I think I broke my presta valve on my roadbike tyre - how do I replace it?

Question

I have zero experience with roadbikes. Before I finally discovered how to correctly inflate my tyre I think I broke one of the presta valves. Its kind of bent and I cannot inflate the tyre. I manage to do one correctly. Thats why I believe I broke the other one. How do I replace the valve or repair it?

Answer 1

I believe it is possible to replace a valve - but it is utterly pointless. Just replace the inner tube - it will only cost a few pounds. You will need to remove the tyre.

Answer 2

Broken Presta Valve

Answer 3

Continental used to have presta tubes with replaceable cores, and so did another brand that I can't recall the name of. If you have one of these, the top of the valve (not the barrel nut) should look silver and be threaded into the brass portion that goes into the tube rubber. There are flats on this part and you can unscrew it....you can probably get a free core from a bike shop from a small parts bin or an old tube in the trash can if they have one handy.



If you have one of the 99% other brands of tubes, you'll have to buy a new tube for a few bucks.



Sometimes you can bend the valve tip straight....try it out and see if that helps. It may break off, but if it does you won't be any worse than you were to begin with. :o)

Answer 4

If its a modern bike (in the last 20 years or more), and not really top end quality, then the tyre will have an inner tube. The inner tube comes complete with the valve required and costs a couple of pounds. Get them from various places - bike shop, sports shop or even supermarket or a large chain of car spares shop does bike bits. On the rim of the trye will be some letters saying what size tyre it is (to gett he right inner tube), though a generic one should also fit (they stretch)





To replace the inner tube you need to take the wheel off. Deflate the tyre (with Presta valves unscrew the end and push the tip in), then loosen the brake (some have a little lever by the brake shoes to loosen it enough) and finally undo the 2 nuts or quick release at the hub of the wheel. The wheel should then fall off.



Now you can get some tyre levers, insert one betweeen the tyre and the rim, and then a second and prize the tyre of the rim on one side. This mught be tight to do. Repeat with the other side and take the tyre off. Now the inner tube should be visible, take it out and put the new oneinside the tyre keeping it smooth inside. Inflate it a couple of pumps just to get the shape. Now thread the valve through the hole in the rim, use the tyre levers (you can use the handles of desert spoons if you want) lever the trye back on. Inflate the wheel, put back on the bike (reverse of tasking it off) and away you go





EDIT

Because you have loosened the brake to gwet the tyre off, make sure it is working after you have finished - THIS IS VERY IMPORTANT



Oh, a last thought, if you get your inner tube from a bike shop, they might change it for you for free

Answer 5

The core of a presta valve is not replaceable. You need to buy a new tube. If your not a fan of that type of valve, you may want to convert to a more common schrader valve. A local bike shop will have the tools to drill out the rim to the appropriate size to accommodate the larger valve. I'd recommend sticking with the presta, but schraders are more common and less likely to be damaged while filling your tire with air.

Answer 6

If it's really broken you need to buy a new tube and replace the old one. BUT, if by "broken" you mean the threaded centre pin with the little knurled nut on it is bent, you may be able to simply straighten it with some pliers. For the knurled nut to screw up and down (locking the valve closed when tight) the centre pin has to be fairly straight. It's easy to bend.



To pump up the tire with prest valves you should back off the knurled nut several turns and press the pin down to free up the valve. Then attach the pump head and clamp it in place. If a floor pump, you are ready to go ... pump until the desired pressure is reached and release the lock and, while holding onto the valve stem to prevent it bending too far over (which can break off the valve at the tube) as gently as possible "work" the pump head off the valve. Screw the knurled nut down and put on the plastic cap.



If using a frame pump you need to take a bit more care pumping. Put your left hand (if right handed) on the pump head ned and wrap your index finger around the valve. Pump with your right hand, while holding the pump head and valve so as to prevent the valve being bent relative to the wheel. It's hard to describe, but you don't want to put too much force on the valve or you can break it off the tube. The most frequent place where tubes fail (other than from punctures) is at the valve/tube joint).



Since pump heads seem to really grab onto valves it's also necessary to be careful "working" the pump free from the valve after the tube is pumped up to pressure. You'll learn how it feels, but basically you rock the pump head back and forth while applying force to pull the head off the valve.



Hope that helps.



Hope that helps.

Answer 7

You will need a new tube. The valves are assembled from the inside and the tube moulded around it.

Answer 8

--->> Tips---> https://trimurl.im/g40/i-think-i-broke-my-presta-valve-on-my-roadbike-tyre-how-do-i-replace-it

Answer 9

new inner tube. Get a less-annoying car-valve type (provided the hole in your wheel is big enough).