
Brompton sells a bag made by Ortleib. The good folks at Bicycle Habitat have one in stock and it’s beautiful. But they’re asking $350 for it! That’s too much money. Eric, at Bicycle Habitat, showed me the Ortlieb “Downtown” and we both agreed that with some tweaks (he reckoned one Sam-Adams’-worth, I figured closer to two) the bag would fit easily on my existing S-frame. The Downtown retails for a still-steep, but slightly more reasonable, $150 (ouch! REI is selling it for $104).
I don’t normally drink Sam Adams, but in honor of Eric I got two from the corner bodega and broke out the tools. Happily, the inner lining of the bag zips open to reveal the padding and guts within. With a phillips screwdriver and torx wrench I removed some grommets, nuts, and bolts and the quick-release mount came off easily. Then I measured and drilled new holes for the straightened bracket.

Measuring for the S-frame, the bracket landed between the two existing mount points, about a half inch (at center) above its factory location. I had to relocate the stabilizing cleat to the upper radius to clear the Brompton S-frame’s hardware.
The Downtown bag is slightly larger than the Brompton O bag (30 liters vs 22 liters, based on my own measurements) and is, in my opinion, better looking. The mount certainly isn’t as elegant as the built-in Ortlieb/Brompton O bag mount (which is really nicely done). But come on… the modified Downtown costs half (or 1/3) as much and is twice as flexible! I can now use this bag on any of my other bikes with a rear rack (I’ll simply remove the bag from the S-frame and click it onto my other bikes’ rear pannier rack).
Also, I have the satisfaction of having built it myself. Degree of difficulty: 1/2 Sam Adams.




There are a number of blogging solutions at Columbia (CUIT and Pressible both offer personal blogs and CCNMTL offers course blogs via EdBlogs). One interesting use is to have students’ personal blogs (like this one) feed into several course blogs via a tag. As an example, I’m feeding 


