Niche! Hard mounting(?) a frame bag … possible to retrospectively do?

I have a, new to me, frame that is peppered with mounting options/bosses.

I’ve used traditional velcro/strapped frame bags over the years and have nothing against them 🙂 but … a hard mounted (possible wrong phrase) would make for a neater installation (and use some of the many bosses).

Have any of you tried a bag like this or modified a bag to do away with the straps?

If so what did you add to stiffen the bag/support the mounts?

I haven’t done it yet, but my plan to convert my top tube bag is to use the flat cover part of wide electrical trunking. If I were doing a frame bag you could put bends where you need them with a heat gun.

Do you have a frame bag that fits the new bike? If you do it’s very quick and simple to mark up the points where the bosses are, then use a soldering iron to melt the appropriate holes.

Get a thin chopping board or similar plastic that you can put on the inside of the bag and put matching holes in that too. Or use some large washers, if the bag is a good fit it probably won’t need much stiffening.

If you want a slightly neater internal space, use disc rotor bolts instead of regular M4 ones as they have a more flush head so won’t wear holes in whatever’s in the bag.

Hope this helps, it’s what I did with my Alpkit frame bag and Genesis longitude a few years ago, and it’s still going strong.

@steezysix – As a fellow Longitude owner … do you have a photo of yours with its bag?

@letmetalktomark – not a super close up one, this is probably the best:

Basically I’ve used every braze on inside the main triangle bar the one nearest the toptube/headtube junction as it’s hard to access.

Still need a few straps, 2 on the seatube and two on the downtube. Ignore the black voile strap on the toptube, it doesn’t live there usually!

The biggest benefit is not having any on the topube where my shorts can catch on the velcro and pull it open. Plus it looks a bit cleaner.

Are you thinking about using a bag with no holes on to currently fixed bosses? Surely this doesn’t need a question? Just bang the holes in it and use something stiff as a base. Maybe some bigger washers or some home made ones.

If you don’t have the bosses use rivnuts then as above.