According to Carradice, the Bagman Sport is not compatible with sprung saddles. In that sense everything I’m about to say is verboten. Don’t do this at home!

I did indeed have a problem after converting the saddle back to its original Flyer form. Maintaining the same saddle height means that the rails are now a centimetre or so lower. And the saddlebag now threatens to rest on the rear mudguard.

View of a saddlebag from behind. The support is so low that the bag sags though onto the mudguard
Bag sag problem
View of the same saddlebag from front. The bag is touching the mudguard.
Bag sag from front
View from rear of saddle. A steel rod is inserted into the bottom ends of the spiral springs and is bent to form a saddlebag support underneath.
Selfman idea

My first attempt to fix this was based on something I’d had in mind for a long time. The springs at the back of the saddle are bolted though the back ends of the rails and a connecting bar. How about making a saddlebag support with threaded ends that simply replace the bolts? If it was braced by stays to the seatstays, it would be steady enough, no? So I spent a happy day (because I’d wanted to try my hand at bending rod) bending and threading a length of 6 mm stainless rod. It might have kinda worked. I don’t know, because, the next day …

The next day I came in and looked at the Bagman and realized something. The Bagman bars fit into a cast piece of aluminium where they are held by grub screws. And this piece normally forms the bottom half of the clamp that attaches the Bagman to the saddle rails. What if I turned the clamp upside down, so that the part with the Bagman bars in it becomes the top part? How much higher would it be? Can it be done? My first estimate with the Vernier caliper was that it would gain a little over 1 cm in height; almost exactly what was lost by the B17-Flyer conversion.

View of the clamp of the Bagman saddlebag support from the side, showing one of the grub screws that holds the rods in the cast piece.
Bagman clamp from side
View of the Bagman clamp from behind, showing how the rods enter the bottom half of the clamp.
Bagman clamp from behind
Picture of the shiny Bagman rods with the clamp removed, showing the indentation where the grub screw grips it inside the clamp piece.
Rods out
Clamp is reassembled the other way up, so that the part with the rods is now on top.
Clamp flipped & reassembled

So I undid the grub screws and flipped the bars over in the cast piece, putting the grub screws back in with plenty of threadlocker. The I tried installing the Bagman on the saddle rails. Now that the Allen bolt has to be tightened from above, this is a bit tricky. You’d need a lot of patience to do it with a normal Allen key. But my little Wera ratchet fits in and allowed me to ratchet it up pretty good. And then I gave it a final tighten with a real Allen key.

Bagman being installed on the saddle rails. A small ratchet wrench is inserted into the Allen bolt.
View of the installed Bagman from the side and a little in front of the saddle springs. We see that the Bagman rods pass over the connecting rod between the springs at the back of the saddle with a clearance of maybe about 5 mm.
View of the installed Bagmen. We see that the bagman is stabilized by two stays connecting it to the seatstays. Two aluminium plates are attached across the bottom of the Bagman where the saddlebag will sit.
View of the Bagman "floor" from below, showing the small steel clamps used to attach the aluminium plates to the rods.

Then we have a potential collision between the Bagman and the connecting bar that links the bottom ends of the two springs in the saddle. I solved this by flipping the connecting bar so that it goes across in front of its bolts, and by moving the Bagman clamp back a tiny bit. The Bagman now passes over the connecting bar. The gap is small, but since the Bagman is fitted with stays, it can’t flex enough to hit the saddle part.

As an extra belt-and-braces measure, I then installed an aluminium floor on the Bagman to stop the bag sagging through. It’s a fairly quick, rough job but it’ll do for the moment.

My current estimation is that this is a fairly solid setup. It’d be interesting to know why Carradice don’t want us combining the Bagman with sprung saddles. One reason that could still apply to mine is that the up-and-down motion of the saddle top, to which the bag is attached, could cause extra wear to the bag. I also realize that the floor and in particular the heads of the screws might wear the fabric. I’ll keep an eye on it to see if there are any signs of that happening.