Converting a little folder

[Ghost1951]

That's with the cutoff set to 17mph (15.5 +10% leeway that is legal). With the @saneagle DNP Freewheel (11 teeth for the highest gear) I can go at a faster speed down the hills without any assistance.
I think it should be OK reliability wise - it's just an Aikema hub motor, PAS sensor, KT controller and LCD and battery

Thanks Peter.

I especially like the way the PAS ring seems from my reading of your account, to simply clip onto the crank... Is that right?

I have an urge to maybe convert my Brompton to electric power and I think the available kits from Woosh look as if you need to pull the crank arm off.... I have had a problem with this when I tentatively tried to pull a crank arm on a cheapish mountain bike I was going to convert. The cheapo crank puller I bought stripped its threads and damaged the threads in the arm I was trying to pull off. It seemed VERY tight to me. I have read that Brompton cranks are tight too, and since it is a very nice bike, I don't want any nonsense like that.

Yours looks REALLY easy, which appeals to me. I wonder if the motor kit you bought would fit my Brompton, and whether the magnet ring will remain durably attached. *** EDIT - obviously the wheel size is different.

After reading stuff here, I would be wanting a KT controller, I think.

This is all a bit vague, because where the Brompton is used in town, I don't really need electrification.

 

[saneagle]

No - its a KT 36/48V 6 mosfet 15A sine wave controller from topbikekit with the power based pas levels -the hills weren't that steep mind

OK, thanks. It must be the 50 - 55kg then. We heavyweights need double the power.

 

[Woosh]

I have an urge to maybe convert my Brompton to electric power and I think the available kits from Woosh look as if you need to pull the crank arm off.... I have had a problem with this when I tentatively tried to pull a crank arm on a cheapish mountain bike I was going to convert

The default PAS option with the Woosh kit is to mount the PAS onto the bottom bracket.
You can also ask for the seat tube mounted PAS with clip on disc. There is no extra charge for this. The latter option is less robust than the default option because the PAS sensor can be displaced accidentally while the traditional method is time tested.

 

[Peter.Bridge]

Thanks Peter.

I especially like the way the PAS ring seems from my reading of your account, to simply clip onto the crank... Is that right?

I have an urge to maybe convert my Brompton to electric power and I think the available kits from Woosh look as if you need to pull the crank arm off.... I have had a problem with this when I tentatively tried to pull a crank arm on a cheapish mountain bike I was going to convert. The cheapo crank puller I bought stripped its threads and damaged the threads in the arm I was trying to pull off. It seemed VERY tight to me. I have read that Brompton cranks are tight too, and since it is a very nice bike, I don't want any nonsense like that.

Yours looks REALLY easy, which appeals to me. I wonder if the motor kit you bought would fit my Brompton, and whether the magnet ring will remain durably attached. *** EDIT - obviously the wheel size is different.

After reading stuff here, I would be wanting a KT controller, I think.

This is all a bit vague, because where the Brompton is used in town, I don't really need electrification.

Yep - the PAS disc came in two parts that just clip on and then fit a clip round it. Then you attach the sensor to frame (which was a little fiddly to get it close enough to sense the magnets

Yep they do Bromptons

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[Ghost1951]

Thanks for the responses of Woosh and Peter.Bridge.

Food for thought.

 

[Waspy]

I have an urge to maybe convert my Brompton to electric power and I think the available kits from Woosh look as if you need to pull the crank arm off.... I have had a problem with this when I tentatively tried to pull a crank arm on a cheapish mountain bike I was going to convert. The cheapo crank puller I bought stripped its threads and damaged the threads in the arm I was trying to pull off. It seemed VERY tight to me. I have read that Brompton cranks are tight too, and since it is a very nice bike, I don't want any nonsense like that.

Buy one of these:

Watch this video:

<iframe width="560" height="315" src="

" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

 

[Ghost1951]

Buy one of these:

Watch this video:

<iframe width="560" height="315" src="

" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

Thanks Waspy... If I had not bought a cheap tool, the problem I had would probably never have happened. I had a similar problem with a nasty universal wiper arm puller when my old car's wiper mechanism fell apart. The bloody Knob which tightened the arm broke loose under my hand tightening and I had to make my own adaptations to get the thing off. I should make a new resolution not to o for cheap Amazon tools.

EDIT:

Excellent video on crank removal and likely issues.

 

[Peter.Bridge]

Unbelievably (and I know noone here will believe it) the battery dropped from 42V to 40.5v

Went for another ride at lunchtime :






Voltage after the ride was 39.4v ( so maybe used 1/4 of the battery?)

I think I've worked out what is going on, that fiendish KT controller is tricking me into putting more effort in ! I've not had a KT controller before, but I'm used to Pas level 2 giving me 40% or level 3 giving me 60 % of the available power, so I'm used to "level 2" and "level 3" hills".

Looking at my heart rate today, that's quite a bit higher than usual in that route, so I suspect that controller Pas levels might not be set up like that (I'm not complaining, the less assist I need, the better !)

@Nealh do you know the KT Pas levels % power ?

 

[saneagle]

Went for another ride at lunchtime :
View attachment 58521


View attachment 58522


Voltage after the ride was 39.4v ( so maybe used 1/4 of the battery?)

I think I've worked out what is going on, that fiendish KT controller is tricking me into putting more effort in ! I've not had a KT controller before, but I'm used to Pas level 2 giving me 40% or level 3 giving me 60 % of the available power, so I'm used to "level 2" and "level 3" hills".

Looking at my heart rate today, that's quite a bit higher than usual in that route, so I suspect that controller Pas levels might not be set up like that (I'm not complaining, the less assist I need, the better !)

@Nealh do you know the KT Pas levels % power ?

With a KT controller, you can pedal as hard or not hard as you want. It just gives constant power. It's up to you to select how much assistance you want and how hard you want to pedal. If you pedal harder, you go faster. It has no influence on how much battery you use other than it shortens the time of your journey.

That's the simple explanation, but here is another point about that constant power, which is actually not constant. At a certain speed the back emf is enough to reduce the current, and the faster you go, the more the reduction, so pedalling hard to go fast can indeed reduce power consumption. Most of the reduction is in the top 25% of the motor's rpm range, so if your motor can do 30 mph unrestricted, it would be between 15 mph and 20 mph, but if your bike is restricted to 25 mph, you don't see much of it.

 

[Nealh]

KT PAS level %'s are very different to other PAS levels found on other bikes.
PAS 1 13%.
PAS 2 20%.
PAS 3 33%.
PAS 4 50%.
PAS 5 100%.

Yes with KT one will be putting more effort in esp on the first two PAS levels.

 

[Nealh]

One would think KT PAS 4 is the % of assitance you have been more used to Peter, so you maybe should try PAS 3 more often so you still generate some input effort .
For me I ride very flat terrain and 99.9% of the time ride in PAS 1, tbh the only time I have used PAS 3 - PAS 5 is out on my 160k rides or some of my ride out into East Sx /Kent border areas. The extra power come sin handy where on the home legs when I am moreweary/ tired and use the extra power to climb up out of Hove up to the Ammex stadium via Ovingdean or the one that really does me after 130 odd km is the drag up from Bolney stage up to Handcross village.
The climb isn't overly steep but is a longer up hill drag of some 4 miles.

There are some short steep sections aorund the East Sx/Kent borders and after some 50 miles I find I need higher PAS on some of the country lanes up hill , Eddie Jefferies would attest to some of the steeper 15 or 17% twisting climbing sections. They are ok if you are Geraint Thomas but not I find for us mere mortals barring the mamils who like to show how beetroot red in the face they can get.

 

[Peter.Bridge]

KT PAS level %'s are very different to other PAS levels found on other bikes.
PAS 1 13%.
PAS 2 20%.
PAS 3 33%.
PAS 4 50%.
PAS 5 100%.

Yes with KT one will be putting more effort in esp on the first two PAS levels.

Brilliant - thanks Nealh that explains it. I feel like I have entered a different phase of my pedelecing journey, instead of seeing how fast I can go I am seeing how little assistance I can use and those % levels will work very well for me