Ate it on the S18 today!

[Rywokast]

3 hours ago, Ek. said:

How is everyone getting accurate enough readings of their pressure to determine whether they are at 32 or 35 etc psi? I have a pump with a gauge but it lets so much air out when disconnecting that I then measure with another gauge, which also lets a little bit of air out. But I'm pretty sure neither could be accurate to within 1 or 2 psi. In fact, my Slime branded gauge only has marks for every 2 psi.

Are you all using some fancy expensive gauge that I don't know about? Are you inflating using a device with a digital gauge? How does anyone know whether their gauge is calibrated anyway? My 27 psi might be someone else's 30 psi yet you're all saying that a difference that large could cause wobbles or bent rims etc depending on weight and tyre size.

I'm on a KS 14D and I pump it up to something like 50 psi on my pump gauge, which results in somewhere just over 30psi when I disconnect and remeasure with the other one. Anything lower than that and I can feel bottoming out just crossing a driveway gutter. I'm around 70kg.

how the hell do you lose 20 psi disconnecting?? it should be like 1 or 2 psi loss.... its literally a split second.. for me i have one of those digital motorised pumps so i just set the psi i want and press on, i think theyre way more accurate than a bicycle push pump because on my push pump i was going to 3 bar or just slightly over usually... which is like 45-50 psi... waaaaay too much for my weight of 120 lbs, but the electronic one since i got it i use 25-30 psi on it and thats what feels good for me.... that seems way way more accurate than the cheap bicycle pump i was using before theres no way i was riding at 50 psi lol

[winterwheel]

I find that using an extender has helped a bit with this problem. Easier to disconnect cleanly from the slightly awkward valve locations.

[Scottie888]

I use a Milwaukee M12 cordless compact inflator (expensive but worth it for all round usage incl autos) attached to the Slime quick release adapter. The M12 itself is very accurate & negates the use of an additional psi gauge. There is some leakage but the quick release adapter minimizes it.

I'm assuming a loss of 1-2 psi on a 16-18" tire. Ofcos a smaller tire would have a bigger psi loss so adjust accordingly.

[Ek.]

Yep, the 20-ish psi loss is on a 14" tyre with a crappy lever release thing on my foot pump. I think it's designed to fit more than one kind of valve, so it has this rubber bit that grabs on when you flip the lever. Problem is, when you then unflip the lever it starts letting air out straight away but it's difficult to pull off the connector because the rubber sticks to the thread. Very poor design (though it's getting easier to remove as the rubber wears in). I'm sure it's negligible on a car tyre but on the 14x2.125 it's quite a lot of pressure lost. 

I got an extender with my new Mten3 so I'll try to use that to mitigate the problem.

[PLEASE_DELETE]

Deleted.

Edited March 18 by PLEASE_DELETE

[enaon]

On 4/10/2021 at 11:45 PM, Scottie888 said:

I ride at 40psi on my S18 & ya I do get the wobblies on a consistent basis.

It is mostly the tire. Our tires up to now had to do some suspension for us, so they are unstructured bicycle tires. On high pressure they bounce when going straight, on low they bend when cornering, so we must balance between. On the s18 the tire movement is affecting the suspension movement, this makes feel like a boat sometimes.

You can try a structured tire since you have the s18 that has suspension. It will not wobble  even at 50 psi when hard stopping from 50kh/h, even if you do it on a curve. Cornering or straight line will be equally safe and predictable. I think this is the main gain of suspension if one does not care about off-roading a lot, the ability to have a structured tire on the road and not feel like riding a rock.  

Edited April 22, 2021 by enaon

[mrelwood]

1 hour ago, Ek. said:

Yep, the 20-ish psi loss is on a 14" tyre with a crappy lever release thing on my foot pump.

I have a similar system in my foot pump. I learned that I was pushing the connector too deep. The connector is not supposed to rich the valve pin until the lever is flipped. That way, when taking off the pump it only loses a psi or two while popping the lever, and none while I fight with removing the grabby rubber connector.

[Scottie888]

4 hours ago, enaon said:

It is mostly the tire. Our tires up to now had to do some suspension for us, so they are unstructured bicycle tires. On high pressure they bounce when going straight, on low they bend when cornering, so we must balance between. On the s18 the tire movement is affecting the suspension movement, this makes feel like a boat sometimes.

You can try a structured tire since you have the s18 that has suspension. It will not wobble  even at 50 psi when hard stopping from 50kh/h, even if you do it on a curve. Cornering or straight line will be equally safe and predictable. I think this is the main gain of suspension if one does not care about off-roading a lot, the ability to have a structured tire on the road and not feel like riding a rock.  

Pardon my ignorance as I've heard of symmetrical v asymmetrical & tube v tubeless but not structured v unstructured. Do you mean balanced v unbalanced? If not can you elborate?

[enaon]

39 minutes ago, Scottie888 said:

Do you mean balanced v unbalanced? If not can you elborate?

Maybe I do not express it correctly, bike tires have a soft rubber on the outside, just like bicycle tires, but the inside is not soft, it has a grid holding the shape. Even without air, a bike tire like the Pirelli Angel will not let the rim touch the floor if you stand on the euc. You can see the difference here, I apply the same force, the soft one is the s18's 5102 tire. 

the "structure" for luck of better word, makes it more easy for the tire to keep the shape, it has less gelli effect, wobbles less and bends less. The downside is that instead of riding a bouncing ball, you ride a rock. It needs suspension. 

 

https://streamable.com/lxvt1k

Edited April 22, 2021 by enaon

[EUCRexy]

8 hours ago, enaon said:

Maybe I do not express it correctly, bike tires have a soft rubber on the outside, just like bicycle tires, but the inside is not soft, it has a grid holding the shape. Even without air, a bike tire like the Pirelli Angel will not let the rim touch the floor if you stand on the euc.

In the automotive/motorcycle industry we call that the carcass of the tire. And yeah, it makes the tire significantly stiffer than a bicycle-like tire that we are used to coming stock on an euc.

[Wrd]

9 hours ago, enaon said:

the "structure" for luck of better word, makes it more easy for the tire to keep the shape, it has less gelli effect, wobbles less and bends less. The downside is that instead of riding a bouncing ball, you ride a rock. It needs suspension. 

 

3 hours ago, EUCRexy said:

In the automotive/motorcycle industry we call that the carcass of the tire. And yeah, it makes the tire significantly stiffer than a bicycle-like tire that we are used to coming stock on an euc.

Thanks @enaon, @EUCRexy

That’s good info. That changes the focus of the S18 tire conversation for me. I wonder if it’s clear when shopping if you’re looking at a structured tire or not. Maybe by evaluating the intended purpose. Bicycle or moto (bike or scooter). 
 

I hadn’t noticed this come up in Kingsong S18 Tire Discussion. 
 

I just got my S18 from ewheels (manufactured Jan, 18, 2021); and it shipped with the Eakia (Jiluer) J-1836. 

So if I understand correctly, that’s a stiffer bicycle tire, but may still provide it’s own ‘bounce’ which could compound the suspension effect and create wobbles.

The Pirelli Angel is a structured scooter tire that wouldn’t bounce as much. 

OK so I think I want to find a structured off-road tire with traction for deep turns or at least a hybrid tire (but better off-road).

[Scottie888]

11 hours ago, enaon said:

the "structure" for luck of better word, makes it more easy for the tire to keep the shape, it has less gelli effect, wobbles less and bends less. The downside is that instead of riding a bouncing ball, you ride a rock. It needs suspension. 

Ah I see. So what you're referring to is stiffer sidewalls. I would think there's some variations in sidewall stiffness on dif makes/models but end of the day, they're all still tubetype tires. The only type of tires with stiff(er) sidewalls as part of design is tubeless. & yes, with stiffer sidewalls, they have much less shock absorption potential as witnessed by the Mten3 & Z10.

Personally I still think wobbles are a causation of rider error (for lack of a better word) which is why its recoverable. IMO the key is to not panic & use experience to minimize its occurrence. Generally I manage to stop wobbles in its initial stages. There's only been 1 occasion where it was so bad I had to vise grip the wheel with my legs.

That said, to a lesser extent I'm sure psi has something to do with it as well. That plus surface irregularities & speed.

[enaon]

1 hour ago, Scottie888 said:

Personally I still think wobbles are a causation of rider error (for lack of a better word) which is why its recoverable.

I was not sure too, mainly because I am not a fast rider, I don't even wear protection. But this week two more s18 here in Athens took the pirelli, one is owned by one of the best riders here, he is faster going backwards down stairs than me going straight. 

I wish I could upload his review, it is in Greek so it is of no use here, but he concludes that this tire makes the s18 feel like no other euc, can hit the breaks cornering on a downslope, no wobbles anywhere up to 50khm/h

[Ek.]

16 hours ago, mrelwood said:

I have a similar system in my foot pump. I learned that I was pushing the connector too deep. The connector is not supposed to rich the valve pin until the lever is flipped. That way, when taking off the pump it only loses a psi or two while popping the lever, and none while I fight with removing the grabby rubber connector.

I'll try this, thanks for the tip!

Update:  works like a charm. Pumped to around 35 on the foot pump dial and barely any air loss on removal of hose. Checked with my other gauge and it's 33ish still. Can't believe I never tried this before! Thanks again for saving me a lot of hassle 

Edited April 22, 2021 by Ek.

[Kagenin]

On 4/21/2021 at 3:18 PM, Ek. said:

How is everyone getting accurate enough readings of their pressure to determine whether they are at 32 or 35 etc psi?

I pump to over my target PSI, disconnect it, then use a gauge with no pump to let air out to the proper pressure.  Not even a digital gauge, just a standard $6 tire gauge from any auto parts shop.  Something that looks basically like this.

 

[FLRocketMan]

This does a reasonable job for less than $10.

[Phi1osopher]

First of all, I am sorry to the original poster's high-speed wobble-induced crash.  that sounds like it really sucked, but I am glad to hear you are basically okay.

I have long wondered about how much air escapes during air hose disconnect.  Assuming a "clean disconnect," I am pretty sure that most of the escaping air sound is from the air in the pump and air hose.  I am also quite curious about how much air leaks out of my KS- s18's shock over time, and would like to monitor this real-time for a while as I am spending more time riding technical off-road terrain. 

So I bought this today on eBay:

https://www.ebay.com/itm/333896272724

It is a small 1.5" 200psi pressure gauge with an integrated schrader valve.  It is my intent to cut off the large bit at the top and thread female schrader threads into the housing (0.302"/7.77mm by 32 threads per inch). 

I intend to leave it semi-permanently attached to the upper chamber of my shock so I can monitor the pressure in real time.  I will test the pressure gauge for accuracy before installation.  As an added bonus I will now be able to observe how much the pressure changes during hose release.  The shock has a VERY SMALL air chamber compared to a tire, so any pressure drop that occurs during air hose disconnect should be quite noticeable.   I will also be able to observer how the shock pressure changes when pumped up using the official KingSOng method with the block, vs, using a valve adaptor.

 

 

Edited April 29, 2021 by Phi1osopher

[pkinpdx]

1 hour ago, Phi1osopher said:

First of all, I am sorry to the original poster's high-speed wobble-induced crash.  that sounds like it really sucked, but I am glad to hear you are basically okay.

I have long wondered about how much air escapes during air hose disconnect.  Assuming a "clean disconnect," I am pretty sure that most of the escaping air sound is from the air in the pump and air hose.  I am also quite curious about how much air leaks out of my KS- s18's shock over time, and would like to monitor this real-time for a while as I am spending more time riding technical off-road terrain. 

So I bought this today on eBay:

https://www.ebay.com/itm/333896272724

It is a small 1.5" 200psi pressure gauge with an integrated schrader valve.  It is my intent to cut off the large bit at the top and thread female schrader threads into the housing (0.302"/7.77mm by 32 threads per inch). 

I intend to leave it semi-permanently attached to the upper chamber of my shock so I can monitor the pressure in real time.  I will test the pressure gauge for accuracy before installation.  As an added bonus I will now be able to observe how much the pressure changes during hose release.  The shock has a VERY SMALL air chamber compared to a tire, so any pressure drop that occurs during air hose disconnect should be quite noticeable.   I will also be able to observer how the shock pressure changes when pumped up using the official KingSOng method with the block, vs, using a valve adaptor.

 

 

 

That looks like a great tool to tell us if there is actually any difference between the various ways of filling the chambers but how much of an effect may be skewed.  With that attached you will be adding volume to a very small chamber.  Any differences between the methods will be reduced I would think.  I also would be careful about riding the wheel with it attached as I would assume that it would change the shock characteristics.  Let us know if it feels wonky.

[Californian]

On 4/22/2021 at 2:14 PM, enaon said:

I was not sure too, mainly because I am not a fast rider, I don't even wear protection. But this week two more s18 here in Athens took the pirelli, one is owned by one of the best riders here, he is faster going backwards down stairs than me going straight. 

I wish I could upload his review, it is in Greek so it is of no use here, but he concludes that this tire makes the s18 feel like no other euc, can hit the breaks cornering on a downslope, no wobbles anywhere up to 50khm/h

Greek would still be helpful! Google can translate some of it (at least if it's on YouTube, though I think some phones can do it for any video), and just the video itself would be great!

 

Do you know which model/size they used? I've never bought a tire before and don't know how to find compatible ones.

[mrelwood]

28 minutes ago, Californian said:

I've never bought a tire before and don't know how to find compatible ones.

The bicycle size 18” x 3.0” is very similar to motorcycle sizes 2.75-14 and 80/80-14. Also the 80/90-14 will often fit. 70/90-14 is probably a better choice if the original 18x3 tire is a tight fit.

 Choosing either size marked in bold above will usually fit to replace an 18x3.

 But the tire sizes do vary a lot per model. For example the Shinko SR-244 in 2.75-14 isn’t even close to fitting on the V11, but the CST C-186 in the same size does fit.

I don’t know which tire models in the above sizes fit the S18 though, as even the original tire tends to scrape with some units.

[Scottie888]

13 minutes ago, mrelwood said:

I don’t know which tire models in the above sizes fit the S18 though, as even the original tire tends to scrape with some units.

Sadly (&unlike the GW 18" wheels), most knobbies will not fit cos the fenders are tighter than a bull's ass in fly season. There's only 1 known knobby that fits sans mods & unfortunately, its only available in Jpn locally. Amazon.jp has it but shipping is higher than the price of the tire. 

Another KS win here....NOT!

[Paulo Mesquita]

I'm still keeping faithful to the 35psi mark on my KS 16x and at 95kg, fully geared up with protection. 

My max speed today was 42km/hour, with my average showed in the whereabouts ok 19km/hour... and today's particular winds were at 20 kms/hour! Bloody messy that was!!!

Yet still no wobbles withe 95kg weight and 35 psi mix. 

... Still myEUC World registered 136km/hour. Not even my Smart ForTwo rides at that speed... 😂😂😂. 

@ShanesPlanet try and beat that speed!!! 😁😁😁

Edited May 24, 2021 by Paulo Mesquita

[.....]

2 hours ago, Paulo Mesquita said:

I'm still keeping faithful to the 35psi mark on my KS 16x and at 95kg, fully geared up with protection. 

My max speed today was 42km/hour, with my average showed in the whereabouts ok 19km/hour... and today's particular winds were at 20 kms/hour! Bloody messy that was!!!

Yet still no wobbles withe 95kg weight and 35 psi mix. 

... Still myEUC World registered 136km/hour. Not even my Smart ForTwo rides at that speed... 😂😂😂. 

@ShanesPlanet try and beat that speed!!! 😁😁😁

If we compare eucw speeds, I get you beat nearly everytime. I have had plenty of tours that teleport me thru the mountain at blistering speeds. WHats more... I do it in shades and a t-shirt..     I run 25psi on my 18 at 130lbs. (60kg all up) 20psi on my sherm and mten.

Sounds like you had fun. Tis good to hear it! Now go sell some houses to rich tourists. With speeds like that, you should be able to run a tight schedule AND save gas $$.

Edited May 25, 2021 by ShanesPlanet

[fbhb]

2 hours ago, Scottie888 said:

There's only 1 known knobby that fits sans mods & unfortunately, its only available in Jpn locally.

The CST 803 is a knobby that fits without mods, although in a smaller size of 2.50-14 but actually comes out at around the same width as the stock tires.

 

Edited May 25, 2021 by fbhb

[Paulo Mesquita]

23 minutes ago, ShanesPlanet said:

If we compare eucw speeds, I get you beat nearly everytime. I have had plenty of tours that teleport me thru the mountain at blistering speeds. WHats more... I do it in shades and a t-shirt..     I run 25psi on my 18 at 130lbs. (60kg all up) 20psi on my sherm and mten.

Sounds like you had fun. Tis good to hear it! Now go sell some houses to rich tourists. With speeds like that, you should be able to run a tight schedule AND save gas $$.

This why I'm always pulling into the forum arena. I luv ya posts,man!!!