Can't inflate Presta valve

Amouar

Hi,

I wanted to top up my bicycle tyres for the first time today using a KLS mini pump (Like this one) but I'm unable to get the pump to lock on the Presta valve in order to inflate it. The pump has an interchangeable head that fits both Presta and Schrader valves and a lock lever.

I tried the pump many times on my daughter's bike with Schrader valve and it locks and inflates the tyres perfectly.

When I change the pump's head to Presta and tried to inflate my bike's tyres, the pump wouldn't lock on the valve no matter how hard I tried and just keeps deflating the tyre.

Anyone has an idea on what's i'm doing wrong here?

Thanks!

TheBlaaMan

"Lock" might be when the lever is horizontal....... or or might be when the lever is vertical. Pumps differ

Try it the other way round, if you follow?

Amouar wrote: »

Hi,

I wanted to top up my bicycle tyres for the first time today using a KLS mini pump (Like this one) but I'm unable to get the pump to lock on the Presta valve in order to inflate it. The pump has an interchangeable head that fits both Presta and Schrader valves and a lock lever.

I tried the pump many times on my daughter's bike with Schrader valve and it locks and inflates the tyres perfectly.

When I change the pump's head to Presta and tried to inflate my bike's tyres, the pump wouldn't lock on the valve no matter how hard I tried and just keeps deflating the tyre.

Anyone has an idea on what's i'm doing wrong here?

Thanks!

Amouar

TheBlaaMan wrote: »

"Lock" might be when the lever is horizontal....... or or might be when the lever is vertical. Pumps differ

Try it the other way round, if you follow?

The lock in my pump is when the lever is vertical and i used it several times before to inflate my daughter's bike tyres.

Tigerandahalf

You need to loosen the top of the presta valve. Then push it down with your finger and air should come out. If it does it is ready to take the pump. You only need to loosen it one turn anti clockwise. That works for me anyway.

Zen0

Some pumps I’ve used in the past required you to reverse the rubber washer thingy in the bit that fits onto the valve when changing from schrader to presta.

Amouar

Zen0 wrote: »

Some pumps I’ve used in the past required you to reverse the rubber washer thingy in the bit that fits onto the valve when changing from schrader to presta.

That's exactly what I've done but the pump still doesn't lock on the valve

Duckjob

Is it possible you have deep rims and are using a tube with a standard length presta valve rather than the longer valve for deep rims?

I bought a tube with a standard length valve by mistake to use in my deep rim wheel and its a pain to inflate - I have to remove the valve nut at the bottom and even then the pump head can just about push open the valve to pump the air in.

ED E

Get C02 for the roadside and a track pump for at home. Mini pumps are obsolete now IMO.

C3PO

Is there a little rubber grommet that needs to be reversed under the head?

Amouar

C3PO wrote: »

Is there a little rubber grommet that needs to be reversed under the head?

Yes there is and I reversed it in the correct position but it still doesn't lock.

Fighting Tao

Maybe you said already and apologies if I missed if. Have you tried another pump?

TheBlaaMan

ED E wrote: »

Get C02 for the roadside and a track pump for at home. Mini pumps are obsolete now IMO.

Carry both, but don't use CO2 unless you really have no option. The last thing we should be using is anything that releases more C02 into the atmosphere. Mini pumps ftw

Brian?

TheBlaaMan wrote: »

Carry both, but don't use CO2 unless you really have no option. The last thing we should be using is anything that releases more C02 into the atmosphere. Mini pumps ftw

We probably produce more CO2 when breathing on a spin than one cartridge contains. You should stop breathing heavy if you’re that worried.

Brian?

Amouar wrote: »

Hi,

I wanted to top up my bicycle tyres for the first time today using a KLS mini pump (Like this one) but I'm unable to get the pump to lock on the Presta valve in order to inflate it. The pump has an interchangeable head that fits both Presta and Schrader valves and a lock lever.

I tried the pump many times on my daughter's bike with Schrader valve and it locks and inflates the tyres perfectly.

When I change the pump's head to Presta and tried to inflate my bike's tyres, the pump wouldn't lock on the valve no matter how hard I tried and just keeps deflating the tyre.

Anyone has an idea on what's i'm doing wrong here?

Thanks!

Can you get someone to video what you’re doing. You have me bamboozled.

As an aside. You need to use a better pump that that fella, you won’t get anywhere near the right pressure with it. A track pump is really essential when you own a road bike.

Agreed, mini pump to get you home if co2 fails or you have none. Track pump is so much less effort. I've one I got in tesco last year for a 10er that does the job, actually a better job than the 30 euro one it replaced.

magicbastarder

Brian? wrote: »

We probably produce more CO2 when breathing on a spin than one cartridge contains. You should stop breathing heavy if you’re that worried.

i'd be more interested in the encapsulated carbon in a cartridge than in the actual contained carbon. i suspect it'd be much higher.
either way, i don't think either figure would be in any way significant; from what i can see, the average person breathes out about a kilo of CO2 a day.

edit: seems 16g is about normal for the CO2 in a cartridge. or about 20 minutes worth of breathing. to compare to a car, a car produces about 2KG per litre of petrol, so about as much CO2 as a car does driving 200m.

ED E

A big reason why people bring mini and C02 is the risk of the C02 going wrong, if you get a good inflator and practice it this won't happen.

I'm using C02 around 1yr now and have used 1 capsule myself with a few donated to other cyclists. The bigmacs I ate during that time have had a far bigger atmospheric impact. I'd go vegan(never) before worrying about C02 use.

Remember Airsofters go through one every 30-50 shots :pac:

Mercian Pro

ED E wrote: »

Mini pumps are obsolete now IMO.

Great way to warm up after a winter puncture and an even better source of "is it hard yet?" jokes 😊

doozerie

Amouar wrote: »

When I change the pump's head to Presta and tried to inflate my bike's tyres, the pump wouldn't lock on the valve no matter how hard I tried and just keeps deflating the tyre.

If it's deflating the tyre then something must be pressing on the head of the presta valve. Maybe something in the pump head is catching on the valve head, or maybe (and probably more likely) the pump is pushing too far onto the valve and the valve head is hitting the back of the pump head.

If the latter then my guess is that the rubber washer in the pump head is too loose (or maybe you are just pushing it on further than necessary). I've no idea of the design of your pump but pumps usually have a threaded outer cap that compresses the internal rubber washer as you tighten it, and in doing so it effectively makes a "smaller" hole in the washer so that it fits tighter on the outside of the presta valve body. That tighter fit makes for a better seal between pump and valve and helps prevent the pump from pushing too far onto the valve too.

So if your pump has a threaded outer cap, try tightening it a little and see if that helps. Only tighten it a little at a time though, tighten it too much and you can shred the washer on the valve threads (if it has them) and end up having to replace the washer prematurely.

doozerie

ED E wrote: »

A big reason why people bring mini and C02 is the risk of the C02 going wrong, if you get a good inflator and practice it this won't happen.

There are many reasons why people prefer pumps (mini, or otherwise) to CO2 inflators. In my case, I prefer the fact that my pump won't run out of air (practical concern). I also like the fact that it produces no waste (empty cannisters) no matter how many times I use it (tree-hugger concern). A pump is also a once-off cost (penny-pinching concern). Etc.

Mini pumps are not obsolete, CO2 is a good option for some but it's not the right option for everyone.

check_six

doozerie wrote: »

If it's deflating the tyre then something must be pressing on the head of the presta valve. Maybe something in the pump head is catching on the valve head, or maybe (and probably more likely) the pump is pushing too far onto the valve and the valve head is hitting the back of the pump head.

If the latter then my guess is that the rubber washer in the pump head is too loose (or maybe you are just pushing it on further than necessary). I've no idea of the design of your pump but pumps usually have a threaded outer cap that compresses the internal rubber washer as you tighten it, and in doing so it effectively makes a "smaller" hole in the washer so that it fits tighter on the outside of the presta valve body. That tighter fit makes for a better seal between pump and valve and helps prevent the pump from pushing too far onto the valve too.

So if your pump has a threaded outer cap, try tightening it a little and see if that helps. Only tighten it a little at a time though, tighten it too much and you can shred the washer on the valve threads (if it has them) and end up having to replace the washer prematurely.

Those mini pumps where you have to switch around the rubber seal for different valve types are very tricky to get working properly. I used to have one and there was a lot of fiddling about required to get it to work on Presta valves including taking a valve bit out of the pump and reversing it along with the rubber seal. Then you had to start messing about with the tightness of the cap as described above in Doozerie's post. A whole lot of trouble to get it to work right.
A track pump is the correct fix long term. I also recommend a minipump with a flexible hose like a Lezyne Pressure Drive.

tomasrojo

doozerie wrote: »

There are many reasons why people prefer pumps (mini, or otherwise) to CO2 inflators. In my case, I prefer the fact that my pump won't run out of air (practical concern). I also like the fact that it produces no waste (empty cannisters) no matter how many times I use it (tree-hugger concern). A pump is also a once-off cost (penny-pinching concern). Etc.

Mini pumps are not obsolete, CO2 is a good option for some but it's not the right option for everyone.

Penny-pinching and tree-hugging are inextricably entwined in my heart, so it's mini-pumps for me .

tomasrojo

check_six wrote: »

Those mini pumps where you have to switch around the rubber seal for different valve types are very tricky to get working properly. I used to have one and there was a lot of fiddling about required to get it to work on Presta valves including taking a valve bit out of the pump and reversing it along with the rubber seal. Then you had to start messing about with the tightness of the cap as described above in Doozerie's post. A whole lot of trouble to get it to work right.
A track pump is the correct fix long term. I also recommend a minipump with a flexible hose like a Lezyne Pressure Drive.

There are mini-pumps with a double Presta/Schraeder head. The ones where you turn around the rubber insert (I think) are really for you to adjust once for your type of bike and leave alone. If you need a pump that can flexibly deal with different valves, get one with the double head.

Track pumps in the house are great. I regret that I didn't know about them sooner.

tomasrojo

It seems to me, as to others, that the contribution of cartridges to the atmosphere's carbon budget is very modest. How often do people use them anyway? A few times a year for somebody doing about 7000km?

I wouldn't make comparisons to a human breathing though, as that carbon isn't directly derived from fossil fuels (though I suppose there is the attendant fossil fuel used in fertiliser production and farm machinery, if you're being strict about it).

Joe1919

On many mini pumps there are two things that need switching around. The first is the rubber as already discussed. But before putting back the rubber, there is a little plastic pin thing that normally presses down on the Schneider valve pin. This need to be turned inwards as its not required with presta and gets in the way. You might need a tweezers/long nose pliers to pull it out.

check_six

tomasrojo wrote: »

There are mini-pumps with a double Presta/Schraeder head. The ones where you turn around the rubber insert (I think) are really for you to adjust once for your type of bike and leave alone. If you need a pump that can flexibly deal with different valves, get one with the double head.

You're right. I managed to have my crappy minipump at the same time that I had a mix of valves on my bike. Presta on the front and Shrader on the back. This was also combined with the world's most uncooperative rims meant that each puncture repair was an exercise in misery and swearing!

check_six

Joe1919 wrote: »

On many mini pumps there are two things that need switching around. The first is the rubber as already discussed. But before putting back the rubber, there is a little plastic pin thing that normally presses down on the Schneider valve pin. This need to be turned inwards as its not required with presta and gets in the way. You might need a tweezers/long nose pliers to pull it out.

That was what I was attempting to describe previously (but clearer!).

07Lapierre

doozerie wrote: »

There are many reasons why people prefer pumps (mini, or otherwise) to CO2 inflators. In my case, I prefer the fact that my pump won't run out of air (practical concern). I also like the fact that it produces no waste (empty cannisters) no matter how many times I use it (tree-hugger concern). A pump is also a once-off cost (penny-pinching concern). Etc.

Mini pumps are not obsolete, CO2 is a good option for some but it's not the right option for everyone.

I used to be indecisive, now i'm not so sure!

I use one of these:

https://www.google.ie/aclk?sa=l&ai=DChcSEwj7uKr7nc_fAhUCtO0KHVYbBrwYABALGgJkZw&sig=AOD64_1Xyk3HVXRvhSEWdqxVz7l5qnCT-g&ctype=5&q=&ved=0ahUKEwjvzqP7nc_fAhViqnEKHWJlCBoQ9aACCEY&adurl=

tomasrojo

I was surprised to see a refillable compressed-air canister system on the market.
https://www.pinkbike.com/news/sks-rideair-tubeless-inflation-bottle-review.html

It's rather large, given that you can't get air to liquefy at relatively high temperature and relatively low pressure the way you can get CO2 to do it.

ED E

tomasrojo wrote: »

I was surprised to see a refillable compressed-air canister system on the market.
https://www.pinkbike.com/news/sks-rideair-tubeless-inflation-bottle-review.html

It's rather large, given that you can't get air to liquefy at relatively high temperature and relatively low pressure the way you can get CO2 to do it.

Yeahhhhhh....no.


Mini pump fans: Do you manage 120psi? Or is it roll home on a soggy 80?

magicbastarder

soggy 80? i never go above 80 regardless.