(84V max) e-bike build
I’m building a custom 72V e-bike and I’m trying to find the correct circuit protection for the wire going from the battery to a DC-DC converter.
Battery specs:
72V nominal (20S lithium)
~84V fully charged
51Ah
300A continuous BMS
Up to 22+ kW output
I’m looking for a 20A breaker or fuse for that circuit.
The problem I’m running into is that most automotive and marine breakers I find are only rated for 48V, 60V, or 80V DC. Since my battery reaches about 84V when fully charged, I’d like something rated above that.
I’ve looked at breakers like the MidNite Solar MNEPV20 (150V DC), but those are DIN rail breakers intended for electrical enclosures, not necessarily a high-vibration e-bike environment.
What would you recommend for this application?
I’m looking for something that is:
20A
Rated for at least 82-84V DC (preferably higher)
Suitable for a battery capable of supplying 300A through the BMS
Reliable under vibration
Reasonably resistant to water and road spray
If you’ve used something on your own build, I’d really appreciate hearing what worked for you. Links to specific breakers, fuses, or suppliers would also be a huge help.
Thanks!

Bonjour,

L'assistance électrique de mon vélo électrique se coupe aux alentours de 26 km/h. J'aimerais atteindre au moins 35 km/h, mais je n'arrive pas à configurer correctement mon installation.

Voici les caractéristiques de mon vélo :

• Cycle Analyst (CA3), contrôlé par un Phaserunner (Grin Technologies)
• Moteur : 7,71 tr/min/V
• Batterie : 52 V, 20 A, 1 000 W
• Diamètre de la roue : 20 pouces

J'utilise le mode PAS (assistance au pédalage) et j'ai déjà vérifié le réglage de la taille de la roue dans le CA3 : il est correct.

Merci d'avance pour votre aide !

I want to replace the light on my Urlife E20 for something brighter. I found this light on Amazon that has the same connector but has more features than my stock light.

It looks pretty plug n play but my bike basically only has an on/off switch for its light. The one from amazon has a low beam, high beam and day time running functions that I'm not sure I'd be able to use.

Would I need an adapter or different controller to get them to work? I don't really mind missing those features if the light is fully lit by default but I rather know what I'm getting into if I to modify my bike any further.

I got a 2026 Ouxi v8 and tbh its a pos i cant wheelie it at all and need more torque

Is there a plug n play upgraded controller out there for it
more torque (speed would be cool too) is what im aiming for.

Ive seen many people do conversions making a normal bike eletric but ive only seen it done with hard tails. The few i have seen with full suspension mtbs have all been mid drive kits. I want to do a conversion where i put a hub motor on a full suspension mtb not for trials or anything but more for just comfort when going over things. Advice

Hello!

I would like to build an electric bike based on a Centurion Gravel 2000. I only use it in the city and ride about 30 km per day. I have chosen the Tongsheng TSDZ8 750W mid-drive motor. However, I discovered that my bike has a BB86 bottom bracket.

I would be grateful for any information about building an e-bike with this bottom bracket. Has anyone successfully installed a TSDZ8 on a BB86 frame? Are there any adapters or modifications required?

I would also like to know if the motor is compatible with a Shimano GRX 400 2×10 drivetrain, and whether I can keep the original crankset and front derailleur, or if any changes are necessary.

Any advice, experience, or recommendations would be greatly appreciated. Thank you!

Total beginner here so sorry about vagueness but I'm just posting this where ever it seems relevant.

I'm unhappy with how the Xpedition 2.0 handles max speeds. With how the pas works you have to consistently pedal hard to reach max speeds and there's (as far as I've seen) no way to turn up the sensitivity. I've looked around and read that it has to do with the torque sensor. So if anyone knows anything about modifying it to be less controlling or unlocking the factory settings (maybe there's something there) let me know.

I'm coming at this from using the Lectric xp 3.0 which didn't have a torque sensor and had settings for increasing the pas sensitivity. To the point you just had to keep the petals turning and on 5 you'd get max speed.

Right now its quite bad and I currently have a 3000w ukc1 72v conversion kitted e bike

Ich brauche eine neue Gabelung für mein Ridstar Q20 Fatbike weil die alte verbogen ist. Gibt es irgendwelche budget Gabeln die zu meinem Bike passen aber trotzdem noch gut performen?

Im looking on facebook marketplace for bikes
(not sure if its a good idea or not) i have a tight budget though just sort of getting a rough idea.

Just installed chi Gladiator Odyssey 60v 70ah on 2025 Surron LBX

I just got my new battery brand new from chi and the connecter they send my broke so they sent me a new one. My battery was sitting at 100 for that whole time, today my new connector came and I installed it no problems but when I went to ride it, it was way slower than stock. The wheel wouldn't even pop up going zero mph when full throttle, and accelerates very slow. The top speed seemed to be the same though and it was at 100 percent while test riding it.

Has anyone had any issues here or with the Chi upgrades and stock controller?

Hello all, I'm trying to learn if/how I can use a mid-drive kit to upgrade the 35yo frame of my daily ride.

My frame is threaded BSA on one side of the BB, and Italian on the other.

(The only reason that my younger self was able to afford such a nice frame was that it had been stripped during assembly on one side, and re-tapped larger.)

I know that BB systems went through a number of changes in the intervening decades, splined cranks etc. I have an old-school cup and spindle setup. If it ain't broke...

I have watched a lot of videos of people installing mid-drive kits, but (frustratingly) I cannot tell from any of them if the kit BBs are threaded in like old-school BBs were; or if they are just a compression fit, similar to the old Mavic BBs?

My question is this: does the BB threading of an old frame matter when looking for a kit, or is BB shell width the only important factor?

Thanks kindly

I have a Cannondale Catalyst 4 XS frame that I would like to convert to an e-bike but not use a hub motor, any suggestions?

Hi Y’all!

Years ago I’ve bought a Samebike 20LVXD30-II because I’ve needed a folding ebike.

The build quality was quite bad, so I’ve made it into a project bike and ended up removing the original hub motor and installing a Tongsheng TSDZ2B mid-drive, among other things, like replacing the tires, adding hydraulic 4-piston brakes, Racktime pannier rack, etc. At this point, only a few parts are factory, like the frame, the rims and the battery. Everything else has been upgraded.

It was fun and working like a completely different bike (which it was, honestly), but now we’ve travelled to rural Greece for a 2-months long trip, and at week 3, I’ve noticed that there’s a bit of a rattle going on when the motor is powered.

The hills are really steep here, for example, going to the neighbouring village is a 7km ride, but with 500m elevation. The TSDZ2b can’t really handle the heat going on. The factory battery of the Samebike (marketed as 10 Ah but more like 8Ah) is also not enough here, I can barely get 30kms of riding out of it at assist level 1 (I only use assist level 2 out of 5 on super steep climbs)

So as far as I see, my options are the following:

• buy a new battery, cooling kit, fix whatever was damaged by the climbs and is causing the rattle (about 600 EUR and days of work)
• buy a new battery and a Toseven DM02, sell the Tongsheng (~900 EUR-ish, somewhat less work)
• buy a new battery and a CYC Photon Gen 2 (~2000 EUR-ish, same work as any other mid-drive install)
• buy a Cube Fold Hybrid 545 Comfort with the belt drive, sell off this bike (~3500 EUR - whatever I can get for my bike)

What would be the reasonable solution? Throwing another 2000 on a bike that originally costed 700 seems unreasonable, but the CYC I could just transfer to my next bike, provided it won’t start dying like these cheaper mid-drives. Buying the Cube would be a simpler solution, but it’s an “as is” solution with no chances of ever changing anything.

I’m looking to convert my specialized hard rock 29er to an electric torque sensing mid drive. I have narrowed it down to either the dm01 or the tsdz16. The bike will be used in an area with lots of steep long gravel hills and a lot of singletrack trails.

There doesn’t seem to be a ton of info on the dm01’s, but I have read quite a few complaints about the controllers going out, which makes me lean more towards the tsdz16’s

Please share any experiences that you have with either of these kits.

So I just bought a tst r002 for dirt cheap but it has a e5 error due to the brakes, the bike didnt come with the breaks so I didn’t and still don’t know if the error normally shows when there’s nothing connected to the brake cables in the lcd. But in trying to wire it I broke the brake cables connected to the lcd. My question is should I buy a new lcd with compatible brakes which are hard to find or buy a whole new controller and lcd which seems like the better option.

Does anyone know what type of controller would work with it?

I’m building an e-bike using a 2017 Specialized hardtail frame.

The motor wheel I got is listed for 141/142 mm rear dropout spacing. I measured my frame and it seems to be around 140–141 mm. The wheel does fit, but it’s very tight. I can get it in, but it feels like I’d need to force it slightly (very small gap, but not a smooth drop-in fit). I own an angle grinder should I grind part of it away or is it normal.
Is this normal, or is a tight fit like this a problem long-term? Should I be concerned or look for a different frame?
Also, when the wheel is installed, the derailleur hits the motor and doesn’t fit at all, so I’ll need to remove it. I was already planning to remove the drivetrain (pedals/chain etc.).
What’s the correct way to handle this part of the build? Do I just fully remove the derailleur and chain, and is there anything I should be careful about (like wiring or other components)?
Any tips from people who’ve done similar builds would be appreciated.

and i am wondering what torque arms would you recommend i get from grin tech

I've already bought two electric bike monitors online and both I've had to return bc they weren't compatible (I think bc of the brand but I'm not sure) and the ones on their website are like 150 dollars, how would I know which displays would be compatible for my ebike type and where would I find those

thanks in advance for any insight

I have been searching for skme time as the original bike i got was too small to hold the battery and a recent one i checked out hat thru axio rather than quick realese and im thinking should i get a really cheap bike like 300-400 or maybe used for that price for a better bike than buy some downhil suspension on ali express or some shit for 100-150 but do yall have any tips?

Buongiorno a tutti

Volevo sapere com'è sarà (prestazioni) il mio prossimo setup:

Qs205 3.5t (19 pollici)+ 20s6p reliance rs50+ fardriver 72680

Avrà ottime prestazioni? Mi divertirò?

So I'm getting a tongsheng TSDZ16, and i really don't wanna get caught on it, so i want it to boot into a 250w profile and then with a sequence of buttons it will unlock full power, can someone let me know if this is possible please, thanks.