Bicycle Software

Misc. Downloads

Bicycle Inner Tube Warning

Watch out for crappy bicycle inner tubes: Some manufacturers are not making presta valve housings correctly. They have stopped removing the threads from the outside of the valve housing at the position where the pump seals around it.

	I had to walk home because of the presta valve on this bicycle inner tube. I had a puncture and decided to use my spare inner tube, rather than repair the hole, because it was cold, wet, and I was in a hurry. The tube manufacturer has not removed the thread where my pump seals! The end of the threads are quite sharp, and cut into the rubber seal of my bicycle pump. The short valve housing exasperates matters by making it difficult to avoid wiggling the pump around whilst pumping. Consequently this bicycle inner tube's valve housing efficiently removed the centre of my pumps rubber seal. Although I also had some patches, I no longer had a pump that worked.
	The presta valve on this bicycle inner tube isn't quite as bad as the one above. It will still damage a pump seal, but not nearly so fast. Partly this is due to the longer stem, but mainly it is because the end of the threads are not so sharp. The valve housing is made of brass, which is softer and easier to machine than the stainless one above.
	This is a good quality presta valve housing. Note the smooth area on the shaft where the threads have been removed. No problems pumping up a tyre with this bicycle inner tube;¬)

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