Frame bag/storage

New bike incoming shortly and looking for recommendations for some storage solutions for tube, multitool, snacks etc. Existing bike has in frame storage which I’m a big fan of but the new one is more xc oriented, it has two sets of bottle mounts and ideally would like to use one set for a bag that would screw to those but struggling to find anything that fits the bill.

Any ideas of products to look at?

I’ve been using a tool keg in a bottle cage on my gravel bike for a while, but having had it eject twice, the second time despite having a strap on it, I’m in a similar position. (found the keg both times, but the last one I ended up having to retrace the previous 2 hrs riding)

Apidura do a 1.3l roll top bag designed to velcro on to  a cargo cage that fits the bill. The bag and cage together are kinda spendy though…

https://www.apidura.com/shop/expedition-cargo-cage-pack/

Tailfin downtube bag?  i think it just has blanking plates for the mounts though rather than screwing directly in.

Alternatively could you just repurpose a top-tube bag designed to bolt on?

Maybe something like the 76Projects ‘Little Piggy’ mounts and either their specific drybag/case or something of a similar size  https://76projects.com/collections/shop-on-bike-storage

Thanks for all the suggestions, not heard of 76 projects before and would probably have tried them if they’d had the bag in stock. Also found that fidlock make a few options which are a bit more expensive but appear a slightly neater solution so ordered one of them to try

We have a new bag developed with 76 Projects on sale shortly, might fit your bill if you dont like the fidlock.

A tool keg is cheap and easy. I have one and have never had it ejected. The shape of the bottle cage helps. I use a Giant one that has a bit of a ‘lip’ on the opening and this holds the tool keg securely in place.

Something like the Mini Cage from Tailfin is a simple option to bolt to the cage bosses. One of those, a small dry bag and a strap and you’re sorted for tube and tool storage.

It doesn’t attach to bottle mounts, but I have been using the Evoc frame bag like this…

https://www.bike-components.de/en/evoc/Frame-Pack-WP-p90348/?o=1000355020-carbon-grey-1-5-litres&delivery_country=GB#product-image-5

One good thing about it is that the velcro can move to either end… so you can attach to top tube/downtube at front of frame, or top tube and seat tube if that plays better with your bottle position.

As above – Tool kegs are a good idea. I use a soft version that On One were knocking out for about £3 – zips in half so a lot easier to access than the top of a plastic bottle. Can get a (very) mini pump, tube, levers and bacon rashers in. So far it hasn’t ejected (but this is on a xc bike… nothing too jumpy)

76 Project Piggy is ok too… in conjunction with a Topeak Ninja cage.