Which kit, and hydraulic front brakes an issue?

[peasjam]

Hi everyone,

First off - great forum and I'm pleased to have found such a great source of information.

Second, I wanted to run some thoughts on a kit purchase past people with lots of experience if that's ok.


I want to ditch my car for the 20 mile round trip commute.
It's flat all the way and I'd like to be able to average minimum 20mph so top speed is more important to me than torque. Essentially I want to do it twice as fast and half as sweaty compared to pure peddle power. I'm fairly fit so will be peddling lots too.

Kit would be fitted to my 2009 Canonndale BadBoy 8 which I used to use every day until I moved out of town.

I was thinking of the Magic Pie front wheel kit. I've heard about some quality control issues, but hope that purchasing through AlienBikes would make that less of an issue. The reason for this kit is that (a) it's fairly quick and (b) I really can't afford something like the Heinzmann which would be the obvious choice if money wasn't an issue.
Am I making a sensible kit choice, and if not any alternative suggestions?

I have hydraulic disc brakes and I've heard that the extra width of the calliper compared to a cable type means a powered hub is likely to touch it. Do you think that if I replaced the 160mm rotor with a 203mm that this would position the calliper high enough on the fork to give me enough clearance or will I have to replace it with a cable brake (I know I'll loose re-gen braking keeping hydraulics).

Many thanks indeed for any help you can offer,
Matt.

 

[NRG]

My thoughts:

Are you aware of the legal implications of the 1000W MP kit?

I've no experience of the MP kit but some of the internet feedback is that quality can be patchy at best. Also at £800 you are only £200 quid off a complete Aurora bike that would meet your needs perfectly.

I was going to suggest you stay legal and go for the standard Alien 36v kit as it can take a disk brake but Alien seem to be out-of-stock.

So...other choices would be an Ezee kit, reported quality is excellent and there is a large choice of motor/battery/controller etc combinations: http://www.ezeebike.com/eZee Conversion KIT.pdf They are more expensive than Alien but given the price of the MP kit is almost comparable to that of an Ezee kit, I'd go the extra £100 and get the Ezee...

Alternatively for lower cost; there a number of users on here of the Sunlova kits, again can support disc brakes but quality as I see it from some of the forum feedback is that quality can again be a bit patchy.

So my choice would be in this case Ezee or a complete bike given the stock situation at Alien.

 

[peasjam]

Hi,

Thanks for your reply. I did look at the Aurora but at 5' 6" I'm way too short for it

I'd missed the higher power ezee kits somehow... these look ideal and would suit my needs on a 700c wheel. They're also somewhat less brash than the Magic Pie...

It looks like onbike is the only UK retailer for ezee, I'll drop them a mail to enquire about which motor is in their kit.

Thanks again,
Matt.

 

[NRG]

It's Ezee's own motor, Onbike are the only UK outlet for these....

 

[Deleted member 4366]

I think that you'd be better off selling your Cannondale and getting a bike more suited to conversion. To keep up 20mph you need at least 500w motor, which is a bit dodgy putting it in the front wheel. With a disk brake there can be problems of off-set as well - depending on which motor you get.

If I wanted a 20mph ebike, I'd get a cheap MTB with rigid back, suspension front and disk brakes. I'd by my kit from BMSbattery, where you can get a 500w rear Bafang BPM motor (laced to 26" wheel), controller, pedal sensor, throttle, brakes with switches and 20ah 36v battery in a kit for about £400 (delivered). Then chuck the crank and pedals and find a 50 or 52 tooth single chainwheel crankset, cartridge BB set, Shimano Tourney thumb-changer and rack on ebay - all for about £50. Not the most sofisticated solution, but will give you lots of fun making it and it should give the power and speed that you need for a total of about £600. Later on, when you've figured everything out you can decide about further improvements - like decent forks, or if you decide that you want a different motor, it shouldn't cost too much to upgrade, as that's probably all you'll need.

 

[piotrmacheta]

I have the ezee kit and I recommend it as it does the job brilliantly. Mine's fitted to a full sus mountain bike with 185mm front hydraulic disc. It's so good I use it every day on the off-road route I have to work.
Go for a high rpm hub 300rpm and/or 48v and you can achieve your aim but remember it's either speed or hill climbing ability.

 

[peasjam]

The Bafang kits look a great option, even with import duty the kit price is excellent and with a good capacity battery. Slight downer that it doesn't appear to be disc compatible and I am quite attached to my disc brakes.

That said, is there a general concensus that 500W or thereabouts on the front wheel is unwise?
I'm really torn now between doing a custom build or fitting the kit to the Cannondale having previously been certain...

Matt.

 

[Fordulike]

That said, is there a general concensus that 500W or thereabouts on the front wheel is unwise?
I'm really torn now between doing a custom build or fitting the kit to the Cannondale having previously been certain...

Matt.

I'm certainly no expert, but i was going to use a powerful front hub on my summer build, but changed my mind.
Mainly due to a lot of research and gut feeling that a powerful front hub wouldn't be a good idea.
Check out the Endless Sphere website for lots of info on this, especially the use of torque arms.
Also, if the worst does happen and the wheel pops out, i reckon the bike would be easier to control without a rear wheel than the front.
Still gonna be messy, but maybe slightly less bumps and bruises
Has anyone had any experiences with wheels dropping out of the mounts?

 

[Deleted member 4366]

The Bafang kits look a great option, even with import duty the kit price is excellent and with a good capacity battery. Slight downer that it doesn't appear to be disc compatible and I am quite attached to my disc.

The Bafang BPM motor is disk compatible!
and most people don't have to pay any import duty!

 

[NRG]

That said, is there a general concensus that 500W or thereabouts on the front wheel is unwise?


Matt.

Only unwise if you don't take steps to prevent the dropouts cracking. Fit a torque arm and you should be OK. I run a Bafang front wheel drive on my Peugeot with 1kw peak draw from the battery and so far it's been 100% OK. I have a good set of forks and have made sure everything is really bolted up tight plus I make sure at low speeds I feather the throttle open and always assist with the pedals.

 

[peasjam]

Thank you for the replies, after all the great pointers I think I'm going to go with the following (onBike couldn't supply a higher wattage Ezee motor):

Bafang BPM 500W front motor kit:
BPM E-Bike Kit Without Battery - BMSBATTERY

48V 16ah battery:
48V 16Ah 40160 LiFePO4 Battery 16 Cells EBike Battery Pack - BMSBATTERY

Carrier:
EBike Carrier for Battery Pack 05 Case - BMSBATTERY

I have no idea which charger I should get...
EBike Charger - BMSBATTERY


I need to find out a few last things - Does anyone know if the batteries come in a lockable case as the kits do? I can't seem to find separate cases on the site.

Where do people buy their torque arms from?

I need to fill in a datasheet for the motor with rim size and real rim size.
For this motor setting both to 700c would give 25kmph. If my target is 45 kph on the 700c real rim size what should I set the rim size to?

The sheet also gives me the option of a Hall sensor, and while I understand what one is I'm less clear on is whether I need on or not.


Thanks again for all the info, it's a bit of a minefield when you have no experience whatsoever and I really appreciate the help!

 

[jbond]

Do a search on here and on ES for BPM. There's a guy who's recently bought a BPM front sensored kit from Cellman with 48v A123 LiFePo. He's claiming 27mph on the flat with good acceleration and hill climbing. I think it's a 20", 36v motor in a 26" rim.

The Aurora is a 26" BPM with 26" rims and 36v LiMnO4 battery. The motor is marked as 26"350w36v No-load speed is 24mph, actual flat speed is about 20mph. So I figure the speeds given by BMS Battery are low for when motor marked rim size equals actual rim size and motor marked voltage = battery voltage. Yes it does 15mph (25kmph) but for that to be a max, the controller would have to cut power. Unrestricted it will spin up to 20mph. As for sensored vs sensorless, the Aurora is sensorless. There's an occasional brief judder from a full stop. Once moving you can't feel it at all when you apply power to the motor from off. So I'd go for sensorless as it's one less thing to go wrong.

In your case, I think I'd go for a 26" 36v motor in a 700c rim with a 48v battery and a 6Fet 25A controller. But as you know there's a lot of variables in there. You might also consider buying the controller from Lyen or Cellman on ES as they've already had the FETs changed for lower resistance ones that make a 6Fet 25A controller no problem in terms of heat generation. And they've already uprated the capacitors for higher voltages so you can go nuts with >48v later.

 

[Fordulike]

I need to find out a few last things - Does anyone know if the batteries come in a lockable case as the kits do? I can't seem to find separate cases on the site.

Where do people buy their torque arms from?

I need to fill in a datasheet for the motor with rim size and real rim size.
For this motor setting both to 700c would give 25kmph. If my target is 45 kph on the 700c real rim size what should I set the rim size to?

The sheet also gives me the option of a Hall sensor, and while I understand what one is I'm less clear on is whether I need on or not.


Thanks again for all the info, it's a bit of a minefield when you have no experience whatsoever and I really appreciate the help!

Chat with BMS Battery on the 'Live Support' feature.
Not always online due to lots of Chinese tea breaks , and don't forget the time difference.
If you catch the right person, then they can speak pretty good english and have always answered all my questions

P.S. Looking at the website, they've only just recently taken off the full BPM kit with battery option, which had the aluminium battery you are after complete with charger.
Keep checking, it might go back on
When i asked about the kit, they said the controller is a 12 Mosfet 28A version and the only accessory you need to buy is the rack for the 05 battery case.

 

[clv101]

The higher power eZee kits are available from here:
The Grin Cyclery

Has anyone got one?

 

[piotrmacheta]

I think that there is only one ezee motor. If you run it at 48v (which I'm told is OK) then you get a more powerful motor and with a higher speed (et voila).
200 or 250rpm motor run at 48v will give you more speed and more power.
300rpm is the motor for the 20" wheels so at 36v this will give you more speed but power will be about the same as standard.
300rpm and 48v gives you more than you need.

 

[Fordulike]

Thank you for the replies, after all the great pointers I think I'm going to go with the following (onBike couldn't supply a higher wattage Ezee motor):

Bafang BPM 500W front motor kit:
BPM E-Bike Kit Without Battery - BMSBATTERY

Here's some further info on anyone thinking of fitting a front hub motor.
No idea how respected or knowledgeable in the electric bike field these posters are, but certainly an eye opener.
Endless-sphere.com • View topic - 350W geared hub on fork with suspension?

 

[flecc]

Here's some further info on anyone thinking of fitting a front hub motor.
No idea how respected or knowledgeable in the electric bike field these posters are, but certainly an eye opener.
Endless-sphere.com • View topic - 350W geared hub on fork with suspension?

I think we only have to look at examples of e-bikes in the "legal" 250 watt commercial field. Many have peak powers between 700 and 1000 watts and they don't exactly use the finest suspension forks, usually quite the opposite!

Since there are numerous examples of these doing high mileages over 5 years and more, I see no intrinsic problem with using 250 or 350 watt rated motors in front suspension forks. Some use anti-torque arms too.
.

 

[Deleted member 4366]

The sheet also gives me the option of a Hall sensor, and while I understand what one is I'm less clear on is whether I need on or not.

You need to check the latest situation with BMS battery directly, but the last I heard was that their controllers have a self-learning mode and can run both with and without hall sensors. In that case it would be best to get a motor with hall sensors and then you have the choice of using them or not. You just connect the motor wires, then either connect or not the hall sensor wires and execute the self-learning mode. Whichever the situation, the controller figures it out and controls the motor. I believe that the hall sensor configuration gives slightly better starting from a stand-still, but I've not tried a BPM without to see the difference. Most people don't want to use hall sensors because they can fail if they overheat or get water in - then your motor doesn't work, but if you have this self-learning controller, you just pull the plug on the sensors and away you go again.

 

[piotrmacheta]

I have been using my kit on suspension forks and without a torque arm for about a year used every day with power up to 800w continuous and no problems with damage to fork stancions or dropouts - they are fitted as standard made by Fox on my Specialized Epic. I do intend to fit a torque arm as I feel it is sensible.
I do go easy on the throttle at start-off by pedalling a bit as opening the throttle wide from a stop is just silly.

 

[BLACKPANTHER]

Hi,

I did look at the Aurora but at 5' 6" I'm way too short for it


Matt.

I'd say look again. It sounds like you've made up your mind, but I'll chip in because I'm a 5'8" Aurora rider. As standard with the suspension seat post AND suspension seat, yes it's a really high riding position. I first tried swapping the seat for my MB seat, and this made it ridable, but still just a bit too high, so I swapped the seat post, and this makes a HUGE difference. I then put the suspension seat (very comfy) back on, and can get both feet flat on the floor. With a standard post and standard seat, I reckon anyone over 5'4" could ride it and get both feet down. Also, though illegal, the Aurora 'looks' legal as the motor is the same size as a 250w, and is hidden anyway by the rotor and panniers. The magic pie kit looks the size of a dustbin lid, and if you're caught doing 30 on the road........

Seeing as you sound fit, the other way to get a bike that averages 20mph on the flat is to get a town/road bike, and ride it every day for a few months, build up the leg muscles and you'll barely break sweat. I can do my 10 mile trip to work on my non electric town bike as quick as I do on the Aurora, as the Aurora is a complete bugger to pedal any faster than 20 mph, and if you hit a big bump flat out, it ain't pretty!