[HN Gopher] Stringbike: Benefits (2020)
___________________________________________________________________
Stringbike: Benefits (2020)
Author : Tomte
Score : 116 points
Date : 2022-08-10 11:36 UTC (11 hours ago)
(HTM) web link (www.stringbike.com)
(TXT) w3m dump (www.stringbike.com)
| dang wrote:
| Related:
|
| _Stringbike - A Chain-less Bicycle_ -
| https://news.ycombinator.com/item?id=11515123 - April 2016 (6
| comments)
|
| _Stringbike: Chain-free bike_ -
| https://news.ycombinator.com/item?id=1716002 - Sept 2010 (47
| comments)
| jstanley wrote:
| A 2012 review in Wired says it rides pretty much like a normal
| bike: https://www.wired.com/2012/02/stringbike/
|
| Other than that I can't readily find any more reviews from anyone
| who claims to have ridden one. I wonder why, given that they
| apparently have been making them for 10 years?
| jackmott42 wrote:
| Almost always the downside to a non chain drive is a loss of
| efficiency. A chain and cog setup is really really good, like
| 99% efficient with a clean lubed chain. Internal hub gears,
| drive shafts, strings, almost all of them have losses a bit
| worse than that, which sucks when you are a 0.5hp motor.
| russellbeattie wrote:
| It's weird they don't have an embedded video or at least a
| prominent link to their YouTube channel. Here it is below.
|
| Wish there was audio, I'm personally a little doubtful of the
| silence of the bike given the sorta clunky front gear system, but
| I'm sure it's quieter than a chain. It's odd that they muted it.
|
| https://youtu.be/-Qjf8Rnn1N4
| rich_sasha wrote:
| I might have missed it but there's no info on efficiency. I can
| both imagine it's great and terrible. Dyneema doesn't really
| stretch so that's on the plus side. But surely there's a ton of
| friction in this system? And that's before you consider the
| gearbox; these tend to be somewhat less efficient than derailleur
| systems.
| digdugdirk wrote:
| This isn't really a gearbox in the traditional sense, they're
| just using the word because it makes sense to people. What
| their "gearbox" does is increase/decrease the lever arm acting
| on the string. This serves the same function, but the
| frictional losses would be mostly constant across all the
| "gears".
|
| There will absolutely be some losses due to rope deformation
| (squish, not stretch) and heat, but I imagine they would be
| relatively consistent across the lifetime of the rope - there's
| not any grease to degrade over time, for example.
| rich_sasha wrote:
| Right, but the actual % efficiency does matter. Derailleur
| and IGH achieve easily 90+% efficiency with low maintenance.
| Is this in the same ballpark? 80% ? 60% ?
|
| Also the string will definitely pick up grime off the roads,
| especially when wet, so efficiency will almost certainly drop
| as a result.
| enragedcacti wrote:
| the FAQ says the string is technically more efficient but
| in practice they are both extremely efficient when properly
| maintained so the difference is academic. They don't
| mention losses when the string is wet or dirty so I'm not
| sure about that.
|
| https://www.stringbike.com/stringbike_support_questionsanda
| n...
| [deleted]
| kretaceous wrote:
| Their FAQ Page[0] and How it works page[1] provide a lot of
| information and answers to the question raised in few of the
| comments.
|
| 0;
| https://www.stringbike.com/stringbike_support_questionsandan...
| 1: https://www.stringbike.com/stringbike_asthemagicworks.html
| digdugdirk wrote:
| Here's the patent, for those interested:
| https://patents.google.com/patent/WO2010084363A1/en
| floodfx wrote:
| Curious how a string drive would perform on a mountain bike
| especially considering climbing advantages and easier shifting?
| egypturnash wrote:
| Huh. Interesting, very interesting. Usually links to bikes here
| are just nonsensical overcomplicated bullshit IMHO, but this is
| close to the simplicity of the $300 bike I'm constantly riding
| around town.
|
| I'm trying to figure out what's going on with the pull-back
| motion of the strings. Is there a spring in the hub? Are they
| stretchy cords that are going to snap someday? How easy are they
| for a passing asshole having a bad day to cut?
| digdugdirk wrote:
| It looks like they're juuuuuuuuuust the right length so they
| perfectly match up to pedal stroke.
|
| i.e. - Your push stroke unwinds the string to its max extension
| length, and then the rotational inertia of the wheel does the
| job of winding the string up again.
|
| EDIT: Scratch that, disregard the above. Looks like they're
| using a spring to wind up one side while it freewheels.
|
| As for assholes? Yeah, they're going to be able to slice those
| with a pocket knife in a few seconds. Even Dyneema and the like
| would likely be quickly frayed with a few good knife swipes to
| the point of being in danger of snapping from a hard pedal push
| when taking off from a stoplight.
| kretaceous wrote:
| From their FAQ page[0], What happens if the
| string snaps? It takes 10 minutes to replace, by
| the rider. No specialist knowledge required, worth watching the
| tutorial on the website. No tool required, no need to remove
| the rear wheel, or other parts. Spare string is provided, and
| neatly stored in the seat pole. The spare comes with
| instructions to install.
|
| 0:
| https://www.stringbike.com/stringbike_support_questionsandan...
| echiuran wrote:
| I'm no mechanical engineer, but this looks way more complicated
| than a traditional chain/derailleur drivetrain. Especially the
| two contraptions, one on each side of the bottom bracket. Instead
| of a continuous circular motion, the rear hub is constantly
| having to freewheel, on one side or the other. What's the
| efficiency loss there? How does the overall weight compare to a
| traditional drivetrain with the same range of gear ratios? Have
| they measured the difference in efficiency?
| digdugdirk wrote:
| I am a mechanical engineer, and I'm 50/50 on it. The rear hub
| contraptions aren't too different from the freewheel that's
| already in a regular bike hub, it just has an extra spring to
| wind it back up.
|
| The super funky gearbox contraption though? That's a different
| story altogether. You have a continuously varying normal force
| on the lever arm throughout the rotation, and I have no idea
| how long it would last compared to a traditional derailleur
| setup.
|
| Here's the patent, for those interested:
| https://patents.google.com/patent/WO2010084363A1/en
| soared wrote:
| Would a chain or carbon belt still work in this configuration?
| gaze wrote:
| How does this compare to a timing belt?
| eckza wrote:
| Do you know what else is nearly whisper-quiet and grease-free?
|
| Degrease your bicycle chain with kerosene or some other solvent,
| and submerge it in molten paraffin for 20 minutes.
|
| I have been doing this to my bike chains for almost a decade now,
| and it makes a big difference.
| oldgradstudent wrote:
| > Degrease your bicycle chain with kerosene or some other
| solvent, and submerge it in molten paraffin for 20 minutes.
|
| Clean it with isopropyl alcohol after degreasing it and before
| submerging in the paraffin.
|
| After a few hundred kilometers you'll need to submerge it
| again. Boil a kettle of water and use it to clean the chain
| before submerging it in the paraffin.
|
| Some people suggest adding PTFE to the paraffin, but I have no
| idea whether it has any benefit.
|
| https://youtu.be/HHr9znwpwmQ
| switchbak wrote:
| Almost any dry lube will achieve the supposed benefits of this
| product. Even dumonde tech lube dries so much that you can
| barely tell the chain is lubed.
|
| We've also had belt driven (with pinion) systems for years,
| both of which would seem to solve this in a much more
| straightforward approach. This seems like a technological dead
| end to me.
| loeg wrote:
| Aka, "wax." I use these products[1][2], but plain paraffin (the
| main ingredient) works fine. There are also drip-on wax
| products[3] that can be applied to a clean or previously waxed
| chain, without removing the chain again.
|
| Totally agree that waxed bicycle drivetrains work very well,
| are quiet, and avoid the mess of oil-based lubricants.
|
| [1]: https://moltenspeedwax.com/
|
| [2]: https://silca.cc/products/secret-chain-wax-blend
|
| [3]: https://www.ceramicspeed.com/en/cycling/shop/ufo-
| products/uf...
| convolvatron wrote:
| I use carnauba wax for finishing metal and have heard about
| using it on chains.
|
| right now about every two weeks I clean the chain with a
| light mineral oil, then a day later I clean again and put
| down heavier oil. keeps the mud away.
|
| would be I happier if I just cleaned the chain and dropped it
| in a pot of hot wax? is there anything to look out for?
| loeg wrote:
| > would be I happier if I just cleaned the chain and
| dropped it in a pot of hot wax?
|
| Quite possibly. Chains stay clean and efficient for longer
| without intervention. And can be handled without dirtying
| your hands. It's nice. Other drivetrain components wear
| slower because there's less grit and the chain stretches
| more slowly.
|
| > is there anything to look out for?
|
| Main downsides:
|
| * For bicycles, a lot of chains (Shimano, KMC) come in some
| kind of factory oil/grease. Stripping that off takes time
| and working with solvents. Fine if you have time and a
| garage, less great for busy people in apartments. I think
| some manufacturers sell dry chains (I've heard YBN does).
|
| * Heating wax up is slow. I use a $12 crockpot and it takes
| a couple hours. Obviously, it's not like it takes any
| effort on your part, but there's some built in latency.
| ("Low" heat is about right in the steady state, but it
| melts faster if you use "high.")
|
| * Again for bicycles, some kinds of quick link / master
| link wear quite quickly and can only be reused a handful of
| times (e.g., Shimano 11 speed). So one surprising expense
| in repeatedly removing chains to hot wax is the consumption
| of quick links. Can be mitigated with different brands of
| quick link, and/or using drip-on wax a few times between
| hot waxes.
|
| * A freshly waxed chain will be stiff from the hardened
| wax. So a pre-install step is going through every link in
| the chain (on bicycles, typically ~110-120 links) and
| making sure each one rotates freely around the pin. This
| takes a few minutes.
| eckza wrote:
| Probably; you wouldn't have to do so much maintenance.
|
| Wax fills in all of the voids between the bushings, roller
| pins, etc - so it physically prevents dirt from getting
| into your chain. And since there's no oil to cause the dirt
| to stick to your drivetrain, your gears don't wear down as
| quickly (as oil / grease + dust is abrasive; each rotation
| wears the chain and rings down ever so slightly).
| forinti wrote:
| I wonder how long the rope will last.
| kazinator wrote:
| I like how the front pulley acts as a 2X gear ratio. For every
| distance x the pulley moves, it draws 2x string. That means you
| don't need a ridiculously small rear sprocket diameter, or make
| the front lever ridiculously large, to get a conventional high
| gear (like 52x12).
| 14 wrote:
| I think it's a neat design but the cost is way to much for the
| average user to adopt this. It's certainly not geared towards
| casual riders like me and my kids. They are way to hard on bikes
| to justify something like this. So it looks cool and I would like
| to try it out but never would buy one at anything even close to
| the price they are offering right now.
| ok_dad wrote:
| Same here, I am intrigued by it, and would plunk down $1k right
| now for something like this even, but $3k+ is wayyyyyyyyy too
| much for just a standard bike with a neat drivetrain. Plus, I
| am sure shipping it to where I live would be another few
| hundred. I do like the idea of this for low-maintenance though.
| BugsJustFindMe wrote:
| This looks weird and interesting and the price of the single
| speed version is actually not bad. The string is just simple
| dyneema cord with crimped ends, so you could probably even make
| them yourself from bulk and carry a dozen spares for basically no
| extra weight.
|
| The prices on their different lines seem way out of whack though.
| Carbon and Aluminum cost basically the same? Aren't carbon bikes
| usually much more expensive than others?
|
| Single speed is _way_ cheaper than the rest. Like unexpectedly
| so. Are they saying their adjustable gear mechanism accounts for
| $2000 of the price?
|
| And Designer is in the middle?
|
| I really don't understand the pricing scale here.
| rich_sasha wrote:
| You can definitely find two fairly priced frames, where the
| better/pricier one is made of aluminium and the cheaper one is
| carbon. It helps carbon fiber prices have gone down
| substantially in the last decade.
|
| Still, it is a bit odd...
| stlynch wrote:
| Esoteric gearing/hubs are really expensive. I have an
| internally-geared bike, and the rear wheel/hub is already 1/2
| the cost of the entire bike... and that's more or less using
| tech that was originally developed in 1957.
| mikestew wrote:
| _Are they saying their adjustable gear mechanism accounts for
| $2000 of the price?_
|
| Look again: the "single speed" includes the gearing:
|
| "The gear shifter was removed however gears can be changed
| manually pulling or pushing the pulley up or down when the bike
| is stationary."
|
| You're paying $2000 to not have to stop and change gears
| manually, or saving $2K by doing without the gear shifter,
| which ever way you wish to look at it. I almost think the price
| is a typo.
| flicken wrote:
| What prices are you seeing? For me in Europe, the single speed
| is only EUR240 cheaper than the cheapest Aluminum bike.
|
| EUR3990-EUR5200 Carbon EUR1590-EUR1990 Designer EUR1490-EUR1990
| Aluminum EUR1250 single speed
| InitialLastName wrote:
| In the US:
|
| Carbon: $3478-$4553
|
| Aluminum: $3100-$3800
|
| Designers: $1386-$1909 (many priceless, presumably expensive)
|
| Single Speed: $1090
| matsemann wrote:
| Good aluminum bikes can be nicer than cheap carbon.
| calvinmorrison wrote:
| Seems cool. On the motorcycle side, I enjoy having a bike without
| a chain. Instead my BMW has a shaft that runs from the
| transmission to the rear wheel. Maintenance over 75K has been
| occasionally lubing the rear splines. There's been some attempts
| at a shaft driven bicycle but the downsides seem to come from the
| tighter tolerance, harder disassembly and overall heavier frame
| construction required. still cool from a longevity POV.
| feb wrote:
| Transmission via shafts is also less efficient. It doesn't
| matter much on a motor bike where there's plenty of power. But
| on a human powered bike, every watt counts. See for example
| https://www.cyclingabout.com/chainless-shaft-drive-bicycles/
| for more information.
| Rnonymous wrote:
| I went down the same path owning a BMW shaft drive
| motorcycle, doing my own maintenance. I decided i had enough
| of re-tensioning the chain on my bicycle (Living in
| Amsterdam) and got a second hand Brik shaft bicycle. Indeed
| maintenance is harder, but i have far less maintenance. So
| instead of ~twice a year giving my chain bike some love, i
| now bring the Brik to the shop once every 2-3 years.
|
| I still ride a normal chain bike regularly, and I can't say i
| find the Brik heavier to ride. It all seems negligible
| compared to the watts wasted by the sitting position of a
| city bike.
| thomasfl wrote:
| A bicycle is in my opinion one of mans greatest inventions. It
| empowers almost everybody to transport themselves five times more
| energy efficiently than walking. For two hundred years the
| bicycle has been improved by countless ingenious inventions.
| Cities where the majority commute by bicycle, are much better to
| live in.
| helixc wrote:
| Fully agreed! A dedicated bike lane that separates riders from
| car traffic could make riding experience very enjoyable.
|
| I was born in China during the 80s, when biking was the most
| common way of transportation. The term "Kingdom of Bicycles"
| [1] was used as a tag line for China in that era. Most roads
| had bike lanes which could be just as wide as car lanes.
| Between the lanes are physical separators: 3-4 ft high, made of
| metal, reliable and heavy-duty [2].
|
| Now I live in the US, and still enjoy biking cause there're
| nice bike trails near my place. However, most city roads seem
| not safe for biking. Biking becomes a recreational activity,
| and no longer a transportation method for me. I appreciate the
| nicely maintained bike trails, but I hope the city build more
| physical bike lane separators, not only painted lines on the
| ground, that can actually stop some reckless drivers entering
| bike lanes.
|
| --- [1]
| https://en.wikipedia.org/wiki/History_of_the_bicycle#China_a...
|
| [2] Another good reading about the bike history in China: The
| Rise, Fall, and Restoration of the Kingdom of Bicycles.
| https://macropolo.org/analysis/the-rise-fall-and-restoration...
| mrtesthah wrote:
| Bicycles are indeed the most efficient mode of transportation,
| but shouldn't we be taking into account the energy cost of the
| entire paved system of roads needed to facilitate that rolling
| efficiency in the first place? Paving a road with asphalt is
| pretty resource intensive.
| ryukafalz wrote:
| Sure we should, but that's the case for all transport modes.
| Remember that you _can_ just pave the smaller amount of space
| needed for cycling down a street and not a full-width road. A
| cycle track uses less pavement than a roadway thanks to being
| narrower, and probably lasts longer too due to less damage
| from heavy vehicles.
| joshlemer wrote:
| And doesn't need to be built to the same standard of
| strength as a roadway that must carry trucks etc. In fact a
| dirt path is enough for a bike.
| bch wrote:
| Bicycles don't need that, and it wasn't made for them, so I
| don't know why you'd charge "road cost" to the bicycle ledger
| when they're such a distant second (at best) citizen on most
| roadways anyway.
| fanf2 wrote:
| Roads were originally paved for bicycles, before cars.
| https://www.cyclinguk.org/cycle/roads-built-cars
| https://www.theguardian.com/environment/bike-
| blog/2013/apr/1... https://roadswerenotbuiltforcars.com/
| tromp wrote:
| These Dutch rowingbikes have also had various forms of string
| drive for over a decade:
|
| https://rowingbike.com/en/modellen/
|
| with cables either in steel or in dyneema (polymer-based).
| Someone wrote:
| https://www.stringbike.com/stringbike_asthemagicworks.html shows
| the mechanism. Looks nice.
|
| There will be a lot of pressure on a relatively small wheel
| there, so I wonder what dust or a grain of sand would do there. I
| would guess making sure the mechanism near the pedals stays
| operating smoothly takes more maintenance than with normal
| bicycles. I wonder whether they considered exchanging rotary
| motion of the pedals for up/down movement so that they could get
| rid of that complex shape.
|
| Also, given that they sell a "seatpole spare string holder",
| those strings don't seem to last as long as a traditional bicycle
| chain.
| kazinator wrote:
| Any serious cyclist carries a chain link tool for fixing a
| broken chain, along with a couple of spare inner tubes.
| Breaking a link doesn't happen often, and you'd typically not
| let a chain get so old that it happens from age; that will
| trash the sprockets. I've had breakage happen, though, and was
| glad to be able to get going again, in minutes.
|
| Since you can't fix a broken string just by removing a link and
| closing it, the only protection against string breakage is to
| carry a full spare.
| switchbak wrote:
| "Serious" cyclists are often using newer chains like those
| from SRAM. Many of these newer ones don't use spare links,
| you'd carry a quick link and remove a portion of the chain to
| get yourself riding again.
|
| Small distinction I agree, but you come off a little arrogant
| with such a strongly worded statement.
| loeg wrote:
| > Any serious cyclist carries a chain link tool for fixing a
| broken chain
|
| Your definition of "serious cyclist" excludes a lot of
| serious cyclists. Precisely because it happens so rarely,
| carrying a bulky tool for a rare problem isn't worth it to
| everyone.
| rtlfe wrote:
| Yeah "serious cyclist" feels so impossible to define that
| it's meaningless. If I ride to work every day but go to a
| shop for maintenance instead of buying my own tools am I
| not serious?
| kazinator wrote:
| I'd say you're not serious about being able to back on a
| working bike in almost any conceivable breakdown
| situation.
| loeg wrote:
| > serious about being able to back on a working bike in
| almost any conceivable breakdown situation
|
| We've seriously shifted the goalposts from "serious
| cyclist."
| kazinator wrote:
| Not really; a serious cyclist is someone who depends on
| and is invested in cycling as a mode of transport, who is
| not able to meet commitments if their bike breaks down
| without an real-time remedy.
| kixiQu wrote:
| So... no one within range of being able to catch a bus is
| a serious cyclist because they have an out? No one who
| can call a friend for a ride can be serious about
| cycling? I don't think this is typically what people
| would mean by that phrase.
| kazinator wrote:
| Yes; if you go out thinking, "I don't have to care about
| the condition of my bike or what to do if it breaks down
| because there are bus routes along the way, or I can call
| a friend," then you're not a serious cyclist.
| oldgradstudent wrote:
| Go to a shop to fix the problem, but have the basic tools
| and knowledge to make the temporary repairs needed to be
| able to ride the bike home or the shop.
| aliqot wrote:
| My chain tool weighs 28 grams, and can fit 3 chain tools in
| a box for a deck of cards. It is the most common form
| factor for this tool. I wouldn't consider it bulky- are you
| very small?
| kazinator wrote:
| It's actually a very tiny tool.
| [deleted]
| oldgradstudent wrote:
| A chain tool is pretty small and is often included in cheap
| pocket multitool collections like
|
| https://www.decathlon.co.uk/p/900-bike-
| multitool/_/R-p-10042...
| elliottkember wrote:
| A spare string weighs a lot less than a chain. They provide a
| spare string in the seat pole apparently.
|
| Edit: there's also two strings, one on each side. So if one
| snaps, I think you can ride home with the other
| wiredfool wrote:
| I bring a breaker tool and a spare magic link. Never needed
| the link, but it's small. The breaker tool has saved a
| couple of riding partners.
| aliqot wrote:
| It's always the clip on the magic link. You ever notice
| that? I've never broken the link itself, always the clip.
| kazinator wrote:
| Right; I've never met anyone who carries an entire spare
| chain. It would not even slightly make sense.
|
| If you put a new chain on old sprockets, it will likely
| skip, particularly on the rear cassette. This will go
| double if you're someone who allowed the chain to wear for
| so long that it just broke. That chain will only work with
| the sprockets that it is on and vice versa.
|
| If you damaged a newer chain due to some freak accident
| (like cross chaining while shifting under load or
| something: shouldn't happen on a quality, well adjusted
| drive train) you probably don't want to replace it; aside
| from the bent/broken link, it is good. Splice the damaged
| link out and get moving.
|
| Swapping in a new chain could be extra work. It likely has
| excess links which you have to remove and set aside, and
| may have stuck links that have to be identified and
| massaged into releasing.
| tetraodonpuffer wrote:
| I just have a couple powerlinks in my bag when riding,
| which take very little space. It is also unlikely to have a
| chain break while riding, however having a chain breaker
| tool and spare links comes in handy if your rear derailleur
| gives up the ghost (due to a fall etc), as in that case you
| can bypass it entirely with a shortened chain.
| [deleted]
| gnopgnip wrote:
| With this string design the end of the string is fixed to the
| freewheel. So they don't have wear related issues that regular
| chains have like skipping gears, dropping a chain
| feb wrote:
| About longevity, on
| https://www.stringbike.com/stringbike_support_questionsandan...
| they say strings last between 500 to 1500km.
|
| Bike chains supposedly last from 500 to 5000 miles
| (https://www.bikeshepherd.org/how-long-do-bike-chains-last/)
| depending on usage and maintenance.
| rcoveson wrote:
| It might cost more to manufacture in the USA, but that 61%
| increase to minimum longevity sure would be nice.
| loeg wrote:
| What is this comment in response to?
| rcoveson wrote:
| Minimum time to failure seems to be 500 in either unit,
| so it makes sense to move manufacturing (or at least
| testing) the the region that uses the larger unit.
| switchbak wrote:
| That's a simplistic analysis. Quality chains almost
| certainly have a life longer than 500 miles, even taking
| into account premature failures.
|
| Regardless, aren't you suggesting here that we should use
| chains and not strings because their upper bound of
| lifetime is higher?
| loeg wrote:
| Ok. Silly quips aside, bike chains do actually last 5000
| miles, not 500, if you keep them relatively clean. That's
| a lot better than 1500 miles or kilometers.
| ElijahLynn wrote:
| If this rope works well and is easy to replace, and is
| inexpensive I think I would be fine with changing it
| every 300 to 1,000 miles or so. They have it listed that
| you can change colors to match your outfit, so I am
| expecting it to be that easy.
|
| > Change the strings quickly and easily in 2 minutes, no
| tool required and no need to remove the wheel. Choose the
| color to match your outfit or mood.
| yetanotherloser wrote:
| It appears to be mild snark about the mixed units (km vs
| miles) caused by quoting two different sources.
| ElijahLynn wrote:
| The maths:
|
| 500km == 310.68m
|
| 1,500km == 932.05m
|
| 500m == 804.67km
|
| 5,000m == 8046.72km
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(page generated 2022-08-10 23:00 UTC)