When using the shockwiz I have noticed over previous years that when I disconnected it I lose sometimes 5psi, sometimes 20psi, but rarely the same.

So I read some reviews on shock pumps and using a Shockwiz they said “none lose pressure when disconnecting” but arguably they can when connecting.

However this one has a secondary release mechanism

https://www.tweekscycles.com/uk/topeak-pocket-shock-dxg-xl-shock-pump-euktpsdxg-xl2/?istCompanyId=56f52ebf-49f3-492a-9cbb-cb6ab0fc1bf0&istFeedId=33b89177-5114-4491-9c2a-09a3a7cb23b2&istItemId=irtrixtiw&istBid=t&gclid=Cj0KCQiA4feBBhC9ARIsABp_nbVItWdqMwApcLo6x1aE4pE5Z6DwkjPPU0-2OT315ri-gMusu6uVtN0aAkkGEALw_wcB&gclsrc=aw.ds

Topeak DXG XL. XL being the long version.

Tested tonight and it’s correct, I lose 0psi when either connecting of even disconnecting. Which should in theory mean we can set our pressure a lot easier. Both me and the lad are getting fussier in terms of settings as we learn more, so better to have a more precise setup we can use.

Recommended

You can buy the connector on its own too, to save buying a whole new shock pump –

https://www.cyclesolutions.co.uk/accessories/pumps/topeak-pressure-rite-connector-adapter–schrader-valve__20718

the DXG is a weird system that allows you to release the schraeder valve internally while leaving the pump still connected, so no pressure loss.

How did you like the shockwiz, struggling to work out which way go with my setup and keen to try one. Looks like you can rent one online for not too much

@weeksy I would also be interested in your experience with Shockwiz.

Yeah I had a collection of shock pumps, all acquired somehow without actually paying for them, and they all had their own foibles like one of them refusing to screw onto a Monarch shock or another having too big a head to connect to the recessed valve in my seatpost. The net effect was that there wasn’t one pump that worked for everything then the handle broke on the least worst one and I decided to get one of those Topeaks. Now I wonder why I waited so long!

I bought a cheap shock pump off amazon:

This One

Its pretty shite quality but has a clever no loss chuck which is very useful. The video on the link explains better than I could.

Agreed weeksy, its really quite lovely in use too. Works well on my rear shock.

However – it doesn’t play well with Manitou forks. Bollocks. I think because Manitou use a funny valve core that opens both air chambers, it doesn’t work consistently.

Good to know you have scientifically tested it though, thumbs up!

Only trouble is, the DXG button is right where you hold the pump when pumping. 😛
Not good for numpties like me

So I read some reviews on shock pumps and using a Shockwiz they said “none lose pressure when disconnecting” but arguably they can when connecting.

You’re always going to lose some pressure when connecting, because pressurised air needs to flow into the hose and the gauge. So if you disconnect and reconnect it the pump there will always be at least some discrepancy.

Also, losing 10psi is moot when you’re trying to read that tiny gauge.

Been using the Syncros digital one for years which has the same sort of facility. Can be got in analog or digital. Makes a big difference when setting up for the lighter rider.

Shockwiz for me is a complete superstar. The good thing is, it’s given me an appreciation for ‘right’ so i can dial in a shock and get it almost exactly as per how Shockwiz says no, purely on feel and bouncing it up and down next to the bike and then in the street. I’m 95% there every single time now.
The settings i prefer are ‘soft/poppy’ as does my lad, so that’s where we run our bikes. Others who ride them say they’re too soft… but that’s OK with me, i like it how i like it.

Also, losing 10psi is moot when you’re trying to read that tiny gauge.

That’s why i use the Shockwiz … It’s a precise figure, i can then work out just how close my gauge is.

Sounds good! Will have to give one a go

Wait until you try a digital shock pump! (highly recommended btw)

I’d argue it doesn’t matter if you lose a bit of pressure as you disconnect, providing that the air volume you lose is constant. Connect pump, pump to x psi. If it’s too sagged, pump to x +5% or whatever. The actual value is pretty meaningless (even if your shock pump is accurate, which it probably isn’t).

I’ve got a Topeak Shock Pump with that little pressure loss prevention gizmo (I’ve had it years). It’s fine, it’s a nice pump but it’s not groundbreaking stuff IMHO.

Only trouble is, the DXG button is right where you hold the pump when pumping. 😛

Also this ^^^

not entirely relevant but a mate was super fussy about setup and claimed to be able to tell the difference between a few psi on his suspension

so I used to let a little bit of air out of his forks and shock when he wasn’t looking to see if he noticed. he didn’t.

lol @ Jam-bo 😀

Weeksy is that the cheapest around, before I Google it. I’m fed up using rubbish ones.

I’ve owned the normal sized Topeak Pocket Shock DXG since my first mountain bike. Great bit of kit and well-built.

Tredz have it available from supplier, which has never been a problem for me, at £33.99 and usually send a £5 off code for over £30 so should drop it to £28.99. Worth the wait ?

Mine is the XL version, so longer….. it does actually make it quite a bit easier than some i’ve used.. Although obviously won’t fit in a pocket etc.

Weird thing is I had that Topeak shock pump, but non XL, and it let loads more air out than any other. Followed instructions to the letter and tried on various forks and shocks. I’m guessing it was faulty. Ended up with a Lezyne that works great.

If it loses air when you disconnect it, it isn’t even a shock pump, just some shit that they’re selling with a dishonest name on it. Every shock pump worth owning is lossless. Whether they do it with a wee switch, or an unscrewy middle like the cheap beto ones I like, or just with a big long nozzle so that it disengages the centre pin before removing.

They’ll still make a little pssh noise as air escapes the pump but that’s fine- it’s only because the pump is pressurised the same as the shock so the shock pressure escapes to air.

(literally the cheapest shock pump I can find, and it has a 2-stage release as it should, I own a couple of these:
https://www.bike-discount.de/en/katana-beto-400-psi-shock-pump?number=20073679&__delivery=11)

I have to say, this has piqued my interest probably more than it should.

I have a couple of old shock pumps in the shed, both lose air on disconnection, but more notably only pump any air at the last 5mm of plunger travel which makes suspension setting up it a frustratingly slow job and often a knuckle bashing experience.

Does the pump mentioned above move a decent amount of air on each pump or is what I am describing just a shock pump thing?

I got one of these, no more time wasted pumping hundred of times with a tiny pump to get up to pressure, may not matter as much to the smaller of you, but for us big lads this is great.

https://ride.lezyne.com/products/1-fp-shddr-v106

aren’t those two step release shock pumps solving a problem that isn’t really there? in that the escape of pressure you hear when removing the pump is mainly coming from the pump as the schraeder vale closes so quickly, and the difference in pressure when you re-connect it is due to the pump re-pressuring? or have i been labouring under this miss-understanding for years??

sofaboy73
Free Member

aren’t those two step release shock pumps solving a problem that isn’t really there? in that the escape of pressure you hear when removing the pump is mainly coming from the pump as the schraeder vale closes so quickly, and the difference in pressure when you re-connect it is due to the pump re-pressuring? or have i been labouring under this miss-understanding for years??

Sometimes. You can have a single stage pump that doesn’t leak from the shock but as weeksy’s found, some (shit pumps) do leak. The 2-stages mean it’s never an issue but also it’s kind of nice that you’re in control of it. The single stage type with the longer valve are a wee bit harder to trust, and also can have issues with specific short valves on some suspension (though, to be fair I’ve never had this for years, it seems like things are properly standard now? No more marzocchi bullshit)

Does the pump mentioned above move a decent amount of air on each pump or is what I am describing just a shock pump thing?

It’s a shock thing. You can only force air into a 250psi shock when the pressure in the pump barrel exceeds 250psi. Which only happens right at the end of the stroke since you start at 0psi (relative to atmospheric pressure).

the DXG is a weird system that allows you to release the schraeder valve internally while leaving the pump still connected, so no pressure loss.

Wierd?? Like Northwind up there says, all proper ones do this. IN fact I didn’t know there were any that didn’t do this. I’ve been using a cheap one I bought about 15 years ago that does that!!

I ordered one from CRC and re read the post saying it’s not good on Manitou forks. So that’s me sending it back then.

Due to buying too many forks over the years I’ve got several basic Rockshox ones that just screw on and off, no clever gubbins that I can see. Have I been deluding myself – they all seem fine?

Fact check: Do you really lose air when you disconnect your shock pump?

If you’re loosing air when disconnecting, you’re doing it wrong or it’s faulty.

how exactly could i undo it wrong ?

Maybe undoing partially, or too slowly or not following the correct procedure with this Topeak head. It is possible.

How do you think you are losing air? Do you hear the hiss and think “bugger, I’ve lost air from the air chamber” and then re-attach the hose? As the article above states, the head is literally designed not to lose air. Re-attaching the hose to the valve will lose air though, as you’re then re-pressurising the hose.

I had an old Scott shock pump a few years back which had a 2-stage head on it. You unscrewed the thumbwheel which released the spring pressure on the valve core, then removed the head from the valve. In principle, this is what all normal heads do. It’s just this one was far better for getting into dropper post valves and their stupid, tiny spaces.

How do you think you are losing air? Do you hear the hiss and think “bugger, I’ve lost air from the air chamber” and then re-attach the hose? As the article above states, the head is literally designed not to lose air. Re-attaching the hose to the valve will lose air though, as you’re then re-pressurising the hose.

No, i use a shockwiz that shows the exact psi, then remove it and you see it drop from say 225 to 200. I trust the Shockwiz and now i’m using the DXG i get 0 pressure loss.

I’m perfectly happy to accept my old pump is faulty and it’s already in the bin.. I’m also happy to accept some/most others wouldn’t lose pressure either…

But i’m also perfectly happy that the DXG does exactly what i want 🙂

“It’s a shock thing. You can only force air into a 250psi shock when the pressure in the pump barrel exceeds 250psi. Which only happens right at the end of the stroke since you start at 0psi (relative to atmospheric pressure).”

Ah, that makes perfect sense, dang it! Thanks for the clarification though.