UST Valves

i have Maxxis UST tyres on Mavic UST rims which work brilliantly.

last night i changed my rear tyre from an Ignitor to a Medusa. The process was pretty straight forward but when i went to inflate the tyre it appeared that the valve was blocked. I am assuming this was due to the milk solution i have in the tyres sealing the valve.

i also have the same problem on the front when i want to increase the pressure slightly…..it is blocked solid with hardened milk!!

Is this normal? Do you normally replace a valve when changing a tyre?

Not had that problem in three years use. What "milk" do you use?

Tom

Valves can get clogged up with latex. Easy to remove the core an pick off the dried latex. Shouldn’t need to replace the valve

You can often pick out the bits of latex from the valve core, but eventually you’ll have to get new cores. They are only about £1 each though.

i use Stans.

When i take the valve out and pull the rubber bit from the central core it frees it up. When i put it back in the rim and tighten the screw to hold it in place it seems to lock up again.

These are the valves i am using

http://www.chainreactioncycles.com/Models.aspx?ModelID=18721

http://www.justridingalong.com/?product=63

i took the valve core out but this didnt seem to be blocked. Would it be further up the valve?

Silly question – am i sealing the bit of the vale where the air escapes inside the rim, when i tighten up the valve via the circular nut on the outside that holds the main part in place?

If you have taken out the core you should be able to see right through the valve housing, if not it is blocked. I have poked these out with a drill bit or similar.

when you take the core out you cant see through the whole valve.

Check out the link below and you will see the circular cap that sits on the inside of the rim on the foam bit that is blocking the view through.

http://www.chainreactioncycles.com/Models.aspx?ModelID=18721

Replace them with these http://www.justridingalong.com/shop.php?pid=481&product=168
Then you can just change the cores when they get clogged.
They should last years though.

I have used the Stans valves (from JRA) and had the same experience as DezB. Can’t really comment on the Joes valves.

i bought the new valve cores and went out to install them.

when i unscrewed the existing valve core i expected all the air in the tyre to come out. Nothing happened!!

can anyone explain the above?

bump