I had a 3 speed sturmey archer 50 years back, worked like a Swiss watch, people with dérailleur gears laughed but the sturmey was very reliable, no twisted dérailleur or crud in the gear cogs,

"Fairly simple mechanical device" I wouldn't want to see a complex device! :o

Fascinating. I've stripped and rebuilt 3,4 and 5 speed Sturmey Archer hubs and they all follow a similar principle of operation, even but this is a different mechanism having three epicyclic trains. You've simplified it and now I understand the 8 speed. Thanks.

When I first started riding with my SA XRF8(W) I weighed in at 247 pounds, and had no problems with the hills in Toronto (some of which are steep). 3 years later, I am down to 225 lbs and still have no problems riding with the hub! Thanks for the great video, it is very informative.

thank you Dan....so nice of you to take the time and lay it out.....

Thanks so much for taking the time & trouble to make this video - really helpful! I also have an 8 speed hub, dating from around 2008, I think, which although little used, has a persistant issue, where it can very occasionally slip which I'm trying to sort out. Your video has been very helpful! Just as an aside, my unit appears to differ slightly to yours, - in yours, there is a gap between the stages, where the planetary gears are clearly visible, whereas the middle ring gear in mine completely covers the planetary gears. I wonder when this change was made and to what purpose.

Thank you sir. I've only recently discovered IGH'S, like last week recently. I was really hoping there would be a vid exactly like this. I appreciate you feeding my curiosity.

Indeed it is Richard, good to hear from you.. I'll check out your group.

very nicely explained thank you sir for making this great video.

Thx for this! I knew how 3 speed hubs worked, but always wondered how those with more did... this was a great (literal) insight!

Informative, concise and thoughtfully demonstrated. Thank you.

Very good video - thanks for making this. Really well explained.

I watched the whole video and enjoyed every second of it, going back sometimes to make sure I understood what you were saying. I wonder how many people would sit and watch this video for entertainment purposes only, I did and I give it a 100% value, other than that, I have no realy use for the information; however, I won't be surprised if some where, some time, some place, someone will walk up to me and say... something and I'll know about it based on your info here, Smile, you did great!

you're a bicycle guru, thanks for the videos! greetings from tampico-méxico!

Thanks Tom. The all overdrive design certainly simplifies things, but I don't think they are ready to give up on underdrive models yet. They certainly have a place.

This sounds like Dan from Boomer Bike in Oakville - I'm Richard from City Bikes. Good to hear you're still around and playing with bikes. I found the link to this video on the Moulton Yahoo group - you'll find many like minded, knowledgable and experienced (hub)gearheads there! Great job explaining this hub!

Thank you very much. Glad you enjoyed it.

Nice demo, glad I don't have to repair mine.... 13,000 miles on my SA8 so far with zero problems.

Very good video, I finally understand how that thing works. Thanks!

Nice job as always, Dan. I think I understand why SA only multiplies and doesn't divide any more. Torque can be greatest in low gear, so the new design reduces torque passing through the hub in that case.

Very nice demonstration!!!

Fantastic video, thank you. I wish I could find one for the 11 speed alfine!

Thanks. Great presentation

That's good to hear. I think it's a pretty good design.

What a great explanation. Thank you. Got it.

They have been mostly very reliable. This hub that I used in the video did have a failure as I documented in an earlier video. Sturmey Archer has shipped me a new hub internal so it's all good.

Bravo. This is awesome.

TonyV195? You're comparing a new derailleur set up in a lab to this. Do 5000kms in the real world and then compare. This isn't fragile and you're not bending your chain or ramming it into the next gear. So in 5'000kms the Planetry gears will run more efficiently and still shift all the time, while your mech set up will have more worn sprockets, stretched chain and cables, and possibly a bent mech or hanger. and you can shift gears without pedaling, so you're in a more efficient gear more often.

Hi Dan Thank you for taking the time to make such an informative video. Do you have an opinion as to comparing the reliability of the Sturmey Archer 8 speed vs the Shimano Alfine 8 speed? I have been using an Alfine for about 6yrs and the shifting has now become unreliable. I guess I have been standing on the pedals a bit too much for the Alfine. Thanks for your help

You are correct that in low gear at least, there is no torque passing through the gear train. The power flows from one stage to the next by direct lockup. That's only in first gear though. There is still a formidable amount of input torque on the hub because of the low ratio necessary. Underdrive models do not need the low ratio high torque input.

Another great video.

Good job explaining

I wish this would work with high torque/speed inputs. That 'cam' engaging various parts at 8k-10k rpm would annihilate the cam and maybe even the engaging parts too. I've come up with a similar setup, but instead of using palls, I used a hydrostatic engagement method, which at least has some give before 1:1 transference from stage X to Y.

Thank you for watching.

Now I know why it's so heavy. I enjoy the ratchet sound on my Sturmey almost as much as the sound of my watch ticking.

Thank you.

That was a different bike in the DC video. That one is a 3 speed. Sturmey Archer makes a bar end shifter for the 3 and 5 speed hubs, but not for the 8 speed. There is an aftermarket bar end shifter available for it from a company called Jtek ( Web site is jtekengineering)

Thanks so much Dan. I believe Richard Feynman would have approved!

Good video! Just a question: Where do I find trigger (lever)shifters or bar-end shifters that work with this hub? I'm not a fan of grip shifters. That has been the reason I haven't bought this hub yet. @2wagondragon In the DC video it shows you using a bar-end shifter?

Nice video, will you be providing the same service for the Rohloff? ;-)

I subscribed to your channel because you sound just like my college professor teaching automatic transmission 101 . He was a great guy smart as hell . Thanks I kinda figured these hub units were planetary drive . Hey do you think one could handle a small two stroke engine like 80cc? It's an experiment I'm doing . The 80cc engine has a 4 speed manual so 7 gears split like a semi truck . Make sense ?

sooo, as I've understand it, the shifter uses wire to open/close ''teeths'' inside axle. That is what fix some gears and other releases?? What is the closer look inside the axle?

Thanks! I just bought a Genesis Super 32 @ Walmart here on Maui. I'm a big guy (66 y.o.) & I bike all over. I am poor & no car. So, I wanted a big enough bike for me and now I want to install the NuVincia N 360. Sounds good to me but I have like pooooor mechanical abilities and my bike shop guy seems scared to do this job. I'm learning on internet & maybe I can install it myself. Q! Doesn't a coaster brake work off the same area inside the hub or all control on the paddle conxn to frame?

I think the issue is both weight and efficiency. In the gears that use all the planetary gear rings, there are a heck of a lot of little gear wheels spinning around in there. If a good deraileur puts out 96/98% of the energy applied to it, those higher gears are probably lucky to put out 90% of what the rider puts in. Obviously, where most of the rings are in lockstep in gears 1, 2 & 3, that won't be the case.

Well, It depends on what you plan to use it for. If you're doing hills, you would probably be better off with a 5 speed Sturmey Archer. It has a bit less range, but it has two underdrive gears whereas the 8 speed is direct in low gear. This requires a much lower input ratio and subjects the hub to much more torque.

Good video. I hope mine doesn't break. I think the principle is "ride it 'till it dies."

proof of the durability van be seen by its use in the Raleigh Chopper bike..and they became adolescent stunt bikes !

Okay, see if I got this right. It appears that each stage has a ratchet which connects to the stage following, so that any stage which does not have its sun gear engaged will be driven at a 1:1 ratio by the previous stage. These ratchets are always engaged, so that when any stage is overdriven by the previous stage, this ratchet will be slipping, which makes the clicking noise you hear. In high gear all three stages are ratcheting, thus the drive has its highest pawl resistance in high gear...?

At the rear wheel, where you have the pin and cable entering the speed hub, I don't have it with a little chain going in the hub, but a part I can pull off to get access to the pin and if I look inside the block i've pulled off, I see the cable. I've put it back on, but can't change gears anymore. I had to take it off to because my chain was too loose and kept derailling. Any video on what's going on in that block and how to pop it back on in the right way? I thought I just had to pop it back on but it isn't that simple apparently. Thy

Inner gear teeth seem to be smaller, do they anyway have longer lifespan ten external? What are common problems with with such gears? Does every gear have also ball bearings?

Considering that you have disassembled most, if not all, of the different brands of gear hubs, you should be able to answer a question. I would like to put a gear hub on an e-bike. Which brand and model do you think is the most durable for a high torque application. I know Rohloff is quality and durable. Although, I don't believe an e-bike needs fourteen speeds. And, Rohloff is expensive.

I can not install the Lockwasher in this type of terminal, I have the cable entry in another place.

Excellent video. If that is a fairly simple mechanical device as you say, please don't show me a complex one. I'd like to see some realistic appraisals of the efficiency of multi planetary ring hubs. There must be a fair proportion of the input energy lost in those higher ratio gears where all the rings are working. My three speed SRF 3 is just about tolerable from the efficiency point of view, but loses out badly in terms of its gear range. I get round this by running two front chain wheels.

Hi Dan, I'm glad you find them simple ! I was happy to service my 3 speeds, and based on this success I figured I'd service my 8 speed. I dismantled the drive side first and can not re assemble the thing to do anything other than direct drive 😣 I'm not sure how. Any avice ? I'm tempted to fully dismantle it so that I can teach myself how the gear selctor actualy changes the gears. There is a group of three pieces around the axle under a circlip on the drive side, it ma be a misalignment there.

Is this hub pretty heavy? I would imagine that given the torque on those gears they have to be made of some pretty strong and heavy materials. Leaving weight aside, is this system more efficient at converting your pedaling to actual bicycle movement than a standard derailleur? Outside of not being exposed to the elements and the ability to shift while standing still or under pedaling pressure, are there any other pros? What are the cons? Great video too.

How do change the sprocket?

Well, I'll resist the temptation to ask why on earth you would want to do that and simply answer your question. If you can remove all the planet gears from each stage, each stage will drive the next in direct lockup. You will then have a one speed direct drive hub. You would get the same result by removing the shift pawls that couple the sun gears to the axle. I'm not sure which would be easier, but removing the planet gears might be more easily reversible if you decide it wasn't a good idea.

Dan Burkhart, you seem to know an awful lot about Sturmey hubs. I'm a mechanic with some experience and I have an X-RD8 that is acting up. In gears 3 and 5 it feels like something is slipping periodically, perhaps once per revolution of something. If I shift to 7 or 8 something causes the cog to seize up, and I can't pedal. At this point the shifter sticks and won't shift back down below 7. The shifter will un-stick if I touch a few things but I can't see what is un-sticking it. Any thoughts? Thanks in advance.

nice explanation....do you think would be possible to use it as direct drive... I mean connect the axis of this drive on pedals and hold the exterior...

I would like to know gear changing mechanism if anybody can help me please.

hi there.. this may be a strange question. but, can i do anything, remove anything from this 8sp hub so that only the first gear works? i just want to have a single speed hub with the drum brake... i now they sell single speed hub with drum brake but i just dont want t buy another hub. thanks for your help in advance.

Nice video, let me know how the speed hub works!!! THX

Had one when I was kid. Still a mystery. Lol

is this available in the philippines?

So have I guessed the advantage? And what are advantages of underdrive models?

Very informative and well explained. Thanks

How to you determine ratio?

So the input is the ring gear and the output is the carrier for all 8 gears?

Hey! 🙃 Is it possible to change a 3 speed hub with drum brake with this 8 gear hub (x-rd8)

HI .. my curiosity about this system is ... can you shift gears while pedaling ? the reason is i might apply this to an electric moped conversion for more power trough gears :)

What? It doesn't run on black magic? Haha, thanks for the very informative video. I see these multi speed hubs in many of your videos. Have you had any problems with any of them?

i want to put one of these on a drift trike since i don't have many hills around

Hi Dan, I have a question to ask you since I put the sturmey archer 8 inner speed hub to my MTB and I am not sure if it was a great idea really because it had a break down after a few miles of use. I have read that Sturmey Archer 8 speed meant to be designed for small wheel size of Brompton bikes and not for 26 inch wheel bikes. For this reason I am planning to change the inner hub for another type of gears that is simpler to repair and maintain. I have found hard to find real information about this, but I found your site long time ago and I did watch some of your videos, which are very genuine. I am opened to your opinion because Sturmey Archer are more popular in the UK than in Spain (Basque land) where I a come from. Here an Sturmey Archer is like to see a futuristic flying car almost owing to its really small market here. Would you give me some advice about this issue. All the best. Aitor

Great...

well done very good

How much torque can it handle?

New transmission CVT design by BitRaptor. Is a continuously variable transmission CVT gear only (the only one functional in the world), very compact and lightweight, and which could replace the current systems both for efficiency, simplicity and not least the costs. Because this CVT work only with pinions is better the all other systems by efficiency and high torque transmission. In the web page bitraptor com you will find more explanations, drawings and a short video of a basic prototype.

I'm guessing you are in Britain using the term hgv and referring to truck transmissions?

I have a question regarding this hub. What is the best way to align the shifter cable so the hub changes between all the gears correctly?

WOW! I have a shimano internal 3 speed. I swore it was black magic.

I have a mantis tryrad trike would like to have a three speed coaster brake , can this be done ?

Hi, my XRF8-W have a noise working in 2-3-4-5-6-4-7-8 velocity... When i ciclyng three o four hours, that squeaking-roinnnng-roinnnng-roinnnnng is disagreeable, very very disagreeable. In spanish... "un coñazo" What do you know about this? All XRF8-W have this problem? thanks ¡¡¡

Well, yeah.

It sounded like the soundtrack changed gear at one point to.

wuh wuz that again?

Why is this technology not used on racing bikes? If weight is a problem couldn't they develop a Ti or Carbon version? Current system seems to antiquated.

I'm just trying to figure out if these things are electronic

Hi Dan, I've been watching your vids but I haven't been able to figure out what's wrong with mine as a result (it won't shift gears with the shifter/cable) I also can't seem to get the unit out of its housing...no ball Ring spanner. I'm in Toronto but can't find a mechanic that's comfortable working on these, any recommendations?

it looks like a hgv range change just 3 of them

Gripping the thread in vice jaws!!!

Where can I get a bike with a Sturmey Archer 8 speed hub? What bike manufacturers use this hub in their bikes? I never see it in any bikes specs, when I am checking Trek, Cannondale, Specialized, Cube, GT, Jamis, Koga, you name it. Why is this?

Not familiar with these. I have a x- rd8 hub on a 18-inch rim. Are these autoshift?

Can a heavy man use this set up.

A quick check of MrEdysma's channel shows he has spammed numerous videos featuring gearhubs with this same message, all in very rapid succession.

Yea or you can just ride single speed. There's also that too.

Don't grip the axle in the vise without soft jaw inserts!

Noisy compared to Shimano dont you think?

Traduzir em português

Yeah but,... you don't have to refinance your house to get it.