Sur-Ron - New Mid drive Bike

Is 72volts worth it for the Sur-ron?

I'm thinking of upgrading the cells in my pack to those Molicells to increase the amps.

I was thinking of just keeping the battery at 60volts like stock to keep keep the battery BMS and just swap the cells out. I don't really need more range or top speed, than the stock battery and I don't want to increase the weight of the bike.

Do you think increasing the voltage is really worth it if you are going to build a new pack? I find the top speed of the stock pack with the nuclear controller is plenty at around 50-55MPH.
 
raising the V is always worth - you can reach same perfromance with less A that means less temperature, more efficiency and finally more battery life.

Having said that, it all depends by your requirements, including budget. Managing energy Vs power is a compromise. there are so much cells out there that you can fine tune your pack at your preferece.

I'm building now a 20s10p pack with Molicel p42a for maximum performance and range. It will reach 42Ah @450A but weight 14Kg
 
I agree, raising the V will often raise efficiency because of lower A (not always - depends on many things). I think with the surron (and since you have the nuc controller), it does raise efficiency. And it should raise your max torque (much more important than top speed in my opinion)... but it depends on the type of riding you do and your desires. If you ride on the street much and sometimes want more acceleration, it's definitely worth it. It doesn't necessarily have to increase the weight to do it. As long as the cells have enough current capability when paralleled to the appropriate 72V "P" value to meet your max Amp goal, you're good.

Regarding spoke length, I have 16/19 wheels on stock hubs, but I'm afraid I don't remember the spoke lengths. You could call Woody's Wheel Works in Denver. They did mine, and have done other surrons as well. I'm sure they would tell you... but since you're apparently in Italy? If you don't want to call them, and can't find them easily, I could get them for you.
 
ggHawk said:
Regarding spoke length, I have 16/19 wheels on stock hubs, but I'm afraid I don't remember the spoke lengths. You could call Woody's Wheel Works in Denver. They did mine, and have done other surrons as well. I'm sure they would tell you... but since you're apparently in Italy? If you don't want to call them, and can't find them easily, I could get them for you.
thanks, I will try
 
Doctorbass said:
I am now looking to find the exact same replacement thermistor.. Nor Digikey, Mouser or Newark seem to have these.
This shop seems to have them in stock (EU): https://www.reichelt.com/de/en/temperature-sensor-40-300-c-kty-84-130-p9604.html
 
Offroader said:
Is 72volts worth it for the Sur-ron?

I'm thinking of upgrading the cells in my pack to those Molicells to increase the amps.

I was thinking of just keeping the battery at 60volts like stock to keep keep the battery BMS and just swap the cells out. I don't really need more range or top speed, than the stock battery and I don't want to increase the weight of the bike.

Do you think increasing the voltage is really worth it if you are going to build a new pack? I find the top speed of the stock pack with the nuclear controller is plenty at around 50-55MPH.


I have both 60V and 72V
I would say that 60V is plenty.

And dont overbuild the pack. Most people here goes with huge amount of Ah and this gets you ridiculously heavy battery.
IMO the stock surron battery is really nice when it comes to weight. And I actually enjoy riding the bike with stock power more becasue of the weight if you like to toss it around in the light offroad conditions. On the pavement it is fine with the heavier battery.
I have 20s8p of Samsung 40T- thats 10,7kg of cells
16s10p Sanyo NCR2070C - thats 9,9kg of cells
stock - thats 7,9kg
I can tell you that you really feel the diff and this is where my packs are on the smaller size compared to other builds.
 
Allex very good point and I even mentioned the same in my last post about not wanting to make the bike heavier. I noticed the same thing as you have and I have actually already decided not to buy or build a heavier battery because of the weight. Actually I wish there would be new battery technology that allowed me to halve the weight of the stock pack at the same capacity and more power, or eliminate 12 lbs of battery weight, that would be so nice.

On my Qulbix bike, I remember I added about 5 lbs (2.27kg), to my battery weight and that 5lbs was noticeable. Since I rarely use the full capacity of my sur-ron stock battery I don't see the point to add more weight to the bike.

I was looking at the chi-battery 72 volt, and that weighs 31lbs (14kg) vs the stock battery which weighs 24lbs (10.8kg).
I really don't want to add that extra weight because its somewhat noticeable and I don't ever need the extra range.
 
As said above 72V is perfect for getting more torque while at the same time keeping your motor cooler.
With 14,4V more than stock battery (72V-57,6V) the motor (kv of ~84 rev/ Volt) runs ~1210 unloaded rpm faster which you can now gear down to the same top speed you had with 16s stock battery while gaining torque and reduce stress on the motor.
As you all know the motor only has one big gear and will thank you in slow, steep enviroment for every extra teeth you got on your rear sprocket. Its important to optimize gear ratio for the average speed you are going most of the time.

For example: I hit temp limits with 58t in steep areas and was tired of having to wait for the motor to cool down for the next round. With 64t my motor is happy and so am I. But this setup would be absolutely shit for street riding because the sweet spot is from 0-30mph.

In my opinion stepping up the voltage + optmizing gear ratio is better than staying at 16s.
 
exactly.

and yes, lightweight is nice. But even with 3kwh the Range for gnarly offroad is about 50km. "less" would be not enough for me.
unfortunately is the Battery per se "the weight" :D

You can ride a surron with stock and have fun...absolutley.

but with "upgrades" you build YOUR Surron with YOUR needs. My Surron weights 70kg now. I hate heavy Bikes. I come from LMX 161 with nice 43kg stock weight and upgraded 53Kg only.
17 additional Kilos(!).......but....it fits for the Surron.

a 70 Kg stock surron with 1,8kwh and 5kw Power would be a fail.
a 70 kg surron with 20kw peak, 20s18p - 4kwh Battery, Plush, Tubliss MX Tires and good Brakes and Top notch suspension is just perfect for what it is.

...an Ultra Light Enduro Machine.
 
stepus said:
Also i thing it could convert ANT BMS data to surron data format, so on l1e version surron there will not blinking error and showing SOC and voltage from aftermarket battery.
Did you figure out how the data gets sent over RS485 ? It would be really neat to send send our own data to the Surron L1E screen and be able to use it with an aftermarket controller.
 
Hi, i have sniffed some communication in bike, and also comunication battery with pc software - there are same commands that are send to battery, and battery will send data. I have about 90% protocol recognised what is what. So now its easy for me send commands via arduino and get response from battery and print it on LCD. - I want to see cell voltages, temps, battery current etc while i ride. But i noticed that BMS refreshing new data about 1 second, so i have new current data by 1 second, and it doesn't matter how many times per second I ask for data, for 1 second i will have same response :/ - not a usefull for online power monitoring.
I have ordered ANT BMS for my FVE project, so i will do some playing with serial data from it, and then it will be easy use some MCU to get data from ANT BMS and convert it to surron dataformat and send it to RS485 bus where controller and LCD waiting for response from batt.
I am doing some house reconstruction so i dont have much time to play with ron, now i only driving it and enjoying wheelies :D

edit: I thought and does it even worth to develop board that converts ant bms data to surron l1e dash ? Because everyone replaces the controller and with it uses diferent display and then bypasses stock bms, or buys aftermarket 60/72V battery. This mod will be usable only for people who using all stock l1e, only wants more range and buys 60V aftermarket battery - and there is next problem. Aftermarket batteries is watersealed, and not everyone be able to open battery and connect this data module to the BMS.
 
There are a lot of battery builders on here. Where do you get the huge heavy duty heat shrink to wrap the pack in? I have a friend w/ a water damaged SurRon Litespeed battery that he'll need reassemble once he replaces the BMS and some cells. My Litespeed battery is also has a manufacturing defect where the power terminals come out. I'd like to cut the sleeve off and fix but I'll need a replacement too. We've looked online and not found a source.
 
Merlin said:
that heatshrink is total crap.
better buy aluminium or steel case.
It works fine and fits. Just looking to repair the packs.
 
yah, works fine....just searching for a repair because of waterdamage. but yea "it works"

normal i would say call litespeed. buy a piece of new heatshrink but internet is full of reports of litespeed giving a shit on customers.

that heatshrink design is well made to catch any single drop of water to flush the battery over time.

another option is: call/write chris and ask for a repair?
 
Maybe you've already tried reaching Chris. That's where I'd start. Even if you (or he) doesn't want him do the repair, he may be willing to give you some sourcing links.
 
I treid contacting Litespeed multiple times. Calls and email. They went radio silent. :(

Anyway, think I finally found it. AliExpress had 335mm (flat dimension) polyolefin. From my measurements (battery is 140x160mm), I need about 300mm so that must be the stuff. All I could find before was the cheap brittle PVC heat shrink.

https://www.aliexpress.com/item/32389821404.html
 
I know rockin' a mullet is nothing new, but a fatty on my Sur Ron is new to me!

sur_ron_fat.jpg


So my Killah has been uselessly worn out for far too long. Bought a fatty air shock for $100 - delivered.

Yes it has less travel, but the fat tire alone makes it more plush than running the pointless worn out shocks and for now at least have a shock that actually functions.

The tire feels like squeezing on a Dodgeball - oh baby! :flame:

Rolls over all obstacles much better of course, while helping keep the front from diving down..

It's currently super icy out on the roads. Riding the fatty with the same conditions as the last ride but I didn't loose control on the front once - compared to several times prior.

Lost control on the back a few times, but it is much less of a problem than when you loose control of the front wheel since it kind of just gets dragged behind you. Versus when the front wheel is sliding sideways it very much wants you to immediately eat shit.

Only downside is it messed with the geometry a tad - feels a bit more squirrelly but overall still more stable (really only noticeable when going slow). Overall it's only an 1" taller in the front. But looks like I can restore a bit of the slacker feel by changing to a longer handlebar stem length.

I guess If I run a taller tire in the back (say also an 1" taller) I guess I would get the slacker back?

I think I'm actually going to run the same tire in the back with the help of a machined extender for the swing arm - it only needs to be like an inch or two longer. I welcome any thoughts and suggestions on the idea. I'd just try it, but I'll need to have a new wheel built to do it.
 
fechter said:
What size is the fat tire?

I think it will be hard to fit one in the rear due to chain clearance.

Supposedly 4" x 26".

But I just measured it and actual width measures at 3.8" (note to self: a wider tire will easily fit in the front)

It just fits in the swing arm with about 3-4mm of clearance from the chain when centered.

Suppose a hub could be laced up a couple mm off-center too?
 
Thanks for the suggestion. So that would drop the rear wheel an inch or 0.75 or 1.5 inches depending on the option chosen?
 
A fat-tire sur-ron would be sweet for AZ sugar sand and deep gravel washes... not so sure I'd like to give up much travel but it does bring a bit of saliva thinking about it
 
3DTOPO said:
I know rockin' a mullet is nothing new, but a fatty on my Sur Ron is new to me!

sur_ron_fat.jpg


So my Killah has been uselessly worn out for far too long. Bought a fatty air shock for $100 - delivered.

Yes it has less travel, but the fat tire alone makes it more plush than running the pointless worn out shocks and for now at least have a shock that actually functions.

The tire feels like squeezing on a Dodgeball - oh baby! :flame:

Rolls over all obstacles much better of course, while helping keep the front from diving down..

It's currently super icy out on the roads. Riding the fatty with the same conditions as the last ride but I didn't loose control on the front once - compared to several times prior.

Lost control on the back a few times, but it is much less of a problem than when you loose control of the front wheel since it kind of just gets dragged behind you. Versus when the front wheel is sliding sideways it very much wants you to immediately eat shit.

Only downside is it messed with the geometry a tad - feels a bit more squirrelly but overall still more stable (really only noticeable when going slow). Overall it's only an 1" taller in the front. But looks like I can restore a bit of the slacker feel by changing to a longer handlebar stem length.

I guess If I run a taller tire in the back (say also an 1" taller) I guess I would get the slacker back?

I think I'm actually going to run the same tire in the back with the help of a machined extender for the swing arm - it only needs to be like an inch or two longer. I welcome any thoughts and suggestions on the idea. I'd just try it, but I'll need to have a new wheel built to do it.
Nicely done.
 
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