Pump for 120psi?

[I like Skol]

The smaller the pump the less likely it will reach that pressure regardless of what the packaging promises it can reach

Many factors at play in regards to a pumps maximum pressure but you actually have it the wrong way round. A smaller bore pump cyclinder will require less force to pump to a higher pressure (although it shifts less air than a larger bore for an equivalent travel so will require more strokes to shift the volume of air needed).
I have an old Zefal pump for my MTB that has a bore of around 1.5" and this can be used to get to about 65-70psi but after that becomes simply too hard to pump any more (and I am a big strong bloke). The much smaller Topeak Pocket Rocket is still childs play to pump even over 100psi, purely due to the mechanical advantage of using a smaller bore. I did get caught out last summer on a family ride and had to inflate a 650b 2.2" MTB tyre with the tiny Topeak. It did a sterling job and as the required pressure was only 40psi it didn't even take very long.

anything smaller will take a lot more strokes and effort and the small one I doubt will get to 100.

All wrong! A smaller pump (narrower) will achieve higher pressures with less effort (force). Using a big pump to get to high pressure is like trying to drive your car up a steep hill in 5th gear.

 

[Blue Hills]

I don't get why you want to ditch the CO2 - the CO2 is the surefire way to get to 120 psi.

Passed this way again - gotta say i can't understand why anyone ever uses those things unless you are racing and it's an every second counts thing. I'd no more pack those than a hand grenade.

 

[Blue Hills]

Many factors at play in regards to a pumps maximum pressure but you actually have it the wrong way round. A smaller bore pump cyclinder will require less force to pump to a higher pressure (although it shifts less air than a larger bore for an equivalent travel so will require more strokes to shift the volume of air needed).
I have an old Zefal pump for my MTB that has a bore of around 1.5" and this can be used to get to about 65-70psi but after that becomes simply too hard to pump any more (and I am a big strong bloke). The much smaller Topeak Pocket Rocket is still childs play to pump even over 100psi, purely due to the mechanical advantage of using a smaller bore. I did get caught out last summer on a family ride and had to inflate a 650b 2.2" MTB tyre with the tiny Topeak. It did a sterling job and as the required pressure was only 40psi it didn't even take very long.

All wrong! A smaller pump (narrower) will achieve higher pressures with less effort (force). Using a big pump to get to high pressure is like trying to drive your car up a steep hill in 5th gear.

This is all true i think even to my non scientific mind, it's the reason the topeak mountain morph is fatter than the road morph. I'd still recommend the road morph over your small pump because of the footstand/flexible hose. Have sometimes considered your pump as a backup/for round town use.

 

[Blue Hills]

Also this
http://www.wiggle.co.uk/lezyne-micro-floor-drive-hp-abs-pump-with-gauge

Have seen in a shop. Was kind of impressed with it but seem to remember that the hose made it more of a fiddle to pack than my road morph. Can you get rebuild kits for it? I wouldn't pay any more than a minimal amount for a pump you can't rebuild.

 

[jefmcg]

Have seen in a shop. Was kind of impressed with it but seem to remember that the hose made it more of a fiddle to pack than my road morph. Can you get rebuild kits for it? I wouldn't pay any more than a minimal amount for a pump you can't rebuild.

Do they not have google where you are?

http://www.lezyne.com/product-hpumps-acc-hpsealkit.php#.WKbHA-DLfqA

It's a good pump. Used to be my only one, and kept my tyres above 100 psi.

I strap it to the bottle cage, and really don't notice it's there.

 

[Blue Hills]

It was only a simple question to someone who appears to have one/is a fan of it.

Most questions you never have to ask of anyone if it comes to that.

But I kind of see this as a forum/community - off to google "politeness".

PS - your link is a to a US site - rather more interested in if stuff is readily available.

 

[jefmcg]

off to google "politeness".

Please let me know if it says it's ok to be rude to someone who goes to some trouble to answer your question, but just doesn't use exactly the form of words you approve of.

I've never had a pump fail on me, so didn't even know what a rebuild kit was until I googled it myself.

FWIW, I bought the pump in 2010, was my only one for 4 or 5 years. Accompanied me on thousands of km of riding. Still going strong now. Couldn't guess how often it's been used, though.

Edit: still with the google https://www.sjscycles.co.uk/pumps/alloy-drive-lezyne-seal-kit/

 

[Blue Hills]

now now it was the somewhat sneering sounding suggestion that I may be too dumb to use google.

So my response was I feel measured.

On the topic, availability of rebuild kits is important if you want to buy a quality pump and presumably want to carry on using it.

I know this to my cost and discovered that expensive doesn't always mean best.

I have had several pumps which eventually developed issues - not usually a problem if it is well made and supported - often it only needs unscrewing and a bit of grease applied to a an internal seal.

Or maybe a new seal or washer inserted.

I paid well over £60 years ago for a nice all metal Specialized track pump.

Great pump. A minor issue was solved with the aforementioned grease application.

Then I had a more serious issue and on entering Specilaized's concept store* in Kingston had some git pretty much laugh at me for expecting spares to be available for something more than a couple of years old.

An email to Specialized in the states went unanswered. (found via google of course)

So now that pump is expensive shiny wreckage and in future I'd buy a Joe Blow - fraction of the price and rebuild kits are very easily available in the UK.

Thanks for the SJS link - so thanks to conversation you now know what a rebuild kit is and can use your favourite pump happy in the knowledge that it will keep running. Far better than the hassle and expense of buying a new pump. And reassurance that you have got a decent item from a decent company.

I may well consider it, it did look very nice, though I do wonder if the amount of flexible hose they use may be a bit of overkill/make it a bit delicate for stuffing it in a tour pannier.


* concept may very well be - stuff you, you stupid brand whore