Gremlin Hill Part II... The Sequel... Now with thrilling 25kph hill climb! And with only 36V and 20A! Hill climbing speed limited by UK legality :-(

guerney

Esteemed Pedelecer
Sep 7, 2021
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Some of you might recall this somewhat stressfully slow hill climb, when the 36V BBS01B controller on my 20" wheeled Dahon Helios 2006 folding bike conversion was limited to 15A:

https://www.pedelecs.co.uk/forum/threads/bike-chased-late-friday-night-by-loons.45686/

There I was... minding my own business proceeding uphill... and as I passed a pub in quite a rough area during my long journey home, I heard a car engine revving up and a horn (it's headlights were already on when I passed it), then expletives and someone shouting "GRAB HIM! GRAB HIM!", and the sounds of running footsteps trying to catch up with me. Luckily it was uphill, no contest lol.

Turn up the volume to hear some of the looniness as their mates overtake in a car, heads sticking out of the windows, after lurking for a time behind me. Other vehicles never pass by too close these days/nights, because of the Oxford Safety Lollipop sticking out 39.9cm from the end of my right handbar (visible at 17 seconds). And this is why I hate failing to avoid cycling home Friday nights!

They sound just like the group of seven Sur-Ron riders I encounter every so often. I probably wasn't going fast enough for my 250W BBS01B converted Dahon folding bike to interest them. Note the grindless sounds of my snappy and smooth gear changes - the Bafang gear sensor works wonderfully on my bike, even when powering uphill chased by loons.
:cool:

Suddenly I'm quite serious about increasing the amp limit from 15A to 19A in the Bafang controller's firmware, for faster hill climbing/uphill chasing loon evasion...



Early this morning I had another go at that hill with the controller limit raised to 20A, and as you can see below, my hill climbing speed is now limited by the 25kph legal cutoff. :p

What's more, my battery's BMS didn't melt (not in any way I could tell anyway) and the battery didn't burst into flames.

Because it was early morning, I've had to brighten the video up a bit. 1080P is selectable. My GoPro Hero 7 Black's 1/384s shutter speed is faster than the DPC-18 OLED display's refresh speed, it doesn't flicker like that when viewed with human eyes (I keep a pair in my toolbag, for special occasions - kind donations under duress).

Audio is from that night. This morning, I didn't have to change gear from my 7 of 8 = 86.7 gear inches.

After shedding well over 3 and 3/4 stones of blubbery body lard over 2 years by intermittent fasting and mostly eating fermented or sprouted beans, I now weigh 61.7kg. Bike weighs a little more than approximately 22.4kg.



:p:p:p:p:p:p
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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BTW - There's no reason to capture a number plate of a vehicle passing too far away to be a threat to my bike's continued good health, but here's a clear number plate of the car at the end of the video above, which allowed my bike oooodles of space, as they all do now...

(original early morning brightness, screengrab from slightly underexposed video, shot with GoPro Hero 7 Black: Max ISO:800, shutter speed 1/384s)
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....thanks to my handbar mounted Oxford lollipop:




They sometimes pass close-ish to the end of the Oxford lollipop, but that's 39.9cm away from the end of my handlebar - further away than a worrying usual close pass. And they don't cut in too close in front anymore either.
 
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Ghost1951

Esteemed Pedelecer
Jun 2, 2024
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If you didn't have to force your metre long lollipops through the air, you might save billions of lithium ions from having to pass through your battery and increase your range or speed.

The sound track on the video is really a bit disturbing. It sounds like you are riding for your life through a camp built to contain lunatics and savages. A sort of Mad Max situation with gibbering nutcases running amok.

:)
 

guerney

Esteemed Pedelecer
Sep 7, 2021
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If you didn't have to force your metre long lollipops through the air, you might save billions of lithium ions from having to pass through your battery and increase your range or speed.

:)
An extremely small price to pay for relaxing stress free road cycling. It's only the ends of the lollipops that are very unaerodynamic. There's no lollipop drag coefficient quoted on the Amazon listing. Besides, I'm legally prevented from ascending hills any faster anyway, and it's a big 19.Ah/691Wh battery.


The sound track on the video is really a bit disturbing. It sounds like you are riding for your life through a camp built to contain lunatics and savages. A sort of Mad Max situation with gibbering nutcases running amok.
That accurately describes that entire area! I was going to do it late last night with my heavy aluminium monopod handy, to teach those unhinged drink & drug maddened luntaic gremlinised savages some manners... but as Clint Eastwood said in The Unforgiven, "I aint like that no more".
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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Especially for all you fast hill climbing fans out there, I've added a second hill climb to this video. I never nomally climb this particular hill this fast, but 20A makes a huge difference - you can see pedal assist cutting out at about 25kph, starting again, ceasing assist etc. To behold my glorious second longer hill ascent, select 1080P then fast forward to the 32 second mark. Then there's a bit of downhill.




The new programming cable arrived this morning. It appears I have in my possession the "New style" variant - what the actual difference is from the "Old style" wasn't made clear in the listing... but I won't be using it for awhile, because climbing hills up to the legal cutoff 25kph speed is too much of an enjoyable novelty. On the other hand, my battery is now more than three and a half years old and has powered the bike for thousands of miles, therefore it'd probably be wise to lower the controller amperage limit back to about 18A. Don't want to kill it. Hill climbs were also fast at 18A, just not this fast, and also up to the legal cutoff speed on most small hills.


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Mid-drive motor on 20" wheels is a lot of fun! Fast acceleration, climb any hill, no need for an expensive 48V high continuous discharge current battery composed of top notch cells. Who doesn't want the option of easy peasy 25kph hill ascents? I'm not even a fit dude.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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Lol I've just noticed I climbed that second hill to cutoff speed with only 18.4A, which is my Level 8. 20A is my Level 9! :rolleyes: There are oodles of hills... I'm surrounded by hills for miles, going to or returning from anywhere requires hill climbs. I even live on a hill.

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(Yes the bolt on the Minoura handlebar extension wobbled loose)
 
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