revenue towards creating bike paths and the like.
I guess they wouldn't really implement it now anyway, they'd be more looking to the future when ebikes start to get more mainstream.
Unfortunately I'm partly to blame, I have put 5 high powered ebikes into the hands of sydney siders in the last 12 months, although if they choose to ride them other than for offroad that's up to them

If they really become assholes about it I'll buy something like a 50cc sachs madass and convert that to electric. Out with the 2kw peak petrol engine, in with 10kw peak of lipo powered goodness

spinning magnets, I like the secret decoder ring idea but I suspect that once they start enforcing this they'll soon become wise to all the tricks, especially when they see you overtaking cars one minute and the next it hasn't got enough power to pull the skin off a custard :lol:

I raised the legal stuff a while ago on here...

Basics are: 250W limit (200 is gone) BUT pedalec only, and no assistance after 25Kph.

The reason why the RTA are prototyping a dyno is because I wrote part of a submission that shot down their testing methodology. They were looking to use a motorbike dyno from Dyno Dynamics that had a very poor resolution at low output (50W or so at 200W), meaning the law couldnt be enforced.

I'll see if I can dig it up, its on the motoredbikes.com forum - I went electric after getting hassled (as in they were going to confiscate the bike if I were seen riding it again) by the local c**tstabulary.

Here is the discussion paper... http://www.motoredbikes.com/showthread.php?t=20584