Bicycle pump.

General cycling advice ( NOT technical ! )
Annoying Twit
Posts: 962
Joined: 1 Feb 2016, 8:19am
Location: Leicester

Re: Bicycle pump.

Postby Annoying Twit » 4 May 2016, 8:09am

scottg wrote:Mini-pumps lie about physics, little tiny barrel = nano gobbets of air into the tube*.

*Except for the amazing Topeak Tardis Airstick w/sonic hex driver,
out of stock at Halfords since 2042.


Nobody recommends the tru-flo mini track pump apart from me. Is there something about it that I don't know?

The barrel on my tru-flo is narrow, but with the telescoping barrel, it gets reasonably long when extended. It doesn't pump up as fast as my full sized Joe Blow track pump, but I'm entirely satisfied with how quickly I can pump up a tyre to a reasonable pressure.

I can't find a picture of it fully expanded (and am too lazy to take one). This photo shows the telescoping bit only extended an inch or so. It extends enough to about double the length of the barrel.

Image

Drake
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Joined: 19 Apr 2012, 9:01am

Re: Bicycle pump.

Postby Drake » 4 May 2016, 8:29pm

I'm getting the impression that although pumps can be mounted on the frame, it is perhaps unwise to do so.
Point taken.
Does anybody know if there is a service kit for the pocket rocket ? I would imagine not.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Bicycle pump.

Postby Brucey » 4 May 2016, 9:25pm

Drake wrote: Does anybody know if there is a service kit for the pocket rocket ? I would imagine not.


you might imagine wrongly; this might do the trick... although there are several different models so do check it is the right one...

http://www.sjscycles.co.uk/topeak-topeak-pump-rebuild-kit-pocket-rocket-speed-master-prod20219/

there is a different kit for the pocket rocket DX.

If it is just the O ring for the main piston seal, you might find it here

http://www.sjscycles.co.uk/pumps-spares-dept963_pg1/#filterkey=brand&brand=TOPEAK&page=8

for about 50p

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mercalia
Posts: 14578
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Bicycle pump.

Postby mercalia » 4 May 2016, 9:29pm

Drake wrote:I'm getting the impression that although pumps can be mounted on the frame, it is perhaps unwise to do so.
Point taken.
Does anybody know if there is a service kit for the pocket rocket ? I would imagine not.


well yes easier to steal. I once had a kid go by when my bike was locked out side the supermarket and his sharp eyes & fumbling fingers started at the velcro - but I was watching him at the pay till so "told" him where to go :twisted: I keep mine in a pouch on my panniers

mountainman531
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Joined: 13 Mar 2008, 10:17pm

Re: Bicycle pump.

Postby mountainman531 » 4 May 2016, 9:55pm

Edinburgh Bicycle co-op do a Revolution which is like a mini track pump, I've had one for years and i use it for all my pumping, I have found that I just don't need a full size track pump anymore. It's probably about £20 but sometimes they have a sale. As for any kind of pump failing to get up to pressure try taking the gromits apart and apply literally a drop oil, it acts as a sealant and prevents air under pressure escaping.

Freddie
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Joined: 12 Jan 2008, 12:01pm

Re: Bicycle pump.

Postby Freddie » 4 May 2016, 10:31pm

Life is too short to get stuck with a mini-pump.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Bicycle pump.

Postby Brucey » 5 May 2016, 8:12am

I have a theory, which is basically that 'most pumps are junk'. There are millions of different ones and nearly all of them are deeply flawed in either conception or execution.

....or both..... :roll:

Like politicians, you choose 'the least bad option available' and there is a small chance that, once selected, something vaguely useful might happen, for a while at least. And then it all goes belly up.

Think about it; with few exceptions, I'd say that most cyclists have had more pumps than bicycles, even though the pump might only get a few minute's use in a year!

So what to do.... I think that Meic's advice is sound. I'd also add that it makes sense to maintain your pump, using some kind of lube that isn't going to dry out or corrupt the seals.

For lube, don't use 'oil' unless you are in dire need; most oils corrupt various different rubbers, which can include the pump workings, but will include your inner tubes. For a cheap lube that seems to work OK in pumps (doesn't attack plastics and rubber, doesn't dry out appreciably) I'd suggest '151 super grease'.

I'd also add that you shouldn't expect miracles; obviously a tiny pump will take much longer to inflate a tyre, and 'clever designs' (ie dual action, telescoping, etc etc) IME just add places where the pump is less efficient and more likely to go wrong; even if they do 'work' they may be no faster or easier than a pump with a simpler design.

Also, many pumps (not just mini-pumps) use an 'O' ring as a main pump seal. This won't ever last as long as a proper cup washer, even if lubricated properly, but if it has run dry, I'd expect it to fail entirely within the length of time that it takes to inflate one or two tyres, which is probably what has happened to Drake's pump.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Tangled Metal
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Joined: 13 Feb 2015, 8:32pm

Re: Bicycle pump.

Postby Tangled Metal » 5 May 2016, 8:42am

My pocket rocket works ok for a get you home pump. That's all it is. Gone are the days of a large frame pump that comes with the bike so you need to own a few pumps these days emergency carry, track pump at home and a more substantial but portable pump for longer tours.

My preference is to not have the need of them. So far I get away with the track pump. Had two pc's in the last 7 years. One a slow p that was only spotted at home with the track pump to hand. The other was 2 minutes walk home to switch to the car. I'm lucky or perhaps just use heavy puncture resistant tyres... or both!

Anyone know where to get a pocket.rocket bottle cage bracket from to carry it in? Mine got stolen with the bike.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Bicycle pump.

Postby Brucey » 5 May 2016, 8:50am

Tangled Metal wrote:
Anyone know where to get a pocket.rocket bottle cage bracket from to carry it in? Mine got stolen with the bike.


http://www.sjscycles.co.uk/topeak-topeak-pump-mounting-bracket-for-pocket-rocket-micro-speed-prod40637/

BTW talk of how few times you have needed a pump in the last few years is a sure-fire way of inviting a big wet kiss from the puncture fairy, isn't it...?.... :roll:

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

pwa
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Joined: 2 Oct 2011, 8:55pm

Re: Bicycle pump.

Postby pwa » 5 May 2016, 9:25am

I find myself in the extraordinary position of having to contradict Brucey! I have several Zefal HPX frame pumps that, with occasional lubing, have lasted years and are still able to get a road tyre up to somewhere north of "too hard for me to ride on". The thing that locks out the spring when you pump needs lubing to keep working, but the pump is a really good, dependable classic. So a truly good pump is possible.

I've come to the conclusion that dual action pumps, that put air in on the push and the pull, are a very bad idea. It is very hard work to force air in on the pull stroke. It's not natural for the arms to work in that way.

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squeaker
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Location: Sussex

Re: Bicycle pump.

Postby squeaker » 5 May 2016, 9:41am

Used a Zefal telescopic MTB pump for many years - no longer made :roll: :lol:
"42"

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Bicycle pump.

Postby Brucey » 5 May 2016, 9:50am

pwa wrote:I find myself in the extraordinary position of having to contradict Brucey! I have several Zefal HPX frame pumps that, with occasional lubing, have lasted years ....



ah, but I said 'most pumps are junk' not 'all pumps are junk'.... :lol:

There are such things as non-junk pumps.

Zefal HP/HPX pumps have a proper cup washer that doesn't wear out too quickly, and a head that isn't overly complicated / is reasonably well constructed. I own three Zefal HP pumps and the only thing that has given me any real trouble is that on one of them, the 'body seal' that seals between the bore of the head and the sliding part within occasionally fails to seal properly. I think it may need a new 'O' ring, but then again it may be a tolerancing issue.

I have even repaired Zefal HP pump barrels that have been dented; it turns out that using a few long series sockets of slightly different diameters, and a little work with a soft hammer, normal function can usually be restored.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

pwa
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Joined: 2 Oct 2011, 8:55pm

Re: Bicycle pump.

Postby pwa » 5 May 2016, 10:12am

Since retiring my Zefal HPX pumps (different sizes for different bikes) I have been using a pump I bought on impulse from Halfords when I really went in for something else. It is their own "Bikehut" version of the mini track pump, with a hose, much like the Topeak and Lezyne ones. It is a bit cheapo in construction and I would not recommend anyone buy that specific model, but it has converted me to mini track pumps as a type. It is easier (less sweat dripping off the end of the nose) to get a road tyre up to the pressure I normally prefer (about 90psi) than with the frame fit pumps I previously used. For a small pump that fits in my rack top bag that is remarkable.

The first time I had to use it was half way up the Taff Trail in South Wales, and it was a sunny day. I had a park bench to sit on and all was well with the world. So not exactly testing under adverse conditions. But I was really pleased when I found how easy to use it was. With the wheel leaning against something, I had no need to hold it. The pump was easily controlled because all the force is directed down into the ground, so I didn't have to strain to keep the pump steady. The strokes were easy, and every one put air into the tyre. I didn't count the strokes, and it may have taken a lot, but they were so easy that the tyre was up to full working pressure in two or three minutes. The only pumps that I have found easier to use have been full sized track pumps.

As I say, that particular model does not look as though it is made to last, so I will eventually move on to a better made equivalent from the likes of Topeak and Lezyne. The Truflo upthread looks like another contender. My Pocket Rockets are at the bottom of a drawer and are likely to stay there.

Tangled Metal
Posts: 7622
Joined: 13 Feb 2015, 8:32pm

Re: Bicycle pump.

Postby Tangled Metal » 5 May 2016, 10:18am

Brucey wrote:
Tangled Metal wrote:
Anyone know where to get a pocket.rocket bottle cage bracket from to carry it in? Mine got stolen with the bike.


http://www.sjscycles.co.uk/topeak-topeak-pump-mounting-bracket-for-pocket-rocket-micro-speed-prod40637/

BTW talk of how few times you have needed a pump in the last few years is a sure-fire way of inviting a big wet kiss from the puncture fairy, isn't it...?.... :roll:

cheers

Yes but I've always been lucky. Went 7 years with the tyres that came with the bike without a puncture despite them cracking and perishing a bit. Skinny tyres run at 110-120 psi without any puncture protection in them too.
Yeah! Tempting fate I know, but I feel lucky.

Thanks for the link but after reading this thread I'm thinking I'll just splash out on something new in the pump department. I'm due a spend I think.

Samuel D
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Re: Bicycle pump.

Postby Samuel D » 5 May 2016, 10:52am

I have a Zefal HPX that leaks around the head area (not exactly sure where). It did this from new, but due to particular circumstances I couldn’t return it. Would it be worth my while trying to find a way to remove the head and attempt a fix? I believe I would need an extremely long screwdriver to do this (hence my not having done it yet).