DIY Seat Pack Stabiliser?

[RonK]

Riders and the tortoise suggestion is a good one.

Since you live in the UK, it would be easier to buy from a local store or Bike24 in Germany, one of my favourite online stores.

Salsa Rack Lock Seat Clamp - be sure to order the right size for your seat post.


Then you can get long rack struts - either Salsa or Tubus.
These Salsa Alternator Straight Struts are 370mm long.  It should easy enough to fashion a clamp to join the two ends.


Salsa Alternator Struts are also available with a 45 degree bend if that would work better.

[flanagaj]

Thanks for that RonK.  I have an idea to create my own version of the Railwing ;-)

[RonK]

Thanks for that RonK.  I have an idea to create my own version of the Railwing ;-)

Let me know if you want more pictures, dimensions.

[vermont]

To take RiderX approach but maybe even simpler would be to use something like this...  http://www.homedepot.com/p/Everbilt-1-2-in-x-36-in-Aluminum-Flat-Bar-800207/204604761
In the States, all our major home/hardware stores carry something very similar.

[werkinit]

https://ridepdw.com/collections/cargo/products/bindle-rack

[pilotintraining]

A little late to the game on this one but, here goes my take.

I blatantly ripped off PR/Hunter's stabilizer design, just on the cheap, with a slight modification to the harness design.

Like riderx and RonK suggest, I used a rack mount seat clamp as the attachment. Because I have more seatpost sticking out and wanted the clamp higher up, I used a semi-circular file to take down the inside lip of the clamp. For the strut, I hammered the ends of a length of lightweight steel pipe flat, then drilled holes and filed off sharp corners, and finally bent the pipe into a U shape. Attached the strut with long m4 bolts, washers, and loctite. Put a wrap or two of electrical tape around the seatpost and clamped it down.

The main failure of Porcelain Rocket's harness design is that there is only one connection between the bottom portion of the harness and the top: that is the strap that runs over the back of the dry bag. This means that when you cinch the strap down on the dry bag, it pulls back on the harness. The top of the harness, secured to the saddle rails stays put, but the bottom piece will slide right off the stabilizing rails if you do not have the angle of the saddle rail just right.

My solution was to build a harness to receive the dry bag that fully wraps the dry bag top, bottom, and sides. The harness velcros around the seat post, and the bag is held in by the rear and side compression straps. In the photos below, you can see the difference that the stabilizer makes in total bag integrity from photo 1(with stabilizer) to photo 2(no stabilizer). I will post a better picture of the stabilizer assembly and harness when I get home.

[ogobogo]

I actually achieved quite success just by using bungee cord around my seatpack. The bungee cord passes though the rails, around the bag and its ends are connected by a carabiner. Although the instability of the bag isn't 100% removed, it is quite effective.

One has to grab a piece of bungee cord, make a ring and voila.

Regards

[MikeC]

I'll throw out the obvious, if outlier, response: Learn to pack and adjust your current bag better.

I have a few different Revelate seabags -- the Viscacha, Pika, and Terrapin.  Loaded unevenly and tensioned poorly they can sway.  Pack them more densely, but not *too* densely, then figure out the sequence of tightening straps that achieves zero to minimal sway.  It can be done -- people have been doing it for a decade.

I don't mean to suggest that any/every seatbag system can be run sway-free.  Some definitely can't.  But spending ~20 minutes fiddling with the one you have might save you a pile of money and get you to the same blissful sway-free state.

Full disclosure: I insist on running dropper posts when bikepacking, thus a rail-less setup is mandatory.  So I went into this with the attitude that it *had* to work, and with some patience and a lot of fiddling, it has.

[Iowagriz]

^^^ this...I'll also add that you really need to experiment with what you pack in the seatbag in order to get the minimal sway nirvana. My only personal requirement was that once closed, I don't want to have to get into the seatbag until the end of the day. It took some experimentation to figure out the proper gear and order of stuffing.

Sent from my SM-N920V using Tapatalk

[cpmeyers]

I posted over in the wrong forum probably (bikepacking rather than MYOG) - but finally road tested a DIY carbon fiber rack that I bodged onto a cheap ebay seat post rack. Horribly over engineered I know but geez, fun to make. I had a 20L dry sac in there for 600K and could have carried a lot more.

Thanks to all previous posters to this thread ... there are a couple of ideas in here that I'll use for prototype number 2.

 

[smoovestjj]

Been a few months since anyone commented, but I wanted post a version of a "bag stabilizer" that has worked - I mean, like, "absolutely badass, why didn't I do this sooner" worked

First off, the suggestions below have been super helpful.  I wanted to have something that supported a drybag, vs a full a complete bag system.

Too, I was most interested in using something I already had laying around...

LBSR SKS Bag support Modular System - 1.0

Packed in the dry bag is 40 degree bag. 







Again, it works.  The strap run around the bag (and under seat) wasn't entirely necessary.  In fact, it's completely stable with just the green strap running from the end of the fender.  A few days after these photos were taken, I did a quick 400+ mile ride out to the desert and back.  No issues.

[mjvk]

Hi everyone,

Here is a system that I have made and used with pretty good luck. It's based off of the Bedrock Railwing design, but with slightly longer arms for more sway reduction. I think this is better for bikepacking than a rack system because it's nearly indestructible in a crash. Its just a piece of bent aluminum stock, and I used the mounting hardware from a Minoura sbh-300.