Seam sealed seatbag, is it worth it to you?

[Smo]

Hoping to get some opinions here.  I'm in Arizona and for my riding, the only bag that I bother to make waterproof is my handlebar roll, because it's easy to seal and it has my sleeping bag in it.  If it's going to be seriously wet I'm just gonna go for a hike instead, since I find that more fun in the rain than riding.  Or I'll just stay home and sew and wait for better weather.  Guess I'm a bit of a wimp?  It just makes sense when you live down here in our climate.

That said, I know other people ride in worse conditions, and it would be possible for me to make my seat bags seam sealed as well.  I've taken my seam sealed backpacks in some rather wet weather and they've done very well, so the technique should work on a seatbag too.

So: who would pay extra for a seatbag if it was waterproof?  Probably not waterproof for submersion, but something you could stuff food and layers in, then go for a ride in wet/muddy conditions and have total confidence that your gear stays dry.  Stuff it and forget about it, basically.

It's something I can do but I'd probably have to charge at least $20 extra per bag for it because the construction is a bit different.  For one, I don't use the standard grosgrain binding tape on bags that I'm going to seam seal.  And of course it takes a while to seal a bag with a lot of seams such as a seatbag, and doing it in production means I need lots of ventilation and a respirator.

So would you be interested if you were buying a seatbag right now?  Say, $115 for a normal seatbag or $135 with trustworthy sealed seams.  Would it change if I took a video of one stuffed with newspaper going through a washing machine?  My guess is that the newspaper would be slightly damp at the end, but not waterlogged.

[tanadog]

A truly waterproof seat bag or handlebar roll would be great, but i think rather than seal the seams with goo I think there might be a better way of achieving it. I'd put a false liner in the seat bag that was tape seam sealed, with the opening integrated into the roll closure. You could attach the back end into the seat post end of the seat bag. It could be reasonably light material (30-40D) as it wouldn't suffer much abrasion. As this is the waterproof layer you could save cost by not using the VX style fabrics that give  false sense of waterproofness and stick with a 600-1000D standard cloth for the seat bag/ handle bar bag. This would work even better on a bar bag, surprises me no-one has done it yet.

[Smo]

Tana,

Thanks for the reply.  For serious water resistance your suggestion might be the best option.  But for protection against rain I think it's overkill.  Heavier than adding seam grip and it would cost a whole lot more.  I tested one of my sealed bags in the washing machine and it got slightly damp on the inside, next to the rolltop - but newspaper packed in the middle was totally dry.  Good enough for me and lighter+cheaper than either adding a liner or using any kind of weldable fabric.

The VX style fabrics are 100% waterproof, as good as anything out there.  They have a plastic layer laminated in the middle of the fabric, protected on both sides by fabric layers (nylon on the outside, polyester on the inside).  No coating to wear off.  So unless you poke a hole in it, the only place they leak is the seams.  In theory if you could seal the seams 100% you should be able to bike through a lake.  In practice that's pretty much impossible, but it's not hard to get a good enough seal for practical purposes (practical porpoises should look elsewhere).

For the record I ended up offering seatbags with a seam-sealed option as well as rolltop framebags.  Might as well!  It's an extra $20 at the moment, which might seem like a lot until you factor in not just the cost of seam grip but also time.