Solved HELP Power jerking after Drivetrain replacement (GEN2)

[Theo]

Whatever you decide to tell Stark is up to you, but I second the suggestion of keeping it polite and diplomatic. Also remember that the person you are talking to probably isn't personally responsible for your issues, so it's also a matter of respect. You do sound like a polite person, but sometimes in these situations we -including me- tend to drop some F-bombs and end up being offensive when we just wanted to be defensive.

That said, technically I've noticed that the inverter was diagnosed to be manlunctioning after a battery replacement, so I tend to suppose that the new battery has caused this issue. A possible explanation could IMHO be that this new battery either delivers power in an erratic way or that it has damaged the inverter, for example maybe the precharge circuit is faulty and has delivered too much current to the inverter, damaging the DC link capacitor or the inverter itself.
Here is an explanation of what I'm talking about, if it's needed:

However, it's just a guess that is as good as yours since I don't have first hand experience, I just have developed an interest for this stuff.

 

[Chaconne]

I imagine the process from when i file the complaint on the consumer action union will take several months, if not years, (specially here in Spain, the land of the lazy) until i get a solution or a new bike, and during all that time i will be without it

Stark is lucky you aren't that like UKLee he would have sent Scotland Yard to arrest the entire company... They would have been sentencing Wass to work on Jaguars for 10 years as punishment... Or maybe it would have been until Wass got those Jags fixed and that would have been a life sentence.

 

[Karinshi]

Whatever you decide to tell Stark is up to you, but I second the suggestion of keeping it polite and diplomatic. Also remember that the person you are talking to probably isn't personally responsible for your issues, so it's also a matter of respect. You do sound like a polite person, but sometimes in these situations we -including me- tend to drop some F-bombs and end up being offensive when we just wanted to be defensive.

That said, technically I've noticed that the inverter was diagnosed to be manlunctioning after a battery replacement, so I tend to suppose that the new battery has caused this issue. A possible explanation could IMHO be that this new battery either delivers power in an erratic way or that it has damaged the inverter, for example maybe the precharge circuit is faulty and has delivered too much current to the inverter, damaging the DC link capacitor or the inverter itself.
Here is an explanation of what I'm talking about, if it's needed:

However, it's just a guess that is as good as yours since I don't have first hand experience, I just have developed an interest for this stuff.

Totally valid words...

My battery wasn't replaced, they told me it was in good condition several times because i asked them so many times to check it. The problem was with the inverter. When they replaced it, the charging problem was fixed, but it seems the mechanic did something wrong, and now the motorcycle is jerking. They keep trying new parts, but they can't find the problem.

I'm going to wait one more time, and if they don't fix it, I'll try to demand a new bike politely. I can file a complaint with Stark before going to the consumer protection agency.

I repeat, I've had this problem for 7 months, which is an excessive amount of time, and the law should have been able to protect me without any issues

It's taken so long because at first they told me to do different things, like 24-hour slow charges, completing several full charge cycles, etc. Then there was a time when if the charging stopped, but if i unplugged the cable and plugged it back in, the charging would continue and reach 100% after doing that like 10 times because it was stoping every 3/4 percent.. It was very frustrating. But i continued like that for a while because I got tired of battling with Stark via email. Until I was completely fed up and complained again, and now we're at this point where they decided to replace the inverter, but the mechanic messed it up.

Thank you guys for all the implication and opinions. I love Stark and the bike, just bad luck i guess.

 

[Theo]

My battery wasn't replaced

Oops, sorry, I thought I remembered it was but after having re-read your first post, I see that I remembered wrong.

 

[Karinshi]

Oops, sorry, I thought I remembered it was but after having re-read your first post, I see that I remembered wrong.

no problem at all, i was just viewing the video you attached and is very interesting

 

[Karinshi]

Does anyone know if keeping the battery at 100% for a month can cause significant damage? My dealer left it fully charged, but because of the throttle problem, he can't drive it, so he can't use up the battery. It's something that worries me.

Since he is so incompetent and i dont think he will notice this i will tell him a few things; like keeping the lights on, leave it in stand by mode so it will go down a little day by day... any other?

 

[Lost]

As long as he's not constantly charging it, you'll be fine.

 

[Theo]

As long as he's not constantly charging it, you'll be fine.

Yes because it should self discharge anyways. My 1.0 self discharges about 20% every two weeks, so probably it won't stay too charged for too much time.

 

[Karinshi]

Yes because it should self discharge anyways. My 1.0 self discharges about 20% every two weeks, so probably it won't stay too charged for too much time.

i think that 20% is in stand by mode right? with red led flashing every 3 seconds... I've read about users who left their bikes completely turned off for 3 months and the battery only dropped by 2/3%. There was even one user who said his battery stayed at the same percentage.

I think thats why we should storage it on stand by mode at 50% and check every 2 weeks if it drops below 30% and then charge it again to 50%

 

[Theo]

Yes, I see that SOC drop in standby mode. People who have stored their Vargs for months after a complete shut down reported a minmal self discharge like you've said.

 

[Karinshi]

UPDATE:

My bike still hasn't been fixed.

My dealer responsible for the repair just called me and said he's ending his contract with Stark tomorrow. He doesn't want to work with them anymore. He says he's losing money. He claims he's replaced all the parts Stark mentioned (drivetrain, wiring harness, docking station, VCU, 3 throttles), and the problem persists. The only thing left to replace is the battery, but Stark says it's fine. I don't believe it, and they're causing a huge problem. They have a video call tomorrow; we'll see how things turn out...

To sum it up, the problem with my motorcycle was: for 7 months, there was an inverter issue that prevented the battery from charging past 78%. I repeat, 7 months!! They replaced the drivetrain, which fixed that problem, but then the stuttering appeared while riding. They replaced all the parts I mentioned before, and there's still no solution. I think I deserve a new bike, there are some in stock ready to ship inmediatly, and that's what I'd like to demand from them tomorrow if they don't give me a solution.

 

[Chaconne]

UPDATE:

My bike still hasn't been fixed.

My dealer responsible for the repair just called me and said he's ending his contract with Stark tomorrow. He doesn't want to work with them anymore. He says he's losing money. He claims he's replaced all the parts Stark mentioned (drivetrain, wiring harness, docking station, VCU, 3 throttles), and the problem persists. The only thing left to replace is the battery, but Stark says it's fine. I don't believe it, and they're causing a huge problem. They have a video call tomorrow; we'll see how things turn out...

To sum it up, the problem with my motorcycle was: for 7 months, there was an inverter issue that prevented the battery from charging past 78%. I repeat, 7 months!! They replaced the drivetrain, which fixed that problem, but then the stuttering appeared while riding. They replaced all the parts I mentioned before, and there's still no solution. I think I deserve a new bike, there are some in stock ready to ship inmediatly, and that's what I'd like to demand from them tomorrow if they don't give me a solution.

Oh god man I am sorry to hear that. That shady dealer is useless, it is not your problem if that jackass is losing money he had no problem selling you the bike in the first place.

You got a lemon and the bike has not been right from the start. Stark should take back the bike and replace it with a new one. That bike needs to go back to the factory and re-QA'd and then sold as a repackage.

 

[Karinshi]

Thanks for your kind words, I'm very discouraged. I don't know if there's a previous case of a complete bike replacement, but I suppose that's what they should do in my case.

7 months is unacceptable.

If I don't get a solution by tomorrow, I'll return to the forum to ask for help and advice on how to file a well-written complaint.

 

[OpaTsupa]

If you believe you can make a strong case for a new bike than go straight to a higher instance. Some consumer protection agency. Even washing machines are covered by EU legislation. There's got to be something.
Otherwise, you'll be relying on Stark goodwill, and they can reasonably claim that they have done a lot already.

 

[Karinshi]

For sure there's got to be something but that can take several months...

they can reasonably claim that they have done a lot already.

a lot? Just send parts to a dealer to have them installed? And even then, those parts don't fix anything? That seems like the bare minimum they should do for a bike that's had problems since day one. They can't just wash their hands of it. They are the ones who gave me a bike that does not meet the expected requirements.

 

[Chaconne]

For sure there's got to be something but that can take several months...



a lot? Just send parts to a dealer to have them installed? And even then, those parts don't fix anything? That seems like the bare minimum they should do for a bike that's had problems since day one. They can't just wash their hands of it. They are the ones who gave me a bike that does not meet the expected requirements.

On top of that Stark bikes have a warranty. Most brands of ICE dirtbikes have almost no warranty. Stark would be obligated to fix this even if it was like this 1 year after you got it. They have not been able to troubleshoot or fix it properly nor has their authorized dealer. That is a lot to make a customer go through. And there are bullet proof ones out there so we know your situation is isolated. Well that jackass dealer didn't help either.

It is probably their option whether to fix the defects or replace the entire bike but you should ask. You have been dealing with this for along time, it is going on the better part of a year. I mean I guess it was rideable with the 78% battery but you didn't buy an MX-1 battery you paid for the EX battery.

Did you have your video call today? Anything new to report?

 

[Karinshi]

You are 100% right.

The video call is with the dealer, not me. It's scheduled for three hours after this post. Stark is supposed to contact me with a solution; that's what they told me yesterday.

I also want to mention that I've been in contact with an employee named Benjamin. He helped me sell the bike, issued the invoice without taxes, etc., and is an excellent professional. He even gave me his personal phone number back then and has always helped me in any way he can. He has been texting me every morning to ask how things are going. Yesterday, he told me he was speaking with the head of technical service, who is handling my case right now, and that they're going to find a solution, no matter what. Better late than never i guess...

It seems that my problem is literally unique, they didn't encountered before. All the more reason for them to take the bike to the factory for a thorough inspection and give me a new one!

I will update if I have more information throughout the day.

 

[DaveAusNor]

All of this sounds very frustrating. I hope its resolved by the end of the day.

 

[Karinshi]

UPDATE:

Soooo... new bike coming.

Translation from Spanish:

Support (Stark Future)

December 4, 2025, 3:49 PM CET

Today we had one last call with the dealer to try and diagnose the bike with the engineers.
We can see the problem, but we don't know where it's coming from or what's causing it.
Therefore, we've decided to replace the bike. We're going to send you a new one to replace the faulty one.
The dealer is already aware of this. We need to coordinate and find a bike with similar specifications to send to you.
We'll let you know as soon as we have more news.
Please don't hesitate to contact us if you have any questions.
We appreciate your patience throughout this process and hope you're very happy with your new bike.
Best regards,

Stark Future Team

---------------

I have a lot of questions I've already asked, but just so you know, I was thinking of ordering any bike they have in stock on their website. There are many with different configurations, but mine didn't have any extras, so they have to give me an equivalent one. My idea was to order one with MX suspension; they had one in stock three days ago, but it's gone now, what a shame! I don't know if it would be possible to order that since it doesn't affect the price.

Also i think they should give me the 80HP version for all the trouble this has caused me. But i dont really care for it, 80 makes no sense

I also have a problem: I need to remove the custom Thrill Seekers seat I installed, the carbon fiber protectors, and a Moto Master front disc brake. All of that together costs over €400, and my dealer needs to give me access to the bike to collect those parts. I also have the original parts and could give them to the dealer to send it bike with the bike.

I also have the charger at home, and I suppose I should give that to the dealer as well.

I also don't want to pay the €300 registration fee again, and the road tax, etc... I've asked Stark to reach an agreement on this and for them to refund my money by showing them the invoices.

Honestly, despite everything, it's the solution I saw coming. I'll have a new bike with a warranty. What I dread is having to reassemble it and wait for the delivery company again. I have a job, and coordinating my schedule when I'm home is difficult. Plus all the paperwork nightmare again...

Thank you all so much for your interest and help, love you all

 

[AL_V]

UPDATE:

Soooo... new bike coming.

That's great that they are replacing your bike!
But I think you should discuss the details with Stark.
I'm thinking they will want to ship your new bike to a dealer, and if you don't want them to ship it to the dealer that has your current bike, you should make that clear to them.
Regarding your aftermarket parts, I would first try to get the dealer that has your bike to let you swap back the stock parts.
And regarding the MX suspension, why do want that? I have an MX Varg with the lightest springs and it's too stiff for anything except jumping triples on an MX track.
If your EX was too soft, look for an EX with heavier springs.
And Congratulations!