with the little cog that you flipped over, if you open it up you can actually flip the orientation of the little springs and the bits that catch. This way you can thread it on as it was intended but it will work in reverse and in the direction needed
Not all of them can do that. Cheapo china special ones don't, they're milled one direction. You need the ones that are specifically made to be like that (milled both sides).
That cheap Chinese rear cog will eventually lock up on him and he's going to break his shins. He needs an American-made White Industries ENO Freewheel as I have on my hub motor. They also have a set screw to lock the threads
I suggest using hub gearboxes, there are some that can withstand 250Nm, the main plus is that you can use single speed chain. Also this bicycle tensioner wasn't holding tension properly, that's why you experienced this skipping teeth. Gearhubs are way better for this kind of applications. Good luck and hoping you finish this awesome project. Also want to see it full throttle
Yep, the cheap gear tensioner you bought online is not up to the task. You need a derailleur with a clutch and probably a heavier duty spring in it than you'd see on a mountain bike. You could see it when you were doing the initial testing. The motor was spinning so fast and there was so much inertia in the chain overpowering it, the derailleur couldn't keep up and so the chain was slacking off, letting it slip teeth.
In the nineties one could get MTB chain tensioner, where a spring would add tension; pull the cage back. It was attached to a bracket in turn attached to the drop out by skewer.
Hey bud! Because your chain is so long, it looks like you definitely need a derailleur with a clutch. Basically when engaged it puts extra tension on the chain. The clutched derailleur does make a big difference but whether this long chain is going to still play up despite having it - not sure on that :) Nice project btw. keep it up
if you add a chain tensioner on one side that has a nice strong spring, but your derailleur has a softer spring then will your extra tensioner not just extend the derailleur a little bit more and keep the issue? I'm not exactly sure but this what comes to my mind
The chain guide block if you insist you using it should be made from low friction plastic, UHMWPE or PTFE probably being the best as they are often used in chain guides already.
Also a lower chain roller tensioner and beefier rear spoke's and sprockets cocks, and spare tubes the valve will brake under full power, that motor is a monster.
A new chain on old rear sprockets will mostly skip teeth. People usually use the last gears not the first 3. These were still good and not skipping teeth.
Moving the pancake motor to the rear wheel, and "lacing" onto the rear rim looks (to me) to be your best option. You might be able to at least partially fix your chain issues by switching to a belt drive instead, it might get rid of the jerkiness of the chain drive. Anyway you try it, this is a really tough build, and a test of even your formidable fabrication skills. Good luck, Chris!
Failure is always an option👍 that little chain still took a bit of abuse before it snapped and I agree it was interesting to see what it takes to break it. Love the channel it's one of my favourites on yt.
You need a second spring tensioner sprocket on the bottom, right near your pedal bearings- that way it cuts that long stretch of sloppy chain in half, and will keep it from bouncing around so much. Also, you probably need a little stronger springs in your rear chain tensioner. (but maybe not, after putting on the second tensioner.
I’ve really enjoyed this project. It’s fun to just get your hands dirty and try things out even if you know it’s a silly and seeing the trial and error/learning taking place is awesome! Keep it up, stay curious!
there no potential. Outrunners like hub motors were mainly being at a high torque less speed. Yes as they are open they cool a lot better than inrunners like qs138 etc but they can cause problems such has cables and rock being stuck on them.
As cool as I think this idea is, I think the motor works better back on the hub. Could keep the pedals and gears for full functionality if the battery is drained. I'll watch whatever you end up doing though I like how you tackle these ideas.
I'd suggest to get a e-bike rated cassette / derailleur / shifter combo from shimano or microshift or so, they are more durable and also you'll need the clutch. However, a big problem is going to be your front cog because it's not made to handle more than a single gear in the back. btw you need to get a chain that matches the correct number of gears and also your front cog is probably only made for wider chains
Seconded. This goes back to my other comment about trying a proper front sprocket and looking into Narrow/wide sprockets in particular. A derailleur with a clutch would absolutely help keep things settled as @maxpet indicated. But yes make the chain and sprockets harmonious and things will become mas simpatico.
the issue is with the motor sprocket so far ahead of the swingarm pivot the chain has to change length where there's no tensioner. the derailleur/cassette system relies on the flexibility of the chain to handle the realignment. a regular factory bicycle design has an analogous front guide that's built into the derailleur for the front sprockets, the system works...
My 3000w setup did the same thing. A clutch type Derailleur will help but it is your weak point. The spring doesn't hold enough tension to keep it on the smaller sprockets even if they are brand new. Shifting while under load is what breaks chains/bends teeth on cassette BTW. Going on 4yrs with this setup on a giant glory and have tried everything from single speed 40mph street basher to 11/46t mountain goat.
Great work Chris. The hub motor is taking much longer to slow down than the wheel thats why your getting that sloppy chain on decel. And thanks for clearing up the free-wheel ratchet question. This is an awesome project.
I have that same type of shifter. confused me for a bit when i first got it, but i soon figured out that it goes under the bar. This allows you to shift whilst still griping the bars. I love it now and recommend this style to everyone that has a bike.
The angels are important for a bike derraileur. If you put chain tensioners over and under the pedals so that the angle of the chain looks like on the original bike. That would do a lot and keep the chain from flapping around like it did in the video.
Try this trick too, stop the motor roll completely before changing gears. This happened to me a lot with my first diy build and it took me a while and even motor bike piece's too figure it out.
Bicycle chain comes in several styles; Single speed/BMX chain is the widest, and then the chain gets narrower and more flexible as you get into multi speeds like 6-7-8-9 speeds. If you're not using the correct "speed" chain for your cassette on the wheel, then it can get snagged between the sprockets, and potentially bind or skip. Measure the thickness of your freewheel sprocket and the cassette sprockets. If they're not the same, then the chain that fits the freewheel will be too big for the cassette sprockets. You can grind thickness off of the freewheel sprocket to make it match the cassette sprockets, and then get the appropriate chain.
You should make your own sprocket with only 3 different types of gears for crawling, mid range and top speed, try to make it switch between gears as it would normally. Attach that on that upgraded wheel with bigger bearings, beefier chain and sprockets
You have to shift one gear at a time, just like any manual transmission, otherwise the chain will snap or the axle will bend. Also look for soft throttle in the controller software, it should help. Glad to hear you're thinking about beefing up the rear-end. It's really the only way it'll work. Good luck!
Also the Chain Tensioner needs a stronger spring, it's struggling to keep the chain tight causing it to jump and skip parts of the wheel's sprockets entirely, especially at higher speeds.
Maybe it's just his rear wheel freehub that isn't freewheeling smoothly causing too much drag and tension on his rear derailleur. It also can be that the SRAM derailleur is not strong enough for his much longer than normal chain - wish he used Shimano 9/10/11 speed clutched derailleur because i feel like they have much stronger tensioner.
HI! To increase strengh of your chain and sprokets you can install 8 speed drivetrain as it uses thicker chain and sprokets, as well you will need to find a cassete that has sprokets attached to each other - not the one where sprokets are spaced with little spacers. That way you wont damage hub that cassete is sitting on as torque will be distributed evenly across 7 (not the last one) gears. I had to change my 9 speed chain every month and now I don"t even remember when was the last time i changed it.
The width of chains for different numbers of gears, according to Park Tool is: 13 rear cogs - 4.9 mm 12 rear cogs - 5.3 mm 11 rear cogs - 5.5 mm 10 rear cogs - 6 mm 9 rear cogs - 6.5 to 7 mm 6, 7 and 8 rear cogs - 7 mm
From what I can see, the rear selector the spring to weak for the motor. When you went past 1:1 you can see it not keeping the chain taunt enough. I would also agree with what you said about changing the power curve so it tones down the toqure
Try a chain tensioner at the swing arm pivot point it should help take out the awful chain slap. I've got a similar set up using a skateboard wheel on a lifted pit bike and that works great 👍
Part of the reason your motor feels so torque is because you have a super small sprocket on it! The motor needs a much bigger sprocket so your rear sprocket can be larger for more teeth on the chain. Custom build rear wheel is def worth doing for this. the bicycle parts for good ones are super $$$ for what you get. Neat project, you could have easily moved the motor up a few inches mounted your controller on the nutcracker bar and then the rear of the battery could be moved up as well. Not a bad try for just a concept. i have faith you will figure this out very soon! PS buddy of mine did a ebike with a small high speed motor on the front wheel worked very well was a ton of fun and was much less work to build :D
Me gustó mucho tu proyecto por la ubicación del motor y tratar de compensar el centro de gravedad que también involucra al pack de baterías, yo he realizado algunos proyectos similares y la cadena que me resultó fue las que utilizan las bicimotos (motocicleta de 50 cm3) fíjate en moto Razor electrica 500/650.(niños) que lleva un estira cadena para que trabaje más estable la cadena. De todas formas otra opción resulta emplear poleas... Ten presente que el piñón cassette económico tiene poca resistencia ante el torque de semejante motor 6000W 😱 que se transfiere de motor a rodamientos, si algo limita al motor no queda otra que romper cadena o que patine rueda/polea Saludos desde Argentina 🇦🇷👋 PDT: Todos los que disfrutamos de innovaciones, inventos, etc "manitas" debemos pasar por momentos quizás ridículos en fase de experimentación 💪
If you go single speed you can use a thicker chain, but those doesn't work with derailleurs. In trials we rip chains like that when we do hard pedal kicks, I've pulled the tooth rim(that the pawls engage with) inside the hub lose once so the hub was scrap. Larger sprocket in the front might be a good idea as well, not just for speed but the chain will probably like it better as well.
So I like RC cars. I remember when brushless motors were just starting to pick up and get cheap enough to actually use, I had a traxxas e-maxx at the time and I thought "more power = more fun". Upgrading the power on that e-maxx frame was fun, but the fun lasted all of two minutes before the shafts from the hub to the wheels snapped from the torque, I got metal shafts and then went out to play again and this time the drive shafts broke, I got metal drive shafts and whent out to play and the slipper clutch burnt up, I upgraded the slipper clutch to a racing metal clutch and went out to play again, this time the rear differential blew, I got metal upgrade differentials and went to play again, this time the wheel spun on the rim, so I got higher power tires and when out to play again, this time the plastic hub that holds the rim to the hub broke, I went back with metal upgrade hubs and by this time it had been months because most of the parts had to be shipped in those days as metal upgrade parts were not widely available and I was ready to just go back to stock. Too much power in a setup that cant handle it is not fun for more than 2 minutes. I would suggest that you build a frame around that motor and get parts that are rated for the torque that motor produces because otherwise I would predict a lot of cascading failures that only serve to indcate the next part in the system that cant handle the power.
Hi! Amazing job! As Deliveroo rider for some years now, on ebike with the BBS02 ("just" 750W) i wanna give you some tips ^^ 1- As you have pedals, try to make all the gears shifting while pedaling, because more than 150w is too much for a shift. You can snap the chain and wear away the chain and cassette so quick. 2- Usually, smaller is the cassette thicker is the chain, as you have more space to sit the chain. So a 7 or 8 speed cassette can avoid some chain skipping, and your Sram x4 handles from 7s to 9s, its my derailleur ^^ 3- Try to go through all the gears or 1-3-5-7 and avoid long ratios on climbs. 4- Your chain needs some tension from the bottom. Long time ago i made like a tensor/chain guide with the last arm from a derailleur and it worked smothly. 5- Other way is the single speed. A single sprocket has bigger teeths. Sorry for my english and don't give up with this proyect!
I ran a snowblower motor using stock derailer. You'll need to get better shifters that lock and fine tune shifter. Use your lock position screws and increase spring tension. Mine is in my playlist labeled mountain monster
buy a better chain, buy a couple more back derailleurs to control the slack caused when the chain spins so fast it lifts out of the troughs on the gears. mount them above and below in the middle...also get rid of the aluminum block fairlead, use the tensioner to correct the angle to the motor. then you will certainly have all you need for the 'hold my beer'' video. ::) keep us posted!
Not a failure, just a stepping stone in the right direction. I think that your chain is longer and therefore the rear derailleur is struggling to keep it in place. I think you could upgrade the spring or add a second chain tensioner. You have only just got it going please do not give up. Just tweaking to get it going from here. I have watched everyone of these videos and although this is slightly unconventional I believe you can get it going and would love to see you do more with it. 👍💪👊🙏🇬🇧
Nice work! Don’t give up with out trying a sturmey archer internally geared hub. This will keep your chain line straight and get rid of your slack chain Issue. Good luck.
i use a #25 chain with my 2000w motor on my scooter i made and it barely holds up mostly because if you dont have enough tension the torque from the motor will cause the chain to skip i hope you can find a chain that will hold up to your idea also i love watching this since it helps give me ideas for the scooter since i keep trying to figure out how to add some type of 2 speed gearbox onto it
I don't know if you know this but you can buy a freewheel crankset. You could have avoided a bunch of unnecessary welding. Origin 8 sells fixed gears that bolt onto existing disk brake mounts. All you would have had to do is flip the motor around and reverse it's direction, bolted on the fixed gear, run a chain from it to a freewheel crank set and than a chain from the crank set to the rear gears.
I think you should leave the right side like a stock bicycle with the stock chain and redo the left side to accommodate a #35 or #40 chain straight from the motor to the rear hub… obviously you’d have to adapt a sprocket to the left of the rear hub and modify the rear brake setup.
fresh brake pads needed proper bedding in... stronger chain and different rear cassette, you can get rear derailleurs that have a really strong spring which should help chain tension. Also do not change gears under power, especially under the motors power. It wears components a lot faster and increases chance of chain skipping. Building a beefed up rear wheel would be best bet, thicker gauge steel spokes, etc. Doing great, hope this helped and good luck
If you add a jack shaft back on the rear control arm you could properly tension the chain from the motor to the jack shaft and have a much shorter rear chain so that it isn't flopping like a wet noodle the whole time. That might not fix all the issues but I think it would really help the skipping teeth at least at the motor sprocket.
You could modify the area where the chain passes over the pedal shaft to be a jack shaft of sorts. Setup 2 gears bound together independent of the pedal shaft; one chain to the hub motor, another to the tire. It would shorten the chain and give more options on gearing.
I think you need some stronger springs in the derailer..would keep chain tighter to help with skip and it getting stuck forward under power....that would help enormously. And yes on the shifter cart!!
In fairness a bike chain is definitely not the play for 8000 wats, but you definitely were only using a fraction of that in your test. It seemed like your main issue there was your derailer couldn't keep tension on the chain line the chain was catching on parts of the frame and trying to snap. Floppy chains aren't much of an issue on normal bikes because when the chain comes off or otherwise gets caught you probably stop pedaling instantly but you've got a massive flywheel attaced to an abnormaly small drive wheel so if something does go wrong you chain gets got. I'd recomend a derailer with much stronger retention (ie a clutch) and a front ring with at least 40 teeth if not 50 or more for better chain engagement and higer top speed. Good luck to ya!
you can always play around with a bigger or smaller front sprocket, but if your sticking with the bike chain. install the front derailure for it and it should help as a chain guide
It's got a steam punk look to it, I like it. I imagine people seeing you test things would be like seeing Doc Brown, just fascinating. When the apocalypse happens you will be a savior to many.
Your problem is when the rear shock compresses, the chain distance shortens along the top causing slack. Also, more tension on that rear derailleur. There are specific eBike chains for this purpose, about 5x the price of a standard chain, or you’ll be breaking them all day! Best of luck! Looks like an awesome project.
The spring rate in the derailleur wont hold a chain that long but 8kw as you found will require a motorbike chain, id go internal hub gear with a belt drive myself it will be quiet and stronger than chain, lasts longer than chain and internal hub gear will eliminate the drivetrain length issues, the windings in the hub are made for torque, id go with a bigger ratio on the front gear
Nice project... i had same problems with my homemade electric bike... snaped chain on 2 places because it skiped(low chain tension) but then someone told me i should shorten my chain because back shifter does not tension chain enough on smaller gears thats why it skips and broke... if you want try it because it worked for me... stay healthy brother and thank you for educational videos i learned a lot from you 🍀🍀🍀🍀🍀🍀
Hi!, As some other people commented, the chain was a little long and that derailleur looks like it doesn't have enough tension. I would recommend you to use a new cassette on the rear with a new chain, just tu make sure it does not skips. Also if you want speed you can try using a larger chainring in the front since that motor has already lots of torque. Nice video btw 👌🏾🔥
I love the build. Need to get a delrin guide for the chain. On the top. your derailer does not have enough tension to keep the chain from skipping teeth on the back wheel. Love the direction your going
Derailleurs are not designed for motor drive. I built a Honda powered bike years ago. It constantly destroyed derailleur tensioners and chains, as you found. Hit any kind of a bump and the chain will misalign and break things. Replace the derailleur with an internally geared hub and a rubber belt drive.
Instead of the aluminum block chain guide to keep the chain aligned with the sprocket, could you make a block with two pivoting trailing arms that you could lock in place with small free spinning sprockets on them that sandwich the chain from the top and bottom to keep it in place? Cool project!
The chain block is putting a sharp angle on the stressed side a lot, put it through a tube that bends where the block is, to reduce the tension at the bend
I would suggest completely enclosing the batter pack in a sheet metal box, vented on the front and back. If you take a spill and lay it down on its side into a rock and damage the battery pack the whole thing might go up in flames. You probably already plan on doing this, but thought I'd throw it out there!
One other thing to try, if you want to make that setup work: try replacing the rear cassette (cogs) a new chain on a old/ worn cassette causes the chain to skip more frequently under load as the rollers on the chain don’t exactly line up with teeth on the rear cogs.
My first thought is a larger freewheel on the motor, and second would be to flip the motor around, machine a hub that would use a secondary motorcycle sprocket and drive chain on the left side, and use only the pedals on the derailleur on the right side.
Hey, nice video mate. If you are gonna build custom wheels anyway, why don't you get a internal hub gear system and weld a bigger sprocket and chain set up on there. The internal hubs are stronger, but if that fails, pop a pan European st1100 gearbox on there- I'm sure that'll take the forces!
Ditch the derailer and pick a gear and make the chain tight it wont jump. Its jumping in lower gears because you are only engaging with 3-4 teeth on the back if you go to lowest gear and remove shifter it will work. Or take two links out of chain so the derailer is super tight and only use bottom three gears.
Wonder if you could get a stiffer spring for the derailer to tighten chain some, keep it on better. Also those Teflon tracks they put on motorcycle swingarms? Or another derailer/sprung tensioner? That alum guide will get worn thru pretty quick by chain & crank too. Skid plate for the motor. You could sort it out.
Here's some thoughts (do with these what you will) A short cage derailleur maybe useful here as this means you can eliminate some less the slack, The higher gears could also just have more wear too.(maybe both) Also geared hubs are another option, You could run a single speed chain to those but at the same time you could also use 415h motorized bicycle chain in place of single speed/bmx chain. Idk figured i'd share some thoughts.
Bro you need to get more chain wrap around the gears on the rear sprocket. I had this issue with a mid drive. I ended up adding a spring to the derailer and bending the limit tab on it to allow it to be pushed forward more. Then we'll see what else needs to be dealt with..
I think if you put a stronger spring on the chain derailleur for changing gears and add a cantilever chain guard that swings from near where your feet pedal to keep the chain from bouncing around so much It might allow the chain to not hop off the gears and keep skipping so much.
This is what I was thinking as well. If Chris doubles the size of the front sprocket, it’ll cut the chain tension in half, and double the rear wheel speed.
Easy quiet idea, instead of the narrow aluminum block chain guide , why not make 2 horizontal twin guides similar to timing chain guides from an engine, or easier yet 2 pieces of old snowmobile track slides. Little to no noise, and no metal to metal contact. You can easily heat and bend them to create a "funnel" action as chain enters front sprocket
I'm pretty sure I have the same kit as yours installed as intended on a Specialized fsr, I'm 200 lbs and it flips me over at 25mph and slower, It tops out at 60mph, it's powered by 4 DeWalt batteries. My version 1.0 had all of the batteries and controller in a milk crate over the back tire and it flipped over if you looked at it funny at any speed level and at any speed. For version 2.0 I moved the controller into the triangle and two batteries on top and two on the bottom. It's night and day as far as usability but it is absolutely terrifying above 30mph, it has immense torque all the way until it tops out
I think you should make it single speed, geared for high speed, and beef it up. If the peddle assist works ok, you could rely on that if you wanted to peddle.
Max RPM for 273 3.5T is about 1500~1600, a new controller will not affect top speed/RPM, unless you want to go higher voltage 96~120V. A higher voltage will allow the motor to spin faster, but just swapping to a different controller will not. You're better off just going with a true mid drive motor that can do a much faster RPM, it will have a smaller package and allow you more ground clearance with the same low CG. There's a reason why most people don't use hub motors as mid drives 🍻
Lots of good ideas here. Due to the amount of torque that motor generates, I think you'd be wise to have a separate chain (#40) on the opposite side from the derailleur setup, just for the motor drive. Using a one way sprag clutch on the motor sprocket would keep it from interfering with the operation of the pedals, and you can play with ratios to get the proper speed and torque you want. Any type of transmission on the motor side is going to be sketchy, since that thing generates a lot more torque than the average human.
I like the idea of the longer frame but I would have used a regular mid drive motorbike the bofang type because I think that they make the motor in the 800amp range or whatever you are using. Also if you are concerned with chain tension that can be fixed just by offsetting the rear derailer slightly on the rear axle it will increase the tension on the chain the other option is to add a spring loaded chain tensioner. Also with the bofang mid drive motor it will help to fix the problem of ground clearance, also if you are interested I have an idea of how you can add both more gears than what you have been using and you won't have to get off the bike while changing gears, and also less chance of breaking the chains.
