Known Issues & Problems with BULLS Products + Help, Solutions & Fixes

[Robie]

Thanks Limbo Jim ,That should get me started on putting a kit together for chain repairs.

 

[bob armani]

Hi Bob, cross-chaining "small-to-small" is one thing, but going from the large front chainring to an oversized, 40-tooth rear sprocket with well over 90Nm of torque is another!

None of my old MTBs ever had more than 32T sprockets (my last was a 2002 Stumpjumper, which I still have). It has a 3X9 setup, and I'm pretty sure I cross-chained it more than once, never breaking a chain, either.

Good to hear Jimbo! My Trek 7000 is awesome made in Wisconsin with next to NO maintenance for over 20 years!

 

[RoadWrinkle]

The stress mid drive motors put on chains and gear teeth needs a fix. Design a more robust chain, cassette, and chain ring that can handle extra torque. Or replace the whole drive train with a belt drive. Industry needs to fix this all too common problem.

 

[Robie]

Thanks Limbo Jim. I checked out the German discount site.
Looks like a good one. Thanks.

 

[pxpaulx]

Thanks Limbo Jim. I checked out the German discount site.
Looks like a good one. Thanks.

if you're talking about bike-discount.de - I second their awesomeness and well stocked e-bike related items (chains in particular!)

 

[bob armani]

Addendum: my Bulls had maybe 120 miles on it at the time of this incident, so the chain was relatively "young."

Last year I had a chain break on my 2015 iZiP E3 Sumo (73Nm of rated torque), but it had a few hundred hardy trail miles on it at the time. I had to walk/coast the bike 3 miles that day...

I've since bought a chain checker tool and check my chains regularly. I also carry a quality multi-tool (with built-in chain-pin breaker) and the right size connector links for my chain with me on all my rides. Sure came in handy this time!

Chain breaks seem to be more common with my eMTBs - in ~30 years of "regular" MTBing, I don't remember ever breaking a chain! Of course, my bike weighed a lot less and my legs never put out this much force.

Same with my MTB-in over 25 years of solid riding, never broke a chain or had any major tune-ups or cable snaps. Just some lubing and light cleaning! A solid ride (Trek 7000 MTB American made in Wisc).

 

[LimboJim]

Yesterday I let a friend ride my E-Stream FS3 27.5+. He'd only ridden Bosch ebikes before this, and didn't remember that I'd told him there were two front chain rings. Although he's an experienced cyclist, he ended up audibly cross-chaining, but I didn't think it necessary to check the chain for damage - OOPS!

A bit later, while climbing a steep hill, the chain broke and the motor spun to what sounded like well over 1k RPMs - it made a frighteningly loud, extremely high-pitched whine for maybe 5-10 seconds before shutting off. While it behaved/performed normally after we fixed the chain (chain tools and spare links are good to keep handy), I worry about the internal (belt/gear) wear and long-term effects this incident might've caused.

Any thoughts? Has this happened to any of you with other Brose (or any brand) equipped ebikes?

Disappointment in Bulls' customer service has prevailed thus far...

Correspondence has ceased from
Bulls regarding my eMTB's Brose motor winding out loudly after a chain break. While the bike continues to perform normally for now, I'm genuinely concerned about long term effects and/or this happening again.

Their last email three weeks ago said I'd have a response from their German HQ tech department two weeks ago (or maybe Brose), but I've heard nothing, nor have they replied to my weekly follow ups. Next time I post on this I really hope it's better news, like maybe a software glitch that can be updated on some such.

 

[Robie]

Thanks one more time Limbo Jim on sharing bike-discount.de , for e bike supplies. I feel I got a good deal on chain ,sprocket, and tools and such. Prices are very reasonable. Delivery was prompt 9 days Germany to Texas ! And they stayed in touch by e mail the whole time, as package was nearing delivery. Just wanted to thank you, and will be back with them I'm sure.

 

[fxr3]

Yesterday I let a friend ride my E-Stream FS3 27.5+. He'd only ridden Bosch ebikes before this, and didn't remember that I'd told him there were two front chain rings. Although he's an experienced cyclist, he ended up audibly cross-chaining, but I didn't think it necessary to check the chain for damage - OOPS!

A bit later, while climbing a steep hill, the chain broke and the motor spun to what sounded like well over 1k RPMs - it made a frighteningly loud, extremely high-pitched whine for maybe 5-10 seconds before shutting off. While it behaved/performed normally after we fixed the chain (chain tools and spare links are good to keep handy), I worry about the internal (belt/gear) wear and long-term effects this incident might've caused.

Any thoughts? Has this happened to any of you with other Brose (or any brand) equipped ebikes?

I have a thought. Stop worrying about it. You've got a lot of warranty left and the peeps at brose likely have better things to worry about than what may happen down the road because of high speed spin up. There are no rod, valves, or any timing issues like a gasser. A belt and a couple of horizontal bearings that likely could spin to 10k.

 

[dusail]

Yesterday I let a friend ride my E-Stream FS3 27.5+. He'd only ridden Bosch ebikes before this, and didn't remember that I'd told him there were two front chain rings. Although he's an experienced cyclist, he ended up audibly cross-chaining, but I didn't think it necessary to check the chain for damage - OOPS!

A bit later, while climbing a steep hill, the chain broke and the motor spun to what sounded like well over 1k RPMs - it made a frighteningly loud, extremely high-pitched whine for maybe 5-10 seconds before shutting off. While it behaved/performed normally after we fixed the chain (chain tools and spare links are good to keep handy), I worry about the internal (belt/gear) wear and long-term effects this incident might've caused.

Any thoughts? Has this happened to any of you with other Brose (or any brand) equipped ebikes?

I have a new Evo FS 3, and with just about 10 miles on the bike, experienced a chain break. The motor over-revved, and then quit, as you reported. No cross-chaining was involved, but I'd been having random chain clunks, and some hopping between gears on the climb. I was almost to the top, when the chain went. I contacted the dealer, (about 90 miles away) and they told me to have the bike serviced at the local shop. According to them, the OEM chain was a low end type, and probably had a "frozen link". I upgraded to a "best" quality SRAM chain, and since have gone about 150 miles, with lots of climbing, and no issues. The dealer was super responsive and refunded my out-of-pocket expenses (Cynergy e-Bikes in Portland, Or).

 

[dusail]

I have a potential problem that perhaps someone else has encountered. I've charged the battery on my new Evo FS 3 27.5 about 5 times, and I think each time when I check on it and find it finished, the charger is flashing red/green, instead of solid green. The documentation says this indicates "Battery Error". I disconnect and check the battery, and it indicates full. My battery life is good; finishing rides with 2 bars on the gauge (maybe 25% left) after 35 miles of significant climbing and roads/trails. I'll make sure my dealer is aware, but has anyone else experienced similar charging issues?

 

[LimboJim]

I have a new Evo FS 3, and with just about 10 miles on the bike, experienced a chain break. The motor over-revved, and then quit, as you reported. No cross-chaining was involved, but I'd been having random chain clunks, and some hopping between gears on the climb. I was almost to the top, when the chain went. I contacted the dealer, (about 90 miles away) and they told me to have the bike serviced at the local shop. According to them, the OEM chain was a low end type, and probably had a "frozen link". I upgraded to a "best" quality SRAM chain, and since have gone about 150 miles, with lots of climbing, and no issues. The dealer was super responsive and refunded my out-of-pocket expenses (Cynergy e-Bikes in Portland, Or).

I figured that there had to be someone else out there who'd had their Brose motor rev up after a chain break! It's a deeply disturbing sound, no? I assume your LBS also adjusted the derailleur when they replaced your chain - I doubt that the gear-jumping and clunking you described was because of the chain.

FWIW at well over 200 miles I'm still on the OEM chain, which now has two quick-links - one where it broke and the original one. I had to adjust the derailleur adjustment about 100 miles in, but that's been the case with my other eMTBs, too (likely due to cable stretch). I also keep it clean and well-lubed (plus no more cross-chaining!), and it's held up great since the breakage. My "0.5%" chain checker still hasn't fallen in yet, so...

I have an e-bike specific KMC chain on-hand for when it does. I wonder how it compares to the top-line SRAM you went with.

 

[LimboJim]

I have a potential problem that perhaps someone else has encountered. I've charged the battery on my new Evo FS 3 27.5 about 5 times, and I think each time when I check on it and find it finished, the charger is flashing red/green, instead of solid green. The documentation says this indicates "Battery Error". I disconnect and check the battery, and it indicates full. My battery life is good; finishing rides with 2 bars on the gauge (maybe 25% left) after 35 miles of significant climbing and roads/trails. I'll make sure my dealer is aware, but has anyone else experienced similar charging issues?

Knock wood, I have not seen this on my charger.

 

[Robie]

Speaking of clunking. My Brose motor on my Bulls Evo fs3 + mtb , chunks on initial start up every few pedal strokes. And then goes away. Any one else's doing this? Odd like the motor is missing a cog when cold.

 

[Tom P]

Hello folks, I bought a lacuba evo8 belt drive. So if the belt breaks, that's it. So I wanted info on where to get a belt and what belt to order. For whatever reason, there is no reply from Bulls USA or the German website. How do I get in touch with tech support?
Odometer reads 250 and I really enjoy this bike! Only one small glitch. The assist sometimes kicks out after a slight bump. Suspect a loose connection and was wondering if I should tighten the battery lock up height or lower the connection fitting?

 

[dusail]

Knock wood, I have not seen this on my charger.

I think I figured out the charger issue. The dealer tried charging it, and didn't see the issue. I think it finishes correctly, turning green, and then, if not promptly disconnected, it "times out" and turns to flashing red/green. The time interval is uncertain, but since I generally leave it overnight, I suspect it's between :30 and 8 hours. I've decided not to worry about it.

 

[dusail]

I figured that there had to be someone else out there who'd had their Brose motor rev up after a chain break! It's a deeply disturbing sound, no? I assume your LBS also adjusted the derailleur when they replaced your chain - I doubt that the gear-jumping and clunking you described was because of the chain.

FWIW at well over 200 miles I'm still on the OEM chain, which now has two quick-links - one where it broke and the original one. I had to adjust the derailleur adjustment about 100 miles in, but that's been the case with my other eMTBs, too (likely due to cable stretch). I also keep it clean and well-lubed (plus no more cross-chaining!), and it's held up great since the breakage. My "0.5%" chain checker still hasn't fallen in yet, so...

I have an e-bike specific KMC chain on-hand for when it does. I wonder how it compares to the top-line SRAM you went with.

My SRAM chain now has almost 600 miles on it with no issues. I've been lubing it with Epic Ride lube every few hours of use. I haven't checked it lately with the gauge.

 

[racer cletus]

Bulls FS3 27.5 plus chain break of internal link. Just bought this bike last week and experienced the exact same chain break issues described including the high pitched noise from the motor. Link that broke was internal and it happened going uphill. Have already contacted Bulls and they said I needed to take it up with KMC. I have to say I'm concerned since this seems to be a known issue. OEM chain is KMC x11e sport so I think I'll upgrade to KMC x11e turbo (coated) to see if that helps. I'll also check to see the derailleur is properly adjusted. I'll keep you guys updated. Also give feedback on motor cutting out - I think this is load protection for the bike. I added a USB cable to charge my iPhone while riding and the bike cut out numerous times on the high level assist + charging the iPhone. Once I disconnected the USB charger, no more power cutouts.

 

[LimboJim]

I don't blame the chain for my breaks on the same bike, I believe it's "user acclimation" to up to 90 Nm of pedal assistance, which makes mindful shifting essential.

My rules for riding my higher-torque eMTBs, especially the ones with two chainrings:

1. Never shift to lower gears when climbing, or when pedaling fast on level terrain.
2. Ease up or stop pedaling briefly for ALL shifting, up or down.
3. Avoid cross-chaining like the plague - it's too easy to forget I'm on the larger chainring!
4. Keep the shifter accurately indexed - smooth shifting's extra crucial with added torque.
5. Check all chain links after each ride - the slightest bend can later break easily, even with "proper" shifting.
6. Clean & lube chain every couple or few rides, depending on conditions.
7. Expect to have to replace chains every couple hundred miles, and always ride with spare quick-links.

I found that even ebike-specific chains stretch fast with 75+ Nm of additional torque, and that I'd rather have to pedal harder when I'm in too high a gear for the climb I'm doing than to try to shift in the midst of the climb. Frequent shifting is way less necessary with high-torque assistance, IMO.[/QUOTE]

 

[racer cletus]

Good guidance for the rider. Issue I have is same as other commenters in that I have ridden MTBs for decades (literally) with ZERO chain breaks. I understand it's a different technology but then the rider AND machines need to adapt accordingly. I'll take the advice AND be looking for the chain makers and bike makers to improve their technology. Let's see what KMC has to say about their sport vs. turbo chains. Would appreciate any comments on best chain brands and types people have experienced.