Shimano Gearbox in the Works - Patents Filed on Hybrid Chain-driven Sequential-Shift Transmission
Jack Luke, an assistant editor at BikeRadar, routinely scours the US Patent Office for cycling-related filings. This one was tucked away under the ubiquitous title, "Sliding Component and Bicycle Internal Transmission Device" by Shimano Inc. in Japan. (See the patent application here)
In his comprehensive article, Luke mentions that the word "gearbox" never appeared in the patent. No doubt an intentional ploy to hide the monstrously huge news that the world's largest component maker in cycling has been developing a comprehensive strategy to produce a sequential-shifting 13-speed hybrid transmission that substitutes heavy, draggy gears with lighter, more efficient roller chain, sealed from the elements and bathed in an engineered lubricant. All this, including advanced drawings of how the gearbox will be mounted in production and its programmable electronic shifting controls, are described in detail.
Honda G-Cross DH bike shared very similar shifting technology. Honda photo
Big news? I'd say so, but the concept isn't new. The famous Honda DH bikes used a similar gearbox. Honda's transmission featured a chain and cassette, sealed from the elements inside an aluminum and carbon shell. It was shifted by a modified derailleur which slid laterally on a shaft to provide a perfect chain line. Rumors point to another large drivetrain maker that "may" have developed and tested a roller-chain hybrid gearbox as well in the not too distant past. What makes Shimano's patent application so important is, um, Shimano.
Shimano Isn't Bluffing
The smoking gun in Shimano's application can be found in the details. The abstract drawings depict a concept that is near production, not a bunch of cut-and-paste bicycle parts adorned with play school cogs and components. The side shot of the bike,
Shimano Isn't Bluffing
The smoking gun in Shimano's application can be found in the details. The abstract drawings depict a concept that is near production, not a bunch of cut-and-paste bicycle parts adorned with play school cogs and components. The side shot of the bike,
Abstract drawings rarely depict concepts at such an evolved level.
The cranks overdrive the transmission, which reduces torque and facilitates lighter-weight components.
Special Lubricants
Shimano's application also describes in detail, a special lubricating fluid that when combined with a surface treatment that traps the substance in the metal, will shear at a prescribed thickness and prevent metal-to-metal contact at high pressures. Both the lubricant and the technical details of the surface treatment are detailed in the application. Does that sound speculative? I didn't get that impression either.
Shimano's application also describes in detail, a special lubricating fluid that when combined with a surface treatment that traps the substance in the metal, will shear at a prescribed thickness and prevent metal-to-metal contact at high pressures. Both the lubricant and the technical details of the surface treatment are detailed in the application. Does that sound speculative? I didn't get that impression either.
Shimano's proposed lubricant and surface treatment work together to eliminate the possibility of metal-to-metal contact.
Why Roller Chain?
Why roller chain? No other strategy can compete with a roller chain for low friction losses in rotary power transfer at low RPM and high torque loads - especially at low power inputs. The enemy of roller chain drives is dirt. Tests at the University of Utah proved that friction losses in roller chain drives were minimal, regardless of the type of lubricant, even when lubricant was absent. Dirt, and angular misalignment, however, contributed to large friction losses in the trials. Shimano's transmission handily solves both of those issues and then some.
According to the application, Shimano's gearbox pairs opposing seven-cog cassettes. A small "derailleur" slides on an angular shaft between them to shift the chain to each gear, while maintaining a perfect chain line in each selection. To extract 13 speeds from only seven pairs, one of the cassettes can be shuttled laterally, which presents six more gearing options. This strategy ensures low friction, because only one pair of sprockets are engaged at any moment, and keeps the transmission simpler, lighter weight and also, minimizes its width.
Shifting to the next gear is proposed in the application to be either electric, or cable operated, but either way, you wouldn't have to figure out which gear you were in. You'd only be pushing one of two levers on the right side of the handlebar. Another plus is that the transmission would be moving as long as the bicycle was in motion, so you would be able to effortlessly change as many gears as you wanted while coasting.
A "derailleur" device moves the chain between two mirror-image cassettes (left image). After seven shifts (middle image), the lower cassette is moved over one space (right image) and offers six additional gears - 13 speeds in total.
What Lies Ahead?
Is there a future for this? Absolutely. Gearboxes that use toothed gears must be constructed from the finest materials, with aerospace tolerances in order to approach the efficiency of roller chain drives on bikes sold at the department store level. Shimano's concept bridges that gap with a protected, permanently lubricated transmission that will operate efficiently when constructed with average quality bearings and moving parts. That means this gearbox will eventually be scalable and thus
Is there a future for this? Absolutely. Gearboxes that use toothed gears must be constructed from the finest materials, with aerospace tolerances in order to approach the efficiency of roller chain drives on bikes sold at the department store level. Shimano's concept bridges that gap with a protected, permanently lubricated transmission that will operate efficiently when constructed with average quality bearings and moving parts. That means this gearbox will eventually be scalable and thus
Gearing options (light band) between two seven-cog cassettes.
We'll keep an eye on Shimano and report further developments.
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Design, material, tolerances. In that order.
Every mountain bike I've owned in the 15 years has shifted just fine, every 6 months half turn on the adjuster, you can do this as you ride along.
Quicker shifting whatever. Just give me the ratios I need to make it up the hill.
It's all just a bunch of BS.
This looks good but it will obviously require all new frames and kit. I’m sure they’ll take the opportunity to muck around with hub standards too.
If we thought changes in wheel size made old 26ers die out fast. Imagine seeing a clunky old 1x setup when these are everywhere!
Am i missing something???
11-14-18-22-27-32
About the number of gears thing. I always find myself wondering what the point of those gears between the middle and the top of the cassette is. On an 11 speed cassette I use the middle cog to the bottom cog a lot, and I use the biggest cog a lot, but those gears in positions 2, 3, 4, 5 never seem to get used other than to get it up to that big one. A high end version of Shimano Mega Range like my daughter’s bike has would be sweet. I could live with a 35-50t jump for my bailout gear. It would not be for everyone, but it would be fine for me.
But even 11 - 42 doesn't really work out. Say 11 42 has a spread of 3.82 and 11to 13 is ratio 1,18 than the total result is 451% and you get like 5 if those 13 gears which are overlapping/almost the same ratio so my honest question is what am i missing. 9 speed with 450% is already available...
But feel free to rant about your party talking points...
en.m.wikipedia.org/wiki/Beer_in_Germany
You're playing with fire :-) 5000 beers from 1300 different breweries should qualify for some kind of variety...
American beer on the other hand is a world renowned water purification, except those ipa micro breweries
(28/11)/(11/28 )=28*28/11*11. This equals 648 %.
It works. I literally had a similar idea a week ago. Talk about timing...
Am I the only one concerned about weight though? Trail bikes have gotten heavier the past few years and this doesn't seem to change that trend..
Sorry, I know we're not supposed to talk about weight ????
Why is the 420 % the magical number? Because Sram used it on 1x11 and it's so much better for whatever arbitrary reason it worked so much better than Eagle? Because i will NEVER go back to 420 % when i have Eagle, since we actually need the range here where we have some decent hills.
But to get back on the topic, if you read the article you could have seen that the patent describes a system, where the first stage after the input is a 'high' geared stage which increases the rotational speed of the two cassettes. That means, for the same power going through the system, less torque (power = torque * RPM, roughly). Less torque means lower forces. Second part is the coating and lubrication system. Third part is the encasement. And the fourth part of the equation is the chain running straight by changing the sprockets it's running on both cassettes simultaneously. These things all add up to MUCH lower loads than we have in our current drivetrains, which all means lighter components can be used without sacrificing durability. Hell, they might even be able to use aluminium sprockets, that would add quite a lot of lightness.
Plus, it is clearly written that using a chain will not decrease the efficiency to the same degree classical gear pairs would. And you don't rotate all the components at different speeds like you do in a car/Pinion/etc. transmission, adding to the losses.
I might sound like i'm all praise, and i am from a technical, idea-wise standpoint. But this being patented worries me what will happen with the competition. You will get a bunch of gearbox only bikes from brands that work with Shimano and a bunch of classical bikes from brands that work with Sram. Two distinct camps if you will with no interoperability.
I would not be surprised if this is in fact used for e-bikes first and foremost due to their integration (you have to decide which motor to use when designing a bike anyways) and am eager to see what this will mean for classic bikes.
@EarIysport: But it still has the possibility of being much lighter than say a Pinion. The shifting mechanism is much simpler and lighter (moving the chain instead of engaging distinct gear pairs), the gears are thin and light, you only power one gear pair at the time, etc. And the loads going into the casing are different.
@Ritgut: But the chain can be thicker and thus stronger, it runs in a straight line, etc. Factors improving the durability of the chain which is the main benefit here. And only having one sproket on each side and a simple tensioner that we've known for years from single speed bikes, which doesn't need to work as hard since you don't have as much chain slack, etc.
@Ritgut: Not neccessarily. With rear wheels growing, the suspension geometry is actually getting compromised. The instant centres of rotation tend to be getting lower in regards to the rear axle, to achieve a desired anti-squat, which means less reaward travel. This means suspension performance suffers (rear wheel doesn't move away from the obstacle as much) and makes frame design harder (the rear wheel moves towards the frame instead of away). With a gearbox with a higher positioned output gear, you can effectively go for what is now known as a high pivot, but don't have to deal with the inefficient and noisy idler gears.
What you get, in fact, is even more freedom when designing your suspension. You could possibly even rotate the gearbox around your BB to influence the height of the output gear and tune the suspension layout this way.
As for the 420%, you don’t need more than that. All you need is a climbing gear to suit your local hills. It could be a single speed. On the way down you don’t need to pedal. Gwin won a World Cup race with no chain! For riding on the road bigger gears are useful I’ll give you that, but 30ks an hour is pretty fast off road. You don’t really need a 32-10 top gear per se.
and he carefully reads an article where it says that additional chain won’t decrease efficiency. Because additional rotating component and chain engaging teeth is causing no future resistance by the power of love of immaculate heart of virgin engineer...
As for the range, yeah, you could, if you actually had no pedalling going down the hill (sadly i'm not Gwin and i brake too much into corners and sometimes have to pedal out of them) and if you only had to go up. Besides having steep ascents i also have flat approaches to the hills so i actually use most of the range on offer by Eagle a lot of the time. While instances of 32-10 (actually 30-10 for me on my 29er, but i had a 32t chainring on my 27,5" bike, where the rollout is very similar) use are very rare, they do nevertheless happen. It's usually on asphalt or gravel, either going to the hill or going back home. Having a slight descent here helps to use the 10T in the back. It's not all offroad, sadly. So i don't mind having that gear there. And it's more about the 50T on the upper end. I had an 11spd on my 27,5" bike and upgraded to Eagle on it. Boy was that the best decision ever.
@WAKIdesigns: so i guess you run single-speed fixed gear hardtails only? With an encased chain running in a pool of lubricant? I mean you want ALL the efficiency for your ride so you look fresh when taking that 100 Mpix selfie to post on Instagram, don't you? Can't have chain tensioners, freehubs, derailleurs and jockey wheels, bent chains, etc.
Classical gearboxes (Pinion & co) suffer from inefficiencies, it's a known fact. Pinion's 12spd gearbox has 14 sprockets rotating and meshing with only 4 powered, has a lot of bearings and selectors. The Shimano patent has a lot less components. It's also written in the article that a roller chain is the most efficient to transfer low power at low speeds, more than classical gear pairs. Could it be that a combination of an encased, clean gearbox with the chains in it running straight and the main driven chain running straight to the rear wheel comes close to the efficiency of the current drivetrains where the chain is dirty, unlubricated and bent to extreme angles? As far as i've read, dirt and off-centre running of the chain is the main enemy of efficiency.
I never said gearboxes are not inefficient. They are, it's a known fact. Shimano, with this patent, tries to solve this. And the premise is good. I'm ot saying it will be more efficient than what we have not, but it sure looks like it will be a lot closer to the current state than the likes of Pinion. And if you get robustness and maintenance free running for a minimal loss in efficiency (does anyone even measure it on current systems?!), isn't that a net gain?
It is as if you had two chainrings on the crankset, one each side and you would attach the second one to a freewheel in the downtube of the frame that does nothing. There will be more weight to move - each of addiitonal rotating components has a mass that needs to be accelerated. Furthermore those cogs are smaller, the smaller the cogs the less efficient is the system. That is why roadies don't use 9t cogs and some even use 12-28 cassettes with larger rings in the front. Any gearbox will be less efficient than a chain and two chainrings - It is plain as ice.
No sane person, capable of taking balanced decisions, being able to weight several factors into an equation, who rides anything else than long travel bikes with emphasis on bicycle handling will use any gearbox.. They just won't. It is less efficient and weighs 500g more, each of these factors being enough to put away most folks on it's own. Add two together and this is good only on E-bike or descend oriented bike
Then there is Effigear from France. I don't even know how those have more efficiency. But they lack the spread MTB requires.
98.6% for one chain therefore 3 chains = 95.9% at best.
Various dirvetrains - www.cyclingabout.com/speed-difference-testing-gearbox-systems
Until i see a lab test which compares the efficiency of both styles of drivetrain, I'm disregarding all the BS being spouted from people who've never even rode a gbox and using my own real world experience which tells me that Pinions are f*cking awesome!
I seen an entry on the Zerode blog that says the more a Pinion gets used, the more polished the gears get and the more efficient it becomes. This corresponds with my experience.
Even if there was a little weight penalty and even if there is a little drag penalty, everything else about the Pinion is so vastly superior to derailleurs that it's gonna be a gbox for me every time.
f*ck the market, I'm not affected by marketing BS. I would honestly ride a Redalp if they worked.
PS for the record I would love Shimano to release this for meat powered bikes.
Even if it is a little bit heavier, most people absolutely will not notice the difference no matter what way the marketing bull shit tries to tell you that the lighter your bike is, the more pro you are regardless of skill level.
But i digress. Sorry, 80 RPM is really uncomfortable for me, i prefer to spin away at higher RPM. And i'm not the only one. Plus i'd be happy to see you come to Slovenia (I think we've talked about this a few times already), i'd love to see you slog on the 32 or 28T of the Eagle cassette up some climbs. Me? I'm happy to do it in 30-50t on my 29er. Time-wise, on an average ride, i probably spend 50 % in the 36T, 42T and 50T gears. So yeah, a bent chain is a real consideration. Even more so on a mountain bike that is, often, used in the hills. Road bikers can and love to do 200 km rides with ~1000 m of vertical. I usually do that in ~25 km.
This will be almost as efficient as your current drive, in fact more efficient than your current drive once your chain gets dirty!
Will post some pics soon, but for now you will have to do with this?
www.pinkbike.com/video/218538
I've also known that pinion gets better with time, with less drag. For sure my next bike will have a gearbox.
They work fine without doing this anyway.
- Shift under load
- Weigh less than a Pinion
- Be compatible with a trigger shifting mechanism
- Have unprecedented drivetrain efficiency
That blows the Pinion out of the water.
But it strikes me that Shimano didn't go with a Continuously Variable Transmission setup. CVTs often use fluids like Shimano mentions to transmit their torque so as to minimize friction and contact surface area. Imagine combining Di2 technology with a CVT transmission to set your own gear ratios, shift distances, custom functions, and more--the opportunities, so to speak, are infinite. I had been thinking of an idea much along the lines of the Shimano patent, a nice combination of Nuvinci's idea, traditional gearboxes, and the bicycle derailleur. It may just end up being the best way to move forward for gearboxes, even if it's not as elegant as a derailleur alone.
Finally, Shimano serves a very wide bike market, from touring to World Cup racing. It may be this gearbox is not targeted for all of our luxury bikes, but rather the lower-end/urban/touring market.
I believe for a chain final drive it’s under 10%.
So no, I doubt a CVT would be good on a bicycle. Certainly not a belt driven one.
Also, any gearbox will never be as efficient as a clean and well lubed traditional system. There is drag in whatever power transfer system you use to get the power from the cranks to the rear wheel. If you add steps in between that, then you're adding drag to the system. A well lubed and clean derailleur doesn't add any steps.
As for classical automatic transmissions, it's actually the torque converter that's the leader in ineffciency with those. Since, you know, it transfers torque by being a fluid pump, again, trying to transfer power through friction, not through shaped elements (gears). What i've been told/read/etc. is that modern torque converter transmissions also employ a classical clutch-like device coupling the engine and the transmission to remove the torque converter pumping losses from the system. While true, that there are much more gear pairs in an automatic, that are also mostly powered (as opposed to only one powered gear pair in a manual or DCT transmission), they are nevertheless much more efficient than older automatic gearboxes. A lot of work has been done on them and these days cars with automatics have lower fuel consumption than manual versions with the same engine (though this is not due to a higher transmission efficiency in itself, but most likely due to increased number of gears, better choice of engine RPMs for a given speed, etc.).
As for a planetary gearbox on a pedal bike, have you met Rohloff? Or Kindernay? Or almost any e-bike mid drive? All of these use planetary gear drives. Which, given the efficiency talk we're having, is ironic to me when talking about e-bikes. A few drives have plastic planetary drives in them. I wouldn't be surprised if making a much more efficient mid-drive unit would result in smaller batteries and lighter system weight as well. But that's the situation we have when all of the major players just take off-the-shelf automotive solutions and repackage them for e-bikes and sell you all the power you want, thus creating an electric motorcycle... But i digress.
indeed, a CVT based gearbox can be made with high efficiency, especially for e-bike use. Check out an article about our system here: www.pinkbike.com/news/revonte-launches-a-stepless-e-bike-motor.html
If we are strictly talking planetary gearsets they will always be far less efficient than a roller chain setup like shown here.
@mountainsofsussex: It is a continuously variable transmission as in it doesn't have any steps. If that's not a CVT i don't know what is. You're probably thinking about the cone and chain type, but CVTs come in multiple different shapes. It's not the cone and chain that defines them, it's in the name, 'continuously variable transmission', a transmission with no steps in the ratios.
As for the Prius, the first gen uses a planetary drive with the wheels connected to the ring gear, the ICE to the planet carriers and the electric motor (first one) to the sun. There's another motor mounted between the planetary drive and the wheels, but the motor on the sun gear can either brake or accelerate the drive in order to change the output gear going to the wheels.
Later generations have much more components and are more complicated, so i prefer to talk about the first gen. It's just so simple, clear and ingenious!
And Tesla is just the first company to make a dedicated electric car. At the same time they completely failed at all point that the automotive industry had learned not to fail at. They are a startup playing in an industry that has long been completely different and requires a different approach. The automotive industry is a battleship. It has been turning for a while now and Tesla will soon be in the crosssight of the big guns it has. Much better cars than any Tesla are coming. Cars that are actually designed and manufactured to be cars and be used as cars.
Remember wondering why Peaty did use one, then I had one for a little while, worked good as a over drive single speed
Tesla are light years ahead of automotive industry
Tesla is light years ahead at being shit. They don't know the first thing about making cars well and making cars that work everywhere. They are a typical hacking startup doing everything they can wrong. I'm talking about making cars, not about making a new electric vehicle platform. They have panel gaps with the consistency of yogurt. The suspension arms are snapping. The 17 inch screen is a total UX failure. They are saving money by not having any buttons on the dash because it's expensive to make a button that actually works reliably so you have to open the freaking glove box via the stupid screen. That shouldn't even be there in the first place. They have to replace complete infotainment units because they have the software architecture done in a failed way where they saved log files to the a cheap flash chip. Which of course gets worn and dies. Because of a few dollar chip a 2000 usd unit needs replacing. They were bragging that model 3 won't be tested, only simulated during the design process. They are insisting the only cameras will be enough for autonomous driving and that it will be available... It should already have been available. Level 5 autonomy is multiple decades away, if it is even coming, ever.
I can assure you, from experience, these are decisions that do not work, especially the simulation only part. The product is something new for the market (at the time). And it's shiny, different. And the business model is different. And the owner has a cult following that was beaten only by Steve Jobs. But that doesn't mean that, as a car, the product is not shit. And if they have a different platform while "the industry is stuffing batteries into golfs" that they are light years ahead. The industry is using proven platforms and adding unknowns (electric drive components) to those. And learning. And testing. And adding other things. And when the industry will have a handle on the product, they will put out well designed, usable and reliable products and Tesla will be dead in the water. They will have a platform that was light years ahead but will at that point be offered by everyone, they will have a shitty product and they will have a company that isn't able to do automotive development at the level of the big brands offering similar designs with better implementation. They will be uncompetitive.
Just because you think you know what your taking about, does make it right!
Obvious question will be 1) weight, and 2) Standardization of layout. Would ideally want a standard for gearbox attachment such that future generations can be swapped in and/or moved between bikes from different manufacturers. Yay, more standards!
worldwide.espacenet.com/publicationDetails/biblio?CC=GB&NR=2434565&KC=&FT=E&locale=en_EP
Im all in for a Shimano Gearbox
Let’s gooooooooo!!!!
The neat thing about this is that the chain will only be jumping gears on one cassette at a time, never 'floating' during a shift. It's a pretty clever design, and I bet the shifter mechanism to move everything will be even more interesting. Definitely gotta respect the engineers over at Shimano.
mbaction.com/hayes-to-market-chain-driven-gearbox-system-oct-5
www.facebook.com/MTBVR/photos/pcb.1746318255618298/1746313558952101/?type=3&theater
TL/DR, you can't out a chain inside a gearbox because Shimano will sue your ass off.
If i remember right, Alex had a hard time digesting the fact that his idea was (also) patented by another guy. If i am not wrong, Alex never applied for a patent.
Some other names, do surface:
-Pete Speed
-Phaser
Am i wrong?
Hang on, are you saying the hub is fixed? That sounds like allot of unnecessary feedback forces to deal with, along with wear and tear and probably noise.
I bet that it is not that big issue on mtb/dh in max speeds of 70km/h.
I am sold to this new gearbox. I want DH bike with it!
cheers!
I don't understand your post?
But if the whole drive train is moving while you're coasting then you're looking at allot of drag and other feed back which is only going to slow you down.
Overall a cool concept, but skeptical of that part...
Yeah, no reason why you can't slap a regular old hub in it though, unless of course the standard axle widths all change... someone will do a free hub to fit it. I can't stand the idea of having all those moving parts under me.
If only I could get the thousands of hours of my life back that I've spent installing, adjusting, bending, aligning, cleaning, and cursing derailleurs...
Not that gearboxes will be zero maintenance and won't break (everything fails at some point and under certain conditions), but compared to the vulnerable and finicky derailleur systems at present, there is promise here.
I’ve been running sram xx1 since I built my frame up 5yr ago or so, and it hasn’t skipped a beat.
Does everyone really want to be able to shift under load? I like timing my shifts with cadence and shit, i dno....I don’t consider shifting a skill ceiling per say lol, but this is definitely lowering it...what’s the upside for someone like me?
Genuine question.
1x11 setup? That made a heck of a lot of sense when it first came out and was a serious game changer, I guess maybe this is the next generation of innovation. I just dont see what’s so exciting about it other than shifting under load.
It wont be as dramatic as the ebike but traction and suspension performance on the pivot ebike (just a fox 36 and DPX2) was on a whole other planet compared to my bike with AVY tuned that I thought was dialed AF.
If moving only a few pounds to the center gives 10% more traction its worth it. Ask anybody who pushes hard in corners and washes out a race they spent a month prepping for and more money than they promised themselves they would (ie everyone).
I hope this turns out to be what many here are speculating - with a standard mounting protocol and the ability to run a normal drive and e-bike drive on the same bike.
"As seen in FIG 1, the second frame B32 is coupled to a hub shaft of a hub assembly of the rear wheel B62...The second link B35 it rotatably coupled to the rear wheel B62..."
A floating chainring will tend to "self align"
I am surprised it never has been tried out, floating pulleys/sprockets are used in many applications to stay in perfect alignment.
If a manufacturer did this, they would have a significant selling point that would stand out from all the other bike companies.
Also I can see it working in one direction, when the chain first drops from a big cog to a smaller one then the rest of the chain, now a bit loose, climbs from a small cog to a bigger one, but in the other way, having first to climb from a small cog onto a bigger one, I'd expect it too crack.
But it's some pretty intricate stuff so there's probably a lot of thing I can't quite picture in my mind.
This just looks like an outdated concept compared to Zerode’s smaller Pinion gearbox unit .....
for real though, This is gonna be gamechanging technology, because it is evolutionary not revolutionary. those motorcycle style gear transmissions will seem unrideable when compared to chain driven transmissions that have already become incredibly efficient, durable, cheap, and light. eliminate chainline issues and seal it in a pot of super lube and this will be insanely efficient and robust while also likely being simple to manufacture. Bravo shimano!
The real question is will they seal in the drive chain with the rear swingarm? seems very feasible and would totally protect from the elements!
And the only way you can have this gear box is to buy a Shimano bike?
Haha it's an evil scheme to take over the bike industry.
This exact same concept has been sitting in my "to do" list and never taken beyond basic design because I'm too much of a wimp to dedicate myself to it and kick other priorities to the side.
Literally two days ago I dusted it off and started looking at off the shelf free wheel driven cranks to work on this.
effffffffff
This is how to make your drive last longer!
worldwide.espacenet.com/publicationDetails/biblio?CC=GB&NR=2434565&KC=&FT=E&locale=en_EP
I understand patents may be usefull but it also seems to drastically slow down progress sometimes, that Honda bike for instance. There should be a clause : If nothing worth it has emerged after 5 years the patent goes free for use.
I'm not even mentionning how unfair it is when Mr nobody has to use all his savings to patent a bright idea when whatever Big Corp may sometimes patent crap just to prevent competitors from developping similar but different idea.
Well that clause I just talked about would be much more tough for Mr Nobody who just spent all his savings on the patent and has no more budget to actually develop his idea...
The first Honda Gearbox was In No Way an inverted gear set and derailleur. The second, Was.
I've a printed copy right in front of me of the European Patent Application .
Here are the European Patent details :
Application number : 03006371.3
Date of Filing : 20.3.2003
Date of Publication : 3.12.2003 Bulletin 2003/49
EP 1 366 978 A1
"Continuously Variable Transmission For Bicycles"
B62M 9/04
It was a unique, linkage drive set up. with moving pivot points, to give varying 'sweeps' of the linkage, to produce varying gear ratios.
An ingenious thing. I believe it was much more than an 'experiment' for bicycles. For 'other' applications as well, or, predominantly.
BUT, for real world testing, under high torque loads, at very low rpm, using human power, I doubt you could find a better way to test for efficiency and smooth shifting. Any 'hang ups', would be brutally evident, and any parasitic loses, the same.
Once the testing on that was done, they went to the infinitely simpler, inverted gear sets and sliding derailleur set up.
Look it up, it's quite the thing...........
Could somebody please enlighten me as to how they know this?
p>CLAIMS/p>
p>1. A drive transmission apparatus for a pedal driven vehicle, the apparatus comprising a two stage drive mechanism mounted on or in a swinging arm, wherein said swinging arm has a first end pivotally connected to a frame of the pedal driven vehicle and a second end connected to a driven wheel of the pedal driven vehicle./p>
p>2. A drive transmission apparatus according to claim 1 wherein the first end of the swinging arm pivots, in use, about a pedal driven rotating shaft of the drive transmission apparatus, said shaft being rotatably mounted to said frame./p>
p>3. A drive transmission apparatus according to claim 1 or claim 2 having a two stage drive mechanism wherein drive is transmitted by belts or chains from the pedal driven shaft to the intermediate shaft and also from the intermediate shaft to the driven wheel./p>
p>4. A drive transmission apparatus according to claim 1 or claim 2 having a two stage drive mechanism wherein drive is transmitted from the pedal driven shaft to the intermediate shaft by means of intermeshing gear wheels./p>
p>5. A drive transmission apparatus according to any preceding claim wherein the intermediate shaft of the two stage drive mechanism is located above the line between the pedal driven shaft and the centre of the driven wheel./p>
p>6. A drive transmission apparatus according to any preceding claims wherein the intermediate shaft of the two-stage drive mechanism is located closer to the pedal driven shaft than to the driven wheel./p>
p>7. A drive transmission apparatus according to any preceding claim wherein the two stage drive mechanism is single speed./p>
p>8. A drive transmission apparatus according to any one of claims 1 to 6 wherein the two stage drive mechanism has variable gearing./p>
p>9. A drive transmission apparatus according to claim 8 wherein the variable gearing is provided by different sized gear wheels, which intermesh in use to provide drive between the pedal driven shaft and the intermediate shaft of the two stage drive mechanism, and are moved in and out of engagement by a gear change mechanism./p>
p>10. A drive transmission apparatus according to claim 8 wherein variable gearing is provided by a derailleur gear system./p>
p>11. A drive transmission apparatus according to claim 10 wherein gear sprockets or drive wheels are mounted on the intermediate shaft and/or the pedal driven shaft of the two-stage drive mechanism./p>
p>12. A drive transmission apparatus according to claim 10 or claim 11 wherein gear sprockets or drive wheels can be displaced along a shaft during gear changing./p>
p>13. A drive transmission apparatus according to any one of claims 8 to 12 wherein the gear changing mechanism for the variable gearing is selected from the group consisting of cable, hydraulic, pneumatic, electromagnetic and servor-assisted mechanisms./p>
p>14. A drive transmission apparatus according to any preceding claim wherein the two stage drive mechanism comprises a freewheel mechanism./p>
p>15. A drive transmission apparatus according to claim 14 wherein the freewheel mechanism is a clutch mechanism./p>
p>16. A drive transmission apparatus according to claim 15 wherein the clutch mechanism is an automatic clutch mechanism./p>
p>17. A drive transmission apparatus according to any preceding claim wherein the two stage drive mechanism is enclosed./p>
p>18. A drive transmission apparatus according to claim 17 wherein the swinging arm encloses the two stage drive mechanism./p>
p>19. A drive transmission apparatus according to claim 18 wherein the swinging arm can be opened./p>
p>20. A drive transmission apparatus according to claim 18 wherein the swinging arm has access ports with moveable covers./p>
p>21. A drive transmission apparatus according to claim 17 wherein the two stage drive mechanism is enclosed by covers./p>
p>22. A drive transmission apparatus according to any preceding claim wherein the swinging arm is reinforced along its lower edges or faces./p>
p>23. A drive transmission apparatus according to claim 22 wherein reinforcement is provided by means of a skid plate./p>
p>24. A drive transmission apparatus according to claim 22 wherein reinforcement is provided by a thickening of the swinging arm material of construction./p>
p>25. A drive transmission apparatus according to any preceding claim wherein the swinging arm or its associated reinforcement is formed and arranged to protect other components of the pedal driven vehicle./p>
p>26. A bicycle comprising a drive transmission apparatus according to claim 1./p>
p>27. A bicycle according to claim 26 wherein the drive transmission apparatus provides drive to the rear wheel./p>
p>28. A bicycle according to claim 26 or claim 27 wherein the bicycle is a mountain bike./p>
p>29. A drive transmission apparatus substantially as described hereinbefore and with reference to the accompanying drawings./p>
p>30. A bicycle substantially as described hereinbefore and with reference to Figure 1 of the accompanying drawings./p>
I've always thought the gearbox is the future of bike transmission, but until now I've never been convinced by any project/product.
This seems to be something really promising...
And with the loss of unsprung weight, I can finally run that motorcycle brake rotor I’ve had lying around!
It’s for little millennial hipster posers that want to be like the hard bearded men of the past that worked real jobs and rode single speeds because they had too.
Exactly how most PB users (including myself) are reacting to the news.
Shift Under Load
I must be doing something terribly wrong, because it's something I don't due... or even try to!
Better weight Distribuition
That's really interesting... really! Even after seeing people ride their long bikes, with their ASS in the Rear Axle Plane
Better suspension due to low sprung weight
It's true... but really... Have you ever seen people adjusting their tyre pressure before a ride? With a gage? Let alone suspension setup!
I'm not willing to spend more money, to the same shit I do with a traditional derraileur! Yeah... system sucks... but it cost less than 150€(SLX)/200€(XT), to replace it. Why bother with it...
make bikes less expensive and more worthy as a product.
#cavaleriebikes ROCK
Still wondering what my bike would be like with a gearbox instead
Pinion has been doing this for years.....