SURRON LB: RESEARCH & DEVELOPEMENT

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by thoroughbred » Jan 23 2021 9:00pm

WWW has been around forever, i see they have wheels for Cake bike and light bee
https://woodyswheelworks.com/collection ... 0-off-road

$450 for a complete wheel with a billet hub. $90 cheaper if you supply your surron hub. Where can you get a billet hub made for $90?

What would be the ultimate hub configuration for the rear wheel? Doesnt the OEM use some weird bolt pattern for the brake rotor? (and sprocket)

I wanted to try a 21 inch front on my SR but all the aftermarket stuff obviously wont work for my DIY Honda forks.It took a ton of fiddling around, ended up using YZ80 hub, XR650L rim and buchanon spokes. 21 incher feels great over logs and rocks, certainly worth the hassle :wink:

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Merlin   10 MW

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Jan 23 2021 9:31pm

sry looks like a china build to me.

way to thick spokes, no name rim and wtf? above 440$ for a frontwheel?
i see the offer is with excel rims but that pic shows no name and that cock thick spokes are a bad wheel build :D

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Jan 23 2021 9:39pm

Uhh, Woody has been doing high end wheels for ages (prob longer than I've been alive.) His reputation is fantastic. I suspect the super thick spokes you're crapping on are real 8-10ga motorcycle spokes since he says he has to drill the hub. The nipples don't look like the hybrid ones I have from Wicked that adapt a heavy 12ga mountain bike spoke to a motocross nipple hole. Woody's looks like a real deal motorcycle spoke/nipple.
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Jan 23 2021 10:16pm

Ya maybe he is, but it's not bad ass using 8g spokes for a 50kg bike.

In UK you can buy for 450 a whole set front and rear from SM PRO... direct from factory.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by sc-surfer » Jan 23 2021 10:47pm

Well, this isn’t Europe. And Woodys makes an amazing wheel. Yes the spokes are thick. Yes, it might be overbuilt. Yes, they do use Excel rims. And yes, my wheel cost $380 using my own hub. That included shipping and tax. And they turned it around in 1 week. That’s one week from the day I dropped my hub at the post office to the day the wheel came back. And yes, it’s a fantastic wheel. So maybe not a great deal in Europe, but unless you can deliver a better deal to us here in USA I’m calling it a good price for a great wheel.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Jan 24 2021 8:37am

i saw pics from "Stock fork surron riders" where the "too thick spokes" hit the brake caliper.

talking about "overbuild" ....no offend to the build itself but thick spokes are bad for "good wheels"
the wheel hast to flex. And with lightweight bikes it doesnt flex at all.
all stress goes to the hub and suspension.

now now you could argue you have a fork for suspension and the hub is beefy enough.
flexing wheels gives you also more grip too.

maybe all of them is on a level the "usually" surron rider doesnt need. but when i pay 450$ for a wheel i expect/want spot on material.

again: no offense.

from experience "wheelbuilders" mostly not that open to critism their work.

if this company is open: ask to get the wheels in 12g spokes.
if he say he has no nipples that match the 8mm holes....well...than you hit the difference between a "wheelbuilder" and a "Wheelbuilder"

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by thoroughbred » Feb 13 2021 6:43pm

Will the light bee motor be ok with 24S battery? I read that Luna melted some motors down and wonder what the actual limits of the motor are. Isn't the storm bee 96V and does that equate to 24S?

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Feb 14 2021 9:33am

thoroughbred wrote:
Feb 13 2021 6:43pm
Will the light bee motor be ok with 24S battery?
The motor limit is a power (thermal) one. Increasing voltage yeilds higher max rpm. If the current is limited, the power can be the same.
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Aebrennan » Feb 17 2021 7:21am

thoroughbred wrote:
Feb 13 2021 6:43pm
Will the light bee motor be ok with 24S battery? I read that Luna melted some motors down and wonder what the actual limits of the motor are. Isn't the storm bee 96V and does that equate to 24S?
Storm bee is 25s15p Sony vtc6 cells 105v hot off charger. The motor is same diameter but twice the width of light bee motor. The cases do look identical tho.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by liveforphysics » Feb 19 2021 1:08am

Aebrennan wrote:
Feb 17 2021 7:21am
thoroughbred wrote:
Feb 13 2021 6:43pm
Will the light bee motor be ok with 24S battery? I read that Luna melted some motors down and wonder what the actual limits of the motor are. Isn't the storm bee 96V and does that equate to 24S?
Storm bee is 25s15p Sony vtc6 cells 105v hot off charger. The motor is same diameter but twice the width of light bee motor. The cases do look identical tho.

That sounds exciting, I love the Sur Ron motor, and a 2x width version is pretty attractive. Can you share pics of it? I'm thinking of retro-fit potential into a light-bee chassis. Swap that motor in and feed it from a pair of ASI BAC8000'S and Sur Rons will cross over the 50hp line.
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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Feb 19 2021 4:52am

Not sure if it's what the storm bee uses but surron makes a SP180-C2 twin motor drive. Much too wide for a light bee frame though.
Image
https://evnerds.com/electric-vehicles/e ... companies/

Someone is working on a 'frankensurron' dual motor light bee. Looks promising. Is going to take an enormous battery pack to be able to draw 2x the current though.
https://www.youtube.com/watch?v=x7lh5Fq95Eg
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 07 2021 8:24pm

Hi guys,

Thanks for continuing the awesome discussions in this thread. So I have been really busy with slightly different two wheel related activities lately (Mountain bikes), so I have been a little out of the loop with all things Surron. Anyway, from what I gather, more and more battery packs and mods are becoming available for the Surry... that's cool.

I just got back from a 20km ride and I'm pretty much had enough with this bike. It's a decent little machine but the suspension (MTb components) and overall bike size is just not good. I'm literally getting arthritis riding this thing and yes, I've modded my suspension and have done all that. All of these mods that everyone is doing to suspension, the seat extensions, are just ugly, band aid solutions on an frame platform that needs an entire re-design. Don't get me wrong, for the money, it's the best bang for the buck that can be had, but I want to build something for the pro's, high end, something that can actually be raced and jumped without blowing your knees out. Oh, and it has to look good, not like a back yard hack job.

So I'm announcing now, that I would like to embark on designing a whole new frame that can accept and take the upgraded components that everyone is using to mod their stock bikes. So this new frame won't be as big as a Storm Bee, but will be somewhere in between a Light-bee and a Storm bee. It will use CR85 suspension components, upgraded brakes. 21" MX wheel upfront, 18 or 19 in rear. Be proper adult height, probably 72V, still using the stock light bee motor....I have a few PM's to look at regarding this endeavor but please message me if you are a company or small team willing to work on this, investors/funders welcomed also...let's get this done.

Last winter, I was involved with the design of the Golden Motors GMX frame, I did the CAD design, which you can see the prototype over at Electric Motorcycle Builds forum on facebook (just search GMX frame). I had to leave that project due to time constraints and also I was interested on focusing on "smaller" frame designs etc.

I will keep everyone updated here. If I can get help funding this, then I can start right away, if no help with funding, then it will have to be done as a side project and will take a lot longer.

Cheers-

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Sep 08 2021 2:41am

Forget using the surron motor.
If you design something go with a proper motor like 3kw qs motors.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Sep 08 2021 7:17am

Anyone ever tried to pot the motor windings? (Warning: I'm thinking out loud :flame: )

We were thermally potting some inductors into an aluminum casting at work the other day in a prototype charge controller (we do this in production a lot.) I had recently been viewing a thread here w/ the SR motor taken apart and looking at those pics got me wondering. I watched my dad rewind a transformer and vacuum pot it w/ varnish as a kid. Messy but simple process. Why can't we put something like a HDPE rod/tube into the center (or a stiff coiled sleeve of plastic), vacuum pot the stator windings, and then press the rod out? I have a venturi based coolant system pump that will get down to ~0.15bar fairly quickly. Not as good as a true vac pump but would be 'good enough' to pull most of the bubbles out. A potted stator should run cooler (by virtue of being able to get the winding heat into the laminations and from those into the shell), have more even temperature distribution (the end windings run hotter w/o cooling), thermistor readings would be more accurate and faster responding, provide slightly more thermal mass for higher peak power. I know the magnets are the limiting factor but anything you can do to keep the stator cool keeps the rotor cooler too.

The epoxy we use at work is too viscous. Some of that it due to it being loaded w/ aluminum oxide for thermal conduction but the base epoxy is still thick (think hobby grade 5-min epoxy levels of viscosity.) Its sets fairly fast too so wouldn't give much working time. I think something much less viscous w/ 30min+ working time would be more suitable.

One could even be clever and bury some aluminum/copper tubing around the end windings before potting to help water cool the motor if you wanted to go really nuts.
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 11 2021 12:18pm

Merlin wrote:
Sep 08 2021 2:41am
Forget using the surron motor.
If you design something go with a proper motor like 3kw qs motors.
Which model do you recommend?

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Sep 11 2021 1:04pm

QS138 70H V3 Motor with 1:2.35 gearbox


https://www.facebook.com/watch/?v=803741160360601


i think nothing can beat this motor "atm"

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Sep 11 2021 1:20pm

Jonathan1981 wrote:
Sep 11 2021 12:18pm
Merlin wrote:
Sep 08 2021 2:41am
Forget using the surron motor.
If you design something go with a proper motor like 3kw qs motors.
Which model do you recommend?
The biggest one you can fit. :lol: One of the 3kW QS mid-drives has the reduction gear in it (edit: see the one posted above) so you can't do the concentric pivot jack shaft like the SurRon does. (which keeps chain length constant and greatly simplifies chain management, noise (slap), and efficiency.) There is a 'plain' 3kW, 4kW & 8kW that are direct shaft output. So you could do the primary reduction like the SR does (but please use a chain (#219 or 35) instead of a belt.) The 4kW would keep you at 72V and only has a kg or two weight penalty. I think the 8kW is higher voltage.

I agree w/ Merlin on the basic point. If you have a new frame, different suspension parts, aftermarket controller, why saddle yourself w/ a hard to get SurRon motor? Maybe use the battery form factor as there are increasing aftermarket options available.

Though I think you are limiting yourself w/ CR85 suspension. After a 21" wheel upgrade you'll end up at ~225mm travel - not much more than a SurRon. My Freeride E-XC has w/ the 85SX forks which start w/ ~25mm more travel than the CR85 and w/ the 21" wheel its limited to 250mm.
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 14 2021 10:04pm

smdub wrote:
Sep 11 2021 1:20pm
Jonathan1981 wrote:
Sep 11 2021 12:18pm
Merlin wrote:
Sep 08 2021 2:41am
Forget using the surron motor.
If you design something go with a proper motor like 3kw qs motors.
Which model do you recommend?
The biggest one you can fit. :lol: One of the 3kW QS mid-drives has the reduction gear in it (edit: see the one posted above) so you can't do the concentric pivot jack shaft like the SurRon does. (which keeps chain length constant and greatly simplifies chain management, noise (slap), and efficiency.) There is a 'plain' 3kW, 4kW & 8kW that are direct shaft output. So you could do the primary reduction like the SR does (but please use a chain (#219 or 35) instead of a belt.) The 4kW would keep you at 72V and only has a kg or two weight penalty. I think the 8kW is higher voltage.

I agree w/ Merlin on the basic point. If you have a new frame, different suspension parts, aftermarket controller, why saddle yourself w/ a hard to get SurRon motor? Maybe use the battery form factor as there are increasing aftermarket options available.

Though I think you are limiting yourself w/ CR85 suspension. After a 21" wheel upgrade you'll end up at ~225mm travel - not much more than a SurRon. My Freeride E-XC has w/ the 85SX forks which start w/ ~25mm more travel than the CR85 and w/ the 21" wheel its limited to 250mm.
The idea with using a Surron motor was that they are widely available in bikes already, so the idea would be, people who have a Surron already would just transplant all of their components into this new frame. But yeah, still trying to figure all of this out. So thoughts and feedback are appreciated.

Regarding the direct drive vs. jackshaft, that brings up a good point. I actually don't think it would be possible to design a frame using a jackshaft, that could accomodate the large AH lightspeed batteries...I mean, actually make them fit properly into the frame and not stick up into you ballz like all these modderz are doing (which is so dumb I can't even go there).... so for a largish 72V batt, would have to be direct drive, ie big ass rear sprocket. Do they make those motors in direct drive?

I've ran a 26" MTB wheel setup, roughly equivalent to a 21" moto wheel on a CR85 fork for years on a custom build light weight dirtbike and I've had no issues with it, and can jump biggish jumps PROPERLY without the bike feeling like it's going to blow apart. Any bike over 125lbs (~300lbs bike+Rider) requires proper motorcycle suspension. Period. I've learned this first hand while building custom frames for the past 10 years. I started out with MTB sus, just like the surry uses, DH forks, upgraded springs etc. and quickly realized it's not good enough. Remember, MX forks are MUCH stiffer (but unfortunately heavier) than MTB components, the stantions are MUCH larger diameter, more oil, larger springs, so even if equivalent travel of 8", you get way more suspending power out of it. The real problem with going with anything Showa is buyers are limited by the used market, there's always a new set of forks but that's like 2K.... but eh, maybe that's the price it will cost.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Sep 15 2021 7:44am

Jonathan1981 wrote:
Sep 14 2021 10:04pm
The idea with using a Surron motor was that they are widely available in bikes already, so the idea would be, people who have a Surron already would just transplant all of their components into this new frame. But yeah, still trying to figure all of this out. So thoughts and feedback are appreciated.
Yeah, but if all you're swapping over is the motor and a (not so great) battery, thats a $4000 motor/battery combo :( You'd be way better off selling it and buying new parts. If you were reusing everything BUT the frame of the SR it would make sense as a donor. But to do it right you really don't want to use any of it.
Jonathan1981 wrote:
Sep 14 2021 10:04pm
Regarding the direct drive vs. jackshaft, that brings up a good point. I actually don't think it would be possible to design a frame using a jackshaft, that could accomodate the large AH lightspeed batteries...I mean, actually make them fit properly into the frame and not stick up into you ballz like all these modderz are doing (which is so dumb I can't even go there).... so for a largish 72V batt, would have to be direct drive, ie big ass rear sprocket. Do they make those motors in direct drive?
They do make the QS motors in direct drive as I've said. You could put the motor on top of the countershaft like Alta did and still leave room in the front for a deep battery.
Image
Doing single stage gear reduction w/ huge rear sprocket is limiting (like the Kalk). I'm running a 60T on the SR. DaveJ is running something he adapted off a Zero (80T??) on his SR so he can climb the hills @ Granville's place. It really puts the sprocket in harms way as it hangs down so far. W/o the 2.4 primary reduction, my 60T would become a 144T sprocket. No thanks! I'm building a #219 chain conversion for the primary drive and going w/ the increased 2.7 primary ratio instead of the stock 2.4 belt now that I have 72V to compensate.
Don't discount multiple batteries either. I've long thought a second parallel pack under the seat would be a good way to increase capacity.
Jonathan1981 wrote:
Sep 14 2021 10:04pm
I've ran a 26" MTB wheel setup, roughly equivalent to a 21" moto wheel on a CR85 fork for years on a custom build light weight dirtbike and I've had no issues with it, and can jump biggish jumps PROPERLY without the bike feeling like it's going to blow apart. Any bike over 125lbs (~300lbs bike+Rider) requires proper motorcycle suspension. Period. I've learned this first hand while building custom frames for the past 10 years. I started out with MTB sus, just like the surry uses, DH forks, upgraded springs etc. and quickly realized it's not good enough. Remember, MX forks are MUCH stiffer (but unfortunately heavier) than MTB components, the stantions are MUCH larger diameter, more oil, larger springs, so even if equivalent travel of 8", you get way more suspending power out of it. The real problem with going with anything Showa is buyers are limited by the used market, there's always a new set of forks but that's like 2K.... but eh, maybe that's the price it will cost.
Boxxer=35mm, DVO 36mm, CR85 & Dorado 37mm, Fox 40mm. So CR85 stanchions are not "MUCH larger diameter" than modern DH forks. FWIW, The Freeride E-XC is using 43mm WPs.
Both the CR and mtb forks are going to need a revalve to work best. W/ me at 185# and the bike over 100# I'm definitely into 'Clyde' territory and need to respring/revalve. Do the little CRs have a midvalve?
If I was making the bike more 'adult sized' (like the 7/8 sized ktm) I'd at least go w/ CR125R forks. That'd get you a bigger axle too. The early ones are the same 43mm as the ktm's WP (which are off their 85SX.) Lots of nice old race bikes had 43mm forks.

My SR has Fox susp & real moto wheels. I've ridden DaveJ's SR w/ CR front end briefly while he rode my Freeride. We were doing more technical than fast stuff. But I've swapped back and forth on laps my me and a buddy sharing my SR & Freeride in tight faster single track. While we both agree the SR is 'different' it doesn't give up much to the KTM. The Fox susp is definitely more 'plush' over small the small roots/bumps if I don't turn up the damping. When going gets fast though, my problem currently is the other end. Still trying tho dial in the new DHX2 to not chatter. The ktm can flat out put down power better uphills in the rooty stuff. I have very little time on the fox shock so far but its clear I need to bring tools w/ me out to the trouble sections on the trail and ride those repeatedly while adjusting it.

Anyway, just my opinions :) Cool project you are thinking about taking on!
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 18 2021 12:51pm

Well I'll be damned, you're right! 37mm on those CR85 stantions...that's weird, must be an optical illusion then. Thought they were much larger than that....maybe because I just had a pair of KTM450 forks in my hand recently...got them confused... But even then, the way they're sprung/valved and oiled, not to mention the tubing thicknesses, it's a totally different world compared to MTb components. Don't get me wrong here though, MTB suspension will "get the job done" on trails, it's a little rough here and there but obviously plenty of people using them. It's when you start jumping and really riding aggressive that it then begs for real MX sus.

Yes, they would need to be setup and valved for rider weight. I only weight 150lbs, so they work well as stock setup. With regards to CR125 suspension, those are big ass heavy forks, they're similar to what we used on the GMX prototype (KTM 450 forks) I just feel that's getting into "Big bike" territory and would be overkill for the size format I'm going for. I want to keep this design small and nimble, I've been riding a gas prototype I built using this suspension setup for years and it is 110% the most fun on a dirt I've ever had. I would like to be able to port that over to electric if I could.

What I don't like about using the MX suspension is the fact that you'd be stuck with trying to source these forks on the used market or buying brand new from Showa. I would LLLLLOOOOVE to be able to get a bespoke suspension manufacturer in on this project too. Build something on par with a Showa CR85 fork, but lighten it up a bit etc. but still, that would not be cheap.... :(

Regarding the direct drive, big sprockets are definitely the easy way, but I agree, not the best. The issue is, sticking a jackshaft in there with the upgraded battery size AND keeping the format nice and "tight" is almost impossible. I've tried to roughly sketch out and play with various designs for something like this and no dice. Even the GMX project I recently worked on required a direct drive and large sprocket AND even with that, it was difficult to get things to fit.

If alta is doing it, it looks like they're using a pretty small diam motor to get it to fit above the axle....custom motor?? and I bet the seat height is pretty tall aswell..

Still no one has given me the size of the larger lightspeed battery (must be extremely accurate, +- 1mm), or of any largish battery build for the Surron. If I had that, I could atleast get started trying to figure this out. Also, do the Q motors listed above have links to CAD files or dimensions? That would help too.

Thanks everyone, keep me posted.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Sep 18 2021 1:06pm

Don't copy surron battery case size. It's shit for 21700 fit.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 18 2021 4:16pm

Merlin wrote:
Sep 18 2021 1:06pm
Don't copy surron battery case size. It's shit for 21700 fit.
10-4, give me dims for a good size 72ah battery enclosure then. Assuming it's not just taped up, like atleast some "padding" within the enclosure, rubber/plastic etc.

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Merlin » Sep 18 2021 4:42pm

sure...

380 x 148 x 158 gives you a tight 20s14p of 21700
for example p42 molicels = 4kwh capacity / 560A peak power/ 20kg weight in 1,5mm Aluminium case.

or 5kwh with 5Ah cells and ~ 280A peak power

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by smdub » Sep 18 2021 4:59pm

Everything on the Alta is custom (of course.) Here is the cutaway diagram:
Image

No one says you can't make the battery compartment bigger but at a minimum it should fit a SurRon battery. There have to be more of those out there than all the other similarly powered e-bikes combined. If people can use an expensive battery they already have it will help sales. I have a Lightspeed Molicel 21700 72V 32Ah pack I'll go measure.

What do the CR85 forks weigh? I ordered some front pull straps and will have to drop my E-XC forks out of the triples to install them. I'll weight the right leg when I do.

You probably have a point about the stanchion material differences. The Fox40s are aluminum. Steel @ 37mm will still be about 2x stiffer given everything else is equal since Youngs modulus for steel is 3x aluminum.
Surron (heavily modded), X160 (kid's), '21 Freeride E-XC

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Re: SURRON LB: RESEARCH & DEVELOPEMENT

Post by Jonathan1981 » Sep 19 2021 11:54pm

smdub wrote:
Sep 18 2021 4:59pm
Everything on the Alta is custom (of course.) Here is the cutaway diagram:
Image

No one says you can't make the battery compartment bigger but at a minimum it should fit a SurRon battery. There have to be more of those out there than all the other similarly powered e-bikes combined. If people can use an expensive battery they already have it will help sales. I have a Lightspeed Molicel 21700 72V 32Ah pack I'll go measure.

What do the CR85 forks weigh? I ordered some front pull straps and will have to drop my E-XC forks out of the triples to install them. I'll weight the right leg when I do.

You probably have a point about the stanchion material differences. The Fox40s are aluminum. Steel @ 37mm will still be about 2x stiffer given everything else is equal since Youngs modulus for steel is 3x aluminum.
Haha, OMG, and that's exactly why they're out of business, that must have cost a fortune to do....


Yeah, ofcourse, at the minimum it will be made to fit a stock Surron batt but but who want's that.....it's tough when you start to go bigger...like the 72V versions, they get long, and that makes it VERY difficult to design something around, unless you want the pack in your ballz, like all the modderz are doing but that's just such silliness. Yes, if you could measure that batt that would be awesome.

CR85 forks, IFICR, are ~ 20lbs... they're not light, but not CR250 or KTM450 fork heavy. A pretty nice sweet spot. But they're also 11.8" travel :) that's the key. But I think an aftermarket company could make something 8-10" and that would be great also. Like a marzocchi trials bike fork. That'd work just fine also.

Yeah so, like I mentioned, I've tried to play around with this before but the longer batt packs are a really issue. I'm not too keen on trading that length for width either...your idea about two seperate packs is interesting. That could definitely free up some design freedom.... I'm not an electrics guy so not sure how feasible that would be, I'm assuming you'd need fairly large cables between them....

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