Just joined the e-bike world - wow!

[juggernaut1]

Nice. Agree on the plush ride of a dual suspension ebike. That Bafang motor is a perfect match for the fatty. I have the same motor in my Frey Beast emtb.

 

[Ringo9]

You might want to consider 26" X 2.4" Super Moto-X tires as a compromise ?
They'll fit up to 70mm wide rims.

The lower rolling resistance should make a measurable difference in your MPG, and your Beast looks Hungry !!??

Super Moto-X | GreenGuard | Black-Reflex | 26x2.40 | Addix | 11101381.01

WIDE, COMFORTABLE, SAFE! Whether travelling on asphalt or trail, the beefy Super Moto-X offers the best riding characteristics and plenty of comfort. The extra-resilient DoubleDefense construction lets you reach your destination safely, even in the tough…

www.schwalbetires.com

Will save that info for the future, cheers

 

[Ringo9]

Nice. Agree on the plush ride of a dual suspension ebike. That Bafang motor is a perfect match for the fatty. I have the same motor in my Frey Beast emtb.

Do you also experience cog slipping when giving it everything you got on the highest gear and highest PAS at the same time? I've read similar complaints about the M620 in that situation.
If I'm being honest that level of effort is not really sustainable for more than a couple hundred meters at a time, and the speed at those levels is kinda scary so it's only when I have a fully empty and long straight and want to break my top speed record that I "need" to combine all of the above, but I'm just that guy that wants his stuff to work as it should despite using it or not.

I got some recommendations already to adjust the derailleur which I did by following the advice for regular bikes, not sure if strong mid-drives need a different fine tuning though, I tried to close the pully/cog gap by adjusting the B-screw, nothing really changed.
Checked the hanger and looks straight at least to the naked eye.
Cleaned the chain and sprockets thoroughly, still no effect.

I then removed two chain links and on the first ride no slipping occurred and new top speed achieved, I thought "I got it!" Then strangely, on the following rides and top speed runs the slipping somehow came back?!

It's got a 9-speed ALIVIO so no Tourney but also nothing special either. Next in line are a new hanger and a hanger extender, before I splash the cash for a new gearset (current one only has 400km on it)

Open to more ideas to try before dropping money...

 

[juggernaut1]

I have done over 2500 klms and haven’t experienced any chain slipping and I am still the original drivetrain. My bike uses a SRAM 12 speed drivetrain (NX 11-50 cassette and GX everything else). Once I dialled it in on purchase, this drivetrain has been absolutely faultless ever since.

One of the first things I did was change the standard (40 tooth ?) chainring to a 48 tooth chainring which is the largest I could fit without hitting the frame, and without using spacers. The larger chainring did require extending the chain with more links. The larger chainring kept me out of the smallest cogs (reducing wear) when cruising at typically 40 klm/hr. I also only use the lowest level of assistance unless I want a faster cruise speed - the Frey Beast is limited to 60 klms/hr.

I have the Alivio 9 speed drivetrain on my other ebike and yes I have experienced chain skipping in sixth gear after around 800 klms. The local bike shop fitted a new shorter 10 speed chain and this has been fine ever since, with crisper shifting.

I would firstly check the hanger alignment with an alignment tool rather than the naked eye.

 

[PedalUma]

Fortunately I have access to an extended bike road network around here so driving in city traffic is almost never the case, at least for any meaningful distance/duration. Still, I have found out that bike roads are not all "carpet-like" so on a bike like this you are able to maintain your speed without sacrificing comfort. Even more when starting to move out of those, like on local parks and off-road terrain, it just goes over everything so casually I love it.

What I meant by the battery was that sooner or later the battery will go bad, given my commute's length. Who knows if the company will still be around or will still provide a replacement so do I buy a spare original now and keep for the future or is it possible to refurbish it when it's time? My understanding was that the form factor is unique to the bike design so I won't be able to find generic replacements of equal quality (it's got LG cells).
+

As to buying a spare now, that is probably not a great idea if it goes on a shelf. And it is one reason to go for an external battery build so you are not stuck stranded on proprietary island. A battery just sitting will go bad. They need to be cared for like a pet and not neglected. Now, you could get a second and put it into rotation with the first. That way they would both last more years. I rode a 6-year-old battery today that is in rotation.

 

[PedalUma]

Open to more ideas

Look into a Box 4 eight group set. It is very strong and has a powerful clutch. If you are using the smallest/fastest cog regularly, then get a larger narrow/wide chainring to still have the same speed while using a cog with more teeth and with less ware.

 

[PCeBiker]

Open to more ideas to try before dropping money...

Dude,.. Seriously, How long are your crank arms ???

WTF Have you gots goin on here ??,..

Maybe 2" long cank arms instead 1" long would help ??

What you have is a moped.
Same as I have,..
But my pedals and entire crank system are entirely functional.

Good for you for your generous input to your torque converting cranks for recognizing that you were helping


With your ENORMOUS Crank arm/Pedal clearance, you could easily lose an inch or so for a more street oriented tire.

 

[Gionnirocket]

Take a photo of the battery and any markings. Many bike builders use known battery cases, no need to keep reinventing the wheel.

Also... Do you know which version of the M620 you have? UART or CANbus?
Reason being that the UART version is end user tune'ble and you can tweak each PAS as you like as well as smooth out the acceleration curve if need be.
Easiest way to tell is to look at the display connector