I recently resurrected my titanium bike. This had donated it’s titanium seatpost to my Specialized Roubaix but now it seemed only fair and right to return the seat post to it’s rightful place.
The main reason I’d moved the titanium seatpost to the Roubaix was to use a Carradice SQR mount during PBP and qualifiers. On long rides quite a bit of luggage capacity can be needed.
The Roubaix had been supplied with a carbon post so I installed that instead. The bike wasn’t entirely without carrying capacity as it had a barbag. But when I had the Elenydd 300km planned I needed a bit more.
A carbon seatpost won’t take SQR block. Well, it might but there is a risk of creating a stress riser in the carbon where the metal clamp tightens on. And I need the seatpost to be as reliable as possible, I’m not going looking for trouble…..
So I had to find an alternative. I had a 6L bag I don’t use much. This could attach to the back of the saddle nicely. But the reason I don’t use it is that it isn’t quite big enough.
I couldn’t fit a rack, and anyway that would be (relatively) heavy. A rack is great for panniers but I just don’t need that amount of stuff.
So I started to consider non Carradice bag options. They had to be waterproof, and fairly light would be good as they are going on the Carbon bike
Then I came across the “Ultralight bicycle touring” blog One of the of many ways of cutting down weight on their touring bikes is to try new and interesting luggage carrying methods.
Inspired by lightweight touring, I’ve got an Alpkit dry bag. This is attached through the bag loops on the saddle. I have an 8L and a 13L sized one to try.
The weight difference between this and a Carradice SQR tour is significant. The Carradice bag, excluding the plastic clamp that fits the seatpost is 1100g. The Alpkit dry bag, size 8L is 150g. So the total difference is around 1Kg.
Extremely waterproof and about the right size, the only little issue I have with it is that it takes a couple of minutes to attach instead of instant on/off with the SQR
I’ve done hundreds of km with it now and it seems to do the job, even in the wet
UPDATE: If you want a more “pro” job of a saddle bag from an Alpkit drybag then just look on Alpkit’s website (I didn’t) Here is an article about making a saddlebag requires sewing machine, seam sealant and manual dexerity…