King Song S18 Discussion

[Jon Stern]

4 hours ago, FinRider said:

Would this be an option to put in between the linkage? Would just need to find the right size...

 

A thrust bearing from BangGood.com? Sounds like it guarantees a happy ending!

[mrelwood]

41 minutes ago, RockyTop said:

I am going to add a small washer on the outside between end of the shoulder bolt and oversized washer so that the shoulder bolt is being crushed rather than the bearings

That's exactly what we did on @FinRider's S18, and combined with an ample amount of (wrong) lubricant at every joint and the sliders made the system somewhat responsive.

A big and perhaps even more challenging issue are the sliders. Even when the linkage system was detached, before lubrication it took two men to move the system around. And still failing to do so at the extremes of the travel. The Russians mentioned the vertical tubes having a slightly different distance than their holes in the sliders. Definitely sounds plausible. Fix? I have no idea.

The fender also dragged against the inside of the shell at the front, having left relatively deep scratches already. This is what makes a lot if not all of the suspicious noise we hear in bumps. The fender is very floppy, so even a small mismatch in the attaching screw hole placements twists it out of place.

7 minutes ago, Jon Stern said:

A thrust bearing from BangGood.com? Sounds like it guarantees a happy ending!

The ending would definitely be so much happier than with a stock S18 "suspension".

[Gustesta]

5 hours ago, FinRider said:

@mrelwood was kind enough to lend me his time and expertise in troubleshooting my suspension. It has been stiff and somewhat unresponsive, which we both believe is not normal. There are a couple of things that we found out:

• The bearings that connect the linkage to each other seemed to be intact
• The linkage arms rubs against each other, causing a pretty high friction point
  • I will attempt to find some thin low friction washers to put in this space. may some plastic or teflon (PTFE)? 
• The bolts that hold the linkage system together seems to compress the linkage and is not free flowing, enhancing the problem with the linkage rubbing against each other
  • We added a washer inside the original washer that presses on the linkage, focusing the fastening pressure on the bearing instead of the linkage.
• We added a bunch of CRC (WD40) to all the sliding points - linkage connection points, fastening points, slider bars, etc

 

The suspension came alive a bit after this, the improvement was definitely very noticeable. Something just dont seem right with the way they put this together. I will have one of our mechanical engineers in the office take a look at it Friday when I ride back in to the office with the wheel.

We also played a bit with the suspension pressure after this, as I had put it at 150/50, which now was making it bottom out

250/150 - Very stiff, very little sag (obviously)

170/70 - to sloppy, too much sag

200/100 - good balance (I will test this out for a while now)

Has oneone else tinkered around with the suspension?

 

 

 

How much do you weight, please?

Also, are you pumping the negative chamber without the KS block?  You should.

[mrelwood]

20 minutes ago, Gustesta said:

How much do you weight, please?

He weighs about 85kg with gear.

20 minutes ago, Gustesta said:

Also, are you pumping the negative chamber without the KS block?  You should.

The KS instructions say otherwise. We followed them. We didn't even check the chamber pressures without the block.

Also, since there is still an ample amount of friction in the mechanism, filling either chamber without a stable neutral position is pretty pointless. 

[redfoxdude]

29 minutes ago, mrelwood said:

Also, since there is still an ample amount of friction in the mechanism, filling either chamber without a stable neutral position is pretty pointless. 

^This! I've been saying this on YouTube and Facebook comments as well. It makes sense to use the block to ensure the shock is in a consistent level of compression every time you adjust the pressure. Otherwise your pressure reading is pretty much useless.

Edited August 19, 2020 by redfoxdude

[dsd317]

19 minutes ago, redfoxdude said:

It makes sense to use the block to ensure the shock is in a consistent level of compression every time you adjust the pressure.

I'm still (impatiently) waiting for my S18 to arrive.  Are there pictures or videos showing how this block method is performed?  I've seen people sit on the S18 while pumping air into shock.

[Shield]

37 minutes ago, dsd317 said:

I'm still (impatiently) waiting for my S18 to arrive.  Are there pictures or videos showing how this block method is performed?  I've seen people sit on the S18 while pumping air into shock.

 

[Mark Wilson]

2 hours ago, Gustesta said:

Also, are you pumping the negative chamber without the KS block?  You should.

 

1 hour ago, mrelwood said:

The KS instructions say otherwise. We followed them. We didn't even check the chamber pressures without the block.

Also, since there is still an ample amount of friction in the mechanism, filling either chamber without a stable neutral position is pretty pointless. 

 

1 hour ago, redfoxdude said:

^This! I've been saying this on YouTube and Facebook comments as well. It makes sense to use the block to ensure the shock is in a consistent level of compression every time you adjust the pressure. Otherwise your pressure reading is pretty much useless.

According to the post from @fbhb, under compression pressure in the negative chamber decreases and even becomes "negative" (I assume this means negative gauge pressure). If this is true wouldn't that mean that if pump the negative chamber while it's compressed that even reading 0 psi could be too much pressure?

I don't know how difficult it is to access the valve for the negative chamber, but what happens if you pressurize the negative chamber while under compression and then decompress the suspension? Does the pressure reading jump up significantly?

[redfoxdude]

47 minutes ago, Mark Wilson said:

According to the post from @fbhb, under compression pressure in the negative chamber decreases and even becomes "negative" (I assume this means negative gauge pressure). If this is true wouldn't that mean that if pump the negative chamber while it's compressed that even reading 0 psi could be too much pressure?

I don't know how difficult it is to access the valve for the negative chamber, but what happens if you pressurize the negative chamber while under compression and then decompress the suspension? Does the pressure reading jump up significantly?

Yep, it jumps up after decompressing the suspension. It makes sense that it would go negative once the shock is compressed far enough, but I don't recall ever seeing 0 or negative on the negative chamber with the plastic brick in place, even when I was trying ~90PSI measured when uncompressed. Filling the negative chamber without the block is pretty finicky, since, as you increase the pressure, the shock wants to compress. Then the reading goes lower, unless you are conscious of keeping the shock fully extended.

Edited August 20, 2020 by redfoxdude

[Mark Wilson]

8 minutes ago, redfoxdude said:

Yep, it jumps up after decompressing the suspension. It makes sense that it would go negative once the shock is compressed far enough, but I don't recall ever seeing 0 or negative on the negative chamber with the plastic brick in place, even when I was trying ~90PSI measured when uncompressed. Filling the negative chamber without the block is pretty finicky, since, as you increase the pressure, the shock wants to compress. Then the reading goes lower, unless you are conscious of keeping the shock fully extended.

The only situation I can think of where using the block when pumping up the negative chamber wouldn't be good is if you want a lower pressure than 0 psi while compressed. For example, if the pressure in the negative chamber jumps up 50 psi from being compressed to uncompressed, the lowest uncompressed pressure you could achieve would be 50 psi. If your ideal riding pressure for the negative chamber is say 30 psi uncompressed, you wouldn't be able to use get to the ideal pressure while using the block (This is all assuming I'm understanding everything correctly). But other than that I guess that if you're using trial and error to find the pressure that works best for you it doesn't really matter what method you're using as long as you're consistent.

Although since people are using different methods of pumping up the shock and checking its pressure, to compare settings everyone will have to specify how they are checking the pressure. (i.e. using the included block, sitting on the wheel, letting the wheel uncompress itself, manually extending the suspension, etc.)

[dsd317]

Does anyone know which shock will be used in the 2nd and 3rd batches of S18's?  If it's one of the two links below...or a completely different shock?

https://www.amazon.com/DNM-Damping-Mountain-Pressure-Adjustable/dp/B00R5OA7HA/ref=pd_sim_468_1/132-0287775-6057522?_encoding=UTF8&pd_rd_i=B00FLTZ2ZS&pd_rd_r=36b2583d-9b32-48a5-9fc6-7f6c757b907d&pd_rd_w=zsMtK&pd_rd_wg=Sgj0B&pf_rd_p=64e5d61b-7067-445e-bd1c-f84491d96b7e&pf_rd_r=38NCV3800RA84HW9YZD5&refRID=38NCV3800RA84HW9YZD5&th=1&psc=1

https://www.amazon.com/AOY-38RC-6-496-7-480-7-874-8-268/dp/B07KK381HF/ref=pd_di_sccai_1/132-0287775-6057522?_encoding=UTF8&pd_rd_i=B07V5Y31P8&pd_rd_r=133bffa6-66a5-4856-8f29-299b6222e258&pd_rd_w=qjsCX&pd_rd_wg=6ypS4&pf_rd_p=5415687b-2c9d-46da-88a4-bbcfe8e07f3c&pf_rd_r=ZWA2D3HCSSG81JQVWC5C&psc=1&refRID=ZWA2D3HCSSG81JQVWC5C

[Electric Dreams]

From recent feedback we are looking at improving the suspension movement. King Song team appreciates everyones feedback and we are investigating and testing the best method resulting in the best suspension ride possible.

We'll keep everyone posted in the next few days! 

[Electric Dreams]

3 hours ago, dsd317 said:

Does anyone know which shock will be used in the 2nd and 3rd batches of S18's?  If it's one of the two links below...or a completely different shock?

https://www.amazon.com/DNM-Damping-Mountain-Pressure-Adjustable/dp/B00R5OA7HA/ref=pd_sim_468_1/132-0287775-6057522?_encoding=UTF8&pd_rd_i=B00FLTZ2ZS&pd_rd_r=36b2583d-9b32-48a5-9fc6-7f6c757b907d&pd_rd_w=zsMtK&pd_rd_wg=Sgj0B&pf_rd_p=64e5d61b-7067-445e-bd1c-f84491d96b7e&pf_rd_r=38NCV3800RA84HW9YZD5&refRID=38NCV3800RA84HW9YZD5&th=1&psc=1

https://www.amazon.com/AOY-38RC-6-496-7-480-7-874-8-268/dp/B07KK381HF/ref=pd_di_sccai_1/132-0287775-6057522?_encoding=UTF8&pd_rd_i=B07V5Y31P8&pd_rd_r=133bffa6-66a5-4856-8f29-299b6222e258&pd_rd_w=qjsCX&pd_rd_wg=6ypS4&pf_rd_p=5415687b-2c9d-46da-88a4-bbcfe8e07f3c&pf_rd_r=ZWA2D3HCSSG81JQVWC5C&psc=1&refRID=ZWA2D3HCSSG81JQVWC5C

We will be using 36RC, there are no plans to change suspension. 

[fbhb]

3 hours ago, Jack King Song said:

We'll keep everyone posted in the next few days! 

Looking forward to seeing full details of the revisions that King Song implements, especially after having conversations via Facebook DM on the use of correct bearing spacers with you @Jack King Song  Thank you for quickly reacting to the feedback from your S18 customers and pre order customers, it is really appreciated!

Edited August 20, 2020 by fbhb

[FinRider]

I discussed this issue at length with our mechanical engineers here at the office today. A thrust washer would be a better solution than the dual bearing setup that KS has put in place, however the thrust bearings are not good at withstanding vertical force, so they would not replace the dual bearing setup with a thrust but one could use both in conjunction. The spacing between the pivot frames is very tight though so I do not believe that there is enough space between them to hold a thrust bearing.

The solution we will try is to use "bearing washers". We have 2 different kinds that we use in our production (see image below). I will ride the wheel to the office tomorrow like I usually do on the days that I do not have my crossfit morning trainings and will disassemble the pivot arms, measure the depth from the bearing to the outer casing and mill the bearings to the right depth. The washers that we have are 10.2 mm inner diameter so they will fit over the bolt nicely.

I will keep you posted.

 

[Mark Wilson]

3 minutes ago, FinRider said:

I discussed this issue at length with our mechanical engineers here at the office today. A thrust washer would be a better solution than the dual bearing setup that KS has put in place, however the thrust bearings are not good at withstanding vertical force, so they would not replace the dual bearing setup with a thrust but one could use both in conjunction. The spacing between the pivot frames is very tight though so I do not believe that there is enough space between them to hold a thrust bearing.

The solution we will try is to use "bearing washers". We have 2 different kinds that we use in our production (see image below). I will ride the wheel to the office tomorrow like I usually do on the days that I do not have my crossfit morning trainings and will disassemble the pivot arms, measure the depth from the bearing to the outer casing and mill the bearings to the right depth. The washers that we have are 10.2 mm inner diameter so they will fit over the bolt nicely.

I will keep you posted.

Thanks for looking into this. Do you feel like the sliders are also a problem area? Do they also provide too much friction or is it just the linkage area?

[mrelwood]

17 minutes ago, Mark Wilson said:

Thanks for looking into this. Do you feel like the sliders are also a problem area? Do they also provide too much friction or is it just the linkage area?

Let me answer with a quote from last page:

9 hours ago, mrelwood said:

That's exactly what we did on @FinRider's S18, and combined with an ample amount of (wrong) lubricant at every joint and the sliders made the system somewhat responsive.

A big and perhaps even more challenging issue are the sliders. Even when the linkage system was detached, before lubrication it took two men to move the system around. And still failing to do so at the extremes of the travel. The Russians mentioned the vertical tubes having a slightly different distance than their holes in the sliders. Definitely sounds plausible. Fix? I have no idea.

 

[FinRider]

53 minutes ago, Mark Wilson said:

Thanks for looking into this. Do you feel like the sliders are also a problem area? Do they also provide too much friction or is it just the linkage area?

Like @mrelwood stated, yes, this is also a major problem, one that I will also look into tomorrow when I tear down the wheel. We have a similar construction on one of our mammography machines, where we have two aluminum casings that slide on a stainless steel tubing system. In assembly of these it is paramount that the tubes are straight and that the carriage is not tightened too much. The casings need to slide effortlessly (one finger push) on the rail system. On the KS S18 we had two grown men pulling with all their might and we got it to move.... so WAY to much effort is needed. 

The rail system on the KS is fixed from the top and the pedal hangers are secured to the rails at the bottom. In between these is the slide carriage. I will tomorrow remove the pedal hangers, as these may pull the rails from perfect parallel and thus introduce too much friction. As usual, I will follow up tomorrow on the findings / progress.

Edited August 20, 2020 by FinRider

[slaweks82]

Hi,

I'm reading you from long time, and also suffer from weak suspension response. My suspension also have bearings pressed against paint, and when removed one screw, the other one rotate with jerking, so I think bearing is too much compressed, and other that I can't reach from both sides, when rotating, they rotate with friction, and creates noise, so there is some area for improvements, BUT just got hint to remove there two square alloy blocks that are located in between tubes, below pedals, and this totally changed wheel response!

With only 190psi pos/125psi neg suspension extends fully when not under load, and while on load it responds for small bumps on low speed - I rode it backway to see suspension, and it definitively helps.

 

https://photos.google.com/album/AF1QipNacuaLgVyiqD32f2LE5ovGT9qpzZXD7qiSbWwy/photo/AF1QipON659nw1kqvGpnAVRQ06TILwXWaKgG212VorS7

https://photos.google.com/album/AF1QipNacuaLgVyiqD32f2LE5ovGT9qpzZXD7qiSbWwy/photo/AF1QipN62ryvwfDJMB9MynIIAgqsxHeQ13sF4suUE8gr

[FinRider]

54 minutes ago, slaweks82 said:

Hi,

I'm reading you from long time, and also suffer from weak suspension response. My suspension also have bearings pressed against paint, and when removed one screw, the other one rotate with jerking, so I think bearing is too much compressed, and other that I can't reach from both sides, when rotating, they rotate with friction, and creates noise, so there is some area for improvements, BUT just got hint to remove there two square alloy blocks that are located in between tubes, below pedals, and this totally changed wheel response!

With only 190psi pos/125psi neg suspension extends fully when not under load, and while on load it responds for small bumps on low speed - I rode it backway to see suspension, and it definitively helps.

 

https://photos.google.com/album/AF1QipNacuaLgVyiqD32f2LE5ovGT9qpzZXD7qiSbWwy/photo/AF1QipON659nw1kqvGpnAVRQ06TILwXWaKgG212VorS7

https://photos.google.com/album/AF1QipNacuaLgVyiqD32f2LE5ovGT9qpzZXD7qiSbWwy/photo/AF1QipN62ryvwfDJMB9MynIIAgqsxHeQ13sF4suUE8gr

Your images do not load.... could you please repost them?

[fbhb]

@Jack King Song  The suspension on the Left has been worked on by it's owner to vastly improve the severe friction still present with the out of the factory set up shown on the Right!!!  This is how the end result should have been if the correct engineering assembly methods had been used to get the very best out of the linkage arrangement. 

This huge improvement has more than likely been achieved by using correctly dimensioned bearing spacers to clamp only against the bearings inner race, instead of randomly placed flat washers and even worse, spring washers that were previously binding the pivot points. 

Careful attention also needs to be paid on the assembly line to making sure the slider tubes are kept as parallel as possible, with no twisting when clamping up the pedal mounting frames.  Hopefully we will soon see if King Song themselves can achieve at least this level of effortless movement in the improvements that they are currently working on.

 

Edited August 20, 2020 by fbhb

[FinRider]

27 minutes ago, fbhb said:

The suspension on the Left has been worked on by it's owner to vastly improve the severe friction still present with the out of the factory set up shown on the Right!!!  This is how the end result should have been if the correct engineering assembly methods had been used to get the very best out of the linkage arrangement. 

This huge improvement has more than likely been achieved by using correctly dimensioned bearing spacers to clamp only against the bearings inner race, instead of randomly placed flat washers and even worse, spring washers that were previously binding the pivot points. 

Careful attention also needs to be paid on the assembly line to making sure the slider tubes are kept as parallel as possible, with no twisting when clamping up the pedal mounting frames.  Hopefully we will soon see if King Song themselves can achieve at least this level of effortless movement in the improvements that they are currently working on.

Do you have more information on what exactly was done to achieve this?

[Chriull]

Some hopefully only minor issues just seen in the disasembly youtube video (somewhere) posted:

Only 8 of the 12 Mosfets are fixed to the heatsink with screws. The other 4 could not be fixed, since the capactitors are covering the holes ;(

Despite the use of a thermal pad some ?thermal grease? is additionally used on both sides of the pad. Never heard of any manufacturer recomendation to use both - just the contrary..

 

[Toledo Spidey]

On 7/28/2020 at 3:07 PM, Garzal said:

Hold up you mean to tell me there is another rider in the Toledo area!?

I'm in Toledo also 

[RockyTop]

Update: 

1) I added a small thin washer to the outside of the joint that was pictured and circled above. In my case the two suspension arms were not touching or grinding. ( just need to remove the large screw with large washer, place small thin washer that is smaller than the hole in the arm between the shoulder of the shoulder bolt  and the large washer.) 
2 ) removes slider wipers and sprayed proper oil in the top. Re installed wipers. 
3) adjusted bottom width of sliders by experimenting with the block width. Removed/ milled 0.010 inch from block and added shims. 
 

Results - night and day. I think that it might complete with the V11 on rough surfaces now while blowing the V11 away on the big bumps.