Alpha Direct 4004 Overbag


This is a made-to-order item. Not in stock. See the home page for the made-to-order lead time.

While we call these “overbags”, technically they are overquilts with a closed footbox and an open upper 2/3rds with a snap closure at the top. The top drawcord can attach to the top drawcord of other Timmermade systems.

An overbag built from one layer of Alpha Direct 4004. Alpha Direct is extremely breathable without a wind blocking layer, so the added warmth will be more variable. If using this between a down system and a bivy sack, the added warmth is likely to be similar to the Alpha / Argon overbag, which is around 10 degrees. If using a bare Alpha overbag over a down system with no shell covering it, you can expect less added insulation, even in the still air of a shelter. If there is any air movement, it will cut right through the Alpha and greatly reduce its added insulation. While this will certainly feel less warm, it’s still untested as to whether this air cutting through the Alpha could be helpful in moisture management. The Alpha / Argon will be a warmer overbag, which will be more likely to reliably move your dew point and trap that moisture. However, the bare Alpha bag could, in theory, move the dew point just enough when the air is still, and when the air is moving through, it may allow that moisture to move out while you’re sleeping. The initial purpose for including this bare Alpha overbag is for use with a bivy, since a bivy user would be adding a redundant shell if they were to use the Alpha / Argon version under a bivy. If moisture management is not a concern, this overbag can also be used as a comfortable inner bag liner to add warmth and separate your skin from your sleep system’s shell fabric.

Alpha Direct colors are subject to change as rolls run out and are re-stocked. If a roll runs out of a color you ordered, you will be contacted and given a new option.

Comes in 58″ wide x 79″ long unless specified otherwise and weighs approximately 9oz. There is a top shockcord and a footbox drawcord. If custom dimensions are used to follow the contours of the down system it’s meant to go over, a lighter weight can be achieved. However, if going this route, one should be very careful to not end up compressing the inner down system. There is a mitten hook at the shock cord exit that can be used to connect to the shock cord exit of another Timmermade system so the two systems stay together. It is possible that it could be used to connect to other systems with a center draw cord or similar attachment point in the center.

Measure the outer dimensions of the system the overbag will go over with a soft tape measure. Stuff pillows or similar inside to mimic your body. Do not compress any loft when measuring. Hold tape loosely. Keep in mind the overbag has a drawcord footbox and the total length includes the part that will be cinched up. When measuring the length of the inner system, don’t just measure the horizontal length. Start from the center of the footbox, up, over, and along its length.


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The Alpha Direct Overbag is a synthetic overbag that can go over a down sleeping bag. Using a synthetic overbag is sometimes a necessary way to keep your down dry in really cold, or really wet environments. In really cold environments the moisture that your body puts out in the night will travel through your sleep system and condense wherever the dew point is, which is typically inside of your down loft somewhere. Adding an Alpha Direct Overbag to the outside pushes that dew point out of the down and into the Alpha Direct 4004 fabric. From here you can remove the moisture from your down and pack it away dry. The moist overbag can either be dried during the day, or left moist and packed separately. If the moist overbag is reinstalled over the down bag the next night your body temperature will continue to push the dew point into the Alpha Direct fabric and the down bag will continue to stay dry. The overbag will continue to accumulate moisture and will need to be dealt with at some point, but Alpha Direct is remarkably good at dealing with moisture. It does not lose loft and dries very fast.

In really moist environments above freezing, the moisture is likely to come from the outside. An Alpha Direct Overbag is not waterproof, but it can catch light moisture that comes in the form of condensation or contact with wet tent/tarp walls or whatever. This moisture will soak into the overbag and need to be dealt with at some point, but it creates a barrier between the moisture and your down system.

It also doubles as an insulated poncho. This can allow you to either leave a jacket at home, or at least bring lighter insulating layers. This can often fit over a small backpack too, keeping things somewhat warm back there.

Weight 0.3 kg


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