Floor Pump Chuck

[Little Jim]

I've got an ancient SKS Rennkompressor track pump that still works really well - it must be at least 15 years old but the chuck, or head is not that great and never really has been.  It does improve when I put a new rubber washer in but give it a few months and it starts popping off the tyre again at about 70psi.  I manage by holding the head on and pumping one handed, but it isn't that easy and since Mrs LJ has discovered bikes in the last couple of years the option is either that I have to remember to check her tyres before I go out or suffer the consequences later.  So I've been thinking about getting a new chuck/head for the pump rather than buy a new one as I'm loath to throw away a perfectly good pump.  I've seen the KCNC head which appears to be a copy of the Hirame one.  Is it any good? (the KCNC one) I'm not buying the Hirame one or, come to that the Silca one as for that sort of money I'll put up with the ear ache!  Or are there any other alternatives which will stand the test of time?  The pump does see a fair bit of use as we do have a bit of a N+1 problem in our house.

[Gattopardo]

The one on my charger broke and have been looking at either
https://www.evanscycles.com/topeak-super-chuck-EV162335

https://www.evanscycles.com/specialized-replacement-switch-hitter-ii-floor-pump-head-EV164603

[Brucey]

all push-on (non lever) presta chucks will wear fairly quickly; 'tis the nature of the beast.  However they will wear much more quickly if the chuck is removed whilst the hose still has tyre pressure in it.  Some chucks have a pressure release valve in the side of them so that you can minimise the wear, but others (like the silca) you need to wiggle a little so that the air comes out of the hose before the chuck is removed.

Both the small brass SKS presta chuck and the similarly-sized Silca chuck (with a pointless Schrader thread in the bottom) are pretty crap; the seals just are not flexible enough to slip over a presta valve without tearing and then seal properly.

 However the large push-on silca chuck is a nice design; the seal gets tighter with more pressure behind it, and a certain amount of seal wear can be accommodated by tightening the collar. There is also a version that has a Schrader thread on the back (and a threaded Schrader fitting on the hose) so that the pump is versatile whilst still being primarily a presta pump.  But even so, a good lever action chuck ought to work better for longer.

At one time the SKS rennkompressor came with a lever action Schrader chuck (standard automotive type) and a screw-on presta adaptor. You can still buy these parts, and unlike many other screw-on presta adaptors, the SKS one seals nicely, has a replaceable seal, and the seal doesn't wear that quickly either. With some presta valves (of exactly the right length) the lever Schrader chuck opens the valve as it is attached to the adaptor, which allows the gauge to read the correct pressure before any pumping (which usually doesn't happen with a presta pump). On the other hand there may be some air loss during disconnection.

I guess the topeak twinhead (presta/Schrader) lever chuck deserves a mention; this is (for a mostly plastic design) pretty good, and you can buy spare seals, top caps etc.

There are very many other chuck designs which (IME) are just waiting to screw up and stop working; in this list I would include-

- any pump where you are meant to push either a presta or Schrader valve into the same hole, and

- most of those where there are two holes (one for presta and one for Schrader) side by side, with some kind of auto-switching valve between the two. The auto valve working properly is very much a temporary state of affairs IME.

There is a whole separate discussion to be had regarding woods valve adaptors...

cheers

[robgul]

Decathlon does a dual valve (separate holes either side) which twists to lock on the valve - I replaced the useless chuck on on my expensive Park Tools pump with one - excellent.

Rob

[P Walsh]

Topeak do double sided ones and I imagine they are standard to other brands. Good quality too. I've seen them available from various sites.

[Biggsy]

Fit and forget a Topeak Smarthead kit.

[tiermat]

The newer SKS heads are only a fiver at bike 24. I have one on the (cheaper model) SKS floor pump I bought a couple of years ago, as good as, if not better than, the head on the Joe Blow that I have.

[clarion]

Fit and forget a Topeak Smarthead kit.

This is what we did.  Worth the effort.

[drossall]

I did too. Not sure what make my old pump is, but only the head was an issue; it wouldn't stay on the valve long enough to inflate a tyre. The Topeak kit comes with various adaptors; in my case none fitted, except that there's also an in-line adaptor, so you cut both hoses and join them with that (and jubilee clips). Works great, and I've got a super-long hose as a result, which is sometimes handy.

[andrewc]

I've got a Silca with the big push on brass head.  It's given good service but now leaks as much as it pumps into the tyre.   


What's the recommended replacement for this ?    I'm quite pleased with the chuck on my Lezyne mini pump, which screws onto prestas & has an air release button.  Can I use something from them ? 


How do you replace these ?  I think the head & hose are ust crimped on.

[Samuel D]

I've got a Silca with the big push on brass head.  It's given good service but now leaks as much as it pumps into the tyre.   


What's the recommended replacement for this ?

https://www.sjscycles.co.uk/pumps/silca-rubber-track-pump-adapter-head-washer-241/

[Brucey]

yup, new washer required.

BTW with the large silca head, temporary relief is often obtained by screwing the end cap on the head a bit harder than normal. It may make things OK until a new seal turns up anyway...

cheers

[andrewc]

Ah! Thanks, didn't realise that bit came apart.  New rubber thingy ordered.