krecik

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krecik

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fietsbob

The other end is screwed into the pump..

Back in the 80s WTB changed the handle on a Zefal soliblock pumps
so rather than fit between 2 clips on the outside of the frame.

the pump fit inside the oversized seat post tube, so It would not fall off on single track rides

Plunger is a tube, so the hose fit inside..

(only check valve is in the valve stem so pump has to overcome the valve core spring , on schrader valve stems )






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CliffordK

Did you buy the pump & hose new or used?

You're right, it should have a pin in there somewhere.

The hoses may be pretty universal, hopefully.

I have a floor pump with a bad pin, and one can overcome the valves with a significant amount of pressure, but it has to have a secondary valve in the pump, and I don't think I'd want to do that with a frame pump.

EDIT:
@fietsbob is probably correct, no valve in the pump. It sounds like a poor design. You might want to "burp" the tire before trying to inflate like one does with presta valves.

krecik

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krecik

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fietsbob

Advantage: Presta valves, only the air pressure differential closes the check valve in the stem .
so you don't have the valve core spring to work against, with every pump stroke.

If, there were there a pin holding the S/V open, it would not retain any air pressure increase,
but push back on the handle.

in a Floor pump there is a check valve in the base,
when you take the pump head off the valve stem , only what's in the hose vents off..

drlogik 

The pump head is missing the valve in the head that depressed the valve stem on the tube. I used to have an old Zefal pump back in the early 1980's with a hose like that.

fietsbob

convert to P/V tubes .. you can screw onto the adapter ..

I have a Campag Steel pump head with the same thread as the hose to pump thread ..

Rather rare , it seems ..

There is .. Woods Dunlop valves

inside latex rubber hose is the check valve ..

krecik

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Crankycrank

That might be a hose made for inflating balls, toys, etc. where you insert a needle into the end. I've seen small pumps with hoses like that made solely for needles.

_ForceD_

I prefer those frame pumps with a hose. In fact...I’ve made a couple of them myself and keep one with me on the bike. There have been a few times without a hose that I’ve broken the preseta valve tube off trying to hold the pump head onto it. The hose I made has a preseta adapter on one end with the Schrader screwed onto the hose (and glued/clamped securely). The other end of the hose has an old preseta valve screwed into it. When I need to inflate, I screw the Schrader adapter end onto the valve, and then put the pump onto the hose’s presta valve on the other end. This prevents me from inadvertently torquing and breaking the valve tube. (I’d post a pic of it but I’m traveling right now and don’t have one with me.

Dan

krecik

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krecik

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fietsbob

'Burping' is when your tubeless tire wheel loses all of the air in it at once .. in , say , a sharp corner ..

Presta valve stems have a locknut , you break loose the sticking of the valve stem's check valve seat
after loosening that nut, by tapping on the shaft the little nut is attached to ..





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Crankycrank

Excellent point. I forgot that part about the frame pump.

krecik

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krecik

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cambiker71

I remember these well, there should be a small bit of plastic in the shape of an X that sits inside the shrader end, they used to often fall out rendering it mostly useless really. But the good news is that the flexible ends are readily available very cheaply on the usual selling sites

krecik

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