EZ Rider Kit - popped one open to see what's inside (Brompton conversion)

[Mkerr]

Hi all.

I'd previously had a commuter DIY project that did me well for many years.
It was a Giant hybrid with a mid drive BBSHD.
Loved the thing to bits and managed to get it to behave exactly as I liked
- PAS settings would go from non existent, to slight increments of power
- felt like you could ramp up the PAS levels to go from the spectrum of emphysema to lance armstrong
- PAS9 was effectively a motor bike (rarely bothered with a throttle, and just ghost wheeled)

Recently bought myself a second hand Brompton and love the thing to bits.

Have a potential 10-15km commute coming up, and figured i'd fiddle with a front hub conversion.

Got one of the EZ Rider kits available online.

Installation was very simple and straightforward.

The ride is rather disappointing, to the point that I'd rather not use it, and have since removed it.

I think it's mostly to do with the programming from the controller. I'm wondering if I can salvage the kit and make it better. Couldn't see this anywhere else online, so figured i'd do it. I've popped it open and will attach piccies of the bits.

I'm likely going to misuse terms, my apologies.

I think my issue is that the controller is modifying the max assist speed with the PAS levels. Default was set to PAS1-3, can change the settings to 1-5 or 1-9
- so PAS 1 will kick in with too much power, to say 15kph, and then die
- PAS 2 will do the same, but to a slightly faster speed
- PAS 3 be ridiculous motorbike mode (as much as 250w can be)

what it means is that with a 3 gear brommie
PAS1
- taking off is fine, it ramps up as cadence increases
- hit around 15kph as switching from 1st to 2nd
- speed limit on PAS1 seems to be hit, and no further power output at all
- rather annoying, pretty much only useful going up a hill
- no power at higher speeds means i can feel the drag and increased weight, for no real benefit

PAS2
- power ramps up too quickly in 1st gear
- second gear is also a bit too powerful
- switching 2nd to 3rd and it totally dies in the arse
- cadence drops with the gear change, and there's no power

PAS3
- it's effectively a motorbike
- not ideal as I want some battery efficiency


What i'm used to is this:

A Hacker’s Guide To Programming The BBS02 & BBSHD​

where i could program the BBSHD PAS levels to cut out at 100% of max speed
so for example:
- if max speed = 30kph
- PAS 1 = 33% max current and 100% max speed
- pas 2 = 66% max current and 100% max speed
- pas 3 = 100% max current and 100% max speed

rather than
- pas 1 = 33% current and 33% max speed (ie 10kph cut off)

or what it feels like it is:
- pas1 = 70% current and 33% max speed

I've gone through the settings and can't seem to make any difference

I'm guessing that this is simply a limitation of the hardware, and i'll need to change the controller.

On that note - I couldn't find any info out there on what was inside.

So here's the guts.

Controller:
Looks like an M15 (has m15 printed on the back of the unit)
Similar to here:

M15 Ebike Centre Control Panel - To7motor​

manual attached
Though might be a different version with more limited functionality
- I wasn't able to get into some of the menu options they show

I'm guessing that I'd need to change both the controller and display to get the sort of experience that i'm after?

cheers!

 

[marka-ee]

I've been considering getting a high quality small folding bike as well. Either a Brompton or a Birdy. Is there any small mid-drive kit that might actually work with one of these? Maybe with a little extra welding? My advice to you on your controller is just replace it entirely with some other more common controller.

 

[Mkerr]

I'm not sure. Haven't come across any builds that have done this. Really not sure I'd bother, when a hub really is more than enough, super simple to install, and minimalist. This was my first hub motor, and I was really shocked at how excessive the power was for city cycling, even if it was only 250w.

Having reflected on it for a bit... There's a certain charm to a Brompton. Its more than the sum of its characteristics. The acceptable weight, very small fold size, reasonable ride character, blah blah blah. Once you get used to it, it really grows on you.

Much of that is ruined by making it electric. The extra weight becomes annoying. The controller and battery getting in the way of the fold. It tarnishes it.

I think if you absolutely needed only an ebike, and had no interest in riding it normally, and needed the minimal size, then it might make sense. If you had space, I'd just use a normal size ebike. I had always intended using it as an ebike, and now much prefer it as a normal bike.

I don't like the ez rider mounting, and would do similar to the post over on pedelec forums (3d printed swytch converter to the carrier block).

I wouldn't recommend the ez rider kit, though I'm really impressed by the akm motor.

I'm contemplating buying one of the Chinese clones and using the hub motor in it. That way I'd have a folding ebike and a normal Brompton.

 

[marka-ee]

I'm contemplating buying one of the Chinese clones and using the hub motor in it. That way I'd have a folding ebike and a normal Brompton.

I know what you mean by ruining the elegant folding bike by burdening it down with all that extra weight. My solution would be to put the battery in my backpack and then use the smallest motor I can find, 250 watts as you have noticed is actually plenty. The idea is just to take the edge off all the pedaling. I actually need the folding bike to fold because I want to bring it on public transportation that doesn't normally allow bicycles on board, such as a bus or a tram.Have you found a easily available via Amazon type small hub motor that would work on either the Brompton or the Birdiy folding bike? The birdie has something going for it as the rear hub spacing is fairly normal from what I understand. So a fairly normal hub motor would fit in there without too much problem. Maybe not the case for the Brompton. Do the Chinese clones use the oddball parts as well or are they more standardized?

 

[E-HP]

I'm guessing that I'd need to change both the controller and display to get the sort of experience that i'm after?

cheers!

I guess if you're going to throw money at it, what were you planning on spending on a controller and display? It may not be your only option.

Looking at the pic of the controller, the label states: Speed Set: 1-4.2V which indicates it should have a throttle input. Do you use one? You could put a Cycle Analyst in front of the controller, and program the PAS in any way you want. You'd also have the option of adding a torque sensing PAS if you want to go that direction later.
The CA will require getting a Grin PAS sensor, so you have to factor that in. It depends on your budget whether it's a viable option/investment.
If you go with replacement, are you chucking the whole battery/controller case? KT controllers have a decent PAS that feels pretty natural.