S18 Suspension Overhaul

[Finn Bjerke]

I wonder what Kingsong S20 will be like ?  ...You guys bloody well rules. 

[fbhb]

 

[Whalesmash]

For anyone who is state side and doesn't want to wait a week for parts from ebay sellers or are otherwise having difficulty sourcing these odd size washers, here's a few of the simpler parts that I used to lightly overhaul the friction points on my own S18. The delrin washer is optional, but I decided to use it between the contact points of the suspension arms/upper body and suspension arm/vertical slider. If you have not used mcmaster, they do not provide quotes for shipping, but shipping (within the US at least) is usually not anything outlandish. On a different note, I also found that WD40 dry lube (the one with ptfe in it) works quite nicely on the vertical sliders.

M10 Screw Size, 10.2 mm ID, 13.9 mm OD Washers  

M10 Screw Size, 10.5 mm ID, 22 mm OD Delrin Washer 

 

Edited December 11, 2020 by Whalesmash

[Ben Hatfield]

I'm about to attempt a tear down/rebuild of my S18, and I feel OK about most stuff, but I really want to know (exactly) how to get the tire/motor centered.  Currently (see photo), my tire sits closer to the left side (if facing the front of the wheel).  It arrived to me brand new in this condition.  I sent it back to eWheels for repair, but after less than 100 miles riding, after I got it back, the tire returned to this position.

How do I successfully center the tire on the vertical plane?

Not sure how obvious this issue is on the photo - the poorly installed inner fender makes the problem look worse

 

[redfoxdude]

Could be that the motor mounting surfaces on the sliders aren't perfectly square. Mine was pretty close out of the box, but it wasn't perfect so I used some shim stock (you could cut up an aluminum can) to get it even closer. Looks like yours is leaning the same way mine was. I added a shim on top of each side of the axle, but little square ones, such that they don't span the full surface, like in this totally pro-quality render:

If it's not actually leaning, but the inner fender is just distorting so that one side comes close to the tire, you can put a shim on the side where the fender is closer. But in that case, you'd want a shim that spans the full surface, so you don't inadvertently tilt the motor.

[fbhb]

On 12/12/2020 at 4:13 PM, Ben Hatfield said:

How do I successfully center the tire on the vertical plane?

@redfoxdude is correct in his suggestion that the axle mounting surfaces on the sliders are most probably out of alignment.

Most early batch S18's will arrive with Only one side of the sliders machined and one side of the axle shimmed by King Song to try and correct this!  However, even then some S18's can still have a poorly aligned motor within the slider assembly, as displayed in your photo. 

Another issue that I found when overhauling my own S18, is that the the axle clamps were drilled with too tight a tolerance, causing the bolts to bind and cut their own thread into the holes!  The clamps are drilled 8mm, but I opened them out to 8.5mm to help with the assembly binding/locking the sliders when the axle is clamped back in place! 

A Full description in my overhaul thread includes a section describing how to rectify the axle/wheel alignment issues and may offer the help you need. I had to get my wheel alignment spot on, because I have now fitted a much wider CST C6004 tire/tyre (with No Clearance/rubbing issues!) than the the stock H-5102:

 

 

Edited March 5, 2021 by fbhb

[Impecable]

On 10/12/2020 at 3:51 PM, NastyFartPants said:

I then replaced the penny washers with M10 x 13mm x 1mm Flat Seal Washers so that the only contact was with the bearing's inner race.

How many did you use and where did you get them? I really want to do this but cant find those seal washers anywhere

[NastyFartPants]

4 hours ago, Impecable said:

How many did you use and where did you get them? I really want to do this but cant find those seal washers anywhere

It wasn't very scientific, I placed just enough washers to create a small gap between arms that were rubbing!

I got mine from eBay UK.

Here's a link to an alternative source:

https://www.aliexpress.com/item/32356890286.html?spm=a2g0o.productlist.0.0.78c21b14E75DB3&algo_pvid=b60503c5-12d8-4982-8bd8-a414a07264db&algo_expid=b60503c5-12d8-4982-8bd8-a414a07264db-0&btsid=2100bdcf16149002413182550eac5d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

I think these would also do:

https://www.ebay.com/itm/10pc-M10-10mm-x-14mm-x-1mm-Copper-Crush-Washer-Seal-Oil-Gasket-Banjo-Bolt-ATV/164290180092?hash=item26407533fc:g:fqkAAOSw9rpfDcAb

[Phi1osopher]

I carefully read this thread while waiting for my s18 to arrive.  It showed up about 1.5 weeks ago (april 2021), and fortunately my suspension seems pretty good right out of the box.  I am a reasonably skilled mechanic, machinist, and am pretty good at tweaking mountain bike and motorcycle suspensions, so I was all excited and a bit concerned about what I might find, but so far so good. I even pre-purchased some Teflon washers and precision spacers.

I guess they figured out how to fix some things, because with the shock disconnected my wheel's suspension moves freely and silently. Jumping off stairs and riding rocky trails the suspension seems to be doing pretty okay.  I mean it's not as good as a correctly tuned KTM motorcycle or a nice mountain bike, but it is still pretty good. 

Anyway.  Thank you guys for pioneering so much effort and sharing your processes with us. I am planning on tearing mine down at 500 miles to inspect the whole wheel (sometime in the next week or two), and maybe that will reveal how it has changed or improved... or maybe it will reveal new problems.  We shall see!

[EUC Forest]

On 9/17/2020 at 2:11 AM, dsd317 said:

My S18 (Batch #2) was delivered on Monday, Sept. 14th.

After disconnecting the linkages, I found that they did not have much friction, if any.  Majority of the friction/binding came from the sliding tubes.

Nonetheless, this is what I did to improve suspension performance:

 

Washer shown here.

 

Showing socket head insert nut protruding slightly past bearing's inner race.

 

After taking this picture, I tightened bolt onto socket head insert nut. (I forgot to take a picture after I tightened it but see video for reference).

 

Video showing spinning socket head insert nut and bolt:

 

Moved seals to spray lubricant down sliding tubes and all other areas of black tubes.

 

Suspension now moves way better than it did out of the box.  It's not perfect, but does the job in my situation without disassembling entire S18.  After I enjoy my wheel and have more time on my hands, I'm sure I'll take it completely apart to make more improvements.

 

The washer can be removed simply by unscrewing the bolt? just need to deflate the shock? The seals can be lifted (with a sharp edged spanner or similar), then apply the shock lube, then lower the seals? Thanks.

 

[FinRider]

On 5/8/2021 at 3:58 PM, fntms_slowdown said:

The washer can be removed simply by unscrewing the bolt? just need to deflate the shock? The seals can be lifted (with a sharp edged spanner or similar), then apply the shock lube, then lower the seals? Thanks.

 

Deflate the shock entirely, then take out the bottom bolt that holds the shock in place. Once the shock is loose, then the washer can be removed.

 

[OldFartRides]

Thought I’d bring this thread back to the top. This and the other two are such valuable resources to s18 owners who want to put their suspension straight. I decided to tear down s18 # 2 while I still had all the tools out and this stuff is fresh in my head. I thought I could cut time required in half at least. 
 Not. 
 On wheel one, the top mounting barrel of the shock was about a 1/4” too wide and the bottom was at least an eighth over width to fit between the suspension links. I used a belt sander to take them down to where the shock was not spreading the links out. 
Wheel two is presenting its own special challenges. This is a used wheel I bought last summer for god knows why.

I found some of those lovely split washers hiding in this one. I’m replacing them with off the shelf metric and nylon washers that require a little modification to fit.

Yesterday I spent the whole afternoon shimming and assembling and tweaking. Now when it comes to fitting the shock, I find the gap between the links changes a bit as the sliders move down. This makes no sense as the tubes are confirmed to be parallel.

Maybe it changes because the attachment at the slider tube is not in line with the attachment at the top casting. 
That’s the only reason I can see for the change. Now why I didn’t notice that with wheel one is another question.

Guess I just missed it.

Edited February 18, 2022 by OldFartRides
Auto correct mistake.

[OldFartRides]

Interestingly, when re-assembling s18 #2 (used),the pedal hanger brackets are the ones with the Al spacers. The one on the left side causes no binding issues when tightened down. The right one does. Now I really didn’t like the idea of just losing these blocks as a fix. Chalk another one up to mr. Ob Comp. I thought perhaps it needed shimmed to keep it from moving the stanchion tubes out of parallel. I shimmed it first with one beer can shim, then a folded one. I put a bolt through the pedal pin holes and tightened it just enough to let me get the shims in. Then I let that loose and tightened the bracket screws. No relief.

Took the whole thing out to my machinist friend and he confirmed my suspicion that I had it bass ackwards, and the block need to be milled down a bit. So that’s happening in the am. 

[Ksmack]

I just got a new S18 with the Molicel battery pack from ewheels. The power delivery is great, but the suspension is a pain. I lubed everything up, but it squeaks like a set of rusty bed springs. 

I’m trying to remove the outer washer from the linkage, but I can’t for the life of me loosen the bolts. They are just on there to tight. I’ve got one Allen wrench on the back and one on the front and it just won’t budge. I’m a reasonably strong guy, but it is in there fast. Are they using loctite on this pivot point? How can I get these bolts off?

Also, the linkages aren’t spaced correctly and there is some rubbing. 
https://share.icloud.com/photos/0fcSfX1z5vTKsyQ4w9VFLG3FA

[fbhb]

19 minutes ago, Ksmack said:

I’m trying to remove the outer washer from the linkage, but I can’t for the life of me loosen the bolts. They are just on there to tight. I’ve got one Allen wrench on the back and one on the front and it just won’t budge. I’m a reasonably strong guy, but it is in there fast. Are they using loctite on this pivot point? How can I get these bolts off?

Yes, King Song has most probably used Loctite on those bolts, so heat will be required to loosen them.

I wrote a suspension overhaul topic that may offer some help in improving the suspension action of your S18.

My own wheel now has ZERO stiction and ZERO squeaks/noise from it's suspension action, with a very plush feeling to the travel.

One WARNING though, the necessary work and precision involved can be very lengthy and time consuming (YMMV): 

 

Edited May 20, 2022 by fbhb

[Ksmack]

13 minutes ago, fbhb said:

Yes, King Song has most probably used Loctite on those bolts, so heat will be required to loosen them.

I wrote a suspension overhaul topic that may offer some help in improving the suspension action of your S18.

My own wheel now has ZERO stiction and ZERO squeaks/noise from it's suspension action, with a very plush feeling to the travel.

One WARNING though, the necessary work and precision involved can be very lengthy and time consuming (YMMV): 

 

Thanks! Your thread it’s inspiring. 
I don’t have a heat gun. Would a hair dryer work?

[fbhb]

1 hour ago, Ksmack said:

I don’t have a heat gun. Would a hair dryer work?

I used a soldering iron when I worked on my S18, if you have one or access to one that should work. A hair dryer may work too if it can direct the heat in a concentrated fashion (maybe make yourself a cone shaped funnel from a drinks can) and has a High enough heat setting!

Hope you go on OK and post back if you need any further help at any point.

Edited May 20, 2022 by fbhb

[OldFartRides]

Yes, those cheapass socket screws will round out if you look at them sideways.

solder iron is best.
Be forewarned, it’s a tedious job revamping the suspension.  I rode mine the first season, then tore it apart this past winter. It was worth it.

Some folks have taken it to the nth degree, others ( myself included) do just enough to satisfy their own level of ob comp.

Its nicely engineered but poorly manufactured/ assembled.

Best of luck !

 

Edited May 20, 2022 by OldFartRides

[Ksmack]

23 hours ago, fbhb said:

I used a soldering iron when I worked on my S18, if you have one or access to one that should work. A hair dryer may work too if it can direct the heat in a concentrated fashion (maybe make yourself a cone shaped funnel from a drinks can) and has a High enough heat setting!

Hope you go on OK and post back if you need any further help at any point.

I removed the bottom bolt that connects the shock for easier access to the two linkage bolts with the dumb washers on the outside. I noticed that there was blue loctite on the bottom suspension bolt.

I bought a soldering iron and heated it up to 900F and spent a long time heating up the bolt with the washer. With a great deal of effort and an impact driver I got it free! The bolt didn’t have blue loctite but rather some white substance on it. It was in there good. I removed the washer and put in the spacers. Lubed everything up and retightened. 
 

for the other side no amount of heat applied with the soldering iron could loosen things sufficiently. I ended up starting to strip the bolt head. I am giving up at this point as I just don’t know how to remove it. Fortunately, it was the other bolt (the one with the washer I successfully removed) that had the most binding. After lubricating everything there is a definite improvement in the movement and the squeaking seems to be gone. There are still some creaks. I think this os going to have to be good enough for me. 

I’d love to know what the white residue is from on the bolts. That stuff is nasty. Superglue?

[fbhb]

21 minutes ago, Ksmack said:

I’d love to know what the white residue is from on the bolts. That stuff is nasty. Superglue?

The white residue is most probably Loctite residue, as the Red can turn that colour when heated to remove stubborn bolts.

[Ksmack]

1 hour ago, fbhb said:

The white residue is most probably Loctite residue, as the Red can turn that colour when heated to remove stubborn bolts.

Thanks. That explains why it is so hard to remove. Why would they ever use the red stuff on a pivot joint? It is so annoying how poorly this is assembled. It is so close to being truly great. 

[Ksmack]

Here is a friction test of the suspension with the shock unhooked from. Very sticky at the bottom of travel.  I think it might be from where the linkages are rubbing on one side. 
 

Suspension movement test

[Tawpie]

That looks pretty good, but yeah, my money is on "the linkages are scraping their paint off" as the clue to where you're binding. Either a shim washer to increase the separation (nylon/delrin or something hard and slippery) or a flat file.

But you're looking really good!

[Ksmack]

35 minutes ago, Tawpie said:

That looks pretty good, but yeah, my money is on "the linkages are scraping their paint off" as the clue to where you're binding. Either a shim washer to increase the separation (nylon/delrin or something hard and slippery) or a flat file.

But you're looking really good!

Thanks! After more inspection I think the majority of the sticking is coming from where the pivot bolts hit the plastic mud guard as shown in the picture. I guess I could file down the mud guard in those spots. 
 

Rubbing against mud guard.
 

[SoleCycle]

It has been 2 years since this thread started and activity has fallen off considerably. Are people generally not having issues with suspension anymore? I figured that KS had resolved the issues by now. The reason I'm asking is because I just bought a KS-S18 new from RevRides a month ago and it is definitely biding. Feeling bummed