Presta 'jumper'?
 

I have just killed a tube because my main source of air is a (large-ish) mini pump. it failed during pumping right around the valve stem base probably from me not being able to keep the head of the pump still enough while pumping.

Does a presta 'jumper' exist?

I'm just looking for something to act as a bit of an intermediary of about 8" of hose between the bike and the pump. I do have a floor pump, but only at 1 of the 3 possible locations by bike could sit for an extended period of time, so there's a 2/3 shot I'm using a hand pump. It doesn't need to be fancy, and I'm willing to over-inflate since I carry a gauge with me to reach proper pressure after pumping. Maybe something that threads onto the presta valve and is a gutted presta on the other side for the pump to grab?

Floor pumps have a hose.. topeak has what is essentially mini floor pumps,
for carrying on the bike, also with a hose.

back in the day.. :50: we used the frame pumps and suspended the wheel
from the head of the pump, so there was no significant force on the stem.
other than a bit of swinging..

you could make 1, buy a Silca fitting for their track pump,
an old stem out of a dead tube, some hose, and 2 hose clamps.

I don't know of any available hoses with presta fittings, but there are plenty with schreader fittings, and there are adaptors to convert schreader to presta.

The Topeak "Morph" pumps and Lenzyne mini-pumps both have separate short hose sections that isolate the pump from the valve stem and prevent the breakage you experienced.

If you are gonna be cycling for a while, you need a floor pump. In my view, a good floor pump should be the next purchase right after a bike and helmet.

Then I'd have to take my wheel off every single time I'd want to ride my bike. A bit of a hassle.

Yea and they were almost my purchase, but I liked how the Master Blaster Frame Pump fit and held itself in. And if I find what I'm looking for, I'll just pump towards the ground anyway and put the head of the pump on the ground and push straight down...

Already have one, but I don't want to buy 2 more just so I have one in every possible start location.

I just want presta female to schrader male with some hose between and I'd be happy. I guess I could do presta adapter-schrader female-hose-schrader male... Where could I find a premade schrader-ended hose? I'm not having any luck with my usual hardware site: www.mcmaster.com

With a bit of creativity you can make one yourself, using a thread-on PV adapter with O-ring, a length of reinforced hose, 2 hose clamps and a barb fitting or cut down Presta valve from an old tube. The hose and other non-bike stuff is readily available at any hardware store.

You might also buy a PV pump hose and simply adapt the pump end to fit your pumps chuck.

BTW- you really don't need a hose if you improve your pumping technique. Most people who break valves do so because they don't properly brace the pump to the rim. Try holding the valve end of the pump, with your thumb extended down to the rim for support so that end of the pump doesn't move. Also use that hand to pull the the wheel or whole bike off whatever it's leaning slightly so it can move with the pump if you're not as steady as you hope. Either or both techniques will effectively make broken valves a thing of the past.

Is there some reason you object to CO2 when you're away from the floor pump? If you have a gauge that works, seems like getting the desired pressure should be doable.

I've broken some presta tubes recently with my floor pump, and thats never happened to me before. I'm suspicious that tube makers are cheapening the product to stay price competitive.

"Where could I find a premade schrader-ended hose? " Auto parts stores have them for checking/adding air to spare tires while they are secured in the trunk. Here's one source: http://www.getagage.com/accessories.cfm You could even cut off the Schrader end and mount a Presta or Presta/Schrader pump head on it if you wanted.

Ding!

And I'm going the route of make something nifty so it's idiot proof/lesson free/loanable without worry.

Current working recipe:
http://www.amazon.com/Topeak-SmartHe...396531&sr=8-21
that has presta+schrader head with M8 x 1.0mm on the other end of the hose but includes M12 x 1.0mm, M8 x 1.0mm, and M8 x 0.75mm adapters.

If my pump fits schrader, will it attach directly to the m8 head? If so I've found my solution...

All bike pumps have hoses, by definition. A bike pump, regardless of whether it is a full-size (floor) one or a portable (frame) one, has a hose, which is connected to the side of the pump (not to the butt end of it). Anything that does not satisfy those criteria is not recognized as a pump at all. For example, here's what a real protable pump looks like

http://mikesbikes.com/product/bikesm...ate-2-4218.htm

It is important to watch for these details to avoid various useless contraptions that are often sold as "pumps".

Very very untrue!

All forum posts have words, by definition. A post, regardless of whether it is a useful one or a useless one, has words, which are arranged to help the OP reach a goal. Anything that does not satisfy those criteria is not recognized as useful. /sarcasm

Does anyone know if a schrader or presta pump will be a secure fit to a M8 fine threaded hose end?

Schrader is 7.7mm OD so I'll probably pull the trigger on this since it's a great starting point regardless.

That's why most presta tubes have a nut on the valve stem, although many people toss them when they install the tube. By threading the nut down to the rim, the stem is stabilized so the base won't tear out of the tube.

The nut would only prevent damage from pushing, not tension from pulling.

On rims drilled for schreader valves, presta valves can be used by putting one nut on the valve before inserting into the rim, and another on the valve after it is inserted through the rim, then tighten it down well and the valve is locked in place.

If you are placing the wheel on the ground and pumping downward, find a rock or a peice of wood to put the head of the pump on. I have used this strategy on the roadside and been able to reach previously unheard of (by me) mini-pump pressures.

Ah possibly, but the jumper is WAY more versatile...

I don't have issues reaching high pressures since the pump I'm using is a frame pump, and the jumper would allow me to position it exactly like the aforementioned morph or regular floor pump minus the funky bracket but plus some versatility.

The best thing to do when using a mini pump without a hose is to lay the wheel or the whole bike down with the prests stem close to the ground. That way the head of the pump can be jammed against the ground and will not "work" the stem.

As a routine method of topping up tire pressure, CO2 is a very poor and expensive way. First, even unthreaded 12 gm cylinders in 25 count boxes are about $.50 each and second, CO2 "leaks" (more properly diffuses) out of innertubes significantly more rapidly than air so you will have to top up the pressure even more often that with a pump.

Next thing you know the nitrogen craze will hit bikes.

Hose will be here Friday (woo Amazon prime!) and I'll post as to whether a mini pump for schrader will grab the 'pump end' of the hose. Fingers crossed!

Making a hose adapter for a frame pump sounds like an excellent idea to me. So much so, that I don't know why there aren't any actually for sale pre-made. You could make one really fancy, with built in pressure gauge, and plastic "floor-pump base" clip to turn your frame-fit pump into "floor pump lite"...

I sense entrepreneurial opportunity here...

I'm not using CO2 for topping off, just on-the-road flat repair to avoid carrying a pump. My floor pump is for keeping pressure up before each ride. I've never computed the cost of CO2/cylinder because I don't use many of them. I didn't realize CO2 escapes the tube faster than air, but it always gets me home to my old faithful floor pump.

What length hose do you intend to use for the jumper? How will the rig be carried on your bike?

talked to a kid so into the Ultralight touring thing,he brought a micro pump
that worked poorly, but it did have a connector hose..

He did not know how to unscrew the pump hose
from its stowed in the center, position.

now he does.

The trick to using hand-pumps and not busting the valve is to grab a spoke or two next to the presta valve along with the head of the pump. Then any motions introduced with your pumping hand moves both the wheel AND valve-stem in unison. Then there's no movement of the stem relative to the rim.