Penrite SF Grease for Alfine 8?

For discussions about bikes and equipment.
buffet
Posts: 17
Joined: 3 Jan 2019, 6:00pm

Re: Penrite SF Grease for Alfine 8?

Postby buffet » 16 Apr 2019, 1:57pm

One thing that got a bit worse after oil lubrication (or just over time?) is gear shifting from 4th to 5th. When I do it when pedaling, sometimes it's rather instant (like all other gear changes), but sometimes it takes 1-2 seconds (or 1-2 crank rotations) to actually switch to 5th. The hub is the most recent Alfine 8, yellow marks are aligned in 4th gear. The hub itself has around 600km on it.
What can cause this? Lack of lubrication? Some cable issues?

Brucey
Posts: 35182
Joined: 4 Jan 2012, 6:25pm

Re: Penrite SF Grease for Alfine 8?

Postby Brucey » 16 Apr 2019, 2:11pm

with that (high normal) model of hub a draggy cable could do it.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

buffet
Posts: 17
Joined: 3 Jan 2019, 6:00pm

Re: Penrite SF Grease for Alfine 8?

Postby buffet » 16 Apr 2019, 2:21pm

Does it mean that the fixing bolt has moved somehow and needs adjustment? Where should I look to correct the cable drag?

Brucey
Posts: 35182
Joined: 4 Jan 2012, 6:25pm

Re: Penrite SF Grease for Alfine 8?

Postby Brucey » 16 Apr 2019, 2:59pm

if the cable is not adequately lubricated then it will behave differently depending on the weather. Water entry (and consequent corrosion, yes even with stainless inner cables) is very common with cables on Alfine/Nexus hubs.

If you know what you are doing you can feel a draggy cable. Occasionally you can pull the inner out, clean/lubricate it, and reinstall it. However the sure-fire cure for a draggy cable is to replace it (inner and outer). Be sure to use a stainless inner cable; it will always last longer than a crappy galvanised cable in this application. Also be sure to use the correct index housing and the correct (tight fitting METAL) ferrule where the cable housing installs in the cassette joint.

You might be wondering why this only happens on the 4-5 shift; this is likely because there is a sliding clutch inside the hub and (although it is the 5-4 shift in a Nexus or the earlier Alfine because it is 'low normal'), when the internal spring has to overcome the clutch, any extra cable drag is liable to affect this shift first.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DreadPirateRoberts
Posts: 5
Joined: 9 Jul 2019, 3:11pm

Re: Penrite SF Grease for Alfine 8?

Postby DreadPirateRoberts » 9 Jul 2019, 3:34pm

Hi All,

New poster here.

I've recently upgraded my Thorn Club Tour to an Alfine S7000 8sp hub. By way of preventive maintenance, I opened up the hub and lubed it with general purpose LM grease and am now realising I probably shouldn't have. Any thoughts on the best way to remove this grease prior to using gear oil or similar?

In terms of what oil to use, would you rate Lucas Oil Stabiliser (https://www.amazon.co.uk/Lucas-Oil-10001-Heavy-Stabiliser/dp/B000AS1XYO) as suitable. It's heavy, sticky but flowing and apparently slows oil leaks! I've used it in the past in a slack differential gearbox to tighten things up.

I've probably got a selection of motor, gear and atf oils in the shed though only the general purpose grease...

alexnharvey
Posts: 754
Joined: 10 Jan 2014, 8:39am

Re: Penrite SF Grease for Alfine 8?

Postby alexnharvey » 9 Jul 2019, 6:36pm

The quick and dirty way would be to add some gear oil or ATF that mixes ok with the grease, effectively diluting it and hopefully preventing it causing poor shifts.

The thorough way would be to degrease with solvent or degreaser, thoroughly flush and dry, it then relubricate.

I guess that oil stabiliser might be useful additive to a home brewed mixture but it would be your experiment. Does it become less viscous when mixed?

Brucey
Posts: 35182
Joined: 4 Jan 2012, 6:25pm

Re: Penrite SF Grease for Alfine 8?

Postby Brucey » 9 Jul 2019, 9:52pm

IME LM style grease isn't terribly good in hub gears; it is OK as a lubricant until the water gets in; then it all goes to pot very quickly. Lip seals wear very quickly if they are not wetted with lubricant, and they only stay wetted with lubricant if the lubricant is both reasonably plentiful in the hub and mobile enough to get around the hub. This means that most forms of grease (that are not at least semi-fluid) are unlikely to work for very long in adverse conditions.

Probably there are some excellent additives which improve gear oils for use in hub gears, but I have no idea if the Lucas additive is one such or not; it might be brilliant stuff, it might be snake oil. Even if it is brilliant stuff it might be meeting a need that doesn't really exist in an IGH.


It is as well to consider what you are trying to achieve here;

1) is to keep water out of the hub (so keeping seal lips wetted then) and
2) is to make sure that if water gets into the hub, the lubricant has enough corrosion inhibitors to forestall damage.

Actually keeping the workings adequately lubricated is normally achieved as a side effect of meeting the objectives above.

IME lubricants that are not specifically designed for similar service conditions are often distinctly lacking in corrosion inhibitors.

Case in point; I recently discovered that a pedal with bearings in good condition, lubed with shimano grease, wore faster than another one did once a tiny amount of water got in there. The thing is that the other bearing was completely knackered; the only thing it had going for it was that it had decent grease inside it. The shimano grease was overwhelmed by a small amount of water and had started to turn brown (through corrosion) where the balls were running. The wear process is accelerated greatly (by at least x10) by any corrosion, and the locally acidic conditions that occur help to degrade lubricants that are not suitably fortified.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DreadPirateRoberts
Posts: 5
Joined: 9 Jul 2019, 3:11pm

Re: Penrite SF Grease for Alfine 8?

Postby DreadPirateRoberts » 9 Jul 2019, 10:41pm

Looking at the oil stabiliser, it flows like honey so would likely leak past seals unless these are properly greased. I've also been reading Brucey's 'Grease is the word' thread which gives me loads to think about. I'm now thinking I should lube the bearings with Moly grease (for EP additives) and the gearbox with the Lucas Oil Stabiliser (LOS). I'll have a look at the left bearing seal to see would it take an O-ring (the cone does appear to have a concave housing around it that a ring might fit.

As to washing out the incorrect LM grease, would white spirit do the job? Or injecting some 5W50 motor oil and going for a 10k ride be a better option?

I've just seen Brucey's repliy. Does that suggest that I don't know what I'm talking about? I thought the LOS had corrosion inhibitors but I'm not seeing that when searching on it now. I'm thinking of the Moly grease for bearings based on the boundary conditions properties. So am I better off hunting down a suitable SFG for the gearbox? I'm finding it difficult to find an Irish supplier and the one source for a substitute for Penrite SF wants more for shipping than for the grease!...

DreadPirateRoberts
Posts: 5
Joined: 9 Jul 2019, 3:11pm

Re: Penrite SF Grease for Alfine 8?

Postby DreadPirateRoberts » 9 Jul 2019, 11:42pm

Update.

Reading back over the thread, I seem to be taking it up wrong. The conclusion I'm drawing now is that I should inject a 75W gear oil through the left bearing, oil the bearing and see how that goes. If, later on, I want to flush the hub, ATF and a ride is a good start. Then open the hub, clean, flush, drain and re-lube with gear oil unless leaking is a problem in which case Land Rover SFG is the preferred lube.

DreadPirateRoberts
Posts: 5
Joined: 9 Jul 2019, 3:11pm

Re: Penrite SF Grease for Alfine 8?

Postby DreadPirateRoberts » 6 Aug 2019, 9:53pm

So, I oiled the hub with around 50ml of gear oil and greased the left bearing with moly CV joint grease from the local motor factor. There was a small bit of leakage out the drive side for a day or so.

Two weeks later the moly grease was oozing out around the bearing cone so I added some more gear oil and re-greased the bearing. I'll see how it behaves on PBP on the 19th...