Optional internal frames with aluminum stays designed to work with any generation of Synapse 25 that has rail loops.
We present for your use these optional, removable internal frames with aluminum stays for the Synapse 25 backpacks.
The frames are made of die-cut .055” thick High Density Polyethylene (HDPE), with a nylon webbing sleeve sewn down the center that encases a 1” / 25mm wide 6061 aluminum stay.
We’ve bent the stay to a generic spinal curve; we recommend you re-bend and/or adjust the curvature to best fit your own back (see here for instructions). If you just want a frame sheet, the stay is removable, though it's worth noting that a frame sheet sans aluminum stay does just about nada when it comes to shifting the weight of the pack onto one's hips. (Read more about that here in our Guide To Backpack Frames.)
Because the Synapses were not originally intended to accommodate an internal frame, they weren't designed with a way to attach one; this required us to make some modifications to the frame design. We took advantage of the loops for the Cache tablet/laptop sleeve at the top of the packs to retain the internal frame: a clever “T” bar holds the frame in place relative to the loops. The lower edge of the internal frame floats free in the Synapse—we’ve found this isn’t much of an issue as the contents of the bag tend to hold this lower extreme in place. Please note: your Synapse must have rail loops in order to use these new, optional internal frames. If your Synapse doesn't have rail loops, you're welcome to try using the internal frame anyhow; let us know how it works for you.
If you order the internal frame on the Synapse 19 or Synapse 25 pages along with the pack itself, it will come pre-installed. If you order the internal frame separately for an existing Synapse, or if you remove the installed frame and then want to add it back, take a look here: Video + Text Instructions On How To Install or Remove the Synapse Internal Frame
And don't worry: even with an internal frame in the Synapse, you can still use the very same loops to secure a Cache.
Benefits of an Internal Frame
• On bags with a webbing or padded hip belt, the vertical stability facilitated by an internal frame with an aluminum stay can help to lift some of the pack’s weight on to one's hips.
• It creates a hard back panel that prevents less-than-carefully packed objects like a thermos or DSLR from poking one in the back.
• It can prevent an overstuffed bag from barreling out against one's back.
• To some folks, a rigid frame against their back (with padding between the frame and their pack) just feels right.
Why You Might Not Want To Use a Frame
• A frame adds weight to a bag. Our Synapse 25 Internal Frame weighs 9.6 ounces / 272 grams. In many cases, you can forgo the frame and achieve similar benefits with careful and thoughtful packing.
• The rigidity offered by the internal frame becomes a liability when you’re squeezing your pack into the overhead compartment or under the seat in front of you, or when you’re packing your backpack inside other luggage. That's a reason it's nice to be able to remove the internal frame when you want to.
• Some folks simply prefer the feeling of a frameless or soft-back pack.
For more on our philosophy and experience regarding internal frames, please see our Guide To Internal Frames.
Sewn in Seattle
Our bags are designed and sewn right here in Seattle, Washington, U.S.A.
That allows us to be control freaks in the best way possible; we have direct control and oversight of the quality of our materials, our products, and the jobs and working environment that we help create. It also offers us a unique spontaneity: when we have an idea for a new product or accessory, we can design it, figure out how to build it, add it to our website and be ready to ship it out our front door all within just a few weeks. How cool is that?
Intrigued? You can find out more about the unusual way we do business on our Company Philosophy page.
THE BIHN Guarantee
Everything you buy from us here at TOM BIHN is satisfaction guaranteed. We’ve been in business since 1972 and we stand behind what we make.
If something goes wrong and it's our fault, we'll fix it for free. Repairs due to normal wear and tear or due to other things that are not our fault will be performed, when possible, at a reasonable charge right here in our Seattle factory where your bag was made. Defects in materials or workmanship are uncommon and almost always evident while the product is still new. Keep in mind that bags and packs are often subject to extreme wear in everyday use: do not expect them to last forever. Only true love lasts forever! You can expect a TOM BIHN product to give years and years of hard service.
- Tony M.Verified BuyerBought For MyselfProduct Standouts High Quality Craftsmanship, High Quality Finishings1 month agoBought For MyselfProduct Standouts High Quality Craftsmanship, High Quality FinishingsRated 5 starsPerfect Fit!
Exactly what I needed. love this.
- Kristine M.Verified BuyerBought For MyselfProduct Standouts Thoughtful Design, Comfortable, Durable, Unique, Easily Adjustable9 months agoBought For MyselfProduct Standouts Thoughtful Design, Comfortable, Durable, Unique, Easily AdjustableRated 3 starsFinally got Internal frame!
I really like the flexibility of being able to add the frame or take it out based on my needs. Definitely helps you carry heavier load especially if combined with external hip belts.
- Zachary R.Verified BuyerBought For MyselfProduct Standouts Comfortable, High Quality Craftsmanship, Durable, Great Gift, Made in USA8 months agoBought For MyselfProduct Standouts Comfortable, High Quality Craftsmanship, Durable, Great Gift, Made in USARated 5 starsAdds structure and comfort
This made the backpack much more comfortable and also reduced fatigue a bit on longer trips by distributing weight. Not very difficult to install. Makes it slightly more difficult to stand the bag up on its own. Also tougher to fit in small spaces, of course. I use this for my hiking/traveling Synapse 25, but not in my work 19 because I have to squeeze it into bins/cubbies more often.
- Kevin M.Verified BuyerBought For MyselfProduct Standouts High Quality Craftsmanship1 month agoBought For MyselfProduct Standouts High Quality CraftsmanshipRated 5 starsSynapse 25 Internal Frame
Just what I needed to stiffen up the backpack I purchased. Just as advertised and highly recommended.
- Allen H.Verified BuyerBought For MyselfProduct Standouts Thoughtful Design, Comfortable1 month agoBought For MyselfProduct Standouts Thoughtful Design, ComfortableRated 5 starsHelpful
Lucky enough to get one before TB ran out in the most recent re-stock, give me the additional structure I like in my S25.