Author Topic: Danneaux in the Desert Dust  (Read 5633 times)

Andre Jute

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Danneaux in the Desert Dust
« on: July 23, 2012, 03:41:34 am »
In another thread Dan wrote:
A tremendous help, Andre; thank you!

I agree, the Hebie Chainglider sounds the stuff of my dreams except for touring on dry desert playa. Last trip through in the car, I came home and found it had even sifted in to fill the interior of the taillights. The lenses are glued solidly in place, and the bulbs are gasketed with dense foam, under trim panels accessible only via the car interior. The stuff silts and sifts everywhere and even seems to condense in quantity from whatever is floating in the air. This corrosive alkali is the stuff that makes my lips and nose bleed after a couple days' exposure. It is an order of magnitude worse than the ashfall we received from Mt. St. Helens' eruption in 1980. You're absolutely spot-on as to what would happen if it entered the chain case, and -- yes -- mine is not the usual situation, where I am sure it would work fine.

Jobst Brandt used to say that a good seal doesn't seal, it lets out enough oil to lubricate itself. This is an important principle of barrier design.

The Rohloff hub is designed to let a fine mist of oil out of its seals to ensure that they are lubricated. It were me going into that dust with a Rohloff, I'd overfill the gearbox with oil to guarantee that the flow is in one direction only, outwards, and refill it once a week while in the desert.

Andre Jute
« Last Edit: July 23, 2012, 11:23:22 am by Hobbes »

Danneaux

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Re: Danneaux in the Desert Dust
« Reply #1 on: July 23, 2012, 04:39:23 am »
Quote
[If] It were me going into that dust with a Rohloff, I'd overfill the gearbox with oil to guarantee that the flow is in one direction only, outwards, and refill it once a week while in the desert...
A suggestion I'll keep in mind, Andre, though I have come across severe warnings against over-filling. I plan to order a complete Rohloff oil-change kit with the bike so I will be prepared with oil on-hand for my first regularly-schedule oil change.

There are so many measures I have to take for this harsh environment already. Allen fittings need to be sealed with plugs, lest any rain concretize the playa dust that settles in them, rendering them unserviceable at a later date (the stuff is almost impossible to dig out if it is allowed to sit...and corrode, since it has a high alkali content). I habitually overfill my hubs with Phil Wood grease, and that includes the dust cap interiors, then allow it to squish out on assembly (same principle as Jobst's you cited). I've even demounted tires after a trip -- ones that were never underinflated or flat -- and found the dust had entered the rim through the spoke holes, then migrated around the tube to coat the inside of the tire casing.

When the stuff gets damp -- after a rain or near the "shoreline" of a dry lake -- it becomes...well, it turns to a grey, clayey goo that literally paints whatever it comes in contact with, and it doesn't come off. It consists of microbeads that slip against one another with the lubrication of water, and anything with inadequate surface area...sinks. This includes bike tires, feet, anything. It is a bit like quicksand in that regard, and one of my real concerns is to be caught mid-playa in a thunderstorm or hailstorm. You can't put up a tent and wait it out; the tent would sink and the water would easily swamp the doorway. About all you can do is to take off your shoes (lest they be sucked off at the next step), stand astride the bicycle with your head bowed on arms crossed atop the handlebars, and wait for the rain to stop pounding. Amazingly, sleep is possible in just that position, though a person starts awake, dizzy and disoriented from time to time. Cat naps are the best one can hope for.

The amazing thing is what happens when the rain stops. At first, it is like being in a bathtub, and of course there is no obvious drainage. Then, with really no foreshadowing, it is as if someone pulled the plug -- it all just vanishes. You'd expect to hear a gigantic "Sluuuuuuurp!", but you don't. The waters don't recede, the ground emerges. And, it takes awhile longer before the stuff firms up enough to actually support the weight of a loaded touring bike and rider.

And, of course, those bare, wet feet are going to suffer when this is over. The rain brings the alkali (dissolved lye, really) out of solution. It doesn't so much burn as it ultra-dries the skin, which then cracks open. It is called "Playa Foot" and can be caused by the dry dust as well. See: http://www.burningman.com/preparation/event_survival/playa_foot.html

The thing that gets me -- and keeps me coming back -- are the Small Miracles, the flowers and vegetation that arise from the water that does fall, arising from the harshest environment to bloom and grow, sometimes at a rate you can actually observe. It's terrifically inspiring to me, and often gives me the boost I need to go onward after being caught in such a deluge (see second photo for an example).

Often, when I go from the mountains to the desert...there's little or no transition, no getting ready and no working-up of nerve. One goes from the mountains, with lakes and streams and potable water to...an entirely different world, literally in just a few pedal strokes. The third photo below shows where I am about to leave Fandango Pass Road (site of a settler massacre in pioneer days) for the open playa of Middle Alkali Lake. As you can see from the real water between the mirages, it is not yet dry, and there's going to be tough sledging ahead. When the very ground steams with boiling geothermal waters, when all the signs tell you "No", you square your shoulders, stand a little straighter, clip-in and set forth.

Best,

Dan.
« Last Edit: July 28, 2012, 10:03:01 pm by Danneaux »

Andre Jute

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Re: Danneaux in the Desert Dust
« Reply #2 on: July 23, 2012, 12:01:25 pm »
You could of course just.... not go, Danneaux.

The thing that gets me -- and keeps me coming back -- are the Small Miracles, the flowers and vegetation that arise from the water that does fall, arising from the harshest environment to bloom and grow, sometimes at a rate you can actually observe. It's terrifically inspiring to me, and often gives me the boost I need to go onward after being caught in such a deluge

My mother used to go annually to Namaqualand, up the west coast of the Cape Province in South Africa, to see the desert bloom on the first day of the rains. They would pitch their tents in the sand, nothing but sand to every horizon, and then in the night it would rain, and when the sun rose, to every horizon there would be a carpet of multicoloured flowers.

Andre Jute

jags

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Re: Danneaux in the Desert Dust
« Reply #3 on: July 23, 2012, 01:41:45 pm »
fantastic photos Dan now i can see why you need such a load, your new Nomad should take all that terraine in it's stride ;)

NZPeterG

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Re: Danneaux in the Desert Dust
« Reply #4 on: July 28, 2012, 10:14:42 pm »
In another thread Dan wrote:
Jobst Brandt used to say that a good seal doesn't seal, it lets out enough oil to lubricate itself. This is an important principle of barrier design.

The Rohloff hub is designed to let a fine mist of oil out of its seals to ensure that they are lubricated. It were me going into that dust with a Rohloff, I'd overfill the gearbox with oil to guarantee that the flow is in one direction only, outwards, and refill it once a week while in the desert.

Andre Jute

Do Not over fill your Rohloff hub!
Over filling your can make your seals come out, which will let loads of dirt in.
Oil is designed to keep dirt away from parts inside! so just change the oil every 5000kms and all is good.
Rohloff's are very strong and designed for MTB.
:-)
Pete.....

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Danneaux

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Re: Danneaux in the Desert Dust
« Reply #5 on: July 28, 2012, 10:26:33 pm »
Quote
Do Not over fill your Rohloff hub!
Yep, Pete; just exactly what Andy advised me last week. I'll fill and change faithfully according to Rohloff recommendations and scheduling and call it good.

I realize I'm a Rohloff newbie, but a conservative and recommended approach will ensure greatest success for me.  It isn't just about the warranty, either. I really *do* want to ensure maximum reliability Out There and for decades to come, so I think it best I stay well inside Rohloff's and Thorn's guidelines and recommendations as I proceed.

All the best,

Dan. (who just wants it to work...and will do everything necessary to ensure it will...)

Andre Jute

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Re: Danneaux in the Desert Dust
« Reply #6 on: July 29, 2012, 01:52:33 am »
Fellows, let's define these terms we use.

1. A Rohloff hub comes from the factory overfilled. 12mm of oil is required to adhere to the gears internally. Rohloff fills it to between 15 and 25ml, depending on whose account you're listening to at the time, to be certain that hub isn't delivered dry. A service kit (25ml) is supplied with the German hubs, and the dealer fills the hub before delivery.

2. Rohloff's own service kit contains 25ml of oil, and overfills the hub by 104%. The excess, small or large, "mists" out of the seals. I know of no case where 25ml of oil blew out the seals of a Rohloff hub gearbox.

3. Herr Rohloff specifically designed his hub to resist sand on a beach. Sand has large grains.

4. Dan is going where the dust is like "talcum powder", extremely insidious. He has also described the way the dust forms a kind of concrete in the presence of liquid.

5. It seems obvious to me that a hub serviced perfectly in accordance with the Rohloff service instructions -- which, as I've described, is an 104% overfill -- will be better able to resist ingress of this fine dust than one on which, for whatever reason, the owner to tried to save a few bucks by putting in only 12 or 15ml of oil, rather than the full 25ml in a service kit.

6. Rohloff seals aren't great big heavy, multilipped industrial fittings. They're lightweight; some are a single layer of paper. They depend on lubrication as well as physical blocking to keep such fine stuff out.

7. I've read what people say about putting in only 15ml of oil. It's probably okay where I live, but I still don't bother trying to save the few pennies. What matters is that a replacement hub can cost around a thousand pounds and, in a desert, dust turning into concrete in the hub can be unhealthy for the rider as well.

8. Having considered the matter in the light of what is being said, and who says it, and where they've toured, I stand by my original statement. If I were going into the playa, where Dan goes, I would put in the full service kit of 25ml (i.e. "overfill" the hub to the limit of the Rohloff instructions, i.e. by 100% over the essential 12ml). And I'd do it right at the edge of that desert, to be certain there is oil misting out at the external seals for my entire stay in the desert, so that the fine dust can't get inside the hub. These are special conditions requiring special considerations.

Andre Jute

Danneaux

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Re: Danneaux in the Desert Dust
« Reply #7 on: July 29, 2012, 02:54:51 am »
Oh!

I understand better now, Andre; thanks very much for the additional explanation. The clarification on what you called "overfill" is very helpful, as is the explanation about the factory fill and dealer top-off prior to delivery.

This is exactly the sort of information I have been curious about and have spent considerable time looking for. I'm becoming more familiar with the Rohloff site by the day, as well as the intiricacies described in Rohloff's downloadable PDF manual.

All good stuff, as is your explanation.

My bit of recent bad luck, combined with a desire to avoid a breakdown that could easily result in my non-return, have made me particularly eager to ensure every possibility for success.

And, yes, the playa dust I encounter really is a special case. I've not seen the like elsewhere myself, and it does indeed go everywhere. The only car air filters I've found to be effective against it are K&N's offerings, and I find after a car journey there, I have to clean the screen-encased cotton gauze and re-oil -- something I never have to do in other environments. The stuff sifts and does indeed concretize on contact with water. Nasty material, that.

Best,

Dan.

Andre Jute

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Re: Danneaux in the Desert Dust
« Reply #8 on: July 29, 2012, 03:52:08 pm »
Someone will find a use for that playa dust, and mine it, and it will be as valuable as gold, mark my words! :)

NZPeterG

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Re: Danneaux in the Desert Dust
« Reply #9 on: July 29, 2012, 06:55:12 pm »
Someone will find a use for that playa dust, and mine it, and it will be as valuable as gold, mark my words! :)


So true

Pete....

The trouble with common sense is it is no longer common[

http://kiwipetesadventures.tumblr.com/

http://kiwipetescyclingsafari.blogspot.co.nz/

Looked after by Chris @ http://www.puresports.co.nz/
For all your Rohloff and Thorn Bicycle's in NZ