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Pinion P1.18  bicycle gearbox How it works

Pinion P1.18 bicycle gearbox How it works


Well those German engineers have been at it again. Frst they gave us the Rohloff 14 speed gear hub. Now we have something called the Pinion gear box. It’s a bottom bracket mounted 18-speed gear. It’s also available in 12 and 9 speed versions but today we’re going to take a look at the 18 speed version. Geared bottom brackets are not exactly a new idea. This particular one was available back in the thirties. I believe it was a three-speed. I did some reading on it I forgot the details but it also required a specially manufactured frame not retrofit able to a normal bicycle frame. Now unfortunately I don’t happen to have one of these here that I can get my hands on, but I do have pictures that I’ve been able to grab off the net and from that I’ve been able to figure out how the thing works and today I’m going to try and explain it to you. Okay so what we’re looking at here is the left side looking at it from the point of view of looking from the front of the bicycle towards the rear. Here we have the input shaft where the cranks mount and it’s also the main shaft of the transmission. This is the countershaft of the transmission. This planetary system that you see on the left end of it is actually the shift mechanism. The shifting is accomplished by means of rising pawls in the countershaft. All of the countershaft gears are free-floating on the shaft and they are engaged to the shaft by means of the rising pawls actuated by the shifter. The six gears on the left end of the input shaft are splined to the input shaft. In other words as the shaft turns all six of these gears turn dedicated to the shaft. The three gears on the right end of the input shaft are mounted on a hollow tube that the input shaft passes through. These three gears are mounted as a unit that do not turn independently of each other. The six gears on the counter shaft that correspond with the 6 fixed gears on the main shaft as you can see are all of varying sizes so when the largest gear on the counter shaft is engaged to the shaft by means of the rising pawl, it will drive the shaft at the slowest available speed. Why they arranged them in what appears to be such a random order I can’t say I’m sure there’s an engineering reason for it i don’t know what it is but anyway. So we’ve got six selectable ratios here that are engaged to the countershaft one at a time. On the right-hand end of the countershaft we have three gears, again free floating on the shaft and we select those one at a time to give us three distinct ranges so in fact what we have is we have six ratios here which we can multiply three times without any overlap. With these three output gears And now we come to the final output the three gears on the output cluster remember I told you those are mounted on a hollow tube which is free-floating on the input shaft. And the chainring is mounted on the output side of that so that’s where the power flows out of the hub and to the wheel. Ok so just to do a little power flow demonstration here. So we have power input here. The cranks turning the input shaft. Now if we have low gear selected that means that we’ve engaged this largest countershaft gear to the shaft so we have the smallest gear on the input side driving the largest gear on the output side and then over at this end of the hub ah, the hub. I keep calling it a hub this end of the gearbox we engage the smallest gear to the shaft and drive the largest gear on the output so the power flow goes through the through here to here to here and out for the slowest ratio in the transmission . By contrast if we couple the smallest gear on the countershaft. Not even sure which one that is. This one I think alright so if we Lock this gear to the countershaft we have the power flowing from the largest gear on the main shaft the smallest gear so we’re driving the countershaft now at the fastest available ratio. And then at this end if we lock the largest gear to the countershaft now the power is transmitted from that gear to the smallest one on the output and we’re driving the chainring at the fastest available output speed or 18th speed. So that’s it that’s a brief rundown on how it works someday I hope to get my mitts on one and can actually get in there with greasy fingers and show you a little bit more detail but for now that’s the best I can do so hope you enjoyed it. See ya later.

76 comments on “Pinion P1.18 bicycle gearbox How it works

  1. Hello Dan, thank you very much for explaining this mechanism. I live 20 kilometres away from Denkendorf, where these gearboxes are produced. A friend of mine told me he had met an employee of this company, and this guy had told him  that the level of engineering and   machining of this hub were on the highest level, to be compared with that of  the car producing industry.If you shold be interested in the answer to the question how efficient this gearbox works, here is a link to an interesting article, written by a German engineer (working at "Schmidt" in Tuebingen   and normally engineering SON bicycle-lights). https://fahrradzukunft.de/20/wirkungsgradmessungen-an-nabenschaltungen-3/He designed a standardized test-site, that allows him to compare the efficiencies of different gear-systems. Unfortenately for you it is written in German, but if you scroll down a Little bit  there is an interesting graphic, comparing several gear-systems directly. (e.g. Rohloff Speedhub, Alfine 11, Alfine 8, Singlespeed etc.) The fat lines Display 200 W , the slim ones 50 W of power. "Wirkungsgrad" means "Efficiency", "Verlust" means "loss". Kind regards from Germany, Fabian

  2. wow, wondered how those work. I wonder why they went with helical on the last set. i suppose that's the granny gear with more torque potential. the array out different teethstrikes me as odd. are automotive gearboxes like that? i can see that the ratio has to have a whole number of teeth and toy on the same center to center.

  3. Thanks for this video. Very good explanation. However don't really understand how the shifting mechanism works tbh. I a typical igh, shifting is done by locking the sun gear with the pawls. But in this design, wouldn't the pawls have to be rotating together with the locked gear? How does sync up this rotation and what is the actual shifting action?

    Basically what i'm asking is, do you have any more insight into how the shifting is achieved with the planetary gear hack in the pinion gearbox =)

  4. I really don't understand about the input and output shaft being the same shaft. I reallly apreciate if you can give or guide me to a clear explanation, sir.

  5. Would a Rohloff rear 500/14 speed hub and Pinion front IGH 18 speed yield any advantages by having 252 speed combinations?

  6. Hope they throw the belts in the bin sooner than later, because it only add more weight and more friction. Belts do serve a purpose in some engineering areas, but not here. Use a normal bicycle chain because it works better, is cheaper and very easy to maintain. Personally I'm very interested in the development of these gearboxes, but to be honest I simply do not want to be a guinnie pig. I'll jump in on it when I know they have shaved off more weight, shaved off more drag/friction and that they also throw the gripshifter in the bin. Gripshift is counterintuitive on a bicycle that is rocking up and down and thrown here and there. It would be awesome if they simply developed their own shifter. Another thing I've heard from testers is that the ratio between each gear is too high.
    Ah well, we can only hope other people want to move forward too.

  7. How much it weighs, what it's gearing width, what input torque will destroy it?
    Oh, the last question: how much it cost?

  8. Thank you for posting this. I too would like to get my mitts on one for my recumbent trike. Hub gearboxes like the Rohloff are great, but they preclude the use of a Hub driven power assist, where as the Pinion would complement it. Yes you can get a 'mid-drive' motor like the Bafang, but these can give a lot of wear on the chain if you live around hills, (I live at the top of one 🙁 LOL). A hub motor actually improves the wear on the chain, as the torque generated by the chain is amplified by the hub directly to the wheel instead of onto the chain. I got 500 miles more on my last chain after fitting the hub drive!

    There is a short review of a pinion drive as fitted to an Azub trike on "Bentrider online" if it is of any interest. Apparently the change is a little stiff when new, but after a few hundred miles they loosen up a bit.

  9. Is this currently available for bicycles like the THORN, KOGA, PATRIA…? How does it compare to Rohloff or Nuvinci?

  10. That is a neat little piece of engineering. It would be interesting to know the input torque or horsepower specs on that unit.

  11. I have both, like the pinion best. Gear down going up hill by just split second stop pedaling. Kinda like a harley trans too.

  12. German products always have a fatal flaw hidden inside the"impressive engineering". Wonder what problem this one will develop.

  13. I am very happy that finally someone had the resources and will to build this. The principle of bigger leverage works and gears are just round levers. The increased mass of the bicycle is compensated with a better chain design out of robber. If you want to improve this concept further, please feel free to consider my recumbent design that has levers of 2000 mm plus combined with pulleys. It is designed to increase significantly the torque exerted by human powered vehicles.

  14. Nice explanation Dan , and that would be a nice set up I think ,
    no more Greasy chain and derailers …… and a silent belt drive.

  15. To those complaining about weight…. First rule of engineering is that EVERY solution is a compromise. There is no "best", only the most suitable solution for a given situation. I seriously doubt the designers have higher end carbon road bikes and the pro peloton in mind with this gearbox. But there are many other types of bike that really benefit from a sealed maintenance-free design with easy shifting. Commuter bikes, which favour robustness over shaving off a few grams, get lots of rain and grime, lots of shifts (many stationary) and not a lot of care or love. Robust, sealed gear units are a prime candidate for these types of bikes. Add in the growing popularity of electric assist (which weighs much more than this gearbox) and this makes a lot of sense.

  16. I'm thinking if they built this thing with much narrower gears, the drag would be greatly reduced. Less surface area=less fractional surface, right?

  17. Bike engineer 1: So the problem is everything that's common sense has been done to death and we are in the red. Product suggests anyone?

    Bike Engineer 2: Ah everything that's not common sense?

    Bike engineer 1: Love it lets go with that.

  18. Nice! Thank you.
    But…
    It almost seems a waste to use a video format to present still photos. Too bad a moving model wasn’t available.

  19. Very interesting video. Did you notice they have two lines of product. A p line and a c line. Do you happen to know the difference?

  20. The manner in which those (unseen) protruding pawls engage the various gears explains why the Pinion Gearbox is do difficult to shift under load. Riders say they have to ease off the pedals almost entirely before a shift will engage, which seems like a hassle.

  21. I want to order a standalone gearbox like this for an ebike build I am working on. However I can't find any sellers that actually have product on the market that I can pickup. Figured I could weld one on to the frame I'm looking at using. I really would like to have no slack in the chain.

  22. Since the shifters wasn't shown is this system basically a 3×6 drive? Because in a 3×6 drive you don't have 18 gears you have 18 ratio combinations with some of the combinations being redundant.

  23. I loved my Sturmey Archer bicycle gears (three speeds inside the hub). Then I got a fancy new bicycle with Italian gears. Fifteen of them, if I remember correctly. I never liked them and my interest in bicycling waned thereafter.

  24. When I said it was simple I was ignoring one thing. The pawls that engage the gears are on a rotating shaft unlike those in a conventional internal gear hub where they are on the stationary axle and engage the stationary sun gears. I would love to know how those rotating pawls are controlled by the pull-pull cables attached to the frame of the bike. ??.

  25. Anyone know how much rotational drag this will create when freewheeling? Does it run dry or in oil, as gear oil is thick and will absorb energy. And what about the bearings, life expectancy and ease of servicing …?

  26. https://youtu.be/h5-Ew9LJXV4
    .Compare to any oscillating pedals in the world, this invention is the best because…

    – Installation is in bottom bracket of conventional bike frame.

    – Very easy to assemble (only 40 minutes…)

    – World's simplest oscillating pedal (fewer parts compare to any oscillating pedals)

    – 30 % more efficient than conventional bicycle crank ..

    – it is the most affordable.
    – Most lightweight and compact.
    – Can be incorporated with derraileur gearing system.

    Inventor: Genaro Francis Tabag
    Email: [email protected]

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