After I got my Carradice saddle bag last year, there didn’t seem to be any need to use my Office Bag any more. So for pretty much all of the last year, it’s sat in my study gathering dust.
But then I got my second hand Brompton – I bought second hand for three reasons:
- Second hand bikes hold their value amazingly well. I wasn’t 100% sure about the idea of a folding bike, so I figured that if it didn’t work out I’d be able to convert it back into ready cash.
- I’m tight / broke (delete as applicable)
- It’s a Green thing. Second hand means that the carbon cost of manufacture has already been well and truly sunk.
But then there’s the issue of luggage – my intention is to use this bike as my runabout. Transport within a 4 mile radius of my office; emergency trips to the shop; a set of wheels to get me to the pub. Stuff like that. But all of these mean that I need to carry a little luggage.
Option a) Buy yet another piece of bike luggage that’s designed to fit the Brompton’s front carrier block. I’m running out of space to store bike luggage, and that’d mean yet more expense.
Option b) Bastardize the Ortlieb bag I already have. It’s 22 litres of waterproof practicality that I just don’t use any more . . . so why not? Especially seeing as the bike I’d bought had come with a Brompton rack (one of the earlier all-aluminium ones).
It proved amazingly easy:
- Remove the rack clip assembly from the Ortlieb bag, and fit this assembly to the Brompton rack. If you have the shims fitted to the rack hooks, you’ll need to take these out first.
- Put the bag onto the rack, so it sits on the rack’s foot. Line it up centrally by eye, and mark the location for the centre hole of the rack clip assembly on the bag.
- Drill this hole from the outside of the bag – 5.5mm drill bit. Make sure it’s a good sharp bit so it doesn’t tear the bag’s fabric, and be careful to only drill through the fabric outer & rigid inner (i.e. don’t make a mess of the bag’s liner)
- Fit the clip assembly using it’s centre screw only. Put it on the Brompton rack, offer-up and mark the location for the holes of the clip assembly’s end pieces.
- Move the clip assembly out of the way, and drill the end pieces’ holes using the 5.5mm bit.
- Fit the end pieces, and check it all fits on the rack – the bottom of the bag should be resting on the rack’s foot.
- For completeness, you should then remove the rack clip assembly, and seal up the original, and now redundant holes with some puncture patches. Needless to say, I haven’t got around to this yet!
For completeness, I’ve also made a template (what can I say? I used to be an engineer!), though bearing in mind that YOUR Office Bag might not be exactly the same model as mine, and YOUR Brompton rack might be quite different . . . I’d probably use the measure-in-situ method described above!
Do The Right Thing 
[…] also pretty damned useful for trips to the shop for the odd pint of milk / loaf of bread – I modified an Ortlieb office bag to go on the front, and at 22 litres, that’s plenty big enough for emergency […]