One key difference, that you can see in the photo, is that the BV uses buckles instead of Velcro on the straps that attach the bag to the underside of the saddle, something much more important than it may seem. A pair of bike shorts (or any shorts) will shred quickly if they’re rubbing against that tiny bit of Velcro protruding from the side of the bag, and it’s sure to destroy expensive sweaters and gym clothes if you stuff the bag into your backpack or messenger bag.
On the other hand, an on-bike repair kit will be a much smarter selection of tools that you are most likely to need. You should figure out the type of screws that are fitted on your bike and the things that are most likely to go wrong on a ride. Address only these things so as not to burden yourself too much with unnecessary stuff. Moreover, there are bike repair kits used on long rides and those used on shorter rides. The longer the ride, the more tools, and spare parts you will have to bring unless you want to have a very long hike back home.
Packed with basic tools, this compact tin rescues puncture-interrupted bike trips. Pedaling away to a picnic spot with a pal, you hear a disconcerting "pop!". Your two-wheeler is now down one wheel, and unless you've got mad unicycle skills, you need tools. Good thing you brought this handsome, compact tin. Just break out the metal tire levers and patch kit, and you're rolling along again in no time. The six-sided, dog bone-style hex wrench adjusts the most common bike screws and bolts and screws. Made in China.
A plastic garbage bag, or $2 disposable poncho: Just in case of an unexpected downpour or getting caught out after dark. More than once, I’ve gone for a ride on a beautiful day with a perfect forecast, not taken a jacket and had the weather go south on me. Being able to cover up can mean the difference between just mild discomfort or a freezing cold, shivering ride home!
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.