Shimano Alfine 11 - Longer term reliability

[bobc]

"If its ferromagnetic you can permanently magnetise it so its collecting the bits up all the time."

The magnet sticks to the drain plug & can pick it up, so the plug exhibits ferromagnetic properties. It looks like it's some grade of stainless (which is not generally magnetic)
Whether it could be magnetised permanently, to a useful level, is unlikely in my opinion.

[Brucey]

the easiest way to mount the magnet would yield a radial field, i.e. axial with the plug. This would collect crud rather well, but upon reflection may not be a very good idea; I think if powerful enough, it will magnetise the hub parts internally, since they will always see the same field in the same direction as they sweep past.This may encourage crud to stick to the gears themselves. Generally hard steels make tolerable permanent magnets.

A better solution would be a set of alternate N/S/N poles so that the hub parts are actually demagnetised by the field as they sweep past. Crud collection would be similar overall. Unfortunately the drain plus isn't big enough for a good magnet of that sort.

cheers

[TonyR]

How can I permanently magnetise it?
Rand.

The two standard ways are either to stroke it with a magnet or to put it in a solenoid energised with DC.

[Brucey]

How can I permanently magnetise it?
Rand.

The two standard ways are either to stroke it with a magnet or to put it in a solenoid energised with DC.

as BobC commented above, I don't think the steel grade used for the drain plug is suitable for being magnetised. You need a proper magnet; this will be x1000 better at retaining crud than any magnetised bolt.

cheers

[rfryer]

In case anyone's interested, I'm now in a position to ship out small quantities of Shimano's snake oil at reduced (though still hard-to-justify) prices.

See my classified ad at http://forum.ctc.org.uk/viewtopic.php?f=32&t=75784

[rand]

"If its ferromagnetic you can permanently magnetise it so its collecting the bits up all the time."

The magnet sticks to the drain plug & can pick it up, so the plug exhibits ferromagnetic properties. It looks like it's some grade of stainless (which is not generally magnetic)
Whether it could be magnetised permanently, to a useful level, is unlikely in my opinion.

Hello Bobc,

I've sourced a supplier of neodymium magnets and I've elected to use a 1"long x 3/4"wide x 1/2" deep magnet with slight curve. The curve is not quite as curved (if you know what I mean) as the hub outline but what curve there is suggests to me that it might be less inclined to slip about under the retaining tape. The magnet in question has just over 1k pulling power. Is this suffiently powerful for the job?
I understand Brucey's concern about inadvertently magnetising the innards of the hub and it's attendant problems but I cannot understand the placings for the N magnet and the S magnet.

If I secure an S magnet over the drainplug does it mean I then need to fix the N magnet on the opposite side of the hub?

Rand.

[Brucey]

one magnet will pick up the crud just fine.

Ideally a drain plug with a magnet set in it permanently would be best, since this could be removed whilst retaining all the crud attached to it.

Once an external magnet is removed, crud will start to drop off the drain plug unless it is set to the low point of the hub and remains undisturbed.

The ability to inspect all the crud by having it attached to the plug is handy if you want to see how much good you are doing.

cheers

[bobc]

Yep, I'll just do as Brucey suggests & take the magnet off when the plug's at the bottom then drain immediately.
The magnets hold themselves on the drain plug but I wouldn't expect it still to be there after a journey, hence the "backup" tape ;^)

Actually Rand, that's a monster magnet! I'm sure a much smaller one would do!

[TonyR]

How can I permanently magnetise it?
Rand.

The two standard ways are either to stroke it with a magnet or to put it in a solenoid energised with DC.

as BobC commented above, I don't think the steel grade used for the drain plug is suitable for being magnetised. You need a proper magnet; this will be x1000 better at retaining crud than any magnetised bolt.

If its ferromagnetic as someone said earlier it can be magnetised, if its not it probably can't. If it can be magnetised it will be quite enough to pick up any iron filings. The 1kg pull magnet cited above is massive overkill and completely unnecessary.

[Brucey]

things can be ferromagnetic and can be magnetised as permanent magnets of various strengths, but materials that are suitable for making bolts out of are not usually like this to any appreciable degree. An unusually hard and brittle bolt (think similar material to ball bearings...) might make a fair permanent magnet, but it is not likely that such material will be used by accident.

I would suggest that whatever magnet is used, it should produce a locally high field strength (~0.5T i.e. 5000 gauss or more) if it is to work as intended. Lower field strengths may attract particles, but probably won't retain them in service; between oil sloshing about and vibration, the particles could just drop off again.

BTW I have designed, manufactured and fitted magnetic devices to oil filtration systems on both petrol and diesel engines, and I have verified their performance by conducting an analysis of the debris collected. The results? -In a nutshell, I will no longer drive any car or motorcycle I want to last without such a device fitted to both the engine and gearbox; normal oil filters remove most particles above ~5um to 10um in size, but this is of limited benefit when journal bearings run with 1-3um clearances, and rolling element bearings run with similar film thicknesses in EHD mode.

Suitable magnetic devices typically collect lots of sub 5um particles in such engines, but long-term use of the magnet devices shows fewer particles with every successive oil change. Something the size of a pinhead could collect thousands of such particles, each of which is capable of scoring a (soft) journal bearing facing, but for the magnet, the bigger the better, more or less.

cheers

[TonyR]

With mine there is a very definite pattern and repeated in two hubs. IIRC 1, 4, 5 are silent, 2, 3, 6 are noisy with a sound like a loudly creaking bottom bracket.

It sounds like the same problem. Try backing them off a tad. With the axle clamped in a vice on the flats and two cone spanners (15 & 17, I think), you can do this without fully loosening them, approx 30 degrees at a time.
Without a vice its a bit more hit & miss. But be careful any detectable slop will cause damage in other areas.

Tried the adjustment and got it just right. Went out for a ride and the noise is still there Next move is to take the innards out and see if there is anything loose inside. The noise sounds a bit like the noise you get from shirt buttons in the washing machine and its only in specific gears; the others are silent.

[bobc]

Trying non- standard oil (rock oil "light gear oil")
Changed the oil at the weekend - all straightforward, old oil was grey rather than black & the first bit to come out was somewhat darker, presumably because of ferrous debris attracted to the magnet. no big nasty lumps.
New oil went in easy (like it does - seems to take me a long time to get the old oil out...) First ride this morning - nothing to report, seemed better than before but things always do when you've worked on them (felt like crisper changes & less draggy). However I can report without any doubt that back pedalling is MUCH free-er, previously it's been like stirring porrage (with a bit of gravel in), now it's ike back pedalling any other bike. Probably telling us something...... ;^) Dunno what.... By MUCH I mean a factor of 2 or 3.

[jfarnhill]

Quick note from me that I've given up on my Alfine11 and I'm back on a derailleur'd bike. After Versa shifters slipping 3 or 4 gears and the gears slipping, it's just not for me, I'm afraid but good luck to all those who are persisting. Looks like there are now quite a few on this thread happy with their hubs, which is great .

[rfryer]

Quick note from me that I've given up on my Alfine11 and I'm back on a derailleur'd bike.

Sorry to hear that. Have you got rid of the Day One altogether, or are you converting it to something more interesting? Maybe view this as an opportunity to try out the NuVinci hub???

[jb]

Quick note from me that I've given up on my Alfine11 and I'm back on a derailleur'd bike. After Versa shifters slipping 3 or 4 gears and the gears slipping, it's just not for me, I'm afraid but good luck to all those who are persisting. Looks like there are now quite a few on this thread happy with their hubs, which is great .

I don't blame you with the trouble you've had, Shimano have completely misunderstood what hub gears are all about with this offering. A shame because its almost, but not quite, a very good hub.