Presta valves & pumps

rob13

I havent yet bought a floor pump as I'd spent up this month and so thought I could get away with using a compressor and a Schrader valve adaptor. Problem is that once I reach about 60psi, the seal between the compressor and valve adaptor starts to leak. Ive tried all ways but it reaches that point and doesnt go further.

So I tried to pump up the tyres with the Topeak Pocket Rocket hand pump but unfortunately I managed to snap the end of the valve off! It appears that unless I get a floor pump, I cant get enough air into the tyre.

Bloody fuming sat here because I've spent the past hour trying to get enough air into the tyres for the bikes maiden voyage tomorrow!

Oh and it turns out the spare tube I bought happened to have a 60mm valve on when it looks like mine is 42mm. Should I take it back?

Is there a knack to presta's and how far to unwind the collar on them? They seem very flimsy when theyre right out.

meanredspider

Floor/Track pump is definitely the way to go. Don't bother with a compressor - I have one and it's far more faff than a few strokes of a track pump. Presta valves are generally pretty crap IMO but they are ubiquitous in the roadie world so just get on with them. I screw them out all the way. The valve stem length doesn't matter too much i think - unless they are too short (aero wheels).

I use a simple CO2 inflator out on the road with an airstick for disasters. The CO2 inflator works brilliantly.

Berk Bonebonce

Rob13 wrote:

It appears that unless I get a floor pump, I cant get enough air into the tyre.

Yup.

I guess most compressors will not handle the kind of 6, 7 or 8 bar pressures you get with road bikes.

Some inner tubes (and tubs for that matter) come with replaceable valve cores. So if you break one off you do not have to scrap the tube/tub, you can just fit a new valve core, like one taken from that spare inner tube of yours.

In fact, there should be a law saying that all tubes/tubs should come with replaceable valve cores. They can save a whole load of hassle.

1stGenRex

but then that would mean less tubes sold :P

rob13

Well theyre Continental inner tubes and heard somewhere that they were replaceable? I'll keep hold of it and if I get a puncture in another, I'll try and swap them over?

I'm going to blow the cash on a track pump tomorrow, not overly hopeful of having success with the pocket rocket if needed in the event of a puncture. I think I'll take a schrader valve adaptor in case I do and use the Schrader option instead.

keef66

Yup, conti tubes have removable cores. So don't use the dust caps on the valves, or a screw-on pump adapter, otherwise you risk unscrewing the valve core when removing them. Then the tube goes pfffffft! and you're back where you started. Apparently :oops: I now tighten the valve cores using a tiny adjustable spanner I inherited.

Don't worry about the length of the valve stem unless you're overly concerned about the extra weight. My last purchase of Conti tubes I ended up with the longer ones.
(you didn't get them from Halfords by any chance?)

rob13

So, aside from the tube issue, I'm struggling to get enough air into the tube (probably around 70-80psi) before it starts to leak from the union between pump and valve. When I'm inflating, I am causing the valve to move and i've tried to isolate that movement but I find air coming from the union between pump and valve. It seems to be fine up to a point but then I cant seem to pump the tyre up any further.

Does it sound like a dodgy Pocket Rocket or poor technique? Off to buy a track pump tomorrow but need to be sure of using the mini pump when out on the road in case of punctures.

ireland57

I have 4 x mini pumps, a compressor (10 cuft) and 2 floor pumps.
They have all ended up in the neighbours yard at some point.

Two days ago I bought a Specialized floor pump for $60 I think. Nearly fell over but sick of focking pumps and adaptors.

Wish I did it sooner. It is sooo easy to inflate a french valve now.

Headhuunter

If you can't afford a track pump yet, just go to a decent local bike shop, the ones near me have track pumps for members of the public to use.... Just nip in once a week for a top up until you can afford your own.

getting_on_a_bit

Get yourself a Lezyne mini pump.It is a 'hose' type with both a presta and a schraeder end that screw onto the valve.I used to snap off presta valves with various naff push fit pumps but the Lezyne is superb.Fits into back pocket of cycling jacket as well.

meanredspider

getting on a bit wrote:

Get yourself a Lezyne mini pump.It is a 'hose' type with both a presta and a schraeder end that screw onto the valve.I used to snap off presta valves with various naff push fit pumps but the Lezyne is superb.Fits into back pocket of cycling jacket as well.

Yup - they a brilliant for changing valve cores - they screw them right out (usually with all of the air you've just put in)

litwardle

I have the same problem with my Topeak Mini-Pump. I just unscrew the core a touch, and remove the wheel so I can properly take the strain of the pump strokes rather than breaking the valve....

REALLY need a track pump but I can't afford one at the mo!

Lee

desweller

I have a Topeak Pocket Rocket floating around somewhere. I don't recall having trouble keeping it on the valve, I don't use it because I prefer my frame pump (also a Topeak).

There is a plastic cap that screws onto the head to hold the gripper in place. I sometimes find I have to loosen this to get the head onto the valve, and then screw it right down to get a good seal and grip the valve well.

ride_whenever

The topeak road morph is a great 1/2way house between mini and track pumps. The little hose is a godsend. Personally for track pumps themselves I've been really impressed with the airace infinity turbo track pump. One of the best heads i've used (better than the renkompressor ones) and goes up to 130+ psi easily.

Headhuunter

ride_whenever wrote:

The topeak road morph is a great 1/2way house between mini and track pumps. The little hose is a godsend. Personally for track pumps themselves I've been really impressed with the airace infinity turbo track pump. One of the best heads i've used (better than the renkompressor ones) and goes up to 130+ psi easily.

Yeah the Topeak Road Morph is amazing, it really isn't that difficult to get 120psi out of it. It's a bit less portable than some of these really small pumps but makes up for it in efficiency. It's like a mini track pump with a flexi hose and psi guauge. I also have a Specialized something or other Pro track pump for use at home...

keef66

+2

I got the Topeak Road Morph 2 1/2 years ago and it's so good I still don't have a track pump