Rockshox pump not working with Lyrik fork

[DaveNewing]

I've had my Turbo Levo for a little while now and decided to play around with fork and shock pressures. I have a Rockshox shock pump. When I screw the pump onto my Rockshox rear shock, it displays the pressure on the dial before I start pumping. However, when I screw the same pump onto my Lyrik Select fork there isn't any pressure reading. Even when I start using the pump I only appear to be pressurising the pump hose.
Any ideas how to fix this, or is it a common problem?

 

[Mikerb]

Sounds like the shraeder vavle on the Lyric is stuck or you are not screwing the pump onto the valve far enough to operate the valve. Operate the valve a few times a remove it if necessary to ensure it is operating freely.

 

[Beekeeper]

I’ve had a few issues in the past because I simply hadn’t screwed the adaptor in far enough to open the valve in the fork and I was only pressuring the pump tube and not the fork.

 

[DaveNewing]

I’ve had a few issues in the past because I simply hadn’t screwed the adaptor in far enough to open the valve in the fork and I was only pressuring the pump tube and not the fork.

I've screwed the pump as far as I can with my fingers. I've released small amounts of air from the fork a couple of times to check the valve works. I still can't get the pump to give a pressure reading. I have another bike with Fox 34's and that works perfectly OK, it's just this Lyrik I can't get a reading.

 

[DaveNewing]

Sounds like the shraeder vavle on the Lyric is stuck or you are not screwing the pump onto the valve far enough to operate the valve. Operate the valve a few times a remove it if necessary to ensure it is operating freely.

I'll try and remove the valve from the fork and then reinstall it. I'll let you know if this works.

 

[RedTed]

My pump has a collar that attaches to the shock valve and then a second knurled ring that actually engages the valve. Means you can connect/ disconnect pressure without removing the pump. Is the a similar feature on the Rockshox?

 

[DaveNewing]

My pump has a collar that attaches to the shock valve and then a second knurled ring that actually engages the valve. Means you can connect/ disconnect pressure without removing the pump. Is the a similar feature on the Rockshox?

No, the standard Rockshox pump only has one knurled part that rotates, this then connects to the rubber hose.

 

[DaveNewing]

I have removed all the air and the valve core from my fork leg. I've checked the valve core operates smoothly and refitted everything back together. The Rockshox website recommends a starting pressure of 93 psi for my weight and ebike. The gauge does read a pressure when inflating the fork, bit not sure if it is correct. I took 140 psi reading on my pump before I could get 30% sag on my fork. Are the Rockshox recommended pressures really that far off, or is my pump still the problem?

 

[Mikerb]

Probably the pos and neg chambers are not equalised. Release the air and start again but cycle the shock a few times every 10 psi.

 

[Mikerb]

Initially the pump should have little resistance and after pressureising to 10 to 15 psi the fork should start to expand. When you cycle the fork with pump removed and then re atfach the pump the pressure should be less showing that air has equalised between the chambers. Repeat. Starting pressure is your weight in kg converted to psi.

 

[DaveNewing]

Initially the pump should have little resistance and after pressureising to 10 to 15 psi the fork should start to expand. When you cycle the fork with pump removed and then re atfach the pump the pressure should be less showing that air has equalised between the chambers. Repeat. Starting pressure is your weight in kg converted to psi.

Still no luck. I have let all the air out of the fork leg and pumped it up at about 15 psi increments, then cycled the fork each time. If I remove the pump and reconnect it, then I have no pressure showing on the gauge. I have to operate the pump until the pump pressure balances with the fork pressure before I can read anything on the gauge. I carried on pumping up and cycling the fork every 15 psi, but I still need about 140 psi on the pump gauge before I get to 30% sag. I just don't understand this.
The rear shock and pump gauge work perfectly, as soon as I connect the pump to the rear shock, it instantly shows the pressure.

 

[Mikerb]

Is this the first time you have pressurized the fork? Pumping to 15psi the cycling the fork is likely to mean a zero pressure reading since by cycling thr fork the air in the upper chamber is transferred to the lower chamber. Also make sure the rebound is on full fast when pressurising the fork. It usually takes 5 cycles to 50% fork travel to balance the chambers. If the fork is new it may need rather more extensive cycling if for example the bypass valve is blocked with grease .

 

[Mikerb]

Maybe just pump it up and then ride it bouncing the bike hard on the suspension. You could also try when the fork is pressurised, burping it. To burp it slip the retaining spring off the dust seal and carefully push a zip tie end between the dustseal and stancion. If air escapes the fork will need a service.

 

[DaveNewing]

Is this the first time you have pressurized the fork? Pumping to 15psi the cycling the fork is likely to mean a zero pressure reading since by cycling thr fork the air in the upper chamber is transferred to the lower chamber. Also make sure the rebound is on full fast when pressurising the fork. It usually takes 5 cycles to 50% fork travel to balance the chambers. If the fork is new it may need rather more extensive cycling if for example the bypass valve is blocked with grease .

The fork/bike is about 3 months old and I've ridden about 700Km with the shop set sag and pressure. I have found the fork to be a little harsh on small bump sensitivity, so I thought I would try different settings. I have just removed the retaining spring on the dust seal and pushed a cable tie past it. No air leaked out at all! I've researched different shock pumps and some have independent knurled sections, one for screwing onto the valve and the other for engaging the shraeder valve pin. My pump doesn't seem to engage the shraeder pin, so it might be worth getting a different brand of shock pump?

 

[Mikerb]

Worth trying a different pump...borrow one? Also worth seeing how many tokens are fitted whilst you are messing about with the fork. Assuming it has one or more tokens fitted you will need less than the psi equivalent of your bodyweight in kg.

 

[steve_sordy]

Replace the valve core on the fork. The nipple could be too short.