trying to get up to speed...

[bcmder01]

hi there, i live in Adelaide, Australia, and am currently visiting London, England. I've cycled a fair bit over the years and done some long distance touring in Australia; some of that on a Catrike Expedition.

a couple of weeks ago i was holidaying in Croatia, which invloved, amongst other things, cycling over some quite hilly islands. i was mightily impressed at how my partner on a Bosch mid drive machine, and some others, similarly equipped, negotiated the terrain. they easily outstripped me on a well geared hybrid. i had a quick ride of about 200mts on my partner's machine and immediately understood how it was possible. it's the push mate.

got me thinking about converting our trikes to electric assist; we've both got them, but my partner, in particular, finds them hard going, especially uphill.

the last couple of weeks i have been trying to get my head around this ebike/ecycle phenomenon and how best to convert the trikes. I'm coming from a long way back and so far my head is spinning. looking around for information i've come across two forums, Endless Spheres and this one. both have some very knowledgeable contributors. hopefully the fact that i see myself as mostly sponge and little water is acceptable.

for me, assist, especially when riding long distances, is the goal. i think the distances in Australia pose a special problem. high speed is not at all important. in any case, high speed - >25 kph - on the road in Australia is illegal. not sure yet how that plays out in practice, but not greatly problematic.

a factor that comes into consideration in our case is the trikes have 14sp rohloffs. didn't know what they were when buying the trikes, but as luck would have it a great piece of kit. i don't know enough to have come to any conclusions yet, but i have read that leaving these on the trikes could be beneficial.

drawing on European standards, Australian regulators have limited motor size to 250watt. once again i don't fully understand what that means in practice, but as yet i haven't yet come to understand what sort of 'power' these converted trikes are going to require.

anyway, questions, questions, questions...

all the best...

Brian

 

[soundwave]

 

[Trevormonty]

Checkout Dillenger Ebike Kits, they are a Aussie company.

 

[bcmder01]

Checkout Dillenger Ebike Kits, they are a Aussie company.

...thanks, i've been looking up Australian outfits who deal in the e-cycle space and seen Dillenger. i've corresponded with Jim from Applied Future Technologies, a Victorian crowd, as they seem to be pretty knowledgeable. they sell Cyclone mid-drive motors.

however, i'd like to know more about the technicalities so for know, while i've got the time, I'm reading and watching as much as i can.

see you...

b

 

[Trevormonty]

The kit middrives are typically cadence sensing, but there maybe some torque sensing ones. Factory middrives like Bosch are torque sensing.

Don't expect kit motor to give same feel as Bosch, but they will still flatten hills.

 

[bcmder01]

...i'm leaning towards the mid-drive motors at the moment, although on a recumbent that seems to mean something different to an upright. i've seen recumbents with the motor situated behind the seat and in front of the back wheel.

Cyclone, the Taiwanese company, picture this configuration on their website and advertise a suitable kit that comes with a mounting bracket for the motor. the motor has two freewheels for chains. one goes to the backwheel, the other to the pedals.

see here - http://www.cyclone-tw.com/doublefreewheel.html

at least one of these double freewheeled motors comes without a controller. I'm assuming that means a controller can be added with a compatible programming box (like Cycle Analyst) to implement whatever type of pedal assist required; i.e. cadence or torque sensed.

the question that keeps popping up is, what size motor is needed to do the job?

see you...

b

 

[anotherkiwi]

Can you pop down to Southend on Sea? Woosh have a GSM mid drive 250W (nominative) motor that would be legal in Oz. Maybe you could have a go on a bike with one fitted? It is PAS not torque, you don't want a torque sensor on a trike, trust me. You want the motor with external controller - then you can choose battery voltage and Amps but 48v and 17 Amp controller is ideal with this motor.

You have Rohloffs (words that make the site filter go crazy go here...). You can choose speed or long range you just need to choose the right cogs. I can't afford a Rohloff so I have a derailleur and as I need to climb mountains and/or roll on flatter roads a double chainring. You can use a double chainring with a Rohloff too so go really low geared or really high geared if you have the strength.

We have a similar goal, mine is 250 km days on the trike. Not when I am in the mountains of course! But even that is on the cards if you have a big enough battery.

 

[Trevormonty]

A 250W motor with low gearing will climb any hill with easy. On max assist expect 2-3 times your unassisted climbing speed, lower without breaking a sweat, higher if you want to work hard. Even eco(low) assist level expect x1.5 increase in climbing speed with moderate work rate.

Given no one is ever likely to check motor I'd go for 350W motor, nice to have little extra if needed. A 400Wh battery on city bike should give 60-80km if you use eco most time and keep speed to 20-23kmh. I'm guessing 600wh battery should give a trike with touring luggage comfortable 100km.

If you want to do topups over lunch, to extend your range, go for fast charge 4A-6A. Ideally with low setting for overnight charging.

 

[Benjahmin]

I think I'm going to write a word document on this and save it so I can paste it in as required.

The wattage stated on a motor is NOMINATIVE only. It is a value put there by the manufacturer saying that it is the wattage that the motor can take continuously without over heating. It has nothing to do with how much power the motor puts out or consumes. That is wholly down to the current rating of the controller and the ability of the battery to deliver that current. It is not possible for the police to test the nominative wattage of a motor, how could they do it? This is assuming that Australian law is framed the same as English/European law. There are a couple of threads , somewhere, that explain how to make your own motor label that conforms to all the requirements of the law.
So don't think that buying a 500w motor gives you more power - it doesn't. It gives you a motor less likely to overheat at high wattages but if you want to do long distances you won't be pulling consistantly high watts otherwise you'll need a road train for your battery (slight exageration there).
I have an Ezee hub motor, it never gets even mildly warm on the longest climbs at high power setting - I've tried. Having said that the Australian climate may mean you have to consider heat loss more carefully. So AK's suggested external controller is a good one. Controllers certainly do get hot and it's better if they're exposed to airflow. Though many do mount them in bags or boxes and they're OK.
Rather than focus on motor wattage, focus on controller maximum current and the ability of the battery to deliver that current without giving voltage sag, resulting in lower power output. The voltage of a battery rated at 20A is going to sag significantly if a 20A controller is pulling that amperage for more than a minute or so. Such punishment will also shorten the overall battery life. So for, say, a 20A controller a battery capable of 30A delivery would be better. (Example figures only to illustrate principle). So cell choice is important. Also the configuration those cells are put into. The more parallel strings the higher current capacity the battery will have.

Sorry - it's Sunday morning, didn't intend to write an essay.

 

[bcmder01]

...thanks to everyone.

i have read about nominative watts etc and it sort of makes sense. (no problems with essays on this stuff even on a Sunday morning. much appreciated actually.)

not overstressing a motor, as in not letting get too hot, seems sensible and it is something i have wondered about, especially in the Australian context. i am reassured that a 250watt motor properly set up should be more than adequate. i have wondered though if getting something a little bigger (e.g. 350watt) might be beneficial for the motor. i have read though that it is not sensible to get a bigger motor than needed.

I'd be happy to travel at the types of speeds i can currently manage unassisted if it could be achieved with a bit less effort. my partner was able to zoom up the hills in Croatia using eco mode. left me for dead. it is not that she didn't work, it just wasn't a killer effort. made for enjoyable riding. it's what I'd like to achieve with the trikes for both our sakes.

i realise i haven't responded to anything about batteries, but i do recognise how vital they are. (electric bike is a hint i reckon ) it is just another area of almost complete mystery.

btw...in the Australian mainland, finding somewhere to recharge an ecycle outside that narrow band of settlement around the coast between Brisbane and Adelaide is problematic. the distances are very often car centric; i.e. hundreds of kilometres.

and to anotherkiwi, thanks for the offer. i can certainly get down to Southend on Sea. any day this coming week Mon-Thu - July 9-12.

questions, questions, questions. thanks again for some of the answers.

see you...

b

 

[bcmder01]

Woosh have a GSM mid drive 250W (nominative) motor that would be legal in Oz. Maybe you could have a go on a bike with one fitted? It is PAS not torque

...

i thought PAS simply meant pedal assist, which is to say the motor doesn't engage unless the rider is pedalling. this is instead of the throttle controlled motors, which are frowned on in the EU and Oz. i further thought that with PAS there needed to be a signal that the rider was pedalling and this could be provided by either a cadence or a torque sensor. that is, a PAS system needs one or the other.

yeah, not at sure what that means for levels of assist, which are just dialled up???

wouldn't be at all surprised if i've got something wrong.

see you...

b

 

[anotherkiwi]

PAS is rotation, not cadence. Some (most modern high end) torque systems have both a torque sensor and PAS rotation sensor which can also capture cadence.

With a KT 12 magnet PAS disk the motor kicks in after less than a quarter of a rotation. The initial power depends on the assistance level chosen - on my upright the GSM on assistance level 5 leaves most cars standing when starting off from a red light (in the correct gear you can pop a wheelie). You choose how much power you get buy selecting the best assistance level so you can use lots of power and just turn the pedals without effort to keep it coming.

Torque sensor gives power in relation to the amount of force you apply, the harder you push the more power. Great for starting from a standing stop on a hill but not much fun if you just want to doodle along in the mountains on the road.

Starting from a stop is where the Rohloff comes into its own, you can change down while stationary so a torque assist system is an unnecessary complication, PAS will work just fine.