I have been riding and looking at the Silvio site since Aug of 08. My question to all Silvio riders is this. Have any of you had problems with the air shock? I have been having air leakage for sometime now, start with 140 6 hrs later 70lbs and 60 miles. John sent a replacement, but would not fit and also the unit was binding and not damping. I did read on this site of the same problem, was the cause ever found. Thanks for listening.
Air shock management
- Thread starter WhiteSilvio
- Start date
WhiteSilvio
Well-Known Member
Re: Air shock problems
I had problems with my front suspension unit. I road with it dropping pressure for some time, pumped it up to 180 psi and yet it always dropped to 60 to 70 almost straight away, and the rubber cover looked like the shock/spring was flat, which it effectively was.
I had to make sure I was inflating the unit correctly, the Kindshock instructions for pump usage only made sense when you new how the pump worked; Catch 22! There is an explanation on the Cruzbike site. Just type "Kindshock pump" in the search box and a link will be revealed.
So, having made sure I was doing that properly, and unfortunately not solved the problem, I investigated the Schrader valve input.
It turned out that this valve was leaking in some way. I replaced the valve core; bought a valve removal tool and cleaned out the threads for the valve in the valve stem body on the bike, and fitted the new valve core (bought some spare valve cores). Pumped the unit up to pressure required and away I went!
The pressure now only drops very slowly, and not by much more than the small volume of air that escapes when one connects the pump.
You may have other problems, but if the unit is reasonably new the seals should be okay (Did you start riding the Silvio in Aug 08?). But there could be problems with these if they have been incorrectly assembled or damaged when being assembled. Not too lightly.
I hope this helps.
Regards,
John R
Hi Landecker,
I had problems with my front suspension unit. I road with it dropping pressure for some time, pumped it up to 180 psi and yet it always dropped to 60 to 70 almost straight away, and the rubber cover looked like the shock/spring was flat, which it effectively was.
I had to make sure I was inflating the unit correctly, the Kindshock instructions for pump usage only made sense when you new how the pump worked; Catch 22! There is an explanation on the Cruzbike site. Just type "Kindshock pump" in the search box and a link will be revealed.
So, having made sure I was doing that properly, and unfortunately not solved the problem, I investigated the Schrader valve input.
It turned out that this valve was leaking in some way. I replaced the valve core; bought a valve removal tool and cleaned out the threads for the valve in the valve stem body on the bike, and fitted the new valve core (bought some spare valve cores). Pumped the unit up to pressure required and away I went!
The pressure now only drops very slowly, and not by much more than the small volume of air that escapes when one connects the pump.
You may have other problems, but if the unit is reasonably new the seals should be okay (Did you start riding the Silvio in Aug 08?). But there could be problems with these if they have been incorrectly assembled or damaged when being assembled. Not too lightly.
I hope this helps.
Regards,
John R
Re: Air shock problems
Yes John, I have been riding the Silvio since Aug 08. And only as of Aug 2009 have I started to have this air shock problem. So the pumping technique is not the problem, it seems to me that there might be some internal wear that causes the air loss.
I also replaced the valve core. Still the air loss continues. And the 140# of air is actual at the start of my rides only to end at 70#. There is a huge difference in handling and comfort without that air shock functioning.
Just wondering how many miles/kilo have you rode your Silvio? Have you any mods, or changes made after riding the bike.
Yes John, I have been riding the Silvio since Aug 08. And only as of Aug 2009 have I started to have this air shock problem. So the pumping technique is not the problem, it seems to me that there might be some internal wear that causes the air loss.
I also replaced the valve core. Still the air loss continues. And the 140# of air is actual at the start of my rides only to end at 70#. There is a huge difference in handling and comfort without that air shock functioning.
Just wondering how many miles/kilo have you rode your Silvio? Have you any mods, or changes made after riding the bike.
John Tolhurst
Zen MBB Master
Re: Air shock problems
The shock internals comprise a single bag of some kind of plastic, there are no interfacing joints within the shock, so if the shock hold air its good; if it doesn't pump up, its bad; and if it leaks, its the valve.
WhiteSilvio
Well-Known Member
Re: Air shock problems
Ah well it was worth mentioning these things as they could have been a problem.
Or it is actually the valve, which seems unlikely if you have replaced the valve core, and made sure there are no burrs or foreign material under the valve core seat where the valve core seats onto the valve stem tube, and that it is tight. If that's all okay, I'd be trying another valve core, it could be that the valve seal itself isn't working. {There are two seal points for the valve core, the valve itself and the seal between the wall of the stem tube and the outside of the valve core.}
It's hard to explain the loss of air. In my case the air went out of the shock fairly quickly. From what you're saying I take it that it is a fairly "slow" leak.
Does it go down without riding it or applying any load?
Also, if you are using the metal cap on the valve, with its rubber seal, do you hear a little "hiss" when you remove the cap after the unit has been pumped up for a while?
I've done over 12000km on my Silvio. No major mods. Just a the odd refinement here and there, like the mod to the rear Ti spring to relieve the stress point.
Otherwise pretty standard. Mine was one of the original pilot production run back in early 2008.
Regards,
John R.
Hi Landecker,
Ah well it was worth mentioning these things as they could have been a problem.
John T is saying that there are no "seals" to deteriorate or damage, which suggests the possibility that the "bladder" is damaged. The bladder must rub against its container and deform somehow. And the "bladder" must be attached to the inlet valve somehow, there will most probably be some relative movement between the two, unless it is fixed somehow at some point, probably the "top" end, and that's where the valve exits.
Or it is actually the valve, which seems unlikely if you have replaced the valve core, and made sure there are no burrs or foreign material under the valve core seat where the valve core seats onto the valve stem tube, and that it is tight. If that's all okay, I'd be trying another valve core, it could be that the valve seal itself isn't working. {There are two seal points for the valve core, the valve itself and the seal between the wall of the stem tube and the outside of the valve core.}
It's hard to explain the loss of air. In my case the air went out of the shock fairly quickly. From what you're saying I take it that it is a fairly "slow" leak.
Does it go down without riding it or applying any load?
Also, if you are using the metal cap on the valve, with its rubber seal, do you hear a little "hiss" when you remove the cap after the unit has been pumped up for a while?
I've done over 12000km on my Silvio. No major mods. Just a the odd refinement here and there, like the mod to the rear Ti spring to relieve the stress point.
Otherwise pretty standard. Mine was one of the original pilot production run back in early 2008.
Regards,
John R.
WhiteSilvio
Well-Known Member
Re: Air shock problems
There have been a few Silvio owners who have suffered broken Titanium rear "springs". This is a link to the thread started by Super Slim.
Broken Titanium Spring 2
I have relieved the top of the rear frame as per Slim's drawing and you can see the result on the second page of the thread, in a post by me on the 29/01/'10.
Have a look at Super Slim's Autocad LT drawing at the beginning of the thread.
I also relieved the other end of the connection of the spring to the mainframe, but that isn't really evident in my picture. This end is not nearly as critical as the rear frame end as it is a line contact rather than the concentrated "point contact" at the rear frame. (See Super Slim's picture of this connection modification in the third picture down in the first post of the thread.)
I haven't modified he elastomer "stop/spring"(cushioning material), but others have done so, in fact, the current Silvio is supplied with a different shaped material to give a "more forgiving" increase in spring rate (your Silvio may even have a different one to the original cylindrical ones). I'm sure there are other threads in the Silvio section on the shape and material of this "stop/spring". There may even be further information on the Cruzbike site, or JohnT or Doug Burton, could help with regards to what is available as replacement "springs".
Regards,
John R.
PS Keep us informed regarding the leaking front shock. I for one am keen to find out what has happened there.
Hi Landecker,
There have been a few Silvio owners who have suffered broken Titanium rear "springs". This is a link to the thread started by Super Slim.
Broken Titanium Spring 2
I have relieved the top of the rear frame as per Slim's drawing and you can see the result on the second page of the thread, in a post by me on the 29/01/'10.
Have a look at Super Slim's Autocad LT drawing at the beginning of the thread.
I also relieved the other end of the connection of the spring to the mainframe, but that isn't really evident in my picture. This end is not nearly as critical as the rear frame end as it is a line contact rather than the concentrated "point contact" at the rear frame. (See Super Slim's picture of this connection modification in the third picture down in the first post of the thread.)
I haven't modified he elastomer "stop/spring"(cushioning material), but others have done so, in fact, the current Silvio is supplied with a different shaped material to give a "more forgiving" increase in spring rate (your Silvio may even have a different one to the original cylindrical ones). I'm sure there are other threads in the Silvio section on the shape and material of this "stop/spring". There may even be further information on the Cruzbike site, or JohnT or Doug Burton, could help with regards to what is available as replacement "springs".
Regards,
John R.
PS Keep us informed regarding the leaking front shock. I for one am keen to find out what has happened there.
John Zabriskie
Member
Air shock problems, fork binding on return solution
I experienced the problem with fork stiction or binding on my Silvio (CBSV-054). Even @ 200 psi, the fork would collapse & not return until I got off the bike. Even then it would take 20 seconds or so to get to full extension.
So far, I've been able to get functionality back by a partial disassembly & limited pressurization. After stripping the fork from the bike, I pulled the rubber boot off the top to get access to the sliding shaft. I bled off all the pressure from the Schraeder valve. I left the star-fangled nut in place, but tried to remove the setscrews, on each side 3" below. The one on the left broke free after a bit of effort & I completely removed it. However, the right one wouldn't budge, no matter what I tried. I even tried to heat the area up a bit over the stove (mild heat, instead of a torch), thinking the aluminum tube would expand faster than the steel setscrew.
I also pulled the Schraeder valve off & was surprised to be able to exercise the fork thru its full range of motion. Looking back on this, I'm wondering if by removing the left setscrew, whatever stresses remained between the parts were shifted to the setscrew on the other side when the parts relaxed. I suspect the parts relaxation eliminated some of the binding in the fork motion, but also transfered more load to the remaining setscrew making it impossible to get out. [Note: Unfortunately, I stripped the hex socket after bending the hex wrench permanently.]
Regardless, the fork seemed to slide now with relative ease. After replacing the Schraeder valve, two strokes of the shock pump (an indicated 5 psi) caused full extension. At this point, I flipped the fork upside down & proceeded to inject lubricant at the shaft / collar interface. I then exercised the fork for about 50 or so strokes. I then bled off all the pressure & collapsed the fork. Again I attached the shock pump & again 2 strokes caused full extension. [EDIT: I don't think it is necessary to inject more lubricant unless you've got grit problems or intermittent smoothness. Then the lubricant would act as a cleansing agent.]
I wiped off all the excess lubricant from the shaft & collar, then exercised the fork (right side up) for 10 more strokes. It was at this point, I noticed an interesting artifact on the shaft. There was a thin, gray oil line on the shaft exactly midway in the travel. I wiped this off again, but it came back again after a few strokes. It seems to be the travel limit of the shaft wiper seal [Thanks, JT for pointing this out].
Finally, I bled off the pressure & reinstalled the setscrew & the boot, since things seemed to be working. Upon repressurization, 2 strokes again caused full extension, implying no more binding. Increasing the pressure to 100 psi, caused no real change, other than increasing the force required to move the fork. I left it overnight & 100 psi to see if it a) lost pressure & b) still functioned properly. No problems in the morning. [Note: rotate the boot so the 2 vent holes are perpendicular to the front of the bike. This will keep the vent holes from being directly in line with junk thrown up from the tire.]
Although some of the binding may be due to displaced lubricant or grit on the shaft, I think the main culprit is some sort of deflection or distortion between internal components. This may be residual stresses from initial assembly, but I suspect we may experience fork binding problems among heavier riders on rough roads & not among lighter riders on smooth roads as the aluminum components move relative to each other under load. Removing the setscrew seems to relax & eliminate the binding. Please note that this is not a factory suggested or condoned procedure; It is just one Silvio owner's experience & your mileage may vary.
I'll keep the forum appraised of the longevity of this success. For now, it's behaving very, very nicely.
I experienced the problem with fork stiction or binding on my Silvio (CBSV-054). Even @ 200 psi, the fork would collapse & not return until I got off the bike. Even then it would take 20 seconds or so to get to full extension.
So far, I've been able to get functionality back by a partial disassembly & limited pressurization. After stripping the fork from the bike, I pulled the rubber boot off the top to get access to the sliding shaft. I bled off all the pressure from the Schraeder valve. I left the star-fangled nut in place, but tried to remove the setscrews, on each side 3" below. The one on the left broke free after a bit of effort & I completely removed it. However, the right one wouldn't budge, no matter what I tried. I even tried to heat the area up a bit over the stove (mild heat, instead of a torch), thinking the aluminum tube would expand faster than the steel setscrew.
I also pulled the Schraeder valve off & was surprised to be able to exercise the fork thru its full range of motion. Looking back on this, I'm wondering if by removing the left setscrew, whatever stresses remained between the parts were shifted to the setscrew on the other side when the parts relaxed. I suspect the parts relaxation eliminated some of the binding in the fork motion, but also transfered more load to the remaining setscrew making it impossible to get out. [Note: Unfortunately, I stripped the hex socket after bending the hex wrench permanently.]
Regardless, the fork seemed to slide now with relative ease. After replacing the Schraeder valve, two strokes of the shock pump (an indicated 5 psi) caused full extension. At this point, I flipped the fork upside down & proceeded to inject lubricant at the shaft / collar interface. I then exercised the fork for about 50 or so strokes. I then bled off all the pressure & collapsed the fork. Again I attached the shock pump & again 2 strokes caused full extension. [EDIT: I don't think it is necessary to inject more lubricant unless you've got grit problems or intermittent smoothness. Then the lubricant would act as a cleansing agent.]
I wiped off all the excess lubricant from the shaft & collar, then exercised the fork (right side up) for 10 more strokes. It was at this point, I noticed an interesting artifact on the shaft. There was a thin, gray oil line on the shaft exactly midway in the travel. I wiped this off again, but it came back again after a few strokes. It seems to be the travel limit of the shaft wiper seal [Thanks, JT for pointing this out].
Finally, I bled off the pressure & reinstalled the setscrew & the boot, since things seemed to be working. Upon repressurization, 2 strokes again caused full extension, implying no more binding. Increasing the pressure to 100 psi, caused no real change, other than increasing the force required to move the fork. I left it overnight & 100 psi to see if it a) lost pressure & b) still functioned properly. No problems in the morning. [Note: rotate the boot so the 2 vent holes are perpendicular to the front of the bike. This will keep the vent holes from being directly in line with junk thrown up from the tire.]
Although some of the binding may be due to displaced lubricant or grit on the shaft, I think the main culprit is some sort of deflection or distortion between internal components. This may be residual stresses from initial assembly, but I suspect we may experience fork binding problems among heavier riders on rough roads & not among lighter riders on smooth roads as the aluminum components move relative to each other under load. Removing the setscrew seems to relax & eliminate the binding. Please note that this is not a factory suggested or condoned procedure; It is just one Silvio owner's experience & your mileage may vary.
I'll keep the forum appraised of the longevity of this success. For now, it's behaving very, very nicely.
John Zabriskie
Member
Re: Air shock problems - solution update
!st day of commuting with the renewed Silvio fork. It worked very well -- I'm elated. It was especially reassuring to hear the "whoosh" of exiting air from the boot as I crossed RR tracks. The ride was almost supple, with no bottoming. [I'm running 185 psi in the shock & weigh 205#.] I actually sought out pothole patches & surface roughness to "test" the suspension. It passed with flying colors.
!st day of commuting with the renewed Silvio fork. It worked very well -- I'm elated. It was especially reassuring to hear the "whoosh" of exiting air from the boot as I crossed RR tracks. The ride was almost supple, with no bottoming. [I'm running 185 psi in the shock & weigh 205#.] I actually sought out pothole patches & surface roughness to "test" the suspension. It passed with flying colors.
georgec
Member
front shock problem
My 2012 Silvio front shock is exhibiting behavior very similar to what John describes here.
It holds air pressure just fine. But it collapses after a few bumps, and does not seem to absorb bumps for the rest of the ride. It returns to full extension when I get off of the bike.
Is the approach that John describes above the recommended way to remedy the problem?
Is there a recommended lubricant?
My 2012 Silvio front shock is exhibiting behavior very similar to what John describes here.
It holds air pressure just fine. But it collapses after a few bumps, and does not seem to absorb bumps for the rest of the ride. It returns to full extension when I get off of the bike.
Is the approach that John describes above the recommended way to remedy the problem?
Is there a recommended lubricant?
super slim
Zen MBB Master
a metal valve cap with a
a metal valve cap with a rubber seal might solve the problem, as car tyres leakage rate is 4 times more without a metal cap!
Water is a good lubricant.
a metal valve cap with a rubber seal might solve the problem, as car tyres leakage rate is 4 times more without a metal cap!
Water is a good lubricant.
