Are Chainless String Drive Bicycles a Genius or Terrible Idea?
String Drive is a chainless bicycle drivetrain that uses ROPES to propel you forward! 📘 The Bikepacking Bike Buyer's Guide: www.cyclingabout.com/bikepack...
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I have a lot more videos on bicycle drivetrains for you to watch! 🤌🏻
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💜 Enviolo CVT internal gear hubs --- • Are $199 Enviolo Hubs ...
❤ Rohloff hub vs Pinion gearbox --- • What's The Ultimate Bi...
💛 Belts are now BETTER than chains --- • Belts Are Now BETTER T...
💙 Effigear Mimic gearbox --- • Is This Bicycle Gearbo...
💜 Chainless shaft drive bicycles --- • Are Chainless Shaft Dr...
💚 Chainless digital drive bicycles --- • Are Chainless Digital ...
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0:00 - Intro
1:52 - How Do String Drive Bicycles Work?
3:43 - The Advantages of String Drive Bicycles
6:34 - The Disadvantages of String Drive Bicycles
9:43 - Why Didn’t String Drive Take Off?
10:25 - Other Interesting String Bike Quirks
11:51 - Summary
There's a LOT of research & development going on in the CVT, digital drive, combined motor+gearbox, and hydraulic drive spaces! What bicycle drivetrain tech would you like me to cover next? 🎉
Hydraulic sounds interesting
What's CVT?
I love your videos on non traditional gear. I share your passion for belt drive bikes. But this tech I feel is not going anywhere. No disc brake + not good for e-bikes tells me that.
@@pumpkinjutsu1249 A single gear transmission that is a continuous variable transmission. Many automobiles use them now.
@@pumpkinjutsu1249 "Continuously Variable Transmission: A continuously variable transmission is an automated transmission that can change through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps."
I wouldn't want to park one of those in any city that had developed scissor technology.
Tweakers/FentHeads in San Francisco (where I live) would cut those strings on purpose, out of spite, just cause they're there.
tbh with a good pliers I can also cut down chains
I also thought it weird that this most obvious flaw wasn't adressed
I fail to see how the strings are more vulnerable than your tires, though...
Because the novel unusual strings, when seen, put the idea into the head of nasty person. @@Jerburger
I really love seeing people just trying to do something different, whether it ends up working or not.
Agreed, it might not takeover chains anytime soon but it's interesting new way to pedal a bike.
If it ain’t broke…
thats what im sayin @@idonjohnson6999
Agreed. So many technologies we take for granted nowadays came from someone asking "what if...?"
There was nothing wrong with horses, but life is a hell of a lot better with a car.
I think it’s really cool, if only for the mechanical novelty aspect of it. The fact that it worked as well as it did, is testament to the team’s knowledge and hard work. Unfortunately, for it to work for the masses, it needs to be much easier to work with, cheaper, and have wider compatibility. Great video once again. Cheers from Australia
yeah string drives have their advantages I like having the choice of which ever one I want to use on a bike chain or string drive cause choice plain and simple
@@SaraMorgan-ym6ue That’s true, the more choices the better.
It's kind of like that Kick 'n' Go scooter that had a pedal behind you you could pump to get going, but it only had a little success for about 2 or 3 years and the concept dropped. Nobody else took it up and ran with it. It didn;t really sell more scooters.
I agree. It's a cool idea. Maybe it can be used in a different application. Hi from California.
It's sort of used in garage doors lol
As a proof of concept it's frankly quite interesting, this clearly was a first gen product. Things like disc brakes, downsizing, efficiency, friction and longevity are addressable. And I'm sure that eventually they could make it so the drums narrower, only on one side, and later on they could even have drums with variable diameters for additional shifting range. But it would need at least another decade of R&D. The problem here being that the inventors patented the technology and kept it to themselves, so it was destined to remain nothing but a short lived curiosity.
Yep, an example of when the profit motive hampers innovation.
The profit motive could not stifle innovation without the help of government. The policies of government reflect the values of society as a whole.
@@calebverdu3091 Government is not the problem, it's who's controlling it. When profiteering companies draw the laws to privatize standards and mechanisms we all lose. Open source has benefited our entire society in ways people don't seem to realize. If Microsoft had their way we wouldn't be able to access your documents without buying a recent version of Word. When freedom prevails we all benefit, when not, only a few benefit. We need open source to become de rigueur everywhere.
@@emdivine The profit motive should incentivise them help third parties license and improve their patents especially when they are not using them in their own products. This is not the profit motive it is the idiot motive and it happens everywhere.
There is a company making a velocar/hpv called Djiker that seems to be using a variant of string drive that ditches rotating pedals for linear pedals so the idea lives on.
I've had a Stringbike a few years ago. It was really finicky to adjust, and those D-shaped things could bend really easily during transport, the complete system seemed to be very complicated and sensitive. Pedaling on it was not bad though, but I think the conception created more problems instead of solving them. Btw the website went down a few months ago, I think they don't exist anymore...
It’s so niche, if mainstream they’d probably work the kinks out.
Thanks for the insight regarding the lever arms, and adjustment! I actually used one for a while in 2012, although that was not long enough to find any issues. I thought it felt nice to ride once I'd adjusted to the elliptical driving path.
looks like sticks would easily get twisted in the strings. the cords would rot before a chain. not so avoidable. @@danparish1344
No shit.... they have re-invented to wheel... but its square..... and trying to convince you its not....
Yes, they went bankrupt a few years ago. The bike industry pushed them out and the selling number was low. I never tried, but theoretically, it brought a better (and, yes unusual) pedaling result. So, it's funny. The video is about an already fallen concept and excited about it.
The other limiting factor for the technology was the company who owns the patent for it. One of my relatives wanted to do business with them as the drivetrain would have been ideal for the particular use case (not a bike). He said they were not flexible in improving or adopting the idea, they created terrible quality of products and in general, were really hard to work with. So they ditched the idea and stayed with a regular chain drivetrain.
Oh well maybe it will be useful whenever the patents run out if it is even remotely relevant at that point and somebody finds out/remember that it was a thing
Society is better with open standards and open information.
Everybody wants to get filthy stinking rich right now.
@@oneofthesixbillion yeah but then no one in their right mind would ever invent anything. It takes years of effort,countless failed attempts to come up with something that works, and then works efficiently, and then works at cost. Then you have a bozo that comes after and copies it. We would have no innovation and people who would invent would never share it to a public avenue in that case. The opposite would happen
To increase competition all patents should be on an open licence, as long as something like 10% of the product price is paid as royalty fees there is no violation.
A very good analysis. I had one (probably the only one in Australia) and did not experience any useful advantages. The disadvantages, as shown here, were severe and there were other snags not shown. For example, I found it impossible to start on a hill.The "Dyneema" ropes are meant to hold 1,500 kg but mine held only 110 kg - maybe not real Dyneema - so I was breaking a rope every week or so. Also, you do get dirty hands on changing the strings.
Thanks for the insight. On seeing the marketing shots of super clean strings, it made me think “in real life it would be dirtier”. Not being able to start on a hill is a dealbreaker. Snapping a rope a week = $40 a month, another dealbreaker. And rim brakes? Nope.
They say it can climb. But every single shot of the product in action is on flat terrain. That is a highly reliable bullsh*t indicator. All "innovative" drivetrains have the exact same issue. They work (at least theoretically) on perfectly flat terrain. But they are a nightmare on the hills. The reason the chain drive is so popular is because it works decently in all road conditions. Flat, uphill, downhill, sh*tty road with potholes, etc.
Regarding oval chainrings, I concur, their benefit is inconclusive. I have one on my mountainbike. As said in the video, I didn't notice an efficiency benefit, but I feel it helps to keep grip in very steep slippery climbs. I also get less knee pain than on my round-chainrig bike.
I owned one of these, bought it second hand. The gear cables are a pig to fit and need special gear wires at the cranks which took forever to get from Hungary (I'm in the UK). The shifter uses two standard gear cables wrapped around a cylinder inside the shifter. Then there was the issue of balancing the gears on the cranks so gears changed in synch on each side. Effectively there were six cable ends to secure and balance at the bottom bracket: two cables coming from the shifter and the two ends of the two special gear wires, one on each crank. I sold it to a friend and he still rides it but getting replacement cords and other spares is a real problem.
I was thinking that at minimum there must be some synchronizing issue with the shift cables between the two sides!
Well, that seems prohibitively technologically limiting and challenging in daily use/maintenance.
sounds like the claim of needing 'no gear adjustment' isn't quite true....
Not in my experience of having one for a year or so! @@adriansue8955
He should be able to get a dyneme line and make his own cords. It's not a big deal. I would love to have one. I'm weird that way. I own Windcheetah.
I find it so interesting that every one of these videos about different drivetrains always come to the same conclusion : belt drives are sometimes the best option, chains are almost always the best or near to the best option
Personally I drive a Rohloff gear hub. But I'm still impressed, that sliding a chain sideways over gears is still such an effektive way to provide gears.
@@chrisridethatbloodything2044It's a case of KISS (Keep it simple stupid) at work. Over engineering doesn't make things better, just more complicated. Go ask the German tank engineers of ww2 how well it worked out for them making overly complex and "advanced" motors and suspension (little hint... they spent more time being repaired than functional)
@@SilvaDreams With a separate supply chain for most of the parts, and being so complicated that they had to be sent back to the factory for a many repairs, at a time when logistics was at a premium. They often couldn't just be cannibalized like a Sherman or a Jeep.
Yup, simplicity just works best. I live in the Netherlands, flooded with bikes, the vast majority with chains and the rest belts. Though you only very rarely crank shafts, despite this system being pretty simple too.
A statisztika alapelve, hogy "a negatív eredmény is eredmény". Magyarán: 1) Ha nem jársz végig egy tévutat, akkor mi igazolja, hogy tévút? 2) Olyan tévút nincs, amiből ne lehetne tanulni. 3) egyébként ez a megoldás pont hogy semlegesíti a holtponton forgatónyomaték problémát.
The design and engineering nerd in me loves these sorts of videos, and it’s interesting to see where the bike industry might go. At the same time, while the video is good, the long distance tourer in me is horrified at all the possibilities for failure in the real world on this particular idea, especially under muddy conditions.
Some time about 1974-1976 one of the bicycle magazines in the US had an article on a cable drive bike. What is shown in this vid looks very familiar to my memory from five decades ago.
I love the way you analyze, examine, think through, organize your presentation, state your case...everything. I have been looking for an exposé on string drives for a couple of years, and this covers everything I wanted to know. Thanks, and all the best.
If anything, this shows us exactly what a revolutionary idea the Belt Drive was.
It shows that belt drives are a good option; not sure they are that revolutionary since belts precede chains by a long way, and have never gone away (car fan-belts, etc). Their advantage is that they leverage other developments in bike tech (notably hub gears). I wouldn't say revolutionary so much as an idea whose time has come.
There really isn't enough different about a belt and a chain for a belt to be revolutionary. Digital drive (maybe should be renamed) would be revolutionary if it ever took off.
yeah I agree on dialing down the "revolutionary" bit. Unless that was merely a pun.
@@chrishowell5718 And the main drive system for Harley Davidson for decades.
wtf is wrong with regular chain jesus christ poeple cmon
an oft touted factoid about Dyneema usually in marketing materials is that it's 15 times stronger than steel. and it is pretty strong, but this the first time I've ever seen specified "tension". in terms of usage as part of a composite laminate fabric, it is definitely susceptible to weakening through abrasion, piercing, bending, and folding. Dyneema cordage such as amsteel blue, lasts for a really long time, but can also be susceptible to abrasion. seeing as it's mostly used in rope & fabric, I imagine it's not too strong in the "compression" direction
it seems very complex and sensitive to change, and that appears to be the most simple that mechanism can be. as an engineer, my first thought was KISS (Keep It Simple Stupid), and this doesn't seem to be the simplest you could design something like this. it may have it's upsides, but I'll trust that the chain on my bike won't snap, and if anything breaks i can replace it easily, quickly and cheaply, and even on the road. dynema is also notorious for performing poorly when heated, so i would trust it even less on a hot day, or riding particularly hard. you mentioned wide gears as one of chain derailleur systems' downsides, but often people want extremely wide gears, especially for road cycling, where the hills can be very steep, but you also may need to ride fast. overall, too complex, too proprietary, too weak, too sensitive, not trustworthy, and incompatible with other technologies. ima stick with my chains :P
In the Stockholm museum of technology (Tekniska museet) they have a "Svea" bicycle from around 1900 that uses a mechanism related to this string setup, but with an almost standard chain - with a twist. Two twists, in fact! It has two platform "pedals" with curved levers, like the string drive but pure up/down movement (which at the time was presented as an advantage over rotary pedaling). The ends of the chain could be moved up or down curved arms with notches, for "gear changes", with pneumatic actuators from squeeze bulbs on the handlebars. The chain ran over freewheels on both sides of the rear hub, then over an idler in front of the wheel. The chain had two "twist links" allowing the mid section to turn around the idler. The idler was spring loaded away from the wheel and had a platform that was pressed against the tire if you pushed down on both pedals at the same time - very simple braking. I *think* (although this is my conjecture since the museum never got them to work) that the pneumatic actuators would move their respective end of the chain up or down along the curved lever arms, depending on the pedals' position when the rider squeezed the corresponding bulb - "up" if the pedal was in its highest position, "down" if it was in the lowest.
I got to try a bike like this once in Finland. Though I don’t recall whether it had shifting or not. Nice experience, though not very efficient. I think they designed it that way to make it easier to balance yourself while pedalling
It looks goofy and awesome at the same time :D Thanks for exposing the hotest new stuff in bikes!
It's definitely one quirky drivetrain! I hope we see more of this weirdness in the future. ⚡️
@@Cyclingabout Wouldn't the best "drivetrain" essentially be similar to a central one-wheel with a gearbox plus front and rear wheel for steering? Basically eliminating belt,chain,string, cardan shaft and instead driving a gearsystem directly. I bet there is a tinkerer that did this. It might also come with rear and front axle steering.
Thank you for this fascinating video. I have long wondered how they work,
Although dyneema fabric has high tensil strenght it drops significantly when heated up i.e. because of friction. That is why in climbing it advised to refrain from pulling dyneema ropes under load through all sorts of climbing hardware. Maybe this is why these dyneema strings last so short. I wonder how big of a friction there is on the surface of all these pulleys and the rear drum. Also, the string moves a fixed lenght when reciprocating so only several and short stripes make contact with the drums and pulleys and carry the load. This may also contribute to its short longevity. Not a good idea - a bit complicated, unrealiable, clunky, not neat with all these shifting cables.
Fantastic review very balanced.
Thanks for watching!
Love the out of the box thinking with the string bike. Dyneema is used as an alternative to stays and shrouds on a sailboat to keep masts up, so that hints at how strong this line is.
It is a nice desk contraption to look at. I guess they should push for mechanical home trainers.... No diskbrakes nor motors needed. Like you said: the individual settings for left and right can be adjusted for compensating an injury or assymmetry. I would guess that architects would like to ride these like their SAAB900's back in the days. I' hope the designers are taken in well care so they'll get their chance to hit something viable.
It also has springs to tension the ropes. Those springs need to be overcome to pedal, so that's also a loss in efficiency.
and the reciprocating mass on the spools
Not a fan of consumable plastic deteriorating into the environment but really like the innovation. Tuning each side could be really useful for physiotherapy/indoor/recovery exercise. Brilliant KZhead channel this one 👍🏻
This is solved for chain drivetrain with variable cranks on each side
Are you a fan of chains spreading grease on a regular basis?
@@aikifab grease? Nobody uses grease on a chain💡
Maybe steel strings instead
@@aikifab job is professional bike mechanic.... so... yes? a fan of doing regular maintenance
That was an interesting description. I might mention though that every problem listed can be fixed. This includes: Adaptation to existing bike frames. Wider gear ratio. Compatibility with disk brake. Greater wear life for cord. Lever based or automatic rather than twist grip shifter.
Wider gear ratio? What makes you think that? This thing has 19 speeds, my shitty mountain bike has 21.
@@iamfreeareyou681 I have no idea what point you are trying to make or how it would relate to my post.
Amazing the strength of the dyneema compared to the bicycle chain. My friend is using it on the Trapeze on his catamaran sailing boat seems to not have the durability that chains or wire in his case. I would like to see the bicycle with the chain ring behind the riders seat and the leverage arms or pedal arms reaching down where the pedals normally sit
I’m amazed you manage to put out quality content like this while cycling around the world. I guess Stellenbosch has better connectivity than some of the areas you’ve been through lately!
I like how they solved a problem which didnt exist
The only people who don’t think chains and cassettes have issues have never ridden a bike for more than a couple thousand miles at most. I’m not saying this is the solution but claiming chains drive bikes are peak perfection shows you’re not a serious or experienced cyclist.
I disagree. Compared to a derailleur drivetrain it offered: gear shifting anytime, zero gear adjustment, fewer wear items, easier rear wheel removal, significantly smaller gear steps, an elliptical driving path, and a grease and lubricant-free setup.
It’s more accurate to say they created more problems than they solved
If peak perfection is something other than peak mechanical efficiency and the ability to get parts - then yes, it is not perfect. In the same way, walking is also inferior to running. Yet, our lives are formed with walking in mind (or, God forbid, driving). While you can argue with years of ingenuity around a regular bicycle, you cannot argue with physics. IMO, the upright bicycle formula is as good, as it will ever be. Safe for one-off components for satisfying very specific needs.
I would, personally, don't mind an attempt on virtually everlasting all-weather BB and spline standards. Better chainring mounts are also possible. More developments in the field of mechanical disk brakes would be lovely. The main difficulty is pushing a new standard to the masses, while being profitable.
OMG! it's a fancy Kick N Go with gears! love it!
Excellent summary, excellent, excellent documentary on the subject..
This is why your channel is the best cycling channel. You’re not jamming some product or fashion down our throats nor buying into the classism that is so prevalent in the cycling world.
99,99% of the people using a bike, commute with it, and would never leave an asphalted road, unless it´s under construction that month... He focusses on the needs of recreational cyclists, an elitist occupation, reserved for 0,01% of all cyclists... A tiny chinese town has more commuter cyclists, than people riding trails on the whole planet... While not trying to jam any products down our throats, it can still be classist... Not having the typical classist´s composure sure helps, in making the channel more likable.
This is literally a product you'll never need being jammed down your throat
Sounds really cool, but all the proprietary compenents sounds like the opposite of what you want in an easily repairable bike
Hi 👋 I'm appriciated you mentioned about this bike. I also designed a bike with strings but not like steing bike. It works in the frame of bike and frame is designed accordingly. Its design allows down tube storage because I wanted it aero. Theoreticaly it allows 43% more watts and pedal system works according to natural leg movement direction. It is like up and down not rotational. And pedal system is also embedded in the frame. Only pedals are seen from out of drivetrain. I wonder wether you would want to try to ride it. It is not produced yet.
This bicycle lecturer is an amazing explainer; fascinating stuff.
Thanks! I love researching these topics and sharing my findings.
Very interesting to hear an in depth dive into this tech, it has intrigued me since I came across it. So the answer is it was a dead end, though well worth developing. I did wonder if it would be the answer for a recumbent bike with their very long chains, but the lack of gear range counts that out.
The design reminds me of the elliptical trainer used in the gym. The device has the option to use leg pedals along with reciprocating handles which resemble the reciprocating motion of the string drive. I often used the elliptical trainer and increased the resistance (compared to higher gear ratio in bikes) by holding the handles closer to the hub, i.e. lower. In my opinion something similar can be used for hand bikes (used by people with lower body paralysis, who cannot pedal). Reciprocating handles would make full use of the simplicity of the string drive because no spinning pedals are required. The hand-cyclist can adjust the gear ratio simply by changing his hands position: Low gear is achieved by holding the top part of the handle. Holding lower can increase the gear ratio.
would like to see the resulting physical development in heavy users at their peaks.
I feel like there could be a steampunk themed bike to better display this engineering as a functional work of art. A large front wheel city cruiser, perhaps looking like a modern penny farther
In 2010 when I first saw this I was in awe. New era started I thought waiting when they will be awailable in my country. And now I'm little sad cus it newer happened. But it clearly needed more of development. When I look at it now I see that it could be possible with only one drum, one string and redesigned lever and crank doing two strokes during one cycle. It would be cheaper, easier to setup (half the amount of cables) and disc brakes ready. I hope that somebody will take this torch and run with it to continue developing this idea.
I had a chain-drive bike with a somewhat elliptical chainring that I bought in 1987. Looking at it more closely, the "long axis" of the ellipse was oriented just about 90 degrees off from where I had imagined it would/should be! Apparently it was supposed to be like that. The ones depicted in this video look correct to me, or how I would have thought they should be oriented. I think I eventually turned mine on the crank assembly, but since it had 5 mounting holes I could not turn it exactly 90 degrees. I could never feel any difference one way or the other, and eventually went to a round chainring and internally geared hub.
Interesting stuff. I use Dyneema cordage in my hammock suspensions and it's a truly amazing material. It doesn't do super well with abrasion though, so I'd be interested in seeing the longevity of this system.
Quoted as 1000km (about 600 miles) which even for pretty light use is multiple changes a year. 6 miles each way 5 times a week (about a 30 min ride, so nothing excessive) is 60 miles a week, so you're potentially changing strings 5 times a year. I suspect that changing the strings 5 times is considerably more hassle than than either regular chain maintenance as you are supposed to, or slightly more involved chain cleaning if you let it slide a bit. Unless you never do anything with your chain until it rusts solid or you need to replace chain, sprockets and chain rings at the same time, and do so frequently, it probably isn't a huge advantage.
No one asked you
@@DoraExploring-ls5vf I bet you're fun at parties.
@@chrishowell5718 The limited mileage of the Dyneema strings is actually a disadvantage. According to my observation from the film, the time it takes to replace them is significantly shorter than any chain maintenance. 😃
A sting drive where strings last around 1000km and there are steel wirres that will corrode as well definitely is not free of maintenance. 😉 A nice design anyway!
Good information really 👍 Salute to your study ❤
Don´t forget those roller coaster wheels! They will wear out and cost alot of friction! I think the belt drive combined with internaly geared motor units will be the futur for alot of bikes like city- and mountinbikes. For roadies the chaindrive will stay the gold standard because of its superb low friction and light waight.
I don’t think I could ever get used to the non-linear pedaling effort/power output be revolution. Maybe I did not give oval chain rings enough of a chance. Interesting idea though and probably worthy of further investigation
I had a bike with the oval 1 Loved it for those up hill slogs made it effortless ...
I love how it can be useful for persons with injuries.
my normal $60 10 speed mountain bike has lasted me 30 years with only needing tyre changes.
Just had to check todays date. Phew, it’s not April 1st. The major downside to this system would be mud, here in the UK we get a lot of rain, so far we’ve had 3 major storms in the last month alone. So lots of leaves and general muck on the roads means riding and more importantly, cornering speeds, are not what they were. Whilst I see no MTBs, I’ll bet off-road and you’d be in for a lot of hike-a-bike, or even pushing it home an/or back to the car. I take it wouldn’t take a tumble well would it? Anything bent or misaligned around the BB area and I’d’ve thought it was a game over.
I considered buying one of these a couple of years ago, but the narrow gear range was a deal-killer. The high price and weird bespoke frame were also turn-offs. I eventually purchased a belt-drive bike with an 11-speed rear hub which was much cheaper, weighed about the same, and had a better gear-ratio spread.
String drive can be used with front wheel drive motors. One might want to employ some kind of traction control to aid adhesion, especially in corners.
I imagine you could do something similar with belts instead of strings for better durability, but the incompatibility with standard frames is a killer. You could likely say the same thing about systems that use a geared rod instead of a chain too.
are belts also incompatible? you need a split in the frame
excellent video. string is a novel idea, not terrible. the challenge remains: how best to transfer power from human to machine. have never understood why belts do not replace chains.
i think belts have slightly more friction, and the frame is also different because belts tend to be made in one piece which means that on a standard upright bike you need to be able to open the frame at one point to thread the belt through it.
Fantastic video/content as usual! Idea isn't terrible, actually I find it very ingenious, but as you clearly stated, it has no feet to walk, so one more to the shelf. Why? 1. Ebikes, what else?; 2. Internal gearboxes and belts; 3. Disc brakes; 4. Efficiency (if only it was suitable for ebikes...)
Sounds like it would be good for casual rides. The advantages presented had me sold off as it would be much more convenient to commute with this kind of bike. Very interesting!
It almost feels like you could rehash this tech using standard-ish ebike frames. I don't know if the geometry works, but if you could build a unit that bolts into the space a Bosch ebike motor (or similar) uses, it'd be an interesting idea. One-sided, of course, maybe even something that fits on a HG freehub.
Its amazing how far engineers will go to solve the problems of bicycle chains, hefore they resort to the obvious solution - a chain cover!!!! Honestly, my daughter's bike has an almost entirely enclosed drive train, and i basically never have to clean it. She's ridden it thousands of miles now with no issue. I wish adult bikes came with enclosed drivetrains more often.
Exactly. I've been advocating drivetrain fairings forever. Why do they say a rear derailleur gets dirty but a IGH does not? So helpless. Just cover it up, then it won't get dirty.
Nah, covers are not cool. Have you heard about dork discs? Usefull, light but absolute no-no.
You can use a full chainguard with a single speed bike, or with internal gears, but not with a derailleur. Oh, I suppose someone could design some montrousity that would fit over a derailleur, but I think it would create other problems.
@@thePavuk The only people who want chain guards want to ride with pants, so I don't think they care much for cool.
I would love to try it. I’ve broken chains on sheer force alone. And to put that kind of strain on this would be fun. Even if it didn’t fail.
Actually rope (manilla or sisal) drives were a method of transferring rotary motion and energy. a single rope would be looped several times between drive (motor) and driven (load) pullies/drums. The drums would have grooves to accept the rope. The grooves are cut in a screw so a single rope could pass around the drive and driven drums many times. check out sisal rope drives on youtube.
Thank you so much for the education on string drive. Never heard of this before, but now I wish it had succeeded, and they lasted for 10x longer, and allowed for electrification, too! It all just seems way better than exposed chain; which we've been using for so long now. Surprised to see there aren't even more types of bikes available out there today. AI might soon change that though.
After >150 years, what works well and is practical has pretty much been figured out.
@@gaoxiaen1 Thankfully no engineers think like you. We wouldn't have cell phones, commercial jets, computers and a million other things that came along after 150 years ago...
@@BitBuhkit So why don't you think of something better than wings for airplanes, or wheels for cars? Get busy Mr. Engineer!
@@gaoxiaen1 lol, I'm not the one that thinks everything stopped >150 years ago!
@@BitBuhkit Me neither. It's just that sometimes the best practical soltions have been worked out long ago. Yes, in some circumstances there are better devices that can be used, but I don't see things like the screw, the nail, the bolt and nut, the table and chair, the metal can and glass or plastic bottle, etc... going away soon. Yes, the string bicycle is an interesting novelty. So is the hubless wheel for motorcycles and turbine engine car and many other inventions, but it takes a long time to replace a tried and true practical solution. Fuel injection (of whatever type) and overhead valves for gasoline engines used to be exotic and futuristic, but have only become commonplace in the last few decades. Most inventions remain only novelties.
imagine replacing transmission parts every 1000km
sell it before 1k
Brilliant video. Thank you :)
I use dyneema rope on my atv winch. It works great and, like he said, it floats. That’s nice when tossing across some water and the hook doesn’t quite make it to shore.
What a fantastic video! Well structured and nicely presented. Congrats! -you could be a great engineer. A comparison between CVT, hydraulic, tradicional/chain and electric drivetrain would be interesting. Especially for pushbikes (analogue not for e-bikes). And it would be amazing to see you testing them in different scenarios and share your impressions based on your vast experience.
My takeaways: Elegant, but complicated design, with few real benefits over chain drive. String drive lasts roughly 1/2 as long as a chain You need to change the rear drum for hilly rides (Chain drive just toggles between high and low on the front sproket) People think you can't use a chain in rain/snow (LOL it's called OIL / Maintaining your chain) Being precision machined lever action, one bump will throw it off and damage it. Good luck changing gears with a crooked arm. Bonus: If you are getting oil on your pants when you ride a bike, you're just clueless. And chains are 100% recyclable...is this string recyclable?
I have heard that a fully enclosed drive-train negates chain fouling concerns. There is a weight and efficiency penalty: since you need to use an internally geared hub.
You actually don't need more gears then one to have a practical transport. Before the 60's speeds are not common. My parents have never had a bike with gears, in the Netherlands. They never used it for sport but to get somewhere.
it's what is often called: "a solution looking for a problem"
@@albertmagician8613 you also dont need planes to travel to the other side of the world, that doesnt mean its the best way to do it or that it wont be replaced immediately if a better option becomes available
The thing holding belts back is the conventional chain stay frame design with the chain routed through the frame.
I won’t pretend to know much about bikes but I’d say the major thing keeping this from ever becoming popular is the compatibility issues. It’s a really hard sell when the three bikes in your garage can all be mixed and matched with nothing but your own tools.
After looking at this video I am not sure what was the problem that the inventors started to solve. Sure, this is one way of solving the "how to make wheels go around problem" but what was the fundamental problem that needed fixing in order to abandon the traditional drive train. If you have a company, your business model cannot be "let's have an alternative way of doing things" - you should have clear benefits and no real draw backs. This way of thinking the drive train means that you cannot update your current bike. So, you have to buy a new frame, backwheen and then the whole drivetrain. Customers have to take a huge risk if this ever goes anywhere so getting parts in the future is not guaranteed and it's much harder to sell the bike for the same reason. Video points out that people have driven 450 km per day with this setup. So, how is that any kind of achievement? You can do that with any modern bike. It would be only an argument if this drivetrain would be ultimately more better than the competition, meaning that this bike could go 450 km when other only did 350 or so. That's the problem with areas that are heavily standardized. You are probably locked into a certain boundaries and if you wander outside of those boundaries, you are in the death zone. You have a small change of hitting the jackpot but that would require that the innovation is "all benefits".
I don't get the disk brake argument. Yes, you can't put a disk on the rear, but you can still make a mullet with a disk on the front and rim brake on the rear.
Most of your braking power is on the front, anyway.
dyneema breaks pretty fast when exposed to the sun long enough so better drive in the shadow :) really cool invention!
If Sheldon Brown were alive today, I'd be really keen to hear his take on this. I know he was a fan of elliptical/near elliptical chainrings (like Biopace), and he didn't seem the type to dismiss new technologies with the 'This is the way we've always done it' line.
Fascinating. The persistence of chain drives after 150 years lies in the surprisingly low overall frictional losses, especially with the refinement of chains themselves, optimized cogs, and good old wax as the basis for the best, easily maintained lubricant. Motorcycles with drive shafts have far higher frictional losses, only offset by sealed systems, and the power to spare from an engine other than a human. This design also has many more pivoting bearings, likely needing service or replacement.
Absolute great idea. Should buy one😊
Just when you think you have seen everything, a video like this proves otherwise. Thanks for sharing.
Discovered this channel thru this video completely randomly. Glad I clicked. Truly an interesting and informative channel
This sounds really cool. I hate dealing with a chain that falls off from time to time.
Wow I learned a lot from this video
gerçekten çok faydalı bir sunum olmuş. eline koluna sağlık olsun. teşekkür ederim. ;)) eliptik aktarma organları benim çok ilgimi çeker. ve bu video çok faydalı.
I am quite intrigued by the concept of the String Drive bicycle. Difficulties offering the shifter and the range of gear ratios available wouldn't be an issue for me since I simply leave it in the highest available ratio anyway. I think the biggest reasons it wasn't particularly successful were the price and obscurity. The lower durability of the strings as compared to either chains or belts is definitely an important factor to consider, but the low cost of replacements and the ease and speed of replacing them, not to mention the ease of keeping spares on the bike, may well have offset that sufficiently for the average rider.
Hey there! I'm just some Joe smo who literally knows nothing about bikes or their drive trains but this video was professionally executed. The perfect amount of information on a topic I never even knew existed but now I want to know more about. Like for instance, could we ever invent a hand crankd wheel chair that could be more efficient (through like maybe micro gearing or some other unknown to me physics law we could apply) to just Help people who can't afford the best of the best new aged electric mobility chairs...' askin fur a friend ya know
The rewinding action of the string is springloaded. Thus you are ALWAYS pushing against 2 springs. They may be weak (they only need to rewind the strings), but, still, they are there.
Noticed that only regular bikes have gear adjustment cables between seat tube and rear wheel, forcing for longer wheelbase. Those performance bikes have been set up other way to pull gearing cables.
Love the design. It's like the compound bow of bicycles.
Wow, very interesting! I'm totally surprised that I never heard about this System.
The drive (chain) wheels, reminded me of the Rotary Wankel petrol engine (NSU, Mazda Norton et al).
I remember the days when bicycles were a greasy mess, constantly in need of small repairs or tweaks or Improvisations. We have come a long way. Personally I would still prefer a very light racing bike type of thing. Not completely stripped off all the protection from rain but built very light and just with the essentials. Those are usually quite easy to repair as well.
12:45 - tensile strength is necessary to propel the bike, but as you point out, that requires relatively low tensile strength anyway. Possibly more importantly, for longevity and resistance to wear and tear, would be shear strength of the material so that it doesn't break due to knocks, road debris, etc - and on that front I think the chains might have the advantage.
👌👌👌 I loved the design, and only if the ropes could last for 4000 to 7000 km, I would have considered it as an option. I guess, to puruse really longer distance cycling at an easy pace, I would now think about Hub gears and biycycle with mechanical disc breaks.
Fascinating- never even heard of this lol
I don't know how I got here. But I've always wanted to live in a city where I can walk or bike. This seems like a great city bike system.
“Hold on guys I got a knot in my drivetrain I gotta get it out” 😂
Looks perfect.
So good🤘🏾
Sheldon Cooper would love it, he's really into String Theory.
I don't know if its better but that's such a cool design.
I think they went with string for two reasons: 1) It's not going to wear the other surfaces, it'll wear out first, and 2) It's not particularly dangerous if it snaps. This could certainly be designed with other materials, but you'd either end up with immense wear and tear on other parts, or danger if it did snap under tension. I feel like they could have probably made these far more robust though in a few ways, like for example, having a metal spring core in the strings, while also making the string thicker. I could imagine for example, a string in the center, wrapped with a metal spring, and then an outer rubbery layer added or something like that, giving it a lot of flexibility and durability.
For the disc break comment, couldn't a disc brake be installed in the front? Also, in principle, a disc brake could be worked into the rear wheel. As someone noted, if they were more popular, the kinks would have been engineered out.
Got the same idea as soon as I saw the video.I had to scroll down way too far for this comment
With a clean drivetrain and pedals that return to a horizontal position automatically, this sounds like it would be really practical on a commuter bike!
I used to be interested in getting one of those, but after this video I think it's a good thing I never got around to it.