Discussion in 'General' started by RTT, 8 May 2008.
I know i have one of those somewhere but where..god knows
Yeah I use those on my 700c. They work great.
Just found one but its leaking air where it goes into the track pump.
Stupid question, but you have closed the nipple of the presta valve after pumping it up?
Yeh it's leaking while I pump it up.
I'm used to the valve type as that's what we had growing up mostly. Take off the dust cap, unscrew the valve nipple a little, give a quick press to make sure it's not stuck then attach pump, blow it up and tighten everything back up.
Cool. Sorry for asking a daft question, I though you would know what you're doing. We used to get a lot of people come into the bike shop i ran who just generally had no clue, so it was something I always checked first.
Leaking while being pumped up can sometimes just be a poor seal between the pump and the valve. The only way to really check the valve properly is to get the tube out, put some air in the tyre and give the valve a wiggle round 360 degrees to potentially open up a split. If there is no split it's the pump connection.
When installing the tube, never tighten the small nut that holds the valve at the rim as it restricts the movement and causes the valve / tube joint to split.
Oddly it's leaking between the adaptor and the track pump but it doesn't do this on my bike which has the Schrader type.
Inside the head of the pump us just a block of rubber with a hole in it, its sometimes not the best at sealing. As @Vault-Tec said, an adaptor is the next thing. When looking, if you can get one with a rubber o-ring around the presta end (like this) it will give a better seal than ones without. There is no guarentee you will get one with the o-ring, the number of times I ordered them and got them without was more often the case.
I've never done it, but you could always PTFE tape (if you have any) the thread of the valve just a little to try and get a better seal.
The adapter should be a schrader thread the same as a schrader valve.
Make sure the O-ring is in there. It'll just pee air otherwise. Also make sure you have locked your pump to it correctly, as some start closed and you open the lever to lock, and some start with it open and you close it to lock. It needs to be locked to the schrader. Practice that before you fit it to the presta.
I put the adapter into my track pump on it's own and opened the lever to seal it, put my finger over the end and pumped and not a single bit of air leaked out, it's really annoying.
A lot of 2021 bikes have been leaked which means I might finally be able to get one soon https://on-off.hr/kategorija-proizvoda/modeli-2021/
Check the Australian Giant website for 2021 bikes, they usually hit that site first. I don’t know if there is anything there though.
The boss was in my shop on sat sitting with the manager doing the 2021 Cube order.
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