This weekend I took part in a social ride up the local peak, and about 2km from the top the hub made crunchy noises.

Full report here (http://www.bv.com.au/forums/viewtopic.php?t=6192&start=24).

How old was the hub?

Thanks for the good story, man. Lots of readers will be waiting to hear what you find inside the hub. I am bummed to hear about snow in Aus. I'd just never considered it.

How old was the hub?IIRC I bought it from aebike near the beginning of this year. About 9000km on it.

Great report on Cycling Victoria forum Jur.

Does the SA 8 speed have smaller planet gears than the AW / SRF3? The structure in the 3 speed ones I have is very strong looking. I see what you meant on the other forum about being glad it didn't happen in the middle of Tasmania. Not exactly hand for spares I'd guess. Keep us informed if you would about the details of what broke and why. I need a full breakdown inquiry.

:)

Well it was as I feared - a broken planet gear. one of the gears split open on one side. Here are 4 images of the same thing:

http://i160.photobucket.com/albums/t188/juried/SA8%20broken%20gear/SA-broken006.jpg
This one shows the crack clearly.

http://i160.photobucket.com/albums/t188/juried/SA8%20broken%20gear/SA-broken003.jpg
Here at the bottom of the tooth there seems to be damage from a foreign body that got lodged in a tooth and probably caused the planet gear to split.

http://i160.photobucket.com/albums/t188/juried/SA8%20broken%20gear/SA-broken005.jpg
Clearer view of the tooth damage.

The foreign body seems still lodged in the tooth of the inner sun gear as it turns with some difficulty in some spots of the rotation. The assembly is riveted so I can't dismantle it further.

The break was extremely difficult to find.

At first inspection everything looked just fine. I began to wonder if the problem was simply caused by cable adjustment and that in my blundering idiocy I forgot to check the adjustment.

But when I began to put the various parts back together and played with them I noticed the smallest planetary system was difficult to rotate. With a sharp pick I began to probe each gear groove to see if a tiny piece of grit was lodged in one of them, until I found one groove that felt very rough. To the naked eye I could see the groove looked a bit wider than its neighbours, and a magnifier showed the problem.

Nikon Coolpix did the rest.

The damage seems to indicate that it wasn't excessive force or inadequate design that caused the break but rather it was contamination. And I doubt that it is a piece of the earth's crust that would be so hard as to not be ground to dust but force the gear to split open. It has got to be a piece of hardened steel.

Jur,
Please reassure me that my 2 X 8 spd SA hubs will not do the same......

I read the posts about 6th gear being a pain at times, so I adjusted the setting and got it right, but now fifth gear is making noises like it's not just right, looks like more experimentation.
Maybe using the hub under extreme stress like hard climbing is not advisable, perhaps they're only meant for commuting??.

Great analysis and investigation. I wonder how whatever it was got inside there. Do you think it was some junk that got in there at the factory, or something that broke off the unit? I'm hoping that the pounding you gave it broke something that smashed the planet gear, rather than random rubbish was left in there by the factory.

I can't imagine you have introduced anything yourself.

I've been inside my three speed SRF 3 a couple of times, I'll be damned careful after this that nothing comes adrift in there.

During the first check-over I was looking for something that looked broken, but nothing turned up. Everything looks very good, no signs of mangling or damage anywhere until I found the crack. So at this stage I'm guessing the foreign body is something from the factory, but the planet gear rivets will have to be removed to be sure.

I don't think overwork was the culprit; even though I do ride very hard at times, I have a high cadence so the force on the gears wouldn't be that high. Of course sometimes climbing out of the saddle is involved but even there I have a tendency to 'dance' rather than grind. Having said that, there are a few places on my daily commute where grinding is required due to steepness. Anyway I would have thought that the gears are designed to withstand that.

I'll be writing to aebike about the guarantee issue, and make a call to Suntour in Taiwan about a replacement part. If Suntour don't want this sub-assembly I'll be drilling the rivets out to see what's going on in the sun gear.

Sorry to hear about your troubles. As the owner of 3 bikes with this hub I am very interested in your findings.

Out of curiosity, what was your impression of the amount and quality of lube in the hub? I have always been suspicious of the "never lube" hype and have always figured the oil bath style of the older 3-speeds would flush away bits of dirt and broken bits of hub gears, etc.

9000 km is enough to break in the hub, but the pictures you posted don't seem to show excessive wear or other damage. I would like to think you could ride one 20,000 to 30,000 km before needing a re-lube or any other repairs.

SA moved away from the oil-bath idea to a thin grease regime. If you compare the various manuals over the years, the early ones give instructions for oil through the port, while the later ones spec a thin grease. The later model 3sp hubs' oil seal labirynths were simplified to cut cost, presumably. The simpler seals are not enough to keep in oil but are OK for the grease.

The grease was everywhere when I opened it, so sufficient in quantity. It is presumably thin enough not to interfere with the pawl operation but is not runny like oil to go past the seals. It's like a gel, quite thin but doesn't run. My hub's grease was black, indicating metal particles from wear in suspension.

The purpose of lube is to prevent direct metal-to-metal contact. It seems to me that as long as it doesn't dry out and is enough to coat all parts, then no further maintenance would be needed for the normal life of the product. If we're talking extreme long use say several decardes, then one could expect the grease to have dried out to some degree and a washing and replenishing would be good.

That's some great riding on a broken hub! It sounds like it is under warranty, yeah? Repairing these hubs via drilling borders on heroic. Wouldn't it be easier to ask for a new hub and rebuild the wheel?

Asking for a new hub is not without its own problems: I would probably have to send the hub back to the US which would require a wheel un-build, postage (expensive), wait ages for a replacement and then rebuild my wheel. Plus they would hit me for postage to send me the new hub. It is probably worth just buying a new hub outright. I have written aebike and Sunrace but I'm not holding my breath about hearing from Sunrace.

Getting in the sub-assembly would be far less costly all round, assuming it is available in the first place. I wouldn't have to drill to repair, that is just for inspection of the broken sub-assembly.

I think the pictures you showed here should be all they need to see what has happened. No sense at all in demanding a chunk of scrap be transported half way around the world as evidence, surely. I hope you get decent treatment anyway. You ought to.

When they send you a replacement hub, it would be the obvious answer just to dismount the internal unit and pop it into the old shell. No need to rebuild wheel or anything, unless you suspect wear in the non-drive side bearing cup.

I think the manuals recommend servicing and re-greasing from time to time.

I've been running my SRF-3 on 10:30 engine oil for a good while now - about 1000 miles. I find that little and often is the best approach, or the oil comes out along the spokes. At first I was putting in about 6cc, but the surplus is spun out pretty quick. Now, I just put in about a half teaspoonful every couple of hundred miles, and it stays put. The old SA hubs didn't exactly have an oil bath either - they recommended two or three drops every month. Overfilling always caused the oil to escape - I know you know this because you have them yourself. As this oil thing was an experiment for me, I have taken out the internals to inspect them for dryness. There has always been a small amount of oil in the bottom of the shell, and the internals were completely soaked in oil, even after a couple of hundred miles. I could probably do it a lot less often than I have been, but it's so easy that there is no reason not to add a few drops. I drilled the shell and made an oil port which is sealed rather nastily with a short bolt screwed in a few threads.

The hub spins VERY easily with the oil regime. If I upturn the bike and pedal it up, the wheel spins on and on for ages, so there is no internal drag. It definitely spins on much longer than before. It changes very easily and is quieter than it used to be too.

Of course, there was no need at all to mess about like this, I just wanted to play around with the hub. As it was supplied it worked fine and is very robust, and quite straightforward in construction. A marvelous piece of kit really.

I had to bring my new Curve SL back to the LBS after only 50km. Same situation - a bad crunching sound from the SA 5 hub after a steep hill climb. I never saw the inside of the hub but the Japanese LBS owner said "something was cracked". He ordered a new hub - Dahon initially sent him the SA 3 speed. Finally, after waiting 3 weeks, I can pick up the bike complete with new SA 5 hub this Thursday. Just to be safe, I think I'm gonna now stay way clear of steep climbs whenever possible.

Finally, after waiting 3 weeks, I can pick up the bike complete with new SA 5 hub this Thursday.

Yet another reason to own multiple bikes.

Just to be safe, I think I'm gonna now stay way clear of steep climbs whenever possible.

That's a rotten thing to happen with a new bike. I wouldn't let this put you off. A multi geared hub is designed for climbing hills and should easily cope. If it doesn't there's something wrong unless you are built like the Hulk and pounding the thing uphill at 25 miles an hour. A hub should normally cope with any NORMAL amount of pedal power. You've had a bad one, maybe with a foreign body inside that broke something. I wouldn't expect that to happen again.

I don't think overwork was the culprit; even though I do ride very hard at times, I have a high cadence so the force on the gears wouldn't be that high. Of course sometimes climbing out of the saddle is involved but even there I have a tendency to 'dance' rather than grind. Having said that, there are a few places on my daily commute where grinding is required due to steepness. Anyway I would have thought that the gears are designed to withstand that.
You don't say what sprocket ratio you were running, but given that you were on 20" wheels, I'm guessing that it was rather higher than would be used on a bike with full-sized wheels, so even though you appear to be a strong rider, you would actually be stressing it less than a rider with full-sized wheels (and appropriate sprocket sizes) would be doing.

I'll be writing to aebike about the guarantee issue, and make a call to Suntour in Taiwan about a replacement part. If Suntour don't want this sub-assembly I'll be drilling the rivets out to see what's going on in the sun gear.
That's SunRace, not SunTour. Totally different company. If you send 'em those pictures, I have no doubt they'll send you whatever parts you need or a new hub.

Sheldon "Epicyclic" Brown

You don't say what sprocket ratio you were running, but given that you were on 20" wheels, I'm guessing that it was rather higher than would be used on a bike with full-sized wheels, so even though you appear to be a strong rider, you would actually be stressing it less than a rider with full-sized wheels (and appropriate sprocket sizes) would be doing.


That's SunRace, not SunTour. Totally different company. If you send 'em those pictures, I have no doubt they'll send you whatever parts you need or a new hub.

Sheldon "Epicyclic" BrownAh. I thought they were the same. I have written to Sunrace in Taiwan and sent them the photos as well, and referred to the exploded diagram in the manual to which part I need for a repair.

The sprocket ratio is 42x25. Tyres are 406x50.

Ah. I thought they were the same. I have written to Sunrace in Taiwan and sent them the photos as well, and referred to the exploded diagram in the manual to which part I need for a repair.

The sprocket ratio is 42x25. Tyres are 406x50.

You got a reply from Sheldon Brown (http://sheldonbrown.org/journal/journal-0709.html)???? Jur is the king of the folding sub-forum...

Heh heh, I cheated by emailing him... :)

You got a reply from Sheldon Brown (http://sheldonbrown.org/journal/journal-0709.html)???? Jur is the king of the folding sub-forum...



Who the heck is Sheldon Brown?..........................:rolleyes:

Who the heck is Sheldon Brown?..........................:rolleyes:
ha ha, very funny

* wonders if stevegor is being serious or not *

You don't say what sprocket ratio you were running, but given that you were on 20" wheels, I'm guessing that it was rather higher than would be used on a bike with full-sized wheels, so even though you appear to be a strong rider, you would actually be stressing it less than a rider with full-sized wheels (and appropriate sprocket sizes) would be doing.

Hmmmm ... so does this mean riding in "low" chainring/rear-cog combinations puts more stress on the internal hub? That is, does a 39t/16t combination puts more stress on the hub than a 52t/16t combination?

ha ha, very funny

* wonders if stevegor is being serious or not *

Actually, I was wondering myself. Then again, there is a link in the previous post.

BTW, Jur ... sorry to hear about your bad luck. I hope it works out for the best.

-G

Hmmmm ... so does this mean riding in "low" chainring/rear-cog combinations puts more stress on the internal hub? That is, does a 39t/16t combination puts more stress on the hub than a 52t/16t combination?

I suppose that anything that allows you to put more torque through the hub would increase its potential stress. Would that be right? If it IS right, a smaller front sprocket, or a larger rear one, would enable you to spin the legs hard and fast on a steep hill, and shoot up the hill. This potential to put power into the hub would possibly strain small parts more than higher gear ratios.

All of the above is a guess. I'm really just wondering aloud.

ha ha, very funny

* wonders if stevegor is being serious or not *


When am I ever serious??.........:o

Sheldon rocks - He was really helpful when I mailed him when I couldn't get the black collar off my UN-72 back in the day. I think he has a special email filter that favours bikes he likes so one is more likely to recieve some sage advice if it's about R20s than - say a Trek FX7100.. :)

... the AW / SRF3? The structure in the 3 speed ones I have is very strong looking.

By-the-by, SunRace claims to have made some 20 changes to the three speed hub, some of which are supposed to make it even more robust/long lasting. Certainly the exploded diagram's part numbers list many differences between the old AW design and the new AW-NIG/SRF3.

TCS

The grease was everywhere when I opened it, so sufficient in quantity. It is presumably thin enough not to interfere with the pawl operation but is not runny like oil to go past the seals. It's like a gel, quite thin but doesn't run.

I'm told SunRace Sturmey-Archer's grease is a synthetic gel, part number SA103A. Where a civilan might aquire some, or an 8 speed ball ring spanner, is unkown.

TCS

I'm told SunRace Sturmey-Archer's grease is a synthetic gel, part number SA103A. Where a civilan might aquire some, or an 8 speed ball ring spanner, is unkown.

TCS
Yeah, the SA103A is what is listed in the various manuals. I am going to use food-grade chain grease (http://www.crcind.com.au/catalogue.nsf/web_brands/Food+Grade+Chain+Lube?openDocument), it seems to have similar consistency.

I made the ball ring spanner from a piece of alum rectangular tubing and some hardened screws.

Hmmmm... I just googled "lubricating gel." Not quite what I was looking for... :D

Hmmmm ... so does this mean riding in "low" chainring/rear-cog combinations puts more stress on the internal hub? That is, does a 39t/16t combination puts more stress on the hub than a 52t/16t combination?
The smaller the chainring, the more pull on the chain for the same push on the pedal.

The bigger the rear sprocket, the more torque on the hub for the same amount of chain pull.

Bikes with small wheels require less torque to drive the bike (but the have to spin faster.)

They also require less "power" from a hub brake, so hub brakes that are marginal on big-wheel bikes can work fine on small wheel bikes. A case in point is the Sturmey-Archer drums on my Greenspeed with 349 mm (16") wheels.

Sheldon "Moment Arm" Brown

Sheldon rocks - He was really helpful when I mailed him when I couldn't get the black collar off my UN-72 back in the day. I think he has a special email filter that favours bikes he likes so one is more likely to recieve some sage advice if it's about R20s than - say a Trek FX7100.. :)


I wholeheartedly agree L.P.....I have found Mr. Brown a wealth of knowledge and only too happy to help....a bit different to the "elite and arrogant" snobbery one sometimes finds in racing cycles.

Yeah, the SA103A is what is listed in the various manuals. I am going to use food-grade chain grease (http://www.crcind.com.au/catalogue.nsf/web_brands/Food+Grade+Chain+Lube?openDocument), it seems to have similar consistency.

I made the ball ring spanner from a piece of alum rectangular tubing and some hardened screws.

The grease needs to be very slippy thin stuff. I have experimented with ordinary grease - the pedals went around like a fixy when coasting in top gear. Too much drag by far ( x10).

The real stuff is very lightweight.

I'm very happy just with a few drops of light oil now and then. My srf-3 has had no grease at all for a thousand miles - not even in the wheel bearings. Spin it up in top gear on a stand and it runs on and on like a perpetual motion machine. The back wheel spins longer than the front one which has grease of course.


I wholeheartedly agree L.P.....I have found Mr. Brown a wealth of knowledge and only too happy to help....a bit different to the "elite and arrogant" snobbery one sometimes finds in racing cycles.

Sheldon's website is a delight. Full of info about anything I ever need to know about bikes.


As for the Lubricating gel google surrprise, you get the same kind of thing if you google 'lubricant'. Considering the relative world demand for the two kinds of products, it tells you something about the interests of Internet users - or maybe Internet marketers.

The grease needs to be very slippy thin stuff. I have experimented with ordinary grease - the pedals went around like a fixy when coasting in top gear. Too much drag by far ( x10).

The real stuff is very lightweight.

I'm very happy just with a few drops of light oil now and then. My srf-3 has had no grease at all for a thousand miles - not even in the wheel bearings. Spin it up in top gear on a stand and it runs on and on like a perpetual motion machine. The back wheel spins longer than the front one which has grease of course.

I wonder... I feel myself gravitating to using thin oil instead... the seals seem sufficient for oil... perhaps I'll put in an oil port a la EvilV.

I wonder... I feel myself gravitating to using thin oil instead... the seals seem sufficient for oil... perhaps I'll put in an oil port a la EvilV.

If you decide to take that route with an SA-8, I would be interested in the details.

Although the schematics for the 36-hole version do not quite match up with the 28-hole version of the hub.

I wonder... I feel myself gravitating to using thin oil instead... the seals seem sufficient for oil... perhaps I'll put in an oil port a la EvilV.

You can put the oil straight into the centre of the hollow shaft and let it run inside. The problem with that is that you can't really clean it of grit and stuff that may get into the axle and then get washed into the inner parts of the hub. I thought that a bad idea.

If you go for a port, I hope you'll execute it better than I did. I just used a hand held electric drill to put a 3mm hole in the shell. Then I tapped in a short bolt as a plug. It is horribly crude. I obviously did this without the gear unit inside teh shell. That way I could clean out the small bits of alluminium swarf from the drill.

The oil sticks around for ages in there - it doesn't need to be swimming in it, though I did try that and got messy wheels. Little and often is the best regime for oil.

You can put the oil straight into the centre of the hollow shaft and let it run inside.No hollow shaft on this one. A port is the only way. I have an old hub with a port lying around which probably will never see a wheel, I may use its port. Depends on whether I can drill a suitable hole in the hub in between the spokes. Maybe from the inside. All this depends on whether a spare part will ever reach me. In the interim I may revert back to 3sp, that wheel is gathering dust at the moment.

I have also seen oil ports on ebay recently.

jur, search for a 90 deg. geared "elbow" fits in your drill chuck. Failing that, a flexible shaft. Drill on the bottom of the hub, so the swarf falls away from the workpiece. To take it one step further, run your shop vac hose as close as you dare, and if the hub shell is steel, run a little magnet (like as magnetized screwdriver tip) and a bent Q-tip around inside the new hole. Swarf is your enemy.

Good tip on the elbow.

Swarf is the least of my problems right now - this hub is ally and stripped down to the shell so any swarf will be vanquished when I wash it upon receiving the spare part (still no word from SunRace).

I have installed the 3sp wheel again, after washing everything internal and external, and put thin (Singer) oil in. I have to agree, it feels good. Tomorrow's commute will tell me how it will go.

I also washed the 8sp planet systems even cleaner, there was still gel in the sun gears, shown by drag on the gears. After washing, very little drag. I'm definitely going with thin oil for the 8sp also. I put all the internals back together, pending getting the spare planetary system, just to pop it in and ride (I hope).

Still no word from SunRace though.

I have installed the 3sp wheel again, after washing everything internal and external, and put thin (Singer) oil in. I have to agree, it feels good. Tomorrow's commute will tell me how it will go.

I also washed the 8sp planet systems even cleaner, there was still gel in the sun gears, shown by drag on the gears. After washing, very little drag. I'm definitely going with thin oil for the 8sp also. I put all the internals back together, pending getting the spare planetary system, just to pop it in and ride (I hope).

Still no word from SunRace though.

I'm surprised they haven't responded. When i asked for instructions from Sugino about how to secure my left hand crank after it came loose, they air freighted me instructions AND a new left crank within five days. It wasn't their fault either.

Don't you have any recourse to the seller of the Hub? I'm assuming it is quite new. In the UK you will almost always get a year's guarantee on new items. Some try to wriggle out by alleging misuse though, or offer to send it back to the manufacturer, but in law, the buyers recourse is to the seller. People don't always realise that here and can be fobbed off. Obviously, different legal systems do things their own way.

Don't be surprised if some of your singer oil comes out at first. It took me a while to realise how little was required.

Yes, I also wrote to the seller (aebike) and they wrote to SunRaceUSA and copied me.

I had another look at the 8sp seals; the seal at the big ball race seems rudimentary, I wonder if I would lose the oil there. I'll see if I can find a description or I'll post some pics for opinions.

Well I received the 'spare parts' hub from aebike this past Friday. It is a used hub and missing some external parts such as the LH cone and the shifting disc on the RH side. It had been laced to a wheel as the spoke holes showed marks.

Anyway I had trouble opening it since there was nothing to hold on to when unscrewing the ball ring. I finally accepted my son's suggestion to screw it to a piece of timber, only I used nails and hammered it to a board :eek: after using a hole saw for the LH side piece to lie in. That worked well enough, once I put in big enough nails for the job, not those sissy panel pins I tried first.

The gear mech looked relatively unworn, compared to mine. I debated just dropping it in whole or just replacing the broken part, I did the latter in the end, as I like the idea of the parts being broken in and therefore running smoother.

After putting the mech back together (nope, I had no parts left over :D ) I oiled it using light Singer oil. I still have to drill an oil port in the hub and am also waiting for new high quality bearing balls since the old ones show signs of wear.

I will probably reassemble it to the bike in a week or two.

Still no word from Sunrace Taiwan. I actually called them and got the email addr of someone in the co. to correspond directly with. No avail. I won't be pursuing that any further. But if I did, I could probably get together another fully working hub as the one sent to me from the US appears to be fine besides the missing parts issue.

Great - keep us informed as to how it goes.

This is a fascinating thread Jur- please tell us how it works out ... maybe 'in anger' up that climb that killed it

I wholeheartedly agree L.P.....I have found Mr. Brown a wealth of knowledge and only too happy to help....a bit different to the "elite and arrogant" snobbery one sometimes finds in racing cycles.

I totally agree - thats why I prefer this folding forums than the roadie ones .... there is much more new stuff here .... less BS and less testosterone (and any there is, is 100% self generated !).