spring collars - safe enough?

see this



what do you think about it? im not doing overhead extensions. they will serve me only for heavy incline db presses and curls

go through the motion of getting them into position, IMO the bar will always go near vertical - when it does this the weight of all the plates will be pushing the spring collar down, if your lucky enough and quick enough that it doesnt pop off having the weights fly everywhere the plates will still almost certainly come a bit loose which just isnt a nice confidence inspiring feeling IMO.
 
you could drill the end of the bars and pop an M10 bolt through and tightn on a wingnut - this would just act as a safety catch to save weight plates landing on your face! 

stick a single wrap of duct tape on them (spring collars won't slip)

Been using mine for years and never had a problem.

lost -> could you explain?
 
thank you

not really sure how to explain it but for the collar to slip the bar and collar have to be properly lined up (if you try to remove a collar at an slightly awkward angle they almost catch on the bar). the duct tape seems to encourage the collar to catch on the bar it also makes the bar a fraction fatter so the collar is tighter. i have been using this idea with a homemade thick handle DB made from scaffolding which spring collars wont grip on but with duct tape i have had no problems

safe

lost - so youre basically wrapping a dumbbell handle in duct tape and putting collar on it, yeah? so tha bar is thicker
 
 

yes its a little bit fatter with greater friction, you literally only need a single wrap otherwise its a nightmare getting the collars off