What’s everyone using for shock pumps, I got a Bontrager one that works ok but the guage doesn’t seem to be very accurate.
Still using the one that came with my Trance 0 back in 2007. No branding on it.
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Digital Fox Shock Pump.
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does the Fox have the 2 stage schrader valve do you don’t lose any pressure the disconnecting it? I cant find anything online that tells me
Me too. Nothing beats it IMO.
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Just ordered in the Topeak Pocketshock through Sportwheels based on this comparison Under pressure! 15 shock pumps in review | ENDURO Mountainbike Magazine
This time around I want to spend more time tuning and dialling in my bike setup. Back in 08 I just rode my Stumpjumper as it was setup for me when I first purchased it and never learned much about working on my bike beyond how to change the tires and tubes.
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No, I have never seen a shock pump with that actually.
For what its worth, I check Tire pressure and fork/shock pressure every ride. Its a tip I picked up a few years ago. Seems obsessive, but it allows you to never have to “adjust” to your bike.
Very small increments of pressure in a rear shock make a huge difference im how the bike reacts.
Cheers
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the bontrager one has it and its a pretty nice feature
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Rock show. It does lose pressure when disconnecting so I go 5lbs heavier before disconnect and it balances out
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You don’t lose air when you disconnect your pump unless the valve on the shock or the pump head is damaged.
When you unscrew the pump from your shock it disengages from the valve on the shock which closes the valve. The hiss you hear after that is pressurized air escaping from the pump hose and body not from the shock.
“But when I reattach my pump the gauge reads lower” you say. Yes, because when you reattach the pump and the valve on the shock is opened, pressurized air flows from the shock into the pump lowering the pressure slightly.
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I would have to argue the no air is lost part. Although I agree some of that is the pressurized air coming back out of the pump/hose, it is virtually impossible with a regular Schrader valve to unscrew it and not have some air escape from the valve side, especially under the 100psi the fork probably has in it and the extremely small volume of air in there, any loss would be a drop in psi.
As well, some shock pumps have a 2 stage valve so you can connect the pump without depressing the valve and then once the pump is attached and sealed, the second stage will open the valve. The manufacturers had to also think there is air loss for adding this to the design, as manufacturing costs would certainly be higher .
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That’s simply not how a Schrader works in conjunction with a shock pump. But hey, don’t take my word for it-
As for why a manufacturer would put an unnecessary feature on a product- so you buy theirs instead of their competitor’s because it has “more features”. You won’t find that function on the majority of pumps for good reason.
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Not trying to argue, but as with anything, you can find a study to prove or disprove any point you want. I’ll will say one thing, any study using a ShockWiz to take, what would require precise measurements to prove, is questionable to begin with. That said, a ShockWiz is simply not precise enough show losses below a give threshold (1 psi it appears). No pump head is fully sealed until fully threaded on, at which time it typically hits an o-ring and causes a seal. On single stage pump head, at a point after starting to thread the head on and before it is completely sealed, the valve is partially opened, that just how they work. Air under pressure will naturally travel to the area of lower pressure, that’s just physics. Given its not completely sealed at the o-ring, and the treads are not air tight, it has to escape somewhere. A loss regardless of its materiality would still be a loss.
You can believe whatever you like. I didn’t think this was an argument but I simply don’t agree with you and neither do suspension manufacturers.
Seems like you’ve made up your mind that the two stage designs are better- power to you, use what you prefer.
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You can as well. Have a great weekend.
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You too!
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Just curious, what was your take?
I was going to say you don’t lose air when disconnecting but you do when connecting the shock pump. The theory makes sense and I would now consider it more than theory cause when I screw the shock pump on as far as I can without opening the shock valve, then pressurize the pump to the shock pressure and then finish by screwing the pump all the way on the shock never loses pressure.
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I used to be under the impression that the shock was losing air and just thought my shock was always just a bit lower pressure than what I had pumped it too.
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Riddle me this then, we all agree that you lose pressure when connecting the pump, no debate there. How could you possibly tell that you didn’t lose any when disconnecting the pump, if the only way to check is to then reattach the pump, in which we all agree loses pressure?
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