EUCzero Posted May 3, 2023 Share Posted May 3, 2023 (edited) 23 hours ago, Cerbera said: I did not ! I asked about that up further in the thread and @Hellkitten said it didn't matter, I thought the kit I bought would be fine !! However when I removed the old valve core it looked absolutely identical to the new one I replaced it with ! I only pump to 200 PSI ish anyway. Thanks for the dish soap trick - that's a good idea I will try later today ! Pumping to 200Psi will give you aprox 350psi on hard landings (bottom out 25mm compressed) Remember that the pressure you pump it to is the zero compression pressure. The pressure inside the shock will increase when in use and compressed. The pressure doubles when the shock is compressed 30mm. Edited May 3, 2023 by EUCzero 1 1 Quote Link to comment Share on other sites More sharing options...
EUCzero Posted May 3, 2023 Share Posted May 3, 2023 (edited) I have serviced my shock many times when working on the volume reducer. Unfortunatly Begode will not sell service kits (rubber rings, gaskets etc). So I have only re-greased and oiled it. Begode airshock do not have a negative chamber It has the main air chamber for compression pressure, and a smaller oil chamber for the dampening. The oil chamber is horrible to refill. DO not try Some grease on the gaskets, and a few drops of shock oil inside the chamber is all that is needed. But the gaskets can of course be broken. The video is shoving the montage of a volume reducer, but there is some free info there as well Edited May 3, 2023 by EUCzero 1 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted May 3, 2023 Share Posted May 3, 2023 (edited) 23 minutes ago, EUCzero said: Begode airshock do not have a negative chamber Since there is a piston, there is a negative chamber. Most shocks just don’t have a separate valve for it, and the pressure will balance with the main chamber through grooves in the cylinder once the piston gets to a certain position. If there weren’t a groove to balance the pressures, the negative chamber would have a huge pressure just from assembling the shock, since all the air volume of the shock would have nowhere to go. Edited May 3, 2023 by mrelwood Quote Link to comment Share on other sites More sharing options...
EUCzero Posted May 3, 2023 Share Posted May 3, 2023 (edited) There are no grooves between the two chambers. And no pressure equalization between the chambers. If so it is extremely well hidden. I have looked for it for hours. Even asked Begode about it (no real answer). And because of it it can sometimes be very hard to close it all up again. The pressure just leaks out to atmosphere. Not between the Chambers. Edited May 3, 2023 by EUCzero 1 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted May 3, 2023 Share Posted May 3, 2023 2 minutes ago, EUCzero said: The pressure just leaks out to atmosphere. Through the stem seal? I find that quite hard to believe. If that were the case, the negative chamber pressure would initially get negative when you get on the wheel, but would slowly let air in to make the pressure equalize with the atmosphere. This would make a clear increase in sag, which would again equalize and drop the sag even further. Does the sag really drop noticeably if you stand on the wheel for a while? Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 3, 2023 Author Share Posted May 3, 2023 1 hour ago, EUCzero said: I have serviced my shock many times when working on the volume reducer. Unfortunatly Begode will not sell service kits (rubber rings, gaskets etc). So I have only re-greased and oiled it. Begode airshock do not have a negative chamber It has the main air chamber for compression pressure, and a smaller oil chamber for the dampening. The oil chamber is horrible to refill. DO not try Some grease on the gaskets, and a few drops of shock oil inside the chamber is all that is needed. But the gaskets can of course be broken. The video is shoving the montage of a volume reducer, but there is some free info there as well Thank you - that really will be tremendously useful when I come to service mine !! Quote Link to comment Share on other sites More sharing options...
EUCzero Posted May 3, 2023 Share Posted May 3, 2023 10 hours ago, mrelwood said: Through the stem seal? I find that quite hard to believe. If that were the case, the negative chamber pressure would initially get negative when you get on the wheel, but would slowly let air in to make the pressure equalize with the atmosphere. This would make a clear increase in sag, which would again equalize and drop the sag even further. Does the sag really drop noticeably if you stand on the wheel for a while? If I put any grease on the "stem seal" at all, I was not able to close the shock. I had to keep it completely dry. Anyway. I agree there should be a a groove somewhere, but I have looked and looked to find it.... no success. But let's not use this thread to discuss that. I will look into it further oner day when I have time. 1 1 Quote Link to comment Share on other sites More sharing options...
Hellkitten Posted May 5, 2023 Share Posted May 5, 2023 On 5/2/2023 at 3:32 AM, Cerbera said: Hellkitten said it didn't matter, Hey that’s not what I said! 🤣 I said I switched the valves on my suspension and used much less pressure than you. I also mentioned never having done it on your style of shock, only that the valve should fit. For the record my shocks are at 140psi below the 200psi limit that I didn’t know about. Glad to hear you can still ride your wheel! 2 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 5, 2023 Author Share Posted May 5, 2023 (edited) Took some photos of it today and did some additional tests to try and find out what the rate of deflation is, or to identify where it is coming from. The whole shock is, I have to admit, generally filthy, from mud and rain and inaccessibility to clean easily, so I am currently imagining that some dirt must have got in and compromised a seal somewhere. I did a macro shot or 2 of the adjustment wheel, noting how much crud there (pic 1) was in there before I tried to swab it all out (pic 2) So with that adjustment wheel fully 'open' I can note the grooves therein (I presume these aren't the same grooves people are looking for further up this thread?) which I can see how dirt might also be compromising, though less so because I normally ride with this control 3 clicks to the left of fully 'in' so these are not exposed during normal riding. Anyway, just posting these for my own reference, and to run my latest thoughts past people that know better ! Have also put a support ticket into Speedyfeet to see if a new unit is a possibility... TBH - I am also considering investing in a spring alternative - I am getting properly fed up with constantly re-inflating this one !! Thank you everyone, for your help with this so far... Edited May 5, 2023 by Cerbera 1 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 9, 2023 Author Share Posted May 9, 2023 (edited) Just to let you know, Begode and Speedy Feet have kindly agreed to replace my shock under Warranty, without me having to send the old one back first, which is very good of them. This brings the total of replacement parts Begode has supplied for this machine to...4 !! 1 x Power pad, original ripped in box 1 x Charge Board RC2 1 x Display board 1 x Shock So, although we might complain that these things need swapping out, we should definitely give Begode some props (not to mention speed feet) for honouring their warranty and keeping me in free replacements ! Every time something like this happens I thank my lucky stars I didn't buy this wheel from AliXpress ! Now, I suppose it would be sensible to also replace the linkages for the updated ones while I'm at it ? Would we recommend that, given that I was mainly happy with the original ones (before the shock started leaking !), or is it a load of old faff / not worth the cost ? What I will be doing is getting @Rawnei's awesome shock cover printed this time to hopefully prevent the new one getting crap in its seals, which is what I assume has buggered the first one ! Edited May 9, 2023 by Cerbera 2 1 Quote Link to comment Share on other sites More sharing options...
EUCzero Posted May 10, 2023 Share Posted May 10, 2023 I got my Master from Loomo on Aliexpress. With NO real discussions I got (all on different occassions) : 2 new shocks Charge board Display board New bearings So. Not a real problem. Do you think Speedyfeet would send you a new one if Begode said no? Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 10, 2023 Author Share Posted May 10, 2023 1 hour ago, EUCzero said: So. Not a real problem. Do you think Speedyfeet would send you a new one if Begode said no? That's hard to say... but as it happens they ordered a load of spares with the main wheel order, so had one in stock which will be with me within a week of first contacting them. Glad to hear you had a good experience with Loomo, but I read about many many others who have tales of extended woe from AXP... Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 10, 2023 Author Share Posted May 10, 2023 (edited) 20 mile dusk ride today, on unfamilar ground. Found a new farm road that led from my home town all the way to the next village that cars aren't meant to use, but remains in pretty good condition, and that was great fun wheeling for a small evening picnic on Buriton Green... But if you're ever thinking that the South Downs Way in Hampshire UK might be a nice place to ride, think again ! I don't know how Google could possibly describe that as 'cyclist-friendly' - it was a living nightmare - huge gravel and big ruts all the time, and massive rocks sticking out of the ground (but solidly buried in it) by an inch or 2. And where there wasn't that there was thick, deep, skatey chalk mud. My poor little Master did not like that AT ALL, and I struggled to stay on it if I'm honest both on the uphills and extreme downs, as the wheel was constantly wrenched out from under me by horrible terrain. My suspension was fully inflated, but it might as well have not been there as I seemed to feel every massive rock as I bounced my way over them. It must have looked extremely ungainly to anyone observing ! Fortunately there was only a couple of miles of that, but I don't think I have ever had to hold 'maximum tension legs' for quite that long ! Was very much a relief to be back on the woodland trails and proper cycle paths for the rest of it, where previous balletic excellence could resume... So that's +5 for grim trail XP, and a strong disinclination to ever do that trail again ! Edited May 10, 2023 by Cerbera 1 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 13, 2023 Author Share Posted May 13, 2023 (edited) 'Interesting' things happening now my new shock has arrived, speedily delivered in under a week by those magnificent guys at Speedy Feet... Having been conditioned over time to not trust anything with Begode written on it until it proves itself OK, I have delayed fitting my new shock until I can establish that the new one works ! It certainly looked nice and new and shiny out of the box. I thought I'd fill her up to 210 PSI, wait 24 hours, and then check again to see if she had lost any pressure. Well I did that, and came back to find that yes, she had lost pressure (down to about 160 PSI) and was sitting in a small pool of machine oil ! Now, I don't know if that is expected on first inflation, and is just some harmless excess, or if it indicates a pre broken / leaky shock ! I have wiped away the excess, re-inflated it, and will check again in another 12 hours. A suspicious puddle of oil, yesterday. The culprit lurks guiltily nearby... I presume that is not normal / expected behaviour of a new shock chamber, but thought I'd mention it here in case anyone had experienced similar, or had any thoughts about whether I should fit this one or not.... Edited May 13, 2023 by Cerbera 2 Quote Link to comment Share on other sites More sharing options...
Raptor Posted May 13, 2023 Share Posted May 13, 2023 7 hours ago, Cerbera said: 'Interesting' things happening now my new shock has arrived, speedily delivered in under a week by those magnificent guys at Speedy Feet... Having been conditioned over time to not trust anything with Begode written on it until it proves itself OK, I have delayed fitting my new shock until I can establish that the new one works ! It certainly looked nice and new and shiny out of the box. I thought I'd fill her up to 210 PSI, wait 24 hours, and then check again to see if she had lost any pressure. Well I did that, and came back to find that yes, she had lost pressure (down to about 160 PSI) and was sitting in a small pool of machine oil ! Now, I don't know if that is expected on first inflation, and is just some harmless excess, or if it indicates a pre broken / leaky shock ! I have wiped away the excess, re-inflated it, and will check again in another 12 hours. A suspicious puddle of oil, yesterday. The culprit lurks guiltily nearby... I presume that is not normal / expected behaviour of a new shock chamber, but thought I'd mention it here in case anyone had experienced similar, or had any thoughts about whether I should fit this one or not.... Hello, Are you sure that the measured pressure drop is not from the volume of the measuring device itself!? The shock absorber has a very small volume and high pressure. there is already quite a large pressure drop at the connection with the internal volume of the measuring instrument itself! However, if you use the pump with the slack for measurement, the volume of the slack and the pump itself is so large that it immediately shows a pressure drop of 20 or 25 psi! To clarify the pressure drop due to the internal volume of the measuring device / pump: Immediately after full pumping, disconnect the pump and reconnect it to measure/check again. It becomes immediately clear how big the change is due to the internal volume of the measuring device/pump. I wrote just in case because I've noticed people neglect this and don't go back and check the pressure immediately after pumping. After that, several days later, the pressure is believed to have dropped. In fact, if you had measured it again, you would have seen a drop in pressure. I believe you are more experienced and the problem is still an air leak, but this explanation may be helpful to some! 2 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 13, 2023 Author Share Posted May 13, 2023 (edited) 34 minutes ago, Raptor said: Are you sure that the measured pressure drop is not from the volume of the measuring device itself!? The shock absorber has a very small volume and high pressure. there is already quite a large pressure drop at the connection with the internal volume of the measuring instrument itself! However, if you use the pump with the slack for measurement, the volume of the slack and the pump itself is so large that it immediately shows a pressure drop of 20 or 25 psi! To clarify the pressure drop due to the internal volume of the measuring device / pump: Immediately after full pumping, disconnect the pump and reconnect it to measure/check again. It becomes immediately clear how big the change is due to the internal volume of the measuring device/pump. Ah OK, that would explain it - I will check it again immediately after inflating. My understanding was that once you had flicked the connection switch on the pump to off it was effectively disconnected from the valve, at which point I have been using the grey button to release pressure from the pump, which I thought didn't drop any inside the chamber - perhaps I am wrong about that... I don't think I have ever checked it immediately after filling ! It is not leaking further oil, which seems like a good sign, but may mean that it has leaked it all and is now empty ! How much oil is meant to be in these things ? Edited May 13, 2023 by Cerbera Quote Link to comment Share on other sites More sharing options...
mrelwood Posted May 14, 2023 Share Posted May 14, 2023 14 hours ago, Cerbera said: My understanding was that once you had flicked the connection switch on the pump to off it was effectively disconnected from the valve, at which point I have been using the grey button to release pressure from the pump, which I thought didn't drop any inside the chamber You were right, it doesn’t. The pressure on the shock remains the same. But do this: Instead of screwing out the pump, after you have closed up the valve and released the pressure from the pump, engage the valve again. The air from inside the shock will pressurize the pump hose, and you will see that the pressure has dropped. But leaking that much oil is definitely concerning! Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 14, 2023 Author Share Posted May 14, 2023 37 minutes ago, mrelwood said: The air from inside the shock will pressurize the pump hose, and you will see that the pressure has dropped. Ah of course - that would make sense 37 minutes ago, mrelwood said: But leaking that much oil is definitely concerning! Yes it is isn't it ? It hasn't dropped any more since, but still worrying that might be because there isn't any more to drop ! I am told refilling the oil chamber is a capital PITA. 1 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted May 15, 2023 Share Posted May 15, 2023 On the same topic, I (finally!) made a video explaining where, when and how you lose the pressure when pumping air shocks: 2 1 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 24, 2023 Author Share Posted May 24, 2023 Having some difficulty finding somewhere in UK to print a shock cover for Begode Master out of flexible TPU - the guys I used to use don't work in that medium any more ! And it was while I was thinking about this I happened to see an advert where something reminded me of condoms ! Can you see where I'm going yet ? Is it a totally mad idea to consider using a condom with the tip cut off to protect my Master's shock from the sort of woodland / mud assault that has presumably broken my current one ? In theory any cover should be elasticated and grippy at both ends, as a condom is, flexible enough to expand and contract (also tick) and it's about the right size, and presumably available in black from some rubber kink shop online somewhere !? My only worry is the robustness over time of course - how does everyone else think that would stand up (no pun intended) ?! Quote Link to comment Share on other sites More sharing options...
mrelwood Posted May 24, 2023 Share Posted May 24, 2023 (edited) 1 hour ago, Cerbera said: My only worry is the robustness over time A reasonable worry I think. In my understanding they get very weak with time. I’ve seen ones laying in the ground that tear and crumble right away when trying to move them with a stick. I think you should be looking for something thicker. Points for the creativity though, I like! Edited May 24, 2023 by mrelwood 1 1 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted May 24, 2023 Author Share Posted May 24, 2023 Yeah, always looking for the crafty workaround if there is one Have no idea how I missed it the first time, but have just found 3dmitech.co.uk, who say they can do it for 15 pounds delivered, so previous condom plans abandoned ! 1 Quote Link to comment Share on other sites More sharing options...
Cerbera Posted June 15, 2023 Author Share Posted June 15, 2023 (edited) Ran out of cat food today, and her majesty won't wait, so had to do a small run into town today under the blazing mid day sun. Went in the bare minimum possible ATGATT, but it was still horribly uncomfortable and sweaty the whole time I was walking rather than riding. What I did notice though, was that about half way through the ride, where I could do some slightly harder acceleration I noticed the feel of the wheel changing to go slightly 'grainy'. It was like the horrible grinding noise I had a while back caused by vibration between top and mainboards, but far less pronounced, in that was only a subtly detectable change in feel, fed-back through the pedals, and perhaps the slightest of graininess introduced to the wheels normal rotation noise. I had 'fixed' the previous time I had the major grinding by injecting a load of silicone between boards, and this has been absolutely fine ever since, until today, which is coincidentally the first time I have ridden it at midday in whip-cracking temperatures, so I wondered if this might be loosening the sealant, or changing its density or flexibility somehow such that it allowed a small portion of the vibrations to return. Anyone got any thoughts on that ? This afternoon I took the top section apart, and did find 2 mainboard screws slightly less tight than I remember them being, and after retightening those and reassembling I took it out for a quick high speed / high acceleration test run on the roads just as it got dark, so temps much lower, and no sign of the problem at all. Interesting... not sure if its absence now is down to that tightening or the lower temps. Anyway, just making a little note of that, lest I forget, and it returns to haunt me later... Edited June 15, 2023 by Cerbera Quote Link to comment Share on other sites More sharing options...
Cerbera Posted September 3, 2023 Author Share Posted September 3, 2023 Well, after putting up with a leaky suspension I have to pump up before every ride, for nearly 3 months now I am forced by a slow tyre leak to finally get in there and swap out the shock and change the inner tube, if not the tyre as well, something I have been nervously procrastinating for quite some time. The question is - should I just replace the inner tube (and therefore only have to get one side of the original CST tyre off, or should I put this Michelin City Extra I have sitting here on at the same time ? having spent nearly a year acclimatising to the tippy CST and wearing it down to the point where it actually isn't that tippy any more I have got rather used to it and appreciate its excellent grip in gravel and mud and off-road. It still has lots of wear left in it, so I could just replace or patch the tube. Or, for those of you who have done it, do you think I am going to seriously appreciate the improved feel of turns and carving if I fit the street tyre ? Cheers for any advice... Quote Link to comment Share on other sites More sharing options...
alcatraz Posted September 4, 2023 Share Posted September 4, 2023 (edited) If the leak is on the sides of the inner tube you have to replace the tube. A patch won't work because the rubber has weakened all way around. It comes from the ground contact spot always flexing the tube at the sides. Tire choice is such a personal thing. I've learned never to take advice on it because we're all different in weight, riding style, area. If you've never tried something else you might just want to try like the 2nd most popular tire and so on. I found mine and it's dirt cheap. It's probably not the best one for a suspension wheel though. In cycling we like supple and flexible tires so they roll smoothly. The sidewalls are razon thin laced with a 300+ tpi mesh of kevlar just so it flexes effortlessly. It'll save battery and will allow you lower air pressures. I noticed my favorite euc tires are also the thinner ones. Only complaint I've seen is that they wear out faster for heavier dudes. I get 5000km+ out of one so I couldn't care less about wear. Grip should be better with a big brand tire but I haven't really had problems and I ride in rain and snow. (CST C1488) Edited September 4, 2023 by alcatraz Quote Link to comment Share on other sites More sharing options...
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