bluefoxicy

I tried to change my tire, attempted to re-seat the tube first before setting the bead on the tire. The tube was empty (I put a pressure gauge on and hit the release button to empty the tube).

200 pumps later, nothing, the presta pin doesn't even seat from air pressure. The tube is still flat.

WTF?

bluefoxicy

Also the Xerox ad on this page is a flash ad that pops out a video when my mouse drifts over it, which doesn't go away until I figure out where the close button is ... and then if my mouse touches the ad again it pops out. Will somebody please shout loudly at the advertising company to not put flash ads here?

Scooby214

Does your pump have the combo Presta/Schrader head? Mine does, and sometimes if there is no air resistance when pumping, the head won't switch over to the Presta hole. It didn't do this in the beginning, which makes me think the pump head is wearing out or gunked up with dried slime from years ago (I don't use slime anymore). What usually works for me is to start off the tube using my small frame pump to start the tube. I prefer to use it in the beginning anyway, as it puts much less air in the tube per stroke. This makes it easier for me to ensure my tire is properly seated before fully pumping the tire with my regular pump.

EDIT: I should say that once I have a little bit of air in my tube, my regular pump always works properly for filling the tire. I think I may shop for a better pump in the near future, hopefully with a Presta only head. The old Giant pump can still be used for my Schrader valve bikes.

bluefoxicy

I only have a small pump that weighs 114 grams stuck to the side of my bike, and it only has one head and an adapter.

The problem turned out to be the nut on the valve. When I deflated it, the tube shrank and retracted the valve into the bike; but the lock nut prevented that, and so the tube got a huge tear around where the valve connects. Bike mechanic found it and explained to me how to deflate a tube properly...

Anyway, I left the bike with them and told them to true the wheels and make sure the spoke tension's right, and to swap both tires off for me since I'm lazy and at work. I also seem to not be able to seat a folding bead properly; wire bead's easy, I don't need 4 hands.

I wonder if I can flip the front wheel backwards if I want to try reversing the tread... I'm not sure about rolling the bearings backwards or inverting the direction of force put on the spokes when braking. That seems like it might cause fatigue; the bearings are probably a non-issue, but the spokes definitely.

Carbonfiberboy 

Buy a floor pump. You're getting into this bike thing and you should have one. Lots of opinions on these. I've gone through several over the years. My current pump is a Specialized Airtool Comp. It's lasted longer than most. 2nd, put your current pump in your spares box and buy a Road Morph. If you're using one of those pumps that comes with a water bottle bracket, the Morph should fit that bracket. If not, you might be able to get that sort of bracket from your LBS. The biggest problem with bike pumps is that vigorous pumping has a tendency to tear the valves out of tubes, which is probably what happened to yours. Deflating with the nut tight shouldn't tear the valve out. Floor pumps and the Road Morph solve that problem by connecting to the valves with a hose. Except when I use my deep aero wheels, I throw the nut away. You can get the pump on the valve just fine by pushing on the back of the valve with your thumb on the tire.

Some tires are designed to only roll one way. They'll have an arrow somewhere on the tire carcass. If you are using a cyclometer with a front wheel pickup, you'll have to move the magnet. Be sure to reverse the skewer so that the quick release is on the non-drive side. Got to look proper. Not to worry about the spokes. In any case, I don't think there is any advantage to be gained by flipping the wheel or reversing the tire's rotation. I've never felt the need to do so in many 10's of thousands of miles.

As long as I'm yakking, when you mount a tire, put the label over the valve, and on the skewer side. Then when you flat and are looking for what caused it, you'll know the orientation of the tire compared with the tube. Unfortunately, the latest style in tires is to put labels on both sides, total bummer. Idiots.

BCRider

A frame pump is a final resort that you really only want to use out on the road or trail. Invest in a decent but not mega cost floor pump for at home since bike tires need regular inflating. It just makes the job a whole lot easier.

If you want to turn your front around go ahead. The bearings will be fine. They aren't complex devices with one way clutches or anything like that. Similarly the spokes on the front wheel are, or should be, a symetrical pattern. If the spokes are tensioned correctly there won't be any issue there either.

With road tires you won't notice anything though. The "tread" on such tires is so lightly molded in that it's really a non tread that serves little or no purpose. On mountain bikes with directional blocks to dig into the soft loamy dirt this is another story. But it doesn't sound like that's what you're riding.

bluefoxicy

Good point about the magnet. The tire tread is minor, and I only expect the front wheel to matter for braking when I'm rolling my 700c x 32 tires through deep mud. The tread is somewhat insignificant anyway.

cyclezen

proper way to deflat tahr - unscrew head, press head, tahr goes weeeesssssshhhhhh.....

hand pumps can be problematic - can't be yankin them around like you;re twistin the head off a chicken...
best way to use hand pump:
spin wheel so valve is at top, thumb on tire behind valve as you push pumphead onto valve
cradle pump head in left hand (iff'n youz pump righty), bring the left thumb over the top of the tahr - this stabilizes the pump/valve so it don;t be wigglin around and tearin; make sure head and valve are pointin straight towards rim hole - have at it...

don't be wigglin the pump to get it off neither
wheel/valve/pump still at top
hold pump by handle, makin sure its all still properly aligned.
sharp rap with the side of the other hand to the pump right next to wheel/rim, pump pops off, screw valve shut.
discard little valve rim screw thingie - or turn into industrial art
gotta be Youtube on this somehwere...

gyozadude

I think the problem here is neither the nut nor the deflation technique. The issue here was the location of the bead in relationship to the rubber tube around the valve stem. When a presta tube inside deflates, it doesn't retract the valve significantly. Having it nutted there is fine. After all, the rubber stretches.

But if you don't have the bead seated and the tube is pinched between bead and the hard thick base of the valve stem, then when you inflate the tube, the bead may do a number of things like slice through the tube, which may hold pressure because the cut is not exposed and pressure by the bead on the cut keeps it closed until deflation. Or the bead could blow off and the tire explodes partly off the rim in a lot bang and you blow the tube as well.

The way you avoid the problem is to mount the outer tire first PRIOR to securing the valve stem nut. I seat the tire completely, then push the valve into the tire and especially check the seat on the bead around the valve area, as the tube is a bit thicker and stiffer there and makes it harder for the tire to seat properly onto the rim at that point. Pushing up on the valve stem gently lets the bead drop into the sides of the clincher rim. As for the nut, some folks ride fine with it. I like the nut because it holds the valve firm and keeps it centered on the hole with less wobble while pumping and riding, so less chance of abrasion forming small cuts over time on the joint where rubber meets up with the base of valve stem.