A recent post on inner tubes "Latex v Butyl" has created interest in another of those topics which can stir passionate debate, whether to use talcum powder on inner tubes. So I shall offer my views on the subject and you can make your own decision.
I shall state from the outset that I do not usually use powder when installing tubes. That being said I have customers that do and I have a canister of 'Johnson's' in the cupboard so, if requested, I can powder up a tube to keep everyone happy.
Firstly, what are the reasons behind some people’s choice of using powder? Well, powder can make the tube easier to glide around against the tire when you are trying to wedge everything together. I know many people have trouble when trying to poke a tube into the tire and pinching the tube under the bead of the tire is a common problem for some. Also, when removing a tube from a tire, it is easier when dealing with a tube that was powdered. I have also heard the argument that when a tube is powdered there is less friction between tube and tire and less likelihood of failure from abrasion. Finally people see that there is often some trace amounts of powder when you get a new tube out of the box so therefore powder must be good.
Okay, I think that covers most of the arguments that commonly get mentioned for the use of powder, now for my rebuttal.
Starting from the bottom of the list, the reason manufacturers use powder is actually during the manufacturing process itself, it is not as some suggest them pre-powdering the tube for you. When the tubes are made the rubber becomes very hot, even by the time the process is over there is still considerable heat left. The powder is actually used on the inside of the tube so that when the tube is folded flat and pressed into the packaging the two sides of the tube will not bond together. Next time you have an old tube at hand cut through it and you will see a fine white powder coating the inside.
Friction. I have never quite got my mind around this one. If anything you are creating a scenario to create more friction by using powder. When a tube is correctly inflated inside of a tire there really is no room for any movement between touching surfaces. Also we have all seen how a tube bonds slightly to the tire, if there was a need for any movement it would be very slight and the tube would be much better flexing instead of sliding against the surface as the powder argument suggests. And before the cries of tubes completely bonded to tires rises to crescendo, this never happens to the extent of tossing a tire away because of a tube that cannot be removed. I have replaced more tubes in my life than I have eaten hot dinners and never have I had a tube that refused to “Part Company” with anything more than a sharp tug. In fact that slight bonding helps out in another way too. When a puncture does occur, due to an errant thorn or some such, having the tube attached to the tire means that the air only comes out through the hole at that spot around the thorn, if you powder the tube and there is no bonding the air will escape from the tube into the cavity and be gone much quicker.
Lastly, the installation. Here at least I do see a benefit for those who struggle with tube replacements. However, if you follow a set of rules such as, inflating the tube enough to give it body, make sure to get it seated up into the tire before popping the final bead on and never sticking tire irons in there, you should be fine. Most issues come when popping the last 6 inches of bead on and no amount of talc is going to help you there.