chain breaking

[JustRideRanch]

I have a Biktrix Juggernaut mid-drive Bafang g510 1000w with a 9-speed Shimano STD system. I have had nothing but trouble with chain stretch, breaking and jumping, not staying on gears, and the cassette gears bending into each other. I have replaced chains, adjusted endlessly, and replaced the derailer and cassette. I am frustrated to no end. Yes, I shift easily and start in low gear while peddling at a fast cadence to minimize stress, all to no avail.
What is a guy to do? I am considering switching to a new setup—a 10-speed cassette and KMC e-bike chain and derrailer—and am looking for advice before the investment. Will that fit? What derrailer and shifter is best? I do not care about investing in a stronger setup if it will keep me riding.
I also have a Shimano IGH built for e-bikes." I believe that would be ideal. For that I need to find a 27.5X3" rim which is rare beyond coming on the juggernaut.
In appreciation Marc

 

[fauconnier]

I suggest you to read or look at vids. about the chain line of e-bikes (Luna). I personally reduced my 9 speeds cassette to 6. I also touch my brake before shifting to stop the motor.

 

[Tom@WashDC]

I have a Biktrix Juggernaut mid-drive Bafang g510 1000w with a 9-speed Shimano STD system. I have had nothing but trouble with chain stretch, breaking and jumping, not staying on gears, and the cassette gears bending into each other. I have replaced chains, adjusted endlessly, and replaced the derailer and cassette. I am frustrated to no end. Yes, I shift easily and start in low gear while peddling at a fast cadence to minimize stress, all to no avail.
What is a guy to do? I am considering switching to a new setup—a 10-speed cassette and KMC e-bike chain and derrailer—and am looking for advice before the investment. Will that fit? What derrailer and shifter is best? I do not care about investing in a stronger setup if it will keep me riding.
I also have a Shimano IGH built for e-bikes." I believe that would be ideal. For that I need to find a 27.5X3" rim which is rare beyond coming on the juggernaut.
In appreciation Marc

Sorry to hear you have such problems, that sounds annoying. I have a Bahang BBSHD that I run with a Microshift 9 speed cassette, derailleur, and shifter, KMC -ebike chain. I have snapped a few chains, and replaced my cassette at least once a year. Chain stretch is going to happen more frequently with those motors in my opinon. How are you repairing your chain when it breaks? When my chain snapped, I always put it back together by breaking a link, and putting the chain links back together with a chain tool, thinking it was a stronger fix than a Power Link, or Quick Link. I was wrong. Since I started using Quick Links on my chain, it does not re-break in the same spot.

I also have two other bikes (mine and my wife's) purchased with the Bafang 510 running about 1,500 peak watts with the 12 pseed SRAM NX system. On my MTB which I rode really, really hard, I still managed snap a chain every now and then, when I would accidentally lug the motor on a hill when caught in the wrong gear. I've had to replace my cassette at least once a year, and managed to strip the pawls in my hub. I installed a Rohloff 14 speed IGH in June of 2023, Since then, no derailleur/cogs = no problems!

What kind of riding do you do? What type terrain?

 

[Nvreloader]

J
You might want to read more info here: https://forums.electricbikereview.com/threads/can-i-change-derailleurs.55373/
I am having the same problems with my Juggs 4 bike,
have posted what I have found and doing to to correct it, I hope. Hth's.
I have been riding/wrenching on an e bike for 2+ yrs now,
so I am a new be at this game, but learning on a steep hill.

 

[Stefan Mikes]

1000w

I can see the culprit here.

The average leg power of a competing pro athlete riding a traditional road bicycle is 300 W.

It is far less for the rest of us.

E-bikes provide far more power, hence chain stretching is common, especially with mid-drives. However, chains do not snap on good e-bikes with reasonable assist. Now, apply the full 1000 W to a cheap (low end) drivetrain and just wait for the trouble

 

[Chargeride]

Bbshd, 1500w, throttle, heavy bikes, yup, I've destroyed freewheel pawls, folded over gears, snapped chainwheel teeth off, wrecked chains, ripped derallieurs clean off the bike.
Life in the big city, putting small motorcycle torque through pushbike parts.

 

[Tom@WashDC]

Bbshd, 1500w, throttle, heavy bikes, yup, I've destroyed freewheel pawls, folded over gears, snapped chainwheel teeth off, wrecked chains, ripped derallieurs clean off the bike.
Life in the big city, putting small motorcycle torque through pushbike parts.

Yup, pretty much.
With that much power, on a bicycle, you will defintely stretch your chain more than normal. When too much power is applied, eventually the weakest link in your transmission array will give out sooner or later.

 

[Gionnirocket]

I can honestly say that I've never broken a chain, derailleur or freewheel on over 11,000 mi with a 750W BBS02B and all with entry level hardware.
I've riden hard through some tough steep trails.. but knowing what things are and understanding the limits, I rarely push beyond reason.
Add now with 2000mi on a 1000w M620 and I'm not showing an inkling of chain stretch on a standard 10s chain. Though I attribute some of that to the 1 to 1 drive setup of the Rohloff.
Understand you're on a bicycle with bicycle parts.

 

[BikerG]

I run 12 speed drivetrains on both, my e-bike and my acoustic bike. But with the e-bike I’m extra careful when shifting under load, I ease up between shifts. And 12 speed chains are relatively thin and fragile when compared to 8 speed chains, for instance…