Mini Pump - Bent Valve

irishmotorist

I've noticed all along that when I get a puncture on the road and have to use my mini pump, the valve cap (i.e. the bit that screws up on the valve) nearly always gets bent. I'm conscious of it happening so I do my damndest to keep the thing straight, but it still bends! This hasn't bothered me too much, but I got some cheap Conti tubes a while back and this has fatigued the metal pin to the point of it breaking off when I try to straighten it up at home.

Does this bending happen everybody or do I have a crap roadside pumping technique or something?

Murph100

Nope, its happened to me the odd time. Mini pumps are a complete balls, murder to get decent pressure and so easy to break the valve top !

Leyzene have at least the solution for the valve, using the yonks old rubber connector tube. Top Peak have brought out one too I think.

http://www.wiggle.co.uk/lezyne-alloy-drive-mini-pump-hose-small/

irishmotorist

I was thinking that something like that would be a great idea and would probably eliminate the problem. It's a bit steep, but it might be worthwhile.

ednwireland

i have alezyne road drive brilliant pump in medium

http://www.lezyne.com/road-drive

just dont use vittoria inner tubes (brass stems with steel valves means you end up unscrewing the valves instead of the tube as it heats up)

I use a Topeak masterblaster, and a presta adaptor. Never bent any valves. But it's a minor bit of extra hassle.

Murph100

I've always been meaning to buy one of those old pump connectors to see if it would work with the regular/modern mini pumps. They're only a few quid, so must give it a go before lashing out on a Leyzene.

superlav

I have one of these and find it great

http://www.wiggle.co.uk/topeak-mini-morph-pump/

The blurb says you can pump to 160 psi, not sure why you'd want to. I find you can get 100 psi quite easliy and no more damage valves. Also it's so much easier with the pump braced against the ground.

sean_d

If you're right-handed, hold the head of the pump in your left hand and wrap your index finger around the spoke adjacent to the valve. Steady the pump and there's no more bent valves.

templer27

I've got a blackburn something or other its completely crap.So I carry a co2 mini pump as well,not yet had a puncture since.Tested it out (co2 pump) by deflating tyre and reinflating it.Seems the business,but I still carry my mini pump just to start in case I puncture the inner tube putting it on.:D

irishmotorist

sean_d wrote: »

If you're right-handed, hold the head of the pump in your left hand and wrap your index finger around the spoke adjacent to the valve. Steady the pump and there's no more bent valves.

Bring right handed, I usually have the heel of my hand on the outside of the tyre and hold the pump tight against the valve. I'll try including the spoke too and hope not to cut my finger to ribbons!

doozerie

If your pump head can be swapped from Schraeder to Presta, double-check that it's not set up for Schraeder right now - in Schraeder mode it has an internal protruding plastic pin as well as using a wider rubber seal. I've seen people repeatedly use a pump set for Schraeder on their road bikes and the protruding pin invariably bent or broke the Presta valve.

With a hand pump I've had a Presta valve bend on a few occasions. Moving the pump while using it is certainly a potential cause of it but it's not the only one I've encountered. On one of my hand pumps the rubber seal that sits around the valve had worn to the point that the valve pushed too far into the pump and the valve tip hit the back of the pump head. The difference in depth was subtle enough so easy to not notice but was a real problem in practice (didn't bend valves every time, just occasionally, probably related to how hard I shoved the pump head on initially amongst other things).

With a track pump of mine with a dual head, where you lock the head to the valve by twisting part of the head, the same issue of a worn seal caused the same problem with the valve pushing too far into the pump head. In that case, twisting the head would snap the valve tip clean off due to the rotating mechanism deep(-ish) within the head. Depending on the style of head on your hand pump you may be experiencing something similar, so I'd suggest checking the rubber seal in the pump head for signs of wear and replace it if necessary (some of them can simply be swapped around to expose a new "face", depends on the pump).

irishmotorist

It's definitely set for presta valves but I never considered that it might be hitting the bottom/inside of the pump. I'll check that out too.