Decathlon describes its 100 bike saddle bag as being designed to carry the minimum amount of accessories to perform bike repairs and some small personal items. I’ll be honest, I’m not totally convinced. I am able to just about squeeze in an inner tube and tyre levers, but that’s about it. I am also able to just about fit my wallet, phone and keys in there. But not at the same time. It is either repair items or personal items, not both.

I guess that is ok really, it depends what you want out of your saddle bag. See, I’m the kind of rider that doesn’t want to carry a lot on my person. My keep the contents of my jersey pockets to a minimum, usually a few gels and some arm warmers if applicable. Everything else goes into my saddle bag. For me, the Decathlon saddle bag isn’t a good fit. I am better suited to one of the larger items such as the 500 saddle bag.
But if you are the other kind of rider, the kind that keeps a banana, spare water bottle, gels, pump, another banana, thermos of coffee, camp bed and portaloo in their jersey (you know who you are), then this is a good overflow solution. Of course, this saddle bag would also be a good fit for commuters. Chuck your repair kit in there, leave it on your bike and forget about it until the day you come to need it.

You’ll be safe to do that too. This saddle bag is made extremely well. It attaches with the standard around the seat post and under saddle velcro straps and because of its small size, it sits there quite snugly. With its strong zip and canvas nylon material with rubber strengthening and decoration, it will probably last a good long time.
Do buy it if you want somewhere to keep a minimal puncture repair kit and spare inner tube. Don’t buy it if you want it to carry any more than that.