Fastone93

Hello, i'm interested to know the reliability, of this product line from Shimano? Particularly The inter 8 speed hub,but also red band 8-speed hub , and the alfine 8-speed hub? I understand they use grease inside their units, and some report a short life span? I'm considering a Diamondback insight Sti 8 hybrid,if its life span is short, and not reliable, then i would chose a traditional cog derailleur set up.



thank-you for your help,
Ps, Mr. Rabbit sent me!

Stu In Tokyo

I'm just rebuilding my Alfine 8 speed hub, an SG-G501 unit. It was a grease only unit, after a year of use and 3000Km I've had to buy a new carrier unit for it, cost over $100. From now I'll be doing the oil bath every three months.
Not impressed Mr. Shimano....

jolly_ross

I don't think this would be thread hijacking ...

Stu in Tokyo - what is "the oil bath" please?

hounslow

The oil bath is a tin of blue oil that cleans and lubricates the internals. you submerge the (removed) internals in it for a few minutes then wipe down excess and re-install.
It isn't particularly cheap, and is one use only.
This is what a guy at Madison (Shimano UK) told me to do, but a quick google search shows this may be excessive.

tcs

Info.

Stu In Tokyo

Yep what they said, but I'll be using the oil many times over thank you very much, on stinking liter of it costs 7,777 yen or about $100 US. I will clean the guts of the hub before I do the oil bath, so I don't see why I can't use the oil many times over. I'll let it sit in the dunking container, any dirt from the hub will settle in the bottom then I'll pour it back into the original container but not pour the last bit or if I do pour it though a coffee filter. At $100 a liter, it will be multiple use!

interested

When the first generation of Nexus 8 IGH's was introduced to the northern European market, they were a total disaster, they would usually break within the first winter or two. Shimano have improved their sealing though, and the latter Alfine model have a reworked and much improved internal structure.

The Nexus 8 series still have some fundamental design flaws though; It is designed for using grease, but the re-greasing procedure is so complicated that even most LBS's simply refused to service the IGH. Shimano therefore introduced a simple oil-bath maintenance procedure that are very easy to do, but way overpriced if you use Shimano oil. But since the Nexus hub wasn't designed for oil, you have to maintain it with oil baths at an increased frequency.

A second problem is the fact that the hub shell is part of the bearing race, so if the bearing race gets pitted, the entire hub is finished. Since they are cup-and-cone bearings, bearing pre-load can be critical too.
Many winter riders also have problems with the hub freezing into one gear position. Usually the problems are cable related (weak return spring), but it also seems that some hubs have non-cable related problems with cold weather. It is suspected that the combination of freezing weather, water ingress and grease contamination, can foul and freeze the internal clutch so it can't move.
Converting to hub oil should also help against the latter problem.

A third problem is the Shimano marketing; they sell Nexus IGH's as a no maintenance, no problem devices. But that is just a lie. Like all other mechanical devices they need service and maintenance. People who believe in the marketing hype often run their Nexus IGH without maintenance until it is dead and beyond repair. The Nexus IGH's can have excellent service life if cared for.

Fast, strong, high mileage, four season riders are the ones most likely to destroy their Nexus IGH. (such riders are hard on any equipment) The cause seems to be, that high speed makes water and road salt ingress more likely, and that the high mileage compound any contamination issues causing accelerated wear. Strong riders could "torque" the low end versions of the Nexus IGH to death. The Alfine series has a torque limiter that reduces this problem.

The Nexus 8 IGH's work well for many people though, especially if they don't ride many thousand of miles per year or spread the load on different bikes if they do, or if they don't ride that much in the rain or when the roads are salted. Servicing and inspecting the hub regularly can also dramatically increase the hubs life span.

Dan Burkhart 

Lots of users out there doing their oil bath with good old ATF, with as far as I know, good results so far. Of course Shimano will say only their oil is approved.

dbg

I had acquired many of the 7 speeds and found them to be quite reliable for low mileage use, --kids bikes and knock arounds. I decided to build a commuter with one of the 7speeds and then ignore it (zero care and maintenance) to see how long it would last. It ran well for 5 years at which point I switched it out for the supposedly less reliable 4 speed shimano IGH. The 4 speed has been fine for 5 years now. But, again these are low to medium annual mileage and slow city trips and/or commutes. I have yet to service any or my IGHs (5 7speed, 1 4speed, 1 8speed). The 7's are 8 or 9 years old.

Fastone93

Thank-you, to all who took time to respond, its appreciated ! Great forum!

closetbiker

I think this is one of the best responses I have heard regarding these hubs.

I built a wheel around a Nexus based on the belief that it would be an - almost - maintenance free gearing system but soon found out it required much more care than I thought.

The description here explains why and had I known about this before I built my wheel, I don't know if I would have had the wheel built.

Don't get me wrong, the hub works great and has advantages I like, it's just that it has a few disadvantages I don't like (such as special maintenance I never thought it would need)

doco

here's some more info if you need it

https://thelazyrando.wordpress.com/20...-alfine-8-igh/

go on over to the mtbr forums, they have a internal gear forum with plenty of info

https://forums.mtbr.com/internal-gear-hubs/

fietsbob

Seattle based shop , Aaron's says a clean and re lube, is desirable for commuting there.

Mass Factory production favors minimal grease, as a cost savings , so will probably benefit from
initial lubrication, supplimental ..

closetbiker

After exchanging emails with a Toronto shop that said these hubs need very little service, I contacted Aaron's for a second opinion and he recommended oil changes twice a year.

At $75 - $100 per servicing it becomes apparent what the fiscal disadvantage of owning a Nexus is.

I think I'm going to stick with the Shimano recommendation of servicing every 5000 kilometers.

closetbiker

Just had an interesting email from Aarons.

He said,

"the factory lube is not enough for rainy weather! ... We use better grease and oil than comes in the hubs and more of it... I recommend you bring your (brand-new) hub into my shop to service it and and then see how it goes!"

Geez. I thought Shimano was bad for their marketing of these hubs as maintenance-free.

Reynolds 

My Nexus 8 reached 2100km, worked flawlessly so far. One of these days I'm going to relube it. Not sure yet if using ATF or another oil/grease (Shimano oil is out of the question).

interested

One of the several design flaws of the Nexus 8 series is that the bearing races are part of the hub shell. If you pit the races, the hub is permanently dead, since a new hub shell can't be bought as a spare part. Water ingression leading to pitted races is a common cause of dead Nexus hubs. Overpacking the bearings with grease may help a great deal with keeping water out.

Another problem is the cup-and-cone bearing design. CC hubs are somewhat technically superior to cartridge bearings when it comes to hubs, but they have to adjusted correctly. Over tightening the cones may lead to accelerated bearing wear, causing pitted races and cones. Not every hub leaves the Shimano assembly lines adjusted correctly, but few LBS's bother to check this before selling the IGH bike. And people usually buy IGH hub bicycles exactly because they don't want to bother with technical details, so they are unlikely to detect such problems.

Shimano Nexus hubs are allegedly also sensitive to non-parallel drop outs or if the wheel isn't seated correctly. No personal experience with that, but this what Shimano dealers said at the time. (Shimano sometimes makes "whisper campaigns" to their dealers regarding certain information without publishing it on their homepage).

Regarding having the Nexus hub serviced before even riding it; for most people this shouldn't be necessary, as long as they service the hub before it is too late otherwise. The caveat is of course if the bearings are over tight from factory.

The service interval is heavily influenced by the riding conditions and riding style. Frequent riding in the rain or on winter salted roads may decrease the time between service intervals quite a bit. The 5K or 2 years between service advice from Shimano specifically says that adverse weather may reduce the intervals needed for service.
AFAIK, Shimano somewhere has a note about increasing service intervals to 3K if one starts to flush it in oil.

The bottom line is, that several factors; hub design, drop out quality, assembly quality from the factory, local climate, riding style, all can conspire to dramatically reduce the life of a Shimano Nexus hub. This is why some people have destroyed such hub in a winter or two, while others can ride thousands of kilometres every year for several years without problems.

A general good advice is to have the hub serviced if it doesn't "feel" or "sound" right, instead of riding it until it dies in the vain hope that it will correct it self over time.

closetbiker

You bet, and considering Shimano provides a 2 year warranty on its components, it's not needed because if it's maladjusted at the factory, any damage would be covered.

interested

There are some caveats here: Shimano may not honour their warranty if they think that wear and tear is the problem. Their warning about smaller service intervals if ridden in adverse weather condition can be used to reject a hub that are obviously rusted and pitted because of water ingression and road salt, even though though it is less than 2 years old. Just like they give a 2 year warranty on chain and chain rings, without one should expect Shimano to honour their warranty if they are destroyed through wear.
Shimano are usually reasonable about warranty, so it may not be a problem.

But even if Shimano honour their warranty, they won't rebuild the wheel, they just give a new replacement hub. So one has to factor in the cost of a new build, and perhaps new spokes and rim if the wheel builder hasn't build the original wheel.

I know /knew several people who trashed their Nexus 8 hub within 12 months (the first batches of the hub, the sealing etc. has improved). I think a former colleague of mine trashed his hub 3 times within 18 months before he gave up and bought a dérailleur bike. So it is a good idea to service the hub if it feels or sounds wrong, even though it is less than 2 years old.

closetbiker

Of course, but Aaron's is not only suggesting a servicing before the hub is used, Aaron's is suggesting a servicing every 6 months, even when those 6 months see little rain.

I find that ridiculous. A money grab even.

Dan Burkhart 

I think warranty replacement usually means a new internal assembly. No wheel build involved.

interested

The problem is, that it is quite common to trash the bearing races of the Nexus, rather than the internal gear system. And since the races are part of the hub shell, you have to use an entirely new hub for the rebuild (or new build). An internal assembly won't help at all in such situations.

Stu In Tokyo

Since I put the new guts into my hub and I've been doing the oil bath dunk maintenance every three months, I've had a lot less to worry about with my Alfine hub. It still skips in 5th gear if I try to start out in that gear, never does it in 4th gear. To be honest, I'm sure I'm way over the parameters set for this hub, I'm a big guy, at 120 Kg and I haul a trailer full of beer around Tokyo, often my trailer and the load on it are well over 100Kg combined, so I doubt very much that Mr. Shimano thought I'd put his hub to this kind of work load.
To say the unit is maintenance free is pure BS, but I could agree, a little, with saying it is low maintenance. What I mean by that is the chain on my bike (a Keirin unit) just needs a bit of cleaning and lube now and then, but it does not need the attention that a derailer bike's chain needs, as it does not have to move around. I agree that the price of the special Shimano oil etc is a bit much, but I've used mine now several times and it seems to be working just fine. The special container that they sell that you put the oil in up to the line is not quite a litre, so I think that it is meant to be used many times over, as the excess will make up any lost when you decant the used oil out of the dunking container. I let the container sit over night full of oil and any debris that might be in the oil, then slowly pour it out of the container back into the tin it comes in. when I'm down to the dregs of the container I will see some discoloured oil and maybe some debris, so I stop, I might loose 10ml each time I do this. With the extra oil that came in the tin, I'm sure that I will be able to do the oil bath for many years to come. Doing the oil bath itself takes me about 30 min, but I do it when I'm doing other maintenance on the bike too, so really it is not that big a deal, IMHO.
Still the Alfine 8 speed hub is a LOT cheaper than any thing else on the market, I could buy, use and wear out a LOT of Alfine 8 speed hubs for the price of one Rohloff hub.

I've not had anything to do with the SRAM hubs, any thoughts on these units?

Maybe when I do wear out this Alfine unit, I'll check into a SRAM i-Motion 9...?

tcs

SRAM withdrew the iMotion 9 hub from the market some two years ago. The T3, Pentasport 5 and Spectro 7 hubs have also been discontinued. They have a new hub called the G8, allegedly spec'd on several 2013 bikes by a number of OEMs, but no one outside of SRAM's extended family has got to play with one yet and SRAM hasn't released any details.

Kimmo

I wouldn't be surprised by a false start or two in the IGH market... I bet there's a few tricks to doing them right.