Thursday, September 18, 2008

A How-To Guide for the Suspended Messenger Bag

So I've had a couple of people email me with questions about the Suspended messenger bag and where exactly should they attach the shoulder strap and whatnot, which is cool, 'cause I like getting emails about bag making...just so long as you're not asking me to make you a bag. Woo.

Unfortunately, I don't have a whole lot of experience with this bag design. It's a really cool design, and the first bag I ever made has a semi-suspended shoulder strap on it. (That's from 2003. Yeah!) But I don't use it on the bags I make now--I've come up with something I like better.

And if you don't know what I'm talking about, be patient, pictures will follow. The Suspended messenger bag is a bag that uses a shoulder strap setup known as a suspension strap. This term is borrowed from backpacking bags, where the harness is also called the suspension system...I'm pretty sure...unless I'm making things up. (The pack is suspended from your back by the webbing, right?) Anyway, on these courier bags, there's a main strap that's attached to the back of the bag and then there are secondary straps (the suspension webbing) that are attached to the corners, which change the shape of the bag. These straps are comparable to the load-lifter straps on a hiking pack.
This feature makes 'em good for holding big things like boxes, while still riding well on your back. Pretty sweet, huh?

They look pretty tricky to make, but once you understand what's going on, they're not so bad...I think.
Oh, and for more on bag designin', check out the first post on this blog.

Okay, so there seems to be two camps when it comes to the strap positioning on these bags: the angled and the horizontal.

Like I said before, I'm no expert on these bags, so I can't say which one is better than the other, I can just show you some drawings and hope they help you with your bag design. I'll leave the research to you.

Here we go...
Let's start with a pattern for a big bag. This makes a pack with a 27" flap that's 14" high, 9" thick & a bottom that's 18" wide. Pretty big. And this pattern has a 1/2" seam allowance. The flap is 13" long...there's definitely room to make it longer...I tend to like my flaps a little shorter. They're more managable that way.

Here's how the strap ends are attached to the back. Put 'em all the way at the top of the back, 14" up.
And here's what the front'll look like.
A word on ladderloc placement on the suspension webbing: put it wherever you want. You can put the buckle on the bag or on the strap. I would probably put it on the bag, 'cause it feels more natural pulling the strap towards me when adjusting it. Though, especially on the top buckle, if you put it on the bag, it might be hard to get to if you want to adjust it while you're riding. Play around with it, see what works for you. I would probably just make the webbing longer on top so I could grab it...
Here's what it looks like when the suspension straps are all the way out. Makes a box, 18x9x14. That's about the size of a copy box...little bit smaller.

So look at the ends of the main strap there: notice that there's an extra piece of webbing there. That's a pretty important reinforcement. I'd include that if I were you. The shoulder strap's like a snake biting the edge of of the bag--won't let go. Yeah.
Okay, here's what the angled pack looks like:
Boom, that's at about 45 degrees.

Again, really reinforce the strap ends. Especially with the angled strap, 'cause you'll get some weird stress points there. Side view. From seam to x-box there, that's about 12". Double check, though. Make a paper bag first and make sure everything matches up okay.
So here's what I've got to say about these two designs: I like angled straps. I angle 'em on the bags I make, and I think they're more comfortable--they have cleaner strap kinking, bending. But here's the thing: with the suspended design, the strap ends are attached lower down on the pack, in effect shortening the height of the bag. In theory--mine at least--you could have problems with your load rocking. This is less likely to happen with the horizontal design, since the straps are still high up...and really, if you have a big bag that wraps around you, strap angle is less of an issue. In my opinion, it's more important in smaller bags (which I tend to make).
So, I hope this helps you with your bag design. Maybe I'll make one someday...we'll see.
Oh, bag makers that use this design: Pac (the first), Bagaboo, Zugster, Archie's, and, I think--I'm not totally sure yet--that ReLoad just came out with a bag with a suspended strap. I know they just came out with a split-strap option, and there's something going on up there on the top. Ha.
Happy trails.

No comments: