Had to make a call of shame back home on Saturday as my Lezyne mini pump failed completely when the seals destroyed themselves.

I'm after a reliable pump for bike packing. Must meet the following criteria:-

- has a hose and presta fitting
- can handle getting wet a lot
- can see off a chav at 30 yards when waved threateningly
- does not need an app or bluetooth
- fit in backpocket of jersey or very small frame bag

I've got a Topeak Race-rocket MT and it does all you ask ... except, it will sometimes unscrew the valve core when you remove it, which sort of defeats the object of blowing yer tyre up. However, if your cores are nicely 'nipped up' it's not a problem.

I use one of these:



Not aware of any seal issues - by losing at least 2 pumps per year I've been able to mitigate that risk before it gets chance to develop.

In Reverse wrote:I use one of these:

Yeah, that one or similar. I've had mine about 6 years now and it's been bulletproof.

That Lezyne is same design as mine that failed

Dave Barter wrote:That Lezyne is same design as mine that failed

I've got the same and not had any issues. How old was it? I think the main seal on the piston is just an o ring. Have you ever greased it?

Mine came apart in my frame-bag, unscrewed itself into the separate parts due to all the vibration I guess. I cleaned up the pieces and re-greased the inside of the barrel with some grease for use in car brake cylinders, put it back together and I've not had any problems since.

Topeak mountain morph. Sturdy!

sean_iow wrote:

Dave Barter wrote:That Lezyne is same design as mine that failed

I've got the same and not had any issues. How old was it? I think the main seal on the piston is just an o ring. Have you ever greased it?

Mine came apart in my frame-bag, unscrewed itself into the separate parts due to all the vibration I guess. I cleaned up the pieces and re-greased the inside of the barrel with some grease for use in car brake cylinders, put it back together and I've not had any problems since.

Quite old, 3-4 years. I had not greased it I admit.

I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I have that leyzne mini pump too and it's been fine for both MTB and road use.

Thankfully I don't seem to get that many punctures, maybe a couple a year, so its not been over worked.

Dave Barter wrote: the unscrewing problem Stu talks of

It's one of the character building tenets of cycling to pump up a tyre, particularly a high-volume one that's taken ages to inflate using a tiny pump, only for all the air burst free in a nano second as the valve core unscrews. Bonus points if you also lose the seal on the rim. Double combo bonus if it happens when other people are waiting for you. And it's raining.

Dave Barter wrote:I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I've got one of them as well, it's what I take in the car to the start of events as it's much smaller (and better) than my Park track pump. It will also unscrew a valve core.

I think any pump with a screw on fitting has the potential to unscrew a valve core. I think the issue is not the pumps but the fact that some tubes and tubeless valve assemblies come with the cores screwed in finger tight. I now check mine and do them up with a proper tool and don't have any issue, and I also don't screw the pump hose on any tighter than necessary.

Have you taken your pump apart? If it's just the o ring it may well be fixable.

In Reverse wrote:It's one of the character building tenets of cycling to pump up a tyre, particularly a high-volume one that's taken ages to inflate using a tiny pump, only for all the air burst free in a nano second as the valve core unscrews. Bonus points if you also lose the seal on the rim. Double combo bonus if it happens when other people are waiting for you. And it's raining.

The first time it happened to me it was raining - and blowing a gale - and dark, pre-tubeless days so I had just put my spare tube in and blown it up only for all the air to escape. I refitted the valve and blew the tyre back up. Turned the bike back over and the other tyre had gone flat. As I was only a couple of miles from the end of the ride and getting colder by the minute I gave up on inflation and just ran with the bike to the end and my car

I've just bought the road version of one of those mini track pumps for taking away on trips with me (so I can use it alongside my airshot if required). On paper they seem fantastic.

sean_iow wrote:

Dave Barter wrote:I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I think any pump with a screw on fitting has the potential to unscrew a valve core. I think the issue is not the pumps but the fact that some tubes and tubeless valve assemblies come with the cores screwed in finger tight. I now check mine and do them up with a proper tool and don't have any issue, and I also don't screw the pump hose on any tighter than necessary.

Apparently it can be eased if you release the pressure between pump and valve before unscrewing. I can see how this increases the tension on the valve. I think

sean_iow wrote: Have you taken your pump apart? If it's just the o ring it may well be fixable.

Yes, the pump head is firmly jammed in the shaft which is full of bits of seal (I think that is a Right Said Fred song?). I just can't trust it again

Richard G wrote:I've just bought the road version of one of those mini track pumps for taking away on trips with me (so I can use it alongside my airshot if required). On paper they seem fantastic.

I'm really pleased with mine. This might be obvious, but it wasn't too me I was trying to screw the end back onto the storage bit on the base with the hose already over the handle and it was quite tricky due to the tension in the hose. Someone pointed out that it's much easier to screw the end to the base then slip the hose into the groove in the handle

I've been very pleased with my Lezyne Alloy Drive. I have a mountain morph as well but I stopped carrying it since getting the alloy drive

Dave, all pumps will contain seals. They are all prone to failure. They're a wear item really.

At least with Lezyne you can take it apart and rebuild it, and buy seal kits.

https://www.upgradebikes.co.uk/Catalogu ... -Seal-Kits

https://www.youtube.com/watch?v=iYZ5Smx4FmQ

Use some silicone grease

So the next question is should I strip my pump down to regrease the seals? Or just ignore it and carry on as per normal?

Dave Barter wrote: I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I have got that pump Dave, it does not unscrew the valve core and I will be replacing with the same when its finished.
Will shake to bits in a bag as the cap unscrews.
Comes with a bracket to fit under your bottle holder on the frame.
Nice and light for the size of it.

Edit - don't get the one with the gauge, not necessary.

Chicken Legs wrote:

Dave Barter wrote: I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I have got that pump Dave, it does not unscrew the valve core and I will be replacing with the same when its finished.
Will shake to bits in a bag as the cap unscrews.
Comes with a bracket to fit under your bottle holder on the frame.
Nice and light for the size of it.

Yep - I got one too. I like it, not used much to be fair , Fits neatly to bike

benp1 wrote:So the next question is should I strip my pump down to regrease the seals? Or just ignore it and carry on as per normal?

Definitely Ben, either silicone grease like Zip says, or suspension grease

Dave Barter wrote:I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

I have one which is referred to as “ The Swedish c##k Pump” for some unknown reason
It’s a great pump, and light.

The only thing is it’s not very small for putting in a frame bag

Tracking this thread, as I also should replace my ancient Lezyne pump, although it has never let me down yet, I have never done any maintenance either, so failure must be imminent!

Dave Barter wrote: I'm wondering about one of these https://www.amazon.co.uk/Lezyne-Micro-F ... r+drive+hp as the pressure relief valve stops the unscrewing problem Stu talks of

That looks a bit over-engineered and bulky for on-the-bike, and the pressure gauge inadequate for normal mtb pressures. That's assuming it is accurate to start with - my Lezyne track pump works fine, but the gauge is massive inaccurate when checked with a proper gauge. Used to have a Mtn Morph, which worked fine, but also a bit large to stow on the bike.

Yeah, the gauges are sh*t on them, but I've used them as a starting point before putting my little electronic pressure gauge on to get the value exactly right.

You could always go for the eyewateringly expensive digital version though: http://www.chainreactioncycles.com/lezy ... prod171328

I switched from the Serfas Big Stick (still alive after 4 years with no maintenance...barely) to the Lezyne HV. The valve core unscrew thing is a PITA but nothing that tightening the core in the first place doesn't fix. Wife swiped my Mountain Morph years ago and I've not seen it in a while.

Greetz

S.