I had a bike with the Nexus 8 (not Alfine) and it covered 50 000km ( I cycle to work). It only needed a new gear cable once, and finally needed a new face plate because part of the face plate that holds the cable end, broke off. Otherwise trouble free and no maintainance! Highly recommend for recreational/commuter cyclists. There is a minimal loss of efficiency that would affect a race cyclist, but not noticeable for regular cyclists
Just a heads up. I had my alfine 8 for two years and started developing problems 6 months ago where certain gears in the higher rang (5,6,7,8) would not engage smoothly and where the 8th gear began continuously clicking. . Adjust was spot on. I just fixed the problem today by changing out the cable and it works perfectly. I opened the hub 8 months ago and everything inside was pristine and well greased. The reason why changing the cable worked so well is that once you get into the higher gears on the alfine the tension in the shifter cable increases causing it to stretch more and be less accurate in the higher gears. This is many alfine users a have issues in the higher gears. Cannot believe that the cable change was so simple, easy, cheap, and effective. Should be the second troubleshooting step after checking adjustment. Best of luck to everyone!!!
Was your cable evidently damaged before changing? Or did it look good? My cable looks like brand new, but bike is 4 years old (but it was not ridden). Is it possible that cable has streched without using (or used occasionally)?
My cable looked brand new. A cable can stretch and still look new. If you left the bike unridden for a long period of time and the bike was sitting in a higher gear then I believe the cable could have still stretched because the higher gears put a lot of tension on the cable.
I ordered the Cube Hyde Pro yesterday... omg would a normal gear-changing-chain-thingy have been a better option? I have literally no clue about bicycles.
Pibbles 'n Bits Thanks for this,about changing the cable. Mine didn’t work from its inception because I’m new at this but still have some knowledge about how and what makes stuff work. I knew the cable was the problem and on till the broken ends stated protruding the shop keep telling everything was okay and I’m hard on the equipment.We changed the cable and I changed bike shops.
Juanuary 18, 2020: Dan, I'm going to upgrade my Atlas Cargo from the Sturmy Archer 3 speed to the Alfine 8 speed for some long trips this summer. I've been a mechanic my whole life and can fix anything if I've got a manual. Now, I've got a complete internal parts breakdown with a dynamic display of internal parts and their function that talks to me !!! Awesome work Mr. Dan !!! I can make a tool kit just for this and be able to repair it roadside if need be. Store it in my phone and play it back when I need to. Thanks a bunch!
Finally. Finally... Been wracking my brains looking at pictures and trying to understand how epicyclic gearing works, and finally you've made it come clear in my mind and I can see it now. At last. Thank you thank you thank you!!
I have the Alfine 11sp hub on road bike, a tad heavy, but no deraileur, exact shift/response, and works excellent. Expensive, but after miles of riding, glad to have made the purchase. So far, 3 yrs use, very durable.
no boat, they shouldn't be noisy, i bought my alfine 8 based on this video....and it works great! the only thing i miss is the speed of my road bike...........i was asking Dan if i could install a 52 or 53teeth chainring in replacement of the 42t chainring i have now and replace the 18t rear sprocket for a smaller one in order to go faster......
Thanks again. I'm not going to admit to the number of times I have watched this video but it has done the trick. I understand how my Shimano gears work. Through watching your videos I have a good understanding of my 3 and 5 speed SA hubs and now my Shimano hub. Great video.
Dan, thanks for the explanation, great video! It really helped me to understand and appreciate the function of geared hubs. Now in the future you should make a comparison video of the Nexus and the (much more expensive) Rohloff Speedhub ;)
Great video, good explanation of the internal parts.. Waiting patiently to put 2500 kms on my hub and then I will be pulling it apart and putting it back together.
Awesome video explaining the workings of an internal gear unit! I've watched around 30 videos on this subject (produced by other people) and Dan Burkhart's is the best I've seen thus far. If you're not familiar with the names of parts then it would be a good idea to thoroughly acquaint yourself with them first, and re-watch the video one or more additional times. I run a Bicycle Collective in St. George, Utah, and I'm referring all my people to this video. Great work, Dan!
You gave a great explanation of the hub. Thank you! I just test rode a bike with this hub and was curious how it worked. I have questions about durability under high torque situations...I'll seek those on other videos.
Wow, well done. I've seen other videos on this device, but none really explained how it works. I have one of these and love it. It's always better to understand it.
Dan, that was the clearest, easiest to understand explanation of how this hub works, that I've ever heard! I'm very impressed you were able to convey the information so simply. It would appear that Shimano have designed and built a very easy to use system. I now have only two questions. 1 - Is it sturdy enough and made with high enough quality materials to last a good long time with minimal maintenance? 2 - How can I get one without selling everything I own to afford it? Thanks for taking the time and obviously a great deal of effort to produce a video that almost anyone with some mechanical knowledge can use to understand this system. Shimano should have you on staff as a technical trainer!
+Thomas Jowett Thank you for the comments. If used for it's intended usage, kept properly adjusted, the hub should give very reliable service for a very long time. Maintenance requirements vary, with more attention required if used extensively in foul weather conditions.
Magnificent video; very well explained and at a good pace too! I must add to the noise of people saying that you sound like the narrator to a 1950s/'60s training/information video.
watching this video I was transported back to my young and care free days. That looks like a dyna flo sprag set up. WOW, what goes around comes around.
Thanks for explaining..had to watch a couple parts over and go back to the illustrations in the beginning to grasp but, you explained it well. Be cool to see a CAD animation.
All I can say is ; holy crap! All that for a bicycle ? How much is it ? About the same as a automobile transmission ? I like it ,but it must be cost prohibitive .
@@boracay12 they are kind of expensive--but it's neat technology. My elliptigo uses this. And adjusting it is really easy (vs. tinkering with the screws and tension adjustments for external derailleur).
@@boracay12 available from about £137 www.google.co.uk/shopping/product/11263393959198283395?q=Shimano+Nexus+Alfine+8+speed&biw=1920&bih=969&prds=epd:7591863736334054134,paur:ClkAsKraX5MzwupjuvOmaxZkW1EWH2t8MWV8dokebV-RyvEXkjbx9QOcKjgN5muBu_nBdR9eXTb8o0GXFc4jhuemJVI1A-_xsDzmImnzsSWBCRp6BwHbnR1u-BIZAFPVH71R1IjT-v7btaBTDDxd070QEA9S9w,prmr:1&sa=X&ved=0ahUKEwi29KOQ9dDtAhWKRhUIHSEvBl4Q8wIIwwM
@@david197407 ok thanks . 13k peso . My cheapy chinese mtb with 29 " wheels and 21 gears ,( working fine ) cost 6.2 k peso . But very interesting set up .
Thanks for the video. i thought it would be like this inside; explains why 5th gear feels the most natural to me. I have this hub on my carbon belt drive system and it feels really nice (acceleration and power transfer).
You did a terrific job with this video. Anyone should be able to understand it. Superb. I want one now that I don't have to disassemble it myself. Only I wonder how much weight / stress that clutch can handle. I'm about 170-175 lbs so I'm sure it should suffice. Thanks again for a great "exploded view" and breakdown.
I am happy to see a video with some detail! The best video on youtube on this subject. Greetings from a bicycle mechanic in Amsterdam (the capital of cycling).
Thank you for this video. I personally have nexus 8 premium in my bicycle, and it is awesome, I'm making over 400 kilometers per month with a minimal amount of service... actually the hub itself doesn't need any kind of service, at least for now. I don't know if I fully understand how it works, but at least it's not science fiction now :)
3:1 difference between low and high ratios but only 8 ratios total, which means they are spread out widely, which is undesirable to many people, including me. Imagine on a piano for example, spanning 3 octaves using only 8 notes (7 intervals). Instead of being only about 5.9% apart, each ratio is about 17% apart from the neighboring ratio(s). That is like a double shift to me (skipping a ratio in between). I need close ratios, as sometimes I feel I need something between 18 tooth rear and the next ratio which is either 20 or 16 tooth rear. This leads me to my conceptual design. Have all 21 tooth ranges in the rear (from 10 tooth to 30 tooth inclusive), but since that will be so wide, have the front sprocket/chainring move laterally to keep the chain properly aligned. That way you have 3:1 difference between highest and lowest ratios, but have 19 more close ratios in between. That is my ideal design and I am waiting to see if someone makes it in my lifetime. If 21 cogs turns out to be too wide, then just reduce it to whatever can be made to work, such as 15, but then make the difference between high and low ratio only about 2.5:1, to keep the intermediate ratios close, or maybe let the user select their own set of ratios, following the manufacturers compatibility rules for them.
Based on my research, a less than 15% difference in gear ratios don't make much difference in pedalling effort (+/- 3%). This is based on my city riding with some hills (Los Angeles). I believe this is why mainstream sprocket clusters on rear wheels have differences ranging between 12 and 18% (eg, 8-speed 11-32 or 7-speed 14-28). Plug these into Sheldon Brown's gear calculator which shows the % differences and you'll see. I understand that as speed increases, you need closer ratios than 15% because of increasingly greater wind resistance which makes pedalling harder. Also racers or highly athletic riders may benefit from closer ratios to squeeze as much speed as possible from their cadence. Also, Rohloff 14-speed has about 14% difference between all gears. I believe manufacturers have done their research on this.
@Dan Burkhart, perfect narration; pace, tone, and articulation. Matched with both still and video visuals, this is pretty hard to improve upon. Thank you!
I use Shimano 8.The someone on ebike. So happy with it. I've always hated the old sproket type. Can't say enough about. Never had any trouble with over 5th km and working great.
Also its possible to double the amount of gears by having a twin or even triple front sprocket and derailer (using a thinner chain so there is some play when changing the ratios on the front sprockets .A triple gives 24 speeds .
2 years ago i tried this bike with this gearbox It's very easy and smooth and it's better than the traditional gears on another bikes It's mini gearbox but with high torque at 1st gear and at 8th gear with high speed I really would by one of these bikes
Excellent! I didn't follow every detail - will watch again at least one more time to get a little deeper - however I have a basic understanding now thanks to this video. I have never run across any other explanation like this and I truly very much appreciate it! I put over 10,000 miles on my former belt-drive Nexus-3 bike, and I recently upgraded to a new belt-drive bike with an Alfine-8 - approaching 1000 miles on the new bike now. I had not understood the two-range, four-ratios per range architecture before I watched your video. Your explanation makes it clear why 5th gear should be the most efficient (least drag), as this is a direct drive with no planetary sets in the power path. I think I can feel this when I ride. After this, it would make sense that 1st, 6th, 7th, and 8th are the next most efficient, having only one planetary set engaged, either just the low-range reduction set (1st gear), or just one of the three overdrive ratios (6th, 7th, and 8th gears). Finally, 2nd, 3rd, and 4th involve two planetary sets in series, the low-range reduction set and one of the overdrive ratio sets, and so would seem to be the least efficient. I believe I can feel this while riding. One thing which I think is very noticeable while riding is the increased efficiency (reduction in drag) in changing from 4th gear to 5th. Thanks to your video I now understand that there are never more than two planetary sets engaged in series in any gear setting. Approaching 1000 miles, I like the Alfine-8 a lot. My new bike has 700c wheels and came set up with a 50 tooth "chain ring" and a 22 tooth rear cog. With 170 mm cranks I like how this choice of "chain drive ratio" balances the extent of the low and high gears. For sure, 1st gear could be lower - I can't take on just any hill, but the ones I normally encounter are manageable. I do like where 8th is at and feel like it's a pretty good balance on my commuter bike. When riding, the gap between 5th and 6th is the one I sometimes wish were a little closer. It's not uncommon for me to run into a riding situation where 5th gear feels like I'm spinning out but I can't make the force needed to hold 6th gear. I end up having to drop back to 5th and slow down to keep a comfortable cadence. Now that I understand how the three overdrive ratios are all based on separate sun gears, I'm not sure why the design couldn't be made with more uniform gear step sizes. However, I suppose it's also possible the the 5th to 6th gear span is driven by the necessary commonality with the 1st to 2nd gear span, where a closer ratio would not be as desirable compared to the design as is. One request would be to provide the gear ratios as exact integer ratios (gear tooth counts) vs. the provided decimal approximations. I suspect studying the integer ratios may provide insight making it clear where the difficulty is in realizing a design with a more uniform set of gear steps. If you have these integer ratios in the form of the actual gear tooth counts, and could provide them here in the comments, that would be awesome and much appreciated. My first bike had a Sturmey-Archer 3-speed. I loved that bike and missed it when I "upgraded" to a Schwinn 10-speed. Now decades later I'm back to riding bikes and back to internal gear hubs. They are so cool. One thing I notice while riding is that I'm shifting gears very often while riding because shifts are so easy allowing a nearly continually optimized cadence vs. pedal force. I don't know if modern derailleurs are this quick and effortless to shift, but if not I'd miss the super easy gear shifts if I went to a derailleur bike. Thanks again so much for the excellent, informative, and highly useful presentation! Joe
Sir, you nailed it. You might actually save my gearhub. I mean, without your video I'll probably at some point try to figure out how it works and the outcome might be a complete disaster. Thanks very much.
This systems is a highly advanced mechanism. I just bought a L train bicycle and I was amazed how it works compared to standard gear systems. I learned alot of information on how this system works thanks to your video. Keep up the good work teaching.
If you happen to have a rohloff on hand sometime.... love to see one of those. I’ve refurbed Sturmey 3 speed stuff, and that’s easy enough to understand. Never opened up anything more complex.
In my Alfine the plastic cage for the roller bearings broke. Due to a lack of spares availability the hub was junk. Taking it to my LBS they were not interested in touching it so I had to dive in. It lasted about five years, the lack of support was very disappointing. Great video though 👍
Question: Could that part have been 3D printed in Carbon Fiber Nylon? I'm working on starting a belt drive ebike project and making everything digitally controlled with an arduino, including shifting. Watching this video my impression was this would last forever if well maintained, and well you just killed that. If it could be 3d printed it wouldn't be a problem and I would be ready for the failure. Also, do you think that part could be replaced with a soft metal like aluminum? If you can make a cad design of the part, China will machine them for you cheap.
@@mborowski2010 Hi Michael, to clarify the cage was for the ratchet pawls not the bearings as I wrote earlier. The pedals locked up with the rotation of the wheels and then eventually the hub locked up. I am not an engineer but to change the material it is made from you would need something that won't wear and contaminate the hub but not wear down the parts it interacts with.The lack of spares for the hub and the bike shops not wanting to touch it was the worst, that hurt. 3D printing I will investigate, I hadn't thought of it so cheers for that👍 PS. The other consideration is i may have had a lemon, reading some of the other comments people seem to be having a good run with theirs but again the parts and tech support would be worth investigating.
I have ridden nexus 8 for three years and it was great experience. However if you pedal hard it makes some grinding noise. So it better fits for relaxed ride. Nothing too aggressive.
Thanks for your video that helped me understand how it works. Is there a clutch in the alfine? I hear you say about roller clutch. I assume that is the only way it changes gear is from this as when I use mine. It feels very smooth on the ride. Only pulling away do i feel a lag as though the clutch is working. Vinnychoff
This reminds me of the class videos i had to study at Los Alamos National lab.... The PHD instructor would ask us if we got all that? We would shake our heads and say sure, good till next years refresher course!! John Cameron Swayze selling a Timex!! I just picked up a Specialized Globe Elite with this rig on it for $25.00 haven't got it home yet has flat tires.
Wow, that was an amazing video. I understood everything, I don't think I have ever done that with a video like this aside from the old 1950s automotive principles videos from GM. The only thing is I wish you had either a better camera angle or a wider field of view lense. Being able to see just a little more without it being so cramped would in my opinion, greatly increase quality of presentation from a viewing point of view. Other than that this video was about as close to damn near perfect as I've seen so far on UA-cam. I haven't checked the channel to see if you have more videos akin to this, but if you do then hit dog, I'm gonna have to subscribe to this. Great video, thanks for the informative, non-bloated education. I really enjoyed it.
Thank you so much from those of us who could understand a semi complex drive train flow path. I would like to rate your video a A+. Viewing it a second and third time does greatly help to understand the drive flow path knowing the rest of the several mechanisms are not engaged. I now understand the unit. I started looking for answers when my Alfina would not shift. I think my handle bar shifter is at fault. Some times my thumb lever action has no reaction to the hub assembly. I am still looking to see how the handle bar shifter works. Any advice would be greatly appreciated. Thx again Dan.
Hi. Great video. I have Shimano Alfine 8 hub in my bike (Kalkhoff Sahel Pro-Connect Disc electric) since 2012 and it ran 17000 km without service. Let me ask you a question. I have my hub adjusted well, yellow points are in the line, but since a few months a metallic clicking noise (like when closing a door) occurs from time to time. It comes when I start pedaling after I have pedaled constantly for say 200-300 meter and then stopped pedaling, maybe for making a turn. It can happen in any gear. I cannot register the clicking through the pedals and the pull is constant and smooth, I can only hear it. Any idea what is the reason and whether I have to be concerned?
Excellent vid mate. How is it that you come to know all this? What I mean is, did you self teach what you know or are you a part of the design team for Shimano? Or what?
Great Explainations .. What are the friction losses in a planetary Hub compared to chains and sropecks.. What are the friction losses comparing chains to a cogged belt drive.. Seems as long as you use a planteray hub may as well use a belt drive..??
Shimano jad a three speed that was used by Raleigh from Nottingham England. I loved those planetary hubs way better then derailleur system, so precise compared to derailleur.
This video is very beneficial, may i know how much it costs that side, it's not yet this side. I need to know about the one that uses the ordinary chain. Thanks for the job well done.
I've had a (very early model) Rohloff for 15 years now, and I'm afraid it too has an Achilles Heel: the shifter cables emerge from the twist-grip at right angles and are prone to damage in everyday use. Plus the cable box seems quite capable of warping and being damaged. The flexible cable housing that enters the hub on some newer models was a response to this problem I suspect. I've replaced the shifter parts three or four times now. They're not cheap. The Rohloff hub itself is a marvel of course, and seems still to be going strong without any issues, despite heavy urban use (trailer, cobbles, kerbhopping...) I'm about to rebuild it for the third time: rim's shot. Would I buy one again? No. Thinking of going back to Sturmey-Archer in fact (seriously). Now that is a proven technology!
outcast566 He said he didn't like the shifter cable with his. I wonder if this is a problem with the current models.. must be or he wouldn't be looking elsewhere.
Do Purchase ! Had one of these for four years in Bristol UK and ridden up and down all the hills there, The bike was kept outside!! I conced shifter cable is tricky to connect.
Hi Dan. I have another question. I have watched this but it really is beyond me. Anyway, If I have a clicking noise, once every rotation of the cranks, and after changing the chain (i.e the relationship between the front sprocket and the nexus gear sprocket), and then even when I change gears, the clicking noise always occurs at the same point in the rotation of the cranks - then would this noise be from the nexus hub or the bottom bracket?
The drive sprocket seems rather large. That seems to be a limiting factor in terms of top drive ratio. Is that fixed? What is it? What are the choices if not fixed?
Hi Dan, i opend my Alfine. took it in the oilbath as described in the shimano maintenence manual and regreased the outer rollers. i put everythink to gether but it seem the hub makes a littlebit louder noise when freewheeling than usual. haub shifts fine through all gears. any suggestions? did i make a mistake?
Do these 8 gears roughly translate into something a bit more common to understand, like tooth cassettes? As in, gear 1 = 14t, gear 2 = 16t, etc. I've had my Alfine 8-speed for 2 years and I still don't understand what tooth each gear translate too haha.
Dan, quick kudos and a question. First, thanks for the easy-to-follow explanation on the inner workings. I had my first negative experience on a 2nd-hand Alfine yesterday and was about to go balllistic on the guy who sold it to me, only to quickly realize that it was drastically out-of-adjustment. Now, a question: Assuming that the shifter-adjuster will only get me so much before it won't extend any more, can you add (or point me to) a video explaining how to replace or tighten the cable? Thanks again.
Hi James. There are tech documents on line showing proper cable instalation. They are somewhere buried on this page. si.shimano.com/#seriesList/26/74 However, I'll just throw out a few suggestions. First, ensure the cable is correctly routed around the cassette joint capstan. That is a very common error which will negatively affect shifting. Second, ensure the cable is free running in the housing. Tight bends should be avoided. Check the general condition of the cable for corrosion or fraying. If all that looks good, and you are able to line up the two yellow marks with the shifter in the 4th gear position, everything should work. Oh yeah, be sure you are using the correct shifter. The new models, the 7000 series have reversed the direction of spring pull and are now high normal. Make sure your hub and shifter are a match.
Thanks for the advice. My question was more "5 years from now, the cable will stretch to where I can no longer use the shifter's adjuster", but this is good detail on when I do have to replace it.
Dan, does the drive sprocket act as a torque multiplier like a torque multiplier tool used to tighten and loosen bolts, like a 4:1 multiplier, or is it just mechanical means of switching between theoretically normal sprocket sizes minus the derailer? hope that makes sense.
Torque multiplication is a function of the ratio between the input and output. The first stage of the drive mechanism is the chain ring driving the cog through the chain. Since this is almost always a step up ratio, the torque multiplication in this stage would be a negative number. In the second stage, the input is through the cog, and the output drives the hub shell. In underdrive gears, the torque multiplication at this stage would be a positive number, but the cog itself would not act as a multiplier. The multiplication takes place through the gear train.
Hi Dan, I really enjoy your Hub videos. I have a FatTad Recumbent Trike, weights ~100Lbs, and has a midmounted 1000W BBSHD. So far I broken two Nexus 8 and most recently broke the freewheel on a NV380. Thinking about giving up on IGHs and going with a cassette, also have a FSA Metropolis Patterson internally geared crankset. The Metropolis broke once, but over four years its been mosly reliable. Would you have any recommendation for the strongest IGH? Thank you for your videos.
Thanks for your comments. I have not done any testing to failure of any of these hubs. Manufacturers specify minimum input ratios to limit torque input from human power, but I'm not aware of any published limits on actual torque values. Anecdotally, from experiences seen online, the Nuvinci is considered to be the most robust in terms of the input torque it will withstand, so if you are breaking one of those, I would say internal hubs don't suit your application.
@@2wagondragonThanks for your reply. Agreed, the 380 is likely the strongest, but the freewheel paws break on the stock 380. Replacement paws are designed differently and are stronger. Alhtough there is the fluid leaking problem, if you push it too hard and get it it hot.
Dan, Can you help me. I removed the core to regrease it. I didn't disassemble the core. I just wiped the old grease off and wiped on new grease.. Upon re-assembly, the gear sequence has changed to something like 2,3,4,1,7,8,5 though it's difficult to tell the exact sequence because of the large jumps. Have you any idea what's wrong.
Sorry, I missed out 6. Should be 23416785. may be the 2 peed high/low clutch is out of phase with the 1 to 4 shifting. is that possible. BTW, thanks for an awesome video.
I had a three speed internal hub drive on my string Ray Bike in the late 1960's .. I had not heard of a Modern 8 s;eed until a few days ago when I saw it on a belt drive electric bike ..
I'm having trouble with my shimano nexus inter-8 since I opened it up. I think it has something to do with the roller clutch because I initially had only 1st and 5th gear. I reopened it and tinkered with the roller clutch spring a bit (not knowing what I'm doing) and I got the other gears to work when I put it back together. Yesterday though, I found out that if I freewheel downhill long enough, I go back to having 1st and 5th only again. It stays that way for a while before I get the other gears back
I have a question comparing this hub to the the classic Sturmey Archer 3-speed AW hub. The AW has just one planetary gearset (and no stepped planet gears), and power flows in opposite directions to achieve different ratios, namely 3:4 or 4:3. In comparison, on the Alfine 8, does power flow in just one direction? Looking at your video, it seems that's the case. This would seem to be an important distinction in the design of these 2 hubs. Thank you for producing the best videos on how bicycle planetary hub gears work. You have a deep understanding.
You are correct that the classic 3 speed achieves underdrive and overdrive ratios by reversing the power flow. ie when the power input is the ring gear, you have underdrive, and when the ring gear is the output. you have overdrive.In the case of the Alfine hub, the underdive gears are accomplished by means of the reduction stage which is bypassed in gears 5 thru 8.
I had a bike with the Nexus 8 (not Alfine) and it covered 50 000km ( I cycle to work). It only needed a new gear cable once, and finally needed a new face plate because part of the face plate that holds the cable end, broke off. Otherwise trouble free and no maintainance! Highly recommend for recreational/commuter cyclists. There is a minimal loss of efficiency that would affect a race cyclist, but not noticeable for regular cyclists
Just a heads up. I had my alfine 8 for two years and started developing problems 6 months ago where certain gears in the higher rang (5,6,7,8) would not engage smoothly and where the 8th gear began continuously clicking. . Adjust was spot on. I just fixed the problem today by changing out the cable and it works perfectly. I opened the hub 8 months ago and everything inside was pristine and well greased. The reason why changing the cable worked so well is that once you get into the higher gears on the alfine the tension in the shifter cable increases causing it to stretch more and be less accurate in the higher gears. This is many alfine users a have issues in the higher gears. Cannot believe that the cable change was so simple, easy, cheap, and effective. Should be the second troubleshooting step after checking adjustment. Best of luck to everyone!!!
Was your cable evidently damaged before changing? Or did it look good? My cable looks like brand new, but bike is 4 years old (but it was not ridden). Is it possible that cable has streched without using (or used occasionally)?
My cable looked brand new. A cable can stretch and still look new. If you left the bike unridden for a long period of time and the bike was sitting in a higher gear then I believe the cable could have still stretched because the higher gears put a lot of tension on the cable.
I ordered the Cube Hyde Pro yesterday... omg would a normal gear-changing-chain-thingy have been a better option? I have literally no clue about bicycles.
This is excellent advice.
Pibbles 'n Bits Thanks for this,about changing the cable. Mine didn’t work from its inception because I’m new at this but still have some knowledge about how and what makes stuff work. I knew the cable was the problem and on till the broken ends stated protruding the shop keep telling everything was okay and I’m hard on the equipment.We changed the cable and I changed bike shops.
Very Informative !!! Thank you for taking the time to do this video !
Marvelous and detailed explanation, thank you for putting in so much effort!
Your video is a remarkably comprehensive explanation of the inner workings of this mechanism. Thank you for the information 🙏
Excellent description. Kind of like an automatic transmission without any hydraulics. Fascinating in my opinion.
Juanuary 18, 2020: Dan, I'm going to upgrade my Atlas Cargo from the Sturmy Archer 3 speed to the Alfine 8 speed for some long trips this summer. I've been a mechanic my whole life and can fix anything if I've got a manual. Now, I've got a complete internal parts breakdown with a dynamic display of internal parts and their function that talks to me !!! Awesome work Mr. Dan !!! I can make a tool kit just for this and be able to repair it roadside if need be. Store it in my phone and play it back when I need to. Thanks a bunch!
Finally. Finally...
Been wracking my brains looking at pictures and trying to understand how epicyclic gearing works, and finally you've made it come clear in my mind and I can see it now.
At last.
Thank you thank you thank you!!
I have the Alfine 11sp hub on road bike, a tad heavy, but no deraileur, exact shift/response, and works excellent. Expensive, but after miles of riding, glad to have made the purchase. So far, 3 yrs use, very durable.
no boat, they shouldn't be noisy, i bought my alfine 8 based on this video....and it works great! the only thing i miss is the speed of my road bike...........i was asking Dan if i could install a 52 or 53teeth chainring in replacement of the 42t chainring i have now and replace the 18t rear sprocket for a smaller one in order to go faster......
Thanks again. I'm not going to admit to the number of times I have watched this video but it has done the trick. I understand how my Shimano gears work. Through watching your videos I have a good understanding of my 3 and 5 speed SA hubs and now my Shimano hub. Great video.
Very impressive overview of the Shimono Nexus Alfine 8 speed. Very impressive!
Great video, it helps me to understand perfectly how it works. Thank you.
Shimano never fails to impress. Thanks for explaining this new engineering marvel.
thank you for explaining this so clearly. In particular I understand now how the shifter works.
Bullshit!!!!!!!!!!
Dan, thanks for the explanation, great video! It really helped me to understand and appreciate the function of geared hubs.
Now in the future you should make a comparison video of the Nexus and the (much more expensive) Rohloff Speedhub ;)
Great video, good explanation of the internal parts.. Waiting patiently to put 2500 kms on my hub and then I will be pulling it apart and putting it back together.
Awesome video explaining the workings of an internal gear unit! I've watched around 30 videos on this subject (produced by other people) and Dan Burkhart's is the best I've seen thus far. If you're not familiar with the names of parts then it would be a good idea to thoroughly acquaint yourself with them first, and re-watch the video one or more additional times. I run a Bicycle Collective in St. George, Utah, and I'm referring all my people to this video. Great work, Dan!
Thank you for the comment.
I grew up watching straight voiced synth fueled instruction videos. Thanks for this.
You gave a great explanation of the hub. Thank you! I just test rode a bike with this hub and was curious how it worked. I have questions about durability under high torque situations...I'll seek those on other videos.
Wow, well done. I've seen other videos on this device, but none really explained how it works. I have one of these and love it. It's always better to understand it.
Dan, that was the clearest, easiest to understand explanation of how this hub works, that I've ever heard! I'm very impressed you were able to convey the information so simply. It would appear that Shimano have designed and built a very easy to use system.
I now have only two questions.
1 - Is it sturdy enough and made with high enough quality materials to last a good long time with minimal maintenance?
2 - How can I get one without selling everything I own to afford it?
Thanks for taking the time and obviously a great deal of effort to produce a video that almost anyone with some mechanical knowledge can use to understand this system. Shimano should have you on staff as a technical trainer!
+Thomas Jowett
Thank you for the comments.
If used for it's intended usage, kept properly adjusted, the hub should give very reliable service for a very long time.
Maintenance requirements vary, with more attention required if used extensively in foul weather conditions.
This is the best planetary gearbox video I've ever seen.
Magnificent video; very well explained and at a good pace too! I must add to the noise of people saying that you sound like the narrator to a 1950s/'60s training/information video.
Thanks for such a great video! That gear hub is nothing less than a piece of art! Liked and Subscribed
Great video thank you, the last bit about the input to output was exactly what I was looking for, Thanks.
watching this video I was transported back to my young and care free days. That looks like a dyna flo sprag set up. WOW, what goes around comes around.
Thanks for explaining..had to watch a couple parts over and go back to the illustrations in the beginning to grasp but, you explained it well. Be cool to see a CAD animation.
This thing is still complicated even after the explanation.
All I can say is ; holy crap! All that for a bicycle ? How much is it ? About the same as a automobile transmission ? I like it ,but it must be cost prohibitive .
@@boracay12 they are kind of expensive--but it's neat technology. My elliptigo uses this. And adjusting it is really easy (vs. tinkering with the screws and tension adjustments for external derailleur).
@@boracay12 available from about £137 www.google.co.uk/shopping/product/11263393959198283395?q=Shimano+Nexus+Alfine+8+speed&biw=1920&bih=969&prds=epd:7591863736334054134,paur:ClkAsKraX5MzwupjuvOmaxZkW1EWH2t8MWV8dokebV-RyvEXkjbx9QOcKjgN5muBu_nBdR9eXTb8o0GXFc4jhuemJVI1A-_xsDzmImnzsSWBCRp6BwHbnR1u-BIZAFPVH71R1IjT-v7btaBTDDxd070QEA9S9w,prmr:1&sa=X&ved=0ahUKEwi29KOQ9dDtAhWKRhUIHSEvBl4Q8wIIwwM
@@david197407 ok thanks . 13k peso . My cheapy chinese mtb with 29 " wheels and 21 gears ,( working fine ) cost 6.2 k peso .
But very interesting set up .
@@boracay12 it’s actually fairly inexpensive. And yes...like an auto transmission without hydraulics. Very cool stuff
Thanks for the video. i thought it would be like this inside; explains why 5th gear feels the most natural to me. I have this hub on my carbon belt drive system and it feels really nice (acceleration and power transfer).
You did a terrific job with this video. Anyone should be able to understand it. Superb. I want one now that I don't have to disassemble it myself. Only I wonder how much weight / stress that clutch can handle. I'm about 170-175 lbs so I'm sure it should suffice. Thanks again for a great "exploded view" and breakdown.
I am happy to see a video with some detail! The best video on youtube on this subject. Greetings from a bicycle mechanic in Amsterdam (the capital of cycling).
Thank you for the kind words.
Thanks for the video. Even though I didn't udnerstand all the terms, it was a great introduction to learning.
Thank you for this video. I personally have nexus 8 premium in my bicycle, and it is awesome, I'm making over 400 kilometers per month with a minimal amount of service... actually the hub itself doesn't need any kind of service, at least for now. I don't know if I fully understand how it works, but at least it's not science fiction now :)
Science friction.
I love, A. the detail and expertise that you put into this and, B. the fact that you sound like Sam the Eagle from The Muppets.
heytreacle hahahahahahhahah
3:1 difference between low and high ratios but only 8 ratios total, which means they are spread out widely, which is undesirable to many people, including me. Imagine on a piano for example, spanning 3 octaves using only 8 notes (7 intervals). Instead of being only about 5.9% apart, each ratio is about 17% apart from the neighboring ratio(s). That is like a double shift to me (skipping a ratio in between). I need close ratios, as sometimes I feel I need something between 18 tooth rear and the next ratio which is either 20 or 16 tooth rear. This leads me to my conceptual design. Have all 21 tooth ranges in the rear (from 10 tooth to 30 tooth inclusive), but since that will be so wide, have the front sprocket/chainring move laterally to keep the chain properly aligned. That way you have 3:1 difference between highest and lowest ratios, but have 19 more close ratios in between. That is my ideal design and I am waiting to see if someone makes it in my lifetime. If 21 cogs turns out to be too wide, then just reduce it to whatever can be made to work, such as 15, but then make the difference between high and low ratio only about 2.5:1, to keep the intermediate ratios close, or maybe let the user select their own set of ratios, following the manufacturers compatibility rules for them.
Based on my research, a less than 15% difference in gear ratios don't make much difference in pedalling effort (+/- 3%). This is based on my city riding with some hills (Los Angeles). I believe this is why mainstream sprocket clusters on rear wheels have differences ranging between 12 and 18% (eg, 8-speed 11-32 or 7-speed 14-28). Plug these into Sheldon Brown's gear calculator which shows the % differences and you'll see. I understand that as speed increases, you need closer ratios than 15% because of increasingly greater wind resistance which makes pedalling harder. Also racers or highly athletic riders may benefit from closer ratios to squeeze as much speed as possible from their cadence. Also, Rohloff 14-speed has about 14% difference between all gears. I believe manufacturers have done their research on this.
@Dan Burkhart, perfect narration; pace, tone, and articulation. Matched with both still and video visuals, this is pretty hard to improve upon. Thank you!
love the presentation style!
Great video, I enjoyed it a lot, before to see this video I couldn't understand how it works this system.
Great video, superbly explained and fascinating to unterstand!
Thanks for the explanation of how it works. It is still complicated but I don't know if there is a simpler way to explain
Thank you for this tutorial. It is just like being told how a magic trick is performed.
I use Shimano 8.The someone on ebike. So happy with it. I've always hated the old sproket type. Can't say enough about. Never had any trouble with over 5th km and working great.
thank you for this video. i have been looking for an explanation to this mechanism for some time now.
Great explanation of a complex gear arrangement.
Also its possible to double the amount of gears by having a twin or even triple front sprocket and derailer (using a thinner chain so there is some play when changing the ratios on the front sprockets .A triple gives 24 speeds .
The biker should be proud because of that genius and complicated system on a bike.
Great video. Fascinating product.
2 years ago i tried this bike with this gearbox
It's very easy and smooth and it's better than the traditional gears on another bikes
It's mini gearbox but with high torque at 1st gear and at 8th gear with high speed
I really would by one of these bikes
Sounds like a 1950s documentary
Ken Witt i was thinking the same ...great video though....can this alfine 8 climb really high hills?
dozzy000 i dont see why it couldnt.
dizzy000 - Depends on the fitness of the rider.
If the rider is from the 1950's, it won't work.
hahahahhaa
Excellent! I didn't follow every detail - will watch again at least one more time to get a little deeper - however I have a basic understanding now thanks to this video. I have never run across any other explanation like this and I truly very much appreciate it!
I put over 10,000 miles on my former belt-drive Nexus-3 bike, and I recently upgraded to a new belt-drive bike with an Alfine-8 - approaching 1000 miles on the new bike now.
I had not understood the two-range, four-ratios per range architecture before I watched your video. Your explanation makes it clear why 5th gear should be the most efficient (least drag), as this is a direct drive with no planetary sets in the power path. I think I can feel this when I ride. After this, it would make sense that 1st, 6th, 7th, and 8th are the next most efficient, having only one planetary set engaged, either just the low-range reduction set (1st gear), or just one of the three overdrive ratios (6th, 7th, and 8th gears). Finally, 2nd, 3rd, and 4th involve two planetary sets in series, the low-range reduction set and one of the overdrive ratio sets, and so would seem to be the least efficient. I believe I can feel this while riding. One thing which I think is very noticeable while riding is the increased efficiency (reduction in drag) in changing from 4th gear to 5th.
Thanks to your video I now understand that there are never more than two planetary sets engaged in series in any gear setting.
Approaching 1000 miles, I like the Alfine-8 a lot. My new bike has 700c wheels and came set up with a 50 tooth "chain ring" and a 22 tooth rear cog. With 170 mm cranks I like how this choice of "chain drive ratio" balances the extent of the low and high gears. For sure, 1st gear could be lower - I can't take on just any hill, but the ones I normally encounter are manageable. I do like where 8th is at and feel like it's a pretty good balance on my commuter bike.
When riding, the gap between 5th and 6th is the one I sometimes wish were a little closer. It's not uncommon for me to run into a riding situation where 5th gear feels like I'm spinning out but I can't make the force needed to hold 6th gear. I end up having to drop back to 5th and slow down to keep a comfortable cadence.
Now that I understand how the three overdrive ratios are all based on separate sun gears, I'm not sure why the design couldn't be made with more uniform gear step sizes. However, I suppose it's also possible the the 5th to 6th gear span is driven by the necessary commonality with the 1st to 2nd gear span, where a closer ratio would not be as desirable compared to the design as is.
One request would be to provide the gear ratios as exact integer ratios (gear tooth counts) vs. the provided decimal approximations. I suspect studying the integer ratios may provide insight making it clear where the difficulty is in realizing a design with a more uniform set of gear steps. If you have these integer ratios in the form of the actual gear tooth counts, and could provide them here in the comments, that would be awesome and much appreciated.
My first bike had a Sturmey-Archer 3-speed. I loved that bike and missed it when I "upgraded" to a Schwinn 10-speed. Now decades later I'm back to riding bikes and back to internal gear hubs. They are so cool. One thing I notice while riding is that I'm shifting gears very often while riding because shifts are so easy allowing a nearly continually optimized cadence vs. pedal force. I don't know if modern derailleurs are this quick and effortless to shift, but if not I'd miss the super easy gear shifts if I went to a derailleur bike.
Thanks again so much for the excellent, informative, and highly useful presentation!
Joe
Thanks so much for your comment. Knowing that I helped even one person to a better understanding is gratifying.
Sir, you nailed it. You might actually save my gearhub. I mean, without your video I'll probably at some point try to figure out how it works and the outcome might be a complete disaster. Thanks very much.
+Adam myarseiskillingme
Thank you so much for the comment. Glad to be of help.
+Dan Burkhart Quick one. Can I put link to the video on my blog please?
+Adam myarseiskillingme
Absolutely. feel free to post it anywhere you like.
Brilliant video - I now understand why fourth gear is the least smooth and efficient. Thank you.
This systems is a highly advanced mechanism. I just bought a L train bicycle and I was amazed how it works compared to standard gear systems. I learned alot of information on how this system works thanks to your video. Keep up the good work teaching.
If you happen to have a rohloff on hand sometime.... love to see one of those.
I’ve refurbed Sturmey 3 speed stuff, and that’s easy enough to understand. Never opened up anything more complex.
In my Alfine the plastic cage for the roller bearings broke. Due to a lack of spares availability the hub was junk. Taking it to my LBS they were not interested in touching it so I had to dive in. It lasted about five years, the lack of support was very disappointing.
Great video though 👍
Question: Could that part have been 3D printed in Carbon Fiber Nylon? I'm working on starting a belt drive ebike project and making everything digitally controlled with an arduino, including shifting. Watching this video my impression was this would last forever if well maintained, and well you just killed that. If it could be 3d printed it wouldn't be a problem and I would be ready for the failure. Also, do you think that part could be replaced with a soft metal like aluminum? If you can make a cad design of the part, China will machine them for you cheap.
@@mborowski2010 Hi Michael, to clarify the cage was for the ratchet pawls not the bearings as I wrote earlier. The pedals locked up with the rotation of the wheels and then eventually the hub locked up. I am not an engineer but to change the material it is made from you would need something that won't wear and contaminate the hub but not wear down the parts it interacts with.The lack of spares for the hub and the bike shops not wanting to touch it was the worst, that hurt. 3D printing I will investigate, I hadn't thought of it so cheers for that👍
PS. The other consideration is i may have had a lemon, reading some of the other comments people seem to be having a good run with theirs but again the parts and tech support would be worth investigating.
excellent presentation dan...
I have ridden nexus 8 for three years and it was great experience. However if you pedal hard it makes some grinding noise. So it better fits for relaxed ride. Nothing too aggressive.
I agree, compared to my Shimano Acera 3x9, the pedaling is easier than the knob 8-shifter of Nexus.
So using this with a electric motor would be a no for you? That's what I was planning on using it on. The motor will be high torque, not high speed.
Thanks for your video that helped me understand how it works. Is there a clutch in the alfine? I hear you say about roller clutch. I assume that is the only way it changes gear is from this as when I use mine. It feels very smooth on the ride. Only pulling away do i feel a lag as though the clutch is working. Vinnychoff
Thanks for the video. Very illuminating. If the internals are not engaging, what do you recommend to get it working again? Thanks!
Epic voice and delivery.
Thank you very much for that detail explanation.
Thank you for the explanation! Have you done any videos for nuvingi hubs ? How will these work with a differential on a recumbent trike ? Thanks !!
I like the way you pronounce Alfine, I would love to hear you say “I’m fine” 😎
This reminds me of the class videos i had to study at Los Alamos National lab....
The PHD instructor would ask us if we got all that?
We would shake our heads and say sure, good till next years refresher course!!
John Cameron Swayze selling a Timex!!
I just picked up a Specialized Globe Elite with this rig on it for $25.00 haven't got it home yet has flat tires.
Awesome! Many thanks. Finally someone who gets it.
Wow, that was an amazing video. I understood everything, I don't think I have ever done that with a video like this aside from the old 1950s automotive principles videos from GM.
The only thing is I wish you had either a better camera angle or a wider field of view lense. Being able to see just a little more without it being so cramped would in my opinion, greatly increase quality of presentation from a viewing point of view.
Other than that this video was about as close to damn near perfect as I've seen so far on UA-cam. I haven't checked the channel to see if you have more videos akin to this, but if you do then hit dog, I'm gonna have to subscribe to this.
Great video, thanks for the informative, non-bloated education. I really enjoyed it.
Thank you so much from those of us who could understand a semi complex drive train flow path. I would like to rate your video a A+.
Viewing it a second and third time does greatly help to understand the drive flow path knowing the rest of the several mechanisms are not engaged.
I now understand the unit.
I started looking for answers when my Alfina would not shift. I think my handle bar shifter is at fault. Some times my thumb lever action has no reaction to the hub assembly. I am still looking to see how the handle bar shifter works. Any advice would be greatly appreciated.
Thx again Dan.
dreaming that kind of internal gear hub.. thats awesome
I'm building a custom e-bike and this will definitely be apart of it!
Excellent video. Thank you.
Excellent! And you sound like a Canadian version of my high school mechanics teacher 😀
You should consider keeping the object visible as you point to parts of it, and use close-up (post-processing?) when pointing to very small parts.
Thanks. I understand it well enough now.
This was super clear and easy to understand... well, for me, at least.
Hi. Great video. I have Shimano Alfine 8 hub in my bike (Kalkhoff Sahel Pro-Connect Disc electric) since 2012 and it ran 17000 km without service. Let me ask you a question. I have my hub adjusted well, yellow points are in the line, but since a few months a metallic clicking noise (like when closing a door) occurs from time to time. It comes when I start pedaling after I have pedaled constantly for say 200-300 meter and then stopped pedaling, maybe for making a turn. It can happen in any gear. I cannot register the clicking through the pedals and the pull is constant and smooth, I can only hear it. Any idea what is the reason and whether I have to be concerned?
Excellent vid mate.
How is it that you come to know all this? What I mean is, did you self teach what you know or are you a part of the design team for Shimano?
Or what?
Great Explainations .. What are the friction losses in a planetary Hub compared to chains and sropecks.. What are the friction losses comparing chains to a cogged belt drive.. Seems as long as you use a planteray hub may as well use a belt drive..??
I use one of these. They are great. I bit on the heavy side
Shimano jad a three speed that was used by Raleigh from Nottingham England.
I loved those planetary hubs way better then derailleur system, so precise compared to derailleur.
Raleigh used Sturmey Archer 3 speeds. Sturmey Archer was owned by Raleigh.
This video is very beneficial, may i know how much it costs that side, it's not yet this side. I need to know about the one that uses the ordinary chain. Thanks for the job well done.
Amazing video!
I used to build and overhaul epicyclic gearboxes.. I had no idea how they worked lol
I'll be watching this several times!!!
I've had a (very early model) Rohloff for 15 years now, and I'm afraid it too has an Achilles Heel: the shifter cables emerge from the twist-grip at right angles and are prone to damage in everyday use. Plus the cable box seems quite capable of warping and being damaged. The flexible cable housing that enters the hub on some newer models was a response to this problem I suspect.
I've replaced the shifter parts three or four times now. They're not cheap. The Rohloff hub itself is a marvel of course, and seems still to be going strong without any issues, despite heavy urban use (trailer, cobbles, kerbhopping...) I'm about to rebuild it for the third time: rim's shot.
Would I buy one again? No. Thinking of going back to Sturmey-Archer in fact (seriously). Now that is a proven technology!
Douglas Carnall I've been considering a Rohloff. Why wouldn't you buy again?
outcast566 He said he didn't like the shifter cable with his. I wonder if this is a problem with the current models.. must be or he wouldn't be looking elsewhere.
Very good. Thanks for this.
Thanks for the video, youre a great teacher!
Do Purchase ! Had one of these for four years in Bristol UK and ridden up and down all the hills there, The bike was kept outside!! I conced shifter cable is tricky to connect.
"conced", is that local Bristolian slang?
Hi Dan. I have another question. I have watched this but it really is beyond me. Anyway, If I have a clicking noise, once every rotation of the cranks, and after changing the chain (i.e the relationship between the front sprocket and the nexus gear sprocket), and then even when I change gears, the clicking noise always occurs at the same point in the rotation of the cranks - then would this noise be from the nexus hub or the bottom bracket?
Thanks Dan !!
whoever invented that hub gear must be a genius (I have that same nexus gear hub on my bike) far better than open gears I think
The drive sprocket seems rather large. That seems to be a limiting factor in terms of top drive ratio. Is that fixed? What is it? What are the choices if not fixed?
Hi Dan, i opend my Alfine. took it in the oilbath as described in the shimano maintenence manual and regreased the outer rollers. i put everythink to gether but it seem the hub makes a littlebit louder noise when freewheeling than usual. haub shifts fine through all gears. any suggestions? did i make a mistake?
Do these 8 gears roughly translate into something a bit more common to understand, like tooth cassettes? As in, gear 1 = 14t, gear 2 = 16t, etc. I've had my Alfine 8-speed for 2 years and I still don't understand what tooth each gear translate too haha.
Dan, quick kudos and a question.
First, thanks for the easy-to-follow explanation on the inner workings. I had my first negative experience on a 2nd-hand Alfine yesterday and was about to go balllistic on the guy who sold it to me, only to quickly realize that it was drastically out-of-adjustment.
Now, a question: Assuming that the shifter-adjuster will only get me so much before it won't extend any more, can you add (or point me to) a video explaining how to replace or tighten the cable?
Thanks again.
Hi James. There are tech documents on line showing proper cable instalation. They are somewhere buried on this page. si.shimano.com/#seriesList/26/74
However, I'll just throw out a few suggestions. First, ensure the cable is correctly routed around the cassette joint capstan. That is a very common error which will negatively affect shifting. Second, ensure the cable is free running in the housing. Tight bends should be avoided.
Check the general condition of the cable for corrosion or fraying.
If all that looks good, and you are able to line up the two yellow marks with the shifter in the 4th gear position, everything should work.
Oh yeah, be sure you are using the correct shifter. The new models, the 7000 series have reversed the direction of spring pull and are now high normal. Make sure your hub and shifter are a match.
Thanks for the advice. My question was more "5 years from now, the cable will stretch to where I can no longer use the shifter's adjuster", but this is good detail on when I do have to replace it.
Dan, does the drive sprocket act as a torque multiplier like a torque multiplier tool used to tighten and loosen bolts, like a 4:1 multiplier, or is it just mechanical means of switching between theoretically normal sprocket sizes minus the derailer? hope that makes sense.
Torque multiplication is a function of the ratio between the input and output. The first stage of the drive mechanism is the chain ring driving the cog through the chain. Since this is almost always a step up ratio, the torque multiplication in this stage would be a negative number.
In the second stage, the input is through the cog, and the output drives the hub shell. In underdrive gears, the torque multiplication at this stage would be a positive number, but the cog itself would not act as a multiplier. The multiplication takes place through the gear train.
Hi Dan, I really enjoy your Hub videos. I have a FatTad Recumbent Trike, weights ~100Lbs, and has a midmounted 1000W BBSHD. So far I broken two Nexus 8 and most recently broke the freewheel on a NV380. Thinking about giving up on IGHs and going with a cassette, also have a FSA Metropolis Patterson internally geared crankset. The Metropolis broke once, but over four years its been mosly reliable. Would you have any recommendation for the strongest IGH? Thank you for your videos.
Thanks for your comments. I have not done any testing to failure of any of these hubs. Manufacturers specify minimum input ratios to limit torque input from human power, but I'm not aware of any published limits on actual torque values.
Anecdotally, from experiences seen online, the Nuvinci is considered to be the most robust in terms of the input torque it will withstand, so if you are breaking one of those, I would say internal hubs don't suit your application.
@@2wagondragonThanks for your reply. Agreed, the 380 is likely the strongest, but the freewheel paws break on the stock 380. Replacement paws are designed differently and are stronger. Alhtough there is the fluid leaking problem, if you push it too hard and get it it hot.
Dan, Can you help me. I removed the core to regrease it. I didn't disassemble the core. I just wiped the old grease off and wiped on new grease.. Upon re-assembly, the gear sequence has changed to something like 2,3,4,1,7,8,5 though it's difficult to tell the exact sequence because of the large jumps. Have you any idea what's wrong.
Sorry, I missed out 6. Should be 23416785. may be the 2 peed high/low clutch is out of phase with the 1 to 4 shifting. is that possible.
BTW, thanks for an awesome video.
I had a three speed internal hub drive on my string Ray Bike in the late 1960's .. I had not heard of a Modern 8 s;eed until a few days ago when I saw it on a belt drive electric bike ..
I'm having trouble with my shimano nexus inter-8 since I opened it up. I think it has something to do with the roller clutch because I initially had only 1st and 5th gear. I reopened it and tinkered with the roller clutch spring a bit (not knowing what I'm doing) and I got the other gears to work when I put it back together. Yesterday though, I found out that if I freewheel downhill long enough, I go back to having 1st and 5th only again. It stays that way for a while before I get the other gears back
I have a question comparing this hub to the the classic Sturmey Archer 3-speed AW hub. The AW has just one planetary gearset (and no stepped planet gears), and power flows in opposite directions to achieve different ratios, namely 3:4 or 4:3. In comparison, on the Alfine 8, does power flow in just one direction? Looking at your video, it seems that's the case. This would seem to be an important distinction in the design of these 2 hubs. Thank you for producing the best videos on how bicycle planetary hub gears work. You have a deep understanding.
You are correct that the classic 3 speed achieves underdrive and overdrive ratios by reversing the power flow. ie when the power input is the ring gear, you have underdrive, and when the ring gear is the output. you have overdrive.In the case of the Alfine hub, the underdive gears are accomplished by means of the reduction stage which is bypassed in gears 5 thru 8.