S18 Suspension Overhaul

[fbhb]

One of the Russian S18 suspension overhaul jobs, showing just how easily/smoothly the set up works if built/re-built correctly even with just One Hand! 

One other important thing to notice, is that he has re-installed the shock upside down and I assume this is done purposely to achieve much simpler access to the fill valves (can't see any reason why it would affect performance) a very simple Genius solution IMHO!

Please note: My apologies for the grainy video, not mine of course!

 

A little hard to see in the grainy video, but here you can see that he has also chamfered the battery/pedal frames for better ground clearance!

Edited September 15, 2020 by fbhb

[Mark Wilson]

20 minutes ago, fbhb said:

One other important thing to notice, is that he has re-installed the shock upside down and I assume this is done purposely to achieve much simpler access to the fill valves (can't see any reason why it would affect performance) a very simple Genius solution IMHO!

I just skimmed through a few mtb forums and it seems that mounting this style shock upside down should be fine (ones with a piggyback reservoir might have problems). This seems like it would be a good solution to allow easy filling and easy comparison of shock pressures.

[fbhb]

19 minutes ago, Mark Wilson said:

This seems like it would be a good solution to allow easy filling and easy comparison of shock pressures.

It could also offer a little more clearance above the fender, where owners have complained of the shock sometimes touching causing the tire to rub! (too hard to tell in the video I posted though)

Edited September 15, 2020 by fbhb

[Stillhart]

It does look a little exposed in the back when it's upside-down.  I'd be worried about it getting damaged in a tumble.  The regular way has it kind of protected by the linkage.

[Beachboy]

5 hours ago, fbhb said:

One of the Russian S18 suspension overhaul jobs, showing just how easily/smoothly the set up works if built/re-built correctly even with just One Hand! 

One other important thing to notice, is that he has re-installed the shock upside down and I assume this is done purposely to achieve much simpler access to the fill valves (can't see any reason why it would affect performance) a very simple Genius solution IMHO!

Please note: My apologies for the grainy video, not mine of course!

 

A little hard to see in the grainy video, but here you can see that he has also chamfered the battery/pedal frames for better ground clearance!

I would love to have that smooth play on my suspension but is it really need that much?

btw, that battery base cuts really nice..👍👍

the upside down shock doesnt really effective in my opionion, only to make easy access to the valves

[Mark Wilson]

5 minutes ago, Beachboy said:

the upside down shock doesnt really effective in my opionion, only to make easy access to the valves

It seems like a lot of people are having trouble inflating the shock currently. Also, not having a repeatable way that people are inflating the shock means that no one can compare what pressures they are using. Flipping the shock upside down might fix both of these issues (I don't know because I don't have the wheel).

[FinRider]

11 hours ago, fbhb said:

One of the Russian S18 suspension overhaul jobs, showing just how easily/smoothly the set up works if built/re-built correctly even with just One Hand! 

One other important thing to notice, is that he has re-installed the shock upside down and I assume this is done purposely to achieve much simpler access to the fill valves (can't see any reason why it would affect performance) a very simple Genius solution IMHO!lease note: My apologies for the grainy video, not mine of ourse!

A little hard to see in the grainy video, but here you can see that he has also chamfered the battery/pedal frames for better ground clearance!

Do we know what they have done to achieve this?

[Stillhart]

27 minutes ago, FinRider said:

Do we know what they have done to achieve this?

Someone posted a full step-by-step earlier in this thread.

[eve]

@fbhb This shock should be fine upsidedown. The problem comes with dual piston airshock where air will go much faster then oil. Making the shock not function properly. The second piston might not work properly.
 

Edited September 15, 2020 by eve

[yon]

Imagine what type of suspension wheel we would get if @luk Luk @feynman @Rehab1 and those Russian guys were locked in a room together with an endless box of spare parts and batteries.  I for sure would be the first person to put me money down for a pair.  One for best one for playing in the mud.

Edited September 15, 2020 by yon

[Feynman]

Final parts list.  I'll refer to these number in instructions and pictures to follow:

1. 15mm L x M6 Cap Bolts (8 total) -- https://www.amazon.com/gp/product/B07L56Z4SY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 $6.89

2. 12mm L x M6 Button Head Bolts (4 total)  -- https://www.belmetric.com/6mm-c-563_581_584_606/sb6x10ss-button-allen-socket-head-stainless-p-3278.html $0.64

3. 20mm L x 10mm OD x M6 round coupler (4 total) -- https://www.amazon.com/gp/product/B07SQLZ568/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1   $7.99

4. 25mm L x 10mm OD x M6 round coupler (2 total) -- https://www.amazon.com/Coupling-Connector-Threaded-Adapter-Stainless/dp/B07X9W4DS1/ref=sr_1_1?dchild=1&keywords=m6+x+25+coupling&qid=1600211214&s=industrial&sr=1-1  $6.99

5. 10mm ID x 18mm OD x 5.5mm thick thrust bearings (3 total) -- https://www.amazon.com/gp/product/B07QKKWM2R/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1  $6.69

6. 8mm ID x 16mm OD x 5mm thick thrust bearings (4 total) -- https://www.amazon.com/gp/product/B0192SOXN0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1  $7.29

7. M6 Stainless Flat Washers (4 total) -- https://www.amazon.com/gp/product/B009OK2AZK/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1  $9.52

8. 0.5" ID x 0.75" OD x 1/32" thick PTFE washers (6 total) -- https://www.ebay.com/itm/1-2-Washer-3-4-OD-1-32-thk-PTFE-Plastic-Insulating-Fastener-Z78070/392789577456?ssPageName=STRK%3AMEBIDX%3AIT&var=661675992196&_trksid=p2057872.m2749.l2649 $9.99

9. 0.25" ID x 0.562" OD x 0.062" thick PTFE washers (6 total) -- https://www.amazon.com/gp/product/B006GHXY90/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 $14.52

10. Custom 3D Printed Bushings -- AMIDEX Glass Fiber Reinforced Filament (1/10th roll) -- https://www.3dxtech.com/glass-fiber-reinforced-filaments/amidex-nylon-gf30/  $68.00

    a. Pocket B - internal bushing with built in spacer

    b. Pocket A - External Bushing 

    c. Pocket A - internal bushing, extends into pocket D

    d. Pocket D - internal bushing

    e. Pocket D - external bushing

    f. Pocket C - internal bushing 

    g. Pocket C - external bushing with built in spacer

11. Blue thread locker (1 tube) -- https://www.amazon.com/Loctite-Heavy-Duty-Threadlocker-Single/dp/B000I1RSNS/ref=sr_1_3?dchild=1&keywords=blue+threadlocker&qid=1600211771&sr=8-3  $6.09

[Feynman]

Here's a pic of the final right side suspension assembled.   I'll refer to the connection points by there letters in the instructions.

[Feynman]

Connection B (longer arm to black aluminum top) Instructions:

1. Press bushing (10a) into Pocket B. The bushing will extend out a bit on both sides of the arm to act as spacers.

2. Place one m6 washer (7) onto a 15mm m6 bolt (1)

3. Place 8x16x5 thrust washer on bolt on top of washer.  This won't be centered, but that's ok.  The bushing pocket will center it when assembled. 

4. Add a drop of locktite onto the end of the threads of this bolt

5. Place 20x10mm coupler (3) through bushing (10a) in Pocket B

6. Screw bolt from steps above into the inside (towards the tire) end of the coupler.  The thrust bearing will sit inside the pocket in the bushing - there's ~ 0.5mm clearance on the sides

7. Place 1/2" PTFE washer (8) over the outside end of the coupler.  This will sit between bushing 10a and the black aluminum top.

8. Holding the bolt in place so things don't fall apart, insert the outside end of the coupler into the hole in black aluminum top.  See pics - the arm is below and the black aluminum is on top. You'll need to keep holding the inside bolt until the outside bolt is attached.

9. Now's a good time to add some lube if desired

10. Place 1/2" PTFE washer (8) over the exposed end of the couple; against the black aluminum top.  

11. Place one of the outside races of a 10x18x5.5 thrust bearing over the exposed end of the coupler.  This should now site exactly flush with the end of the coupler (see 2nd pic).

12. Add some locktite to a 12mm m6 bolt (2) and screw into outside end of the coupler.  

13. Tighten both inside and outside bolts simultaneously using two m6 allen keys.  Feel free to tighten as much as you like - this connection won't bind when tight.

 

My pics are too big so I'll post the others below in a few minutes.

Edited October 18, 2020 by Feynman
apparently I can't count to 13

[Rehab1]

On 9/13/2020 at 6:59 AM, fbhb said:

Yes, there is definitely a misunderstanding here!  What they meant about removing the paint "because the bearing can't move if there is paint" is that when King Song left paint inside the pockets of some linkages, it would have decreased the internal diameter of the bearing pockets.  Subsequently any bearings pressed into a pocket that is basically "Too Tight" a fit will in turn be forced to close up on it's own tolerances and therefore unable to rotate freely!

Looks like everyone is still working hard on their mods.  

@fbhb You’re definitely on to something......either your scenario or what I  discovered on my new suspension arms today ......or a combination of both.

4 of the12 piggy back bearings contained in the arms are not perfectly aligned resulting in a complete disruption of installing the bushing and screw. ( I now have a theory as to why some bearings fell completely apart upon disassembly..)

Each polished bushing should slide effortlessly through both paired bearings or a bind will occur. This happened to me today when I attempted to slide a bushing through a set of bearings with a rubber mallet.   Both bearings froze up until I was able to wiggled the bushing out by hand.

Tomorrow I’m planning on compressing each of the 4 sets of asymmetrical siamese twins in an effort to realign the bearings. If that doesn’t work I’ll just press out the ugly ones and install new.

Well good luck all and time to Git R Done! 

[Feynman]

More pics for Connection B.  The shaft should be flush with spacer before bolt is added.  Also, a closer look at bushing for pocket B (10a on parts list).  I'm out of time tonight, sorry.  I'll try to add the instructions for the other connections tomorrow.

 

 

Edited September 16, 2020 by Feynman

[Rehab1]

6 hours ago, yon said:

Imagine what type of suspension wheel we would get if @luk Luk @feynman @Rehab1 and those Russian guys were locked in a room together with an endless box of spare parts and batteries.  I for sure would be the first person to put me money down for a pair.  One for best one for playing in the mud.

I may end up there once this project is over.

[Rehab1]

3 minutes ago, Feynman said:

More pics for Connection B.  The shaft should be flush with spacer before bolt is added.  Also, a closer look at bearing 10a.  I'm out of time tonight, sorry.  I'll try to add the instructions for the other connections tomorrow.

Terrific job!!! I commend you on your professional, well defined parts and assembly process!  

[Rehab1]

It may appear like a mess but I’m actually making excellent progress. Waiting for my new DNM 38RC shock to arrive Friday. All of the articulations are smooth so far. I will gladly post my parts/ procedures when I’m completely satisfied with the performance. 
 

In some aspects I believe my mods will be simpler than master craftsman  @Feynman but I plan to add zert fittings at the slider attachment points so that may prove to be somewhat difficult.

 

The hardest part of this mod process is keeping it a secret from my wife. She has no idea I bought an S18. 

[wheel-life]

52 minutes ago, Rehab1 said:

The hardest part of this mod process is keeping it a secret from my wife. She has no idea I bought an S18. 

 Hey, if questioned, no need to lie, just say you built an S18!

[dsd317]

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:

 

 

Removed "infamous" block (located behind foot pedals).  Picture shows block already removed and laying on wheel hub.

 

 

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.

 

[Rehab1]

15 minutes ago, dsd317 said:

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.

Congratulations!  Nice to hear the S18’s are improving.

Speaking for myself I could have easily lived with my suspension but @Feynman shammed me into rebuilding it.

In my opinion compressed air and lubrication are going to be key for cleaning and maintaining the S18’s suspension.

Enjoy!

[Rehab1]

49 minutes ago, manieuc said:

 Hey, if questioned, no need to lie, just say you built an S18!

Unfortunately she is very observant but part of your well thought out excuse would be true. 

[eve]

Did you buy a 38RC?   @Rehab1

Edited September 17, 2020 by eve

[Rehab1]

4 hours ago, eve said:

Did you buy a 38RC?   @Rehab1

Yes sir! I hope it solves this malalignment issue as well. I’ve methodically assembled each linkage component and evaluated for possible binding. Attaching the shock to the arms has now become an issue as the shock’s threaded nut does not line up with the contralateral suspension arm. 

I’m not sure if the shock’s attachment point is skewed or the actual suspension arm has a twist. I tried the spare suspension arm and the nut was oblique as well. 

If the new shock does not resolve the issue I’ll need to heat up the arm and twist it. This is a  regular occurrence at work when designing braces but unfortunately I’ll need to repaint the arms after melting the paint. 

Suppose I could just hammer the suspension system back together until the pieces fit but then I’d have to change my last name to Song.  

I truly love this wheel and the R&D that went into the design. I consider my mods a labor of love.

[Feynman]

Sorry for the slow posting.  My day job is crushing my soul lately.  Here are pics and instructions for Pocket C - this is the connection between the short-fat arm to the gray slider.  I've changed the interior bushing slightly so that the thrust bearing doesn't bind to the shaft, but rather to the bushing.  This requires an extra washer to be added to the outside.  Will update procedure and pic shortly...

There are interior and exterior bushings for Pocket C that connect to form a continuous hole for the shaft; increasing the ID surface area.  The exterior bushing also fill that strange depression they've left in the arm - I guess this was for the lock washers.  Anyway, at full tightness this connection now has almost zero friction

 

1. Place an M6 washer (7) onto a 15mm M6 bolt (1)

2. Place a 8x16x5 thrust bearing (6) onto the bolt after the washer.

3. Press interior bushing (10f) into Pocket C from behind - see pics 3 and 5 above of this bushing inserted

4. Insert exterior bushing (10g) into the top of pocket C - see pic 4 above.  This shouldn't require much force.

5. Place a drop of thread locker (11) onto the internal threads of a 20mm x 10OD coupler (3).

6. Place this end of the coupler through bushing 10g and into bushing 10f from the top (pic 3).  This coupler won't go all the way through bushing 10f.

7. Screw your bolt from steps 1-2 into the coupler from the back side.  The thrust bearing will sit in the pocket of bushing 10f.  

8. Place a 0.5" ID Teflon washer (8) onto the shaft - this will sit between the exterior bushing and the gray slider.

9. Insert the free end of the shaft into the hole in the gray slider.  See pic 2.  It goes on the inside of the slider.  If you want to add lube, now is a good time.

10. Place a .5" Teflon washer (8) over the exposed end of the shaft.

11. Place a 0.25" ID Teflon washer (9)  onto a 12mm M6 Bolt (2).

12. Place a drop of blue thread locker (11) on the threads of this bolt.

13. Screw bolt into exposed end of shaft.  Tighten bolts on both ends.

Edited September 19, 2020 by Feynman