Originally Posted by
Smaug1
The OP's daughter has already chosen, but I hope he won't mind if I continue the discussion on a tangent.
I have a Topeak MTX trunk bag, the one with the fold-down panniers. I just love it, but sometimes, it's a bit small. (each side will hold just a 5 qt. engine oil jug)
I'm THINKING about buying a set of panniers, but they would only get occasional use, so I definitely can't justify new Ortleib. Amazon has a few highly-reviewed brands for 1/3 the price, so I'm thinking of going that way.
I could also just wear my big backpack for the occasional larger grocery run.
For occasional use there is no need to spend gobs of money. Take a look at RockBros Waterproof Panniers.
But, I don't trust anyone's waterproof claims, and especially a low-price budget model. What you would need to do is buy a box of trash compactor bags, these are a lot more heavy duty than any trash bag, and they're white so you can see inside easier, then simply put the bag inside the pannier, put your stuff into the bag, roll the top of the compactor trash bad tightly, then close your pannier. I have a pair of Axiom Seymour Oceanweave 45, those were on the higher end of the price scale, but even with those I use the compactor bags.
Using a trash bag for a liner also prevents something spilling inside that could ruin the interior of the pannier.
The other thing is if you have something you want to make sure it doesn't get wet, put it in a ziplock bag, again, rain may not get in, but something inside leaking could ruin something else.