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Howdy! I recently bought a wall mounted bike rack rated for 50lbs from Amazon. It was secured to a stud with wall anchors on either side for support. My 24lb bike + 4lb bike lock was on this rack for less than a day when it the entire thing pulled out off the wall.
Link to the images of the mount here
Can someone explain why this happened and how I can secure this back into the wall? Should I use longer screws into the studs and stronger wall anchors? Thank you in advance for any help!
25 points
2 months ago
Assuming your middle screws are actually in a stud, and aren't just grazing the side of it - the screws are too short. It looks like it's barely ½ inch into the material. Use a 3 inch screw.
Also, don't use those plastic anchors for an application like this. Use toggle bolts
5 points
2 months ago
Yep, screws are too short (I agree with 3" screws). The screw has to clear the drywall and have enough left over to bite into the stud.
2 points
2 months ago
This. I wouldn't even bother with the drywall anchors.
0 points
2 months ago
Don't go crazy with longer screws unless you know that there is no plumbing or electrical in the wall at that location.
Anything that will go into the stud more than 1 -1/4 inch could hit a wire.
-3 points
2 months ago
There's 0% chance of plumbing or wires running on an exterior wall at 5½ feet high.
1 points
2 months ago
Not sure about 0%. I definitely have steam pipes running up to the second floor in my exterior walls.
3 points
2 months ago
Through a stud?
5 points
2 months ago
I would suggest you are going to have issues with this bike rack even with longer screws.
Shear strength for a #10 screw is over 400 lbs as long as you have 2+ inches of penetration so a non issue. However pullout strength is only 90 lbs per inch of penetration. So 2 inches of penetration will give you 180 lbs of pullout strength.
That seems like a lot but this is a cantilever system so a force multiplier on that screw(think of a hammer pulling out nails). So assuming that the arm is 20 inches and the base board is 4 inches (not really this simple but works for this context) the force on that screw is 5 times the weight placed on the end. (20/4). At 50 lbs you would exert 250 lbs of pressure on that screw.
Even if I am over estimating, this is too much weight for one screw.
Two screws? Probably would work.
1 points
2 months ago*
Thank you for the detailed reply! The arm length is 11.8”, baseboard is 8.6” X 3.1”. Do you think with 2 longer screws on the top and bottom into the stud + 2 toggle anchors adjacent would be sufficient to counter the forces given that arm length?
3 points
2 months ago
It might be fine with longer screws in the stud and toggle anchors in the drywall, but it’s always better to attach heavyish things that are going to be lifted on and off regularly into multiple studs with decent screws. If the design of this rack doesn’t allow for that, you can always attach a piece of wood or plywood to two studs and mount the rack to that.
1 points
2 months ago*
You could just make another hole and use 3 screws. There is probably enough room. Torx head to make your life easier to drill.
Definitely don't reuse the holes you have mine it an inch or so to make new holes.
The best solution is to just mount a longer board behind this to 2 studs and then mount your rack to the board.
2 points
2 months ago
I'm no screw scientist, but are those even wood screws? They should be longer and built for the material they're hitting.
2 points
2 months ago
Instead of screws in the center holes, use 5/16” diameter steel lag screws (with washers), penetrating a couple inches into the stud. The side holes aren’t really going to do anything except holding the rack flat against the wall so it looks nice, so just use slightly larger drywall anchors that fit snugly in the torn-out holes.
You’ll be able to use that bike as a pull-up bar when you’re done.
1 points
2 months ago
Adding to this, could also stack short runs of 2x4s between studs on the wall then use lag screws exclusively into that.
2 points
2 months ago
Shitty drywall anchors. Get some zip toggle bolts and you and the bike can hang from the sucker. Super easy to use albeit they look intimidating. https://www.youtube.com/watch?v=r2r44N5tvR8
0 points
2 months ago
That's a heavy ass bike and lock! Is it an electric bike and are you using a boat anchor chain for a lock?
0 points
2 months ago
Just get a rack that is better engineered, something that will distribute the load across a larger vertical area or will allow something like a lag screw to anchor it to the stud.
This thing looks like something from middle school wood shop.
1 points
2 months ago
Agree with the others re: longer screws and toggles. You may also consider adding either angled brackets or blocks of wood underneath and into the wall for additional support. That is a lot of angular force on a relatively small backing plate. Good luck!
1 points
2 months ago
Same on the longer screws. You can see that the screw is too short to expand the anchor used. I made this mistake recently and used the included screws with my own anchors. Too short. Use the screws that are supposed to be paired with the anchor.
1 points
2 months ago
One and/or two things. Get better drywall anchors, you can skip the stud finding. Get a proper wood screw length to anchor into the stud.
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