Sur-Ron - New Mid drive Bike

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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efMX Trials Electric Freeride   100 kW

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Re: Sur-Ron - New Mid drive Bike

Post by efMX Trials Electric Freeride » Aug 14 2019 10:05am

EICMA is only 3 months away, where the public can see the new bikes and dealers can place orders for 2020 models..
some ride & sk8 videos:
metacafe.com/channels/NATAS666DAMIEN
http://www.youtube.com/natas666damien
i have nothing for sale.. :)

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madin88   100 MW

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Re: Sur-Ron - New Mid drive Bike

Post by madin88 » Aug 14 2019 10:39am

engate wrote:
Aug 14 2019 3:47am
Luna belt drive kit. It's nice and quiet,but there is an issue what was discussed on their facebook page and confirmed that "this wookie growl sound is normal".
Unfortunately they deleted the discussion to hide the facts from future customers.
The issue is a buzzing sound if you accelerate hard.If you accelerate very slowly then it doesn't make that noise.
What i noticed is theire drive pulley is a two-piece part. Imagine if these two parts have not been exactly aligned during installation, then one half of the belt will see higher loads as the other half. I would not be surprised if this would make an ugly noise then.
The other thing is that it is CNC fabricated which means the tooth profile probably is a bit off.

What is the tooth count of the small pulley?
Last edited by madin88 on Aug 14 2019 12:25pm, edited 1 time in total.

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madin88   100 MW

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Re: Sur-Ron - New Mid drive Bike

Post by madin88 » Aug 14 2019 10:58am

fechter wrote:
Aug 12 2019 10:12am
dirkdiggler wrote:
Aug 11 2019 2:33pm

There's two nts thermistors that broke and fired up. Obviously can't get any numbers now. I know Holmes hobbies did a video about turning down the amps on the charger and his had same issues. He connected the wires to get his to work. My electronic knowledge isn't that great, but what I understand is the thermistors limit current based on the heat.
Anyway if anyone knows the part numbers or what kind/size, I'll grab new ones and solder them. Or if I can harvest them from somewhere.
I've shorted the wires and it will charge, got the battery to storage level, but don't know how safe that is.
It seems the NTC thermistors are their approach to prevent large sparks on the charger connector if the battery is connected before the charger AC.
If you always plug in the AC on the charger first, there won't be any sparks anyway, so shorting those thermistors should be OK. If you forget, the charger connector may be damaged by the spark.
If I get time, I can take mine apart and try to get a part number off it.
These NTC's are normally on the AC side to limit inrush current (the sparks) if you plug it in your house socket. Most chargers have this cheap solution.
I would ask someone to open up his charger and take a picture of the part. Then i would buy one with lower R, or simply the next larger size.

Joachim   1 kW

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Re: Sur-Ron - New Mid drive Bike

Post by Joachim » Aug 14 2019 11:39am

madin88 wrote:
Aug 14 2019 10:58am
fechter wrote:
Aug 12 2019 10:12am
dirkdiggler wrote:
Aug 11 2019 2:33pm

There's two nts thermistors that broke and fired up. Obviously can't get any numbers now. I know Holmes hobbies did a video about turning down the amps on the charger and his had same issues. He connected the wires to get his to work. My electronic knowledge isn't that great, but what I understand is the thermistors limit current based on the heat.
Anyway if anyone knows the part numbers or what kind/size, I'll grab new ones and solder them. Or if I can harvest them from somewhere.
I've shorted the wires and it will charge, got the battery to storage level, but don't know how safe that is.
It seems the NTC thermistors are their approach to prevent large sparks on the charger connector if the battery is connected before the charger AC.
If you always plug in the AC on the charger first, there won't be any sparks anyway, so shorting those thermistors should be OK. If you forget, the charger connector may be damaged by the spark.
If I get time, I can take mine apart and try to get a part number off it.
These NTC's are normally on the AC side to limit inrush current (the sparks) if you plug it in your house socket. Most chargers have this cheap solution.
I would ask someone to open up his charger and take a picture of the part. Then i would buy one with lower R, or simply the next larger size.
is this the 1st gen sur-ron chargen are the new one :?: the boards shows kingpan so i think this is the 1st gen charger?
the new one is way beter and bullet proof so maby beter buy a new one 2nd gen :idea:

engate   1 W

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Re: Sur-Ron - New Mid drive Bike

Post by engate » Aug 14 2019 11:46am

Joachim wrote:
Aug 14 2019 9:56am
spray some water on it and then pull away hard .... see if the buzzing noise stays away. if so then you can provide the edges of the belt (not the tread / teeth themselves) with a thin layer of bee wax or other natural fat without plasticizers that can damage the rubber of the belt.
I tried basically everything including spraying water on the belt. It's just a badly designed product.

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fechter   100 GW

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Re: Sur-Ron - New Mid drive Bike

Post by fechter » Aug 14 2019 2:03pm

madin88 wrote:
Aug 14 2019 10:58am
These NTC's are normally on the AC side to limit inrush current (the sparks) if you plug it in your house socket. Most chargers have this cheap solution.
I would ask someone to open up his charger and take a picture of the part. Then i would buy one with lower R, or simply the next larger size.
Yes, you are correct, these things are typically on the AC side and I asked the OP about the location but maybe it wasn't obvious to him. Either way, these parts can generally be bypassed. If you get sparking on the AC plug, it will take a lot before needing replacement and replacement is cheap.

I'm not likely to have time to dissect mine for at least another week. If anyone has more time, it would be nice to get some pics of the insides without damage.
"One test is worth a thousand opinions"

dirkdiggler   10 kW

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Re: Sur-Ron - New Mid drive Bike

Post by dirkdiggler » Aug 15 2019 12:03am

Yes. It's on the AC side. Yes it's the original Kingpan version charger. I'll probably end up getting another charger at some point, but why throw away one that just needs a five dollar part replaced?
If it's just spark prevention I'm okay with that. My 72v lipo had much scarier sparks!

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fechter   100 GW

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Re: Sur-Ron - New Mid drive Bike

Post by fechter » Aug 15 2019 11:18pm

In some cases, the inrush can be enough to trip a breaker or possibly blow the bridge rectifier. But I've seen plenty of similar supplies without thermistors that worked fine.
"One test is worth a thousand opinions"

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