I switched my saddle yesterday, and reinstalled my saddle bag. It is mbag that clips to the saddle using a doc attached to the saddle rails, with two screws. I have had it for a while, and actually do like it. When I picked up the bag from the road, one screw was missing, on the doc. I.m not sure if it came lose or broke are such saddle bags unsafe, since there is a single point of failure ? Should I get something else ? What do you recommend ?

I choose this design, bc it is easier to detach and attach, since I travel with my back using a bike rack, for my rides, and I remove all accessories from the bike during transit. Below is the saddle bag link, which broke yesterday.

https://www.trekbikes.com/us/en_US/e...pack/p/552240/

A photo of the actual bag that fell off would be useful.

I don't see anything broken in that picture, just one screw missing and one unscrewed. I'd call that user error, didn't screw the mount on tight enough. Alternatively, you might want to use some Loc-Tite on the screws.

loc tite ? I could google, but could you provide a link, just so I’m looking at same thing ?

you don’t think the screw itself could have broke ?

I have used a Presto seat bag for 15+ years without any issues, however it has a more thought out clamp arrangement than the Trek bag. Instead of simply threading into the backing plate, the backing plate, which is fiber reinforced plastic, has nylock nuts inserted in it. These typically do not loosen.
The way Trek does it is flawed in that there is no safeguard to prevent the bolt from backing out of the backing plate, whereas the Presto bag does. Just add a dab of blue Lock-tite to the threads of the bolts and all will be well.

any draw backs to Velcro ones that come over each side of rails and also seat post ?

No draw backs for me. Unless you mean how I have to double the strap back through the saddle rails because it's too long. I suppose the only drawback will be that you have to get used to doing something else. And certainly the Velcro straps probably take a little more time to swap the bag between bikes than just having a clip to fasten into on each bike.

No.

Looks like the screw backed out and is lost. Go to a hardware store and get a new screw. May be was not tight enough. Loctite or any medium strength removeable threadlocker will help.

https://www.google.com/search?q=medi...hrome&ie=UTF-8

https://www.amazon.com/Loctite-Heavy...435179578&th=1

Yeah, after a while the velcro gives out, and either your saddle bag falls off, or it almost falls off. One time I was riding, and felt something hitting the back of my thighs as I pedaled. Turns out the velcro straps that go over the rails had come undone and it was just hanging by the loop around the seatpost, so it was swinging side to side with each pedal stroke.

I still use that saddlebag, but I cinch it up to the bottom of the saddle with an old toe strap.

Not unless you found part of a screw someplace. It's a lot easier for a screw to back out when subjected to vibrations for a while than for a screw as big as that to break. (I'm assuming it was the same size as the one that's still there.

If it had broken, I would expect to see the threaded part still retained by the bracket. Instead, it's entirely missing, which makes a loose fastener more likely.

Possible, as in Schrodinger's cat may have slept here. Unlikely. First, no corrosion (rust) is visible, so it wasn't weakened. Second, you mentioned the bag had been mounted on another bike; if it were a case of infant mortality (i.e. the bolt was flawed at manufacture) I'd expect it would have broken previously. Occam's Razor-inspired conclusion is that the bolt unscrewed, probably due to vibrations while riding. That's why I suspect it wasn't screwed in tight enough; that's what torque values on bolts prevent if applied during assembly. And a thread-locker might hold a bolt on that wasn't screwed in tight enough, but it's best to torque the bolt during assembly.

A no from me too. I think it came loose and just fell out.

Agree with everyone above screw did not break, it came loose and fell out. Nothing wrong with the attachment system just needs some help. As suggested above Loctite on the threads of the screws will do the job. Link below this blue version is removable.

https://www.homedepot.com/pep/Loctit...728/100371826?


Since one screw is missing and will need to be replaced, when you go to the hardware store you might want to pick up a couple of these Nylon lock nuts as TiHabanero mentioned above. Link below is just a sample, you will need to get one that matches the threads on your screws. It looks like there is enough length on existing screw(s) they could just be added, but if not you could get the screws a 1/4" longer. Either Loctite or nylon lock nut should do the job, use both and you will have a redundant back-up.
https://www.homedepot.com/p/Everbilt...274148#overlay

what kind of person are you? You reference Schrodinger & Occam (both of whom Ive never heard of before)!

Sorry, my previous post was meant for /\

this loctite, there is two versions on Amazon, permanent one and non permanent one, which would you recommend?

Hence my suggestion of a photo.

Blue loctite should be sufficient. It (or equivalent) is what is used on V-brake mounting bolts to prevent them from loosening due to road vibrations.

one thing I will say, the clamps don’t sit flush with the seat rails with them even being at center .

Primary drawbacks are the strap rubbing the finish off the seat post, and possibly wearing holes in the legs of your bike shorts, depending on your personal physiology.

[QUOTE=Awesomeguy;23484973]It is mbag that clips to the saddle using a doc attached to the saddle rails/QUOTE]

Doer future reference, doc is typically short for doctor. A dock is where things connect to each other.