S18 Full Strip Down, Suspension Overhaul, Tire Upgrade, Mods and Rebuild - My Personal Comprehensive Account

[Dominic Winsor]

6 hours ago, fbhb said:

…Please bear with me as this one is a huge task due to having approx. 60 images to reupload, but I will definitely get it resolved during this week for you and the rest of the community!

Thank you so much - it is people like you who make the community awesome! I share what I've done, but your stuff is on another level! It is appreciated.

[fbhb]

S18 Pedals Conversion to 4mm Screw-In Pins (The Ultimate upgrade from grip tape)

 

Edited on: 13/04/2021

Just made a change to the OneUp pedal pins by reversing them for the more aggressive "Hex" side up!  Another huge change in grip, without risk to the soles of your footwear or being unable to bail if required!

I think I much prefer the pedals with the pins screwed in this way around, especially when riding off road...…it's definitely a keeper!

 

Edited April 13, 2021 by fbhb

[Dominic Winsor]

I've just put some "Vicious" grip tape on my S18. I have this on all my wheels and it is pretty good for me. Spikes look like they would be amazing, but I haven't had a need for them yet.

[fbhb]

Loving the feel of the OneUp pedal pin upgrade to my S18 pedals, especially since swapping the pins around to the more aggressive grip option! (as shown in the above post) 

[Kagenin]

Hey fbhb, I've been following this post and many other of the S18 posts on these boards, and finally decided to make an account.  I'm in the process of swapping out my tire for a Japanese-made IRC TR-1 in 2.75-14, and had a few questions.

I'm reusing the stock tire tube, would that be an issue since the tube is for 3x18"?  I'm also curious about the process of shimming the axle, this the part that I'm really worried about screwing up.  The official kingsong tire tube video doesn't exactly go over that point in any detail (It pretty much just says "tighten the motor side axle clamp to 80%, flip and clamp the other side down, flip back to finish the other side, and then made adjustments..."), and yet it seems to be so crucial to the balance of the wheel and ensuring that the sliders aren't binding.

Prior to ordering my tire, I crashed my S18 going about 28mph... busted up some of the plastic paneling, bent and lost some screws in the carnage.  I was able to order replacement shells, but you wouldn't happen to have a list of the shell's fastener sizes handy?  I definitely want to replace them, too.

Thanks much!

[fbhb]

@Kagenin All the information you have asked about can be found in my original post, including the list of fasteners and where they actually fit and some further detail regarding aligning/shimming the wheel.  Hope that helps you find the info that you need, but post back here if you need to ask anything further and I'll try to help you out.

[Kagenin]

Ah, so you did, I'm just blind.  Many thanks for that, guess I have a shopping list for the hardware store.

Just finished up with the tire swap, I think I have the shims in right.  After getting it all put together, my first test was to just pick it up and carefully let it free-spin in my hands.  Didn't seem to wobble, so I took it around for a test lap, and things seem really smooth.  The tire looks pretty well centered in the fender, no lean to one side that I can tell.

At this point the only thing I'm questioning is whether or not the bead is properly set, but I might take it to a local motorsport shop in the morning and see if one of their tire techs can give my work a once-over.

Thanks for all the information you've already provided here, it's been a huge help.

[Kagenin]

So in my crash, I lost some of the screws that attach the inner shell to the rear battery packs, the three of them on each side under the rear cover.  Lost half of them, actually.

I don't see these in the listing, and the m3s and m5s don't seem to fit... Are they m4?

[fbhb]

3 hours ago, Kagenin said:

I don't see these in the listing, and the m3s and m5s don't seem to fit... Are they m4?

Those screws were specific to that fixing point and had a flanged head IIRC, so I was unable replace them with a stainless equivalent.  If memory serves me correctly though, they will be a 3mm thread (as per All the other battery mount holes) so if 3mm now seems too loose there is a good chance they got stripped during your crash!

You have to remember the battery housing's are aluminium, so it's soft enough to strip very easily and you may well have to re-thread the holes the next size up at 4m if the thickness in that area allows.  The other option is to use a longer 3mm machine screw and put a nut on the back side, but beware of the lack of clearance to enable doing this easily. 

I myself found one of those same screws had already stripped out during my re-build and just about managed to sneak a nut onto a longer machine screw to solve the issue.

[Kagenin]

I just went out for some M4 screws anyway, and yeah, they're too big to go through the shell.  When I tried using one of the old M3x8 screws off the body, it fit through the hole, but failed to thread, so yeah, the threads are likely just plain shorn.  I found a couple screws from elsewhere off the body - no clue where! - that seem to be just slightly bigger than an M3 but still otherwise fit, so that's keeping those together for now 

Looks like one more trip to the hardware store for some size M3x10 or 12 and a few nuts.  The last thing I want is for those battery packs to be flopping loose.  I think I can get creative and find a solution to sneak the nut in that tight space (heyoo!).

As a side note, I swapped out the twelve M3x8s on the front and rear edges of the pedal hangers with some stainless (actually, reusing the M3x8s I'd bought for the rear battery/shell fastening... and buying more to finish the set...).  Since I take it off-road a lot, I thought that elevating the pedals while I was swapping those out anyway might be interesting to try for that extra ground clearance.  Man, what a difference that CM or so makes.  Felt much more squirrelly, much less stable, getting speed wobbles when I hadn't really felt them much at all with the new tire.  Might give it one more session but I'm leaning towards going back down.

[dsd317]

On 4/19/2021 at 1:11 AM, Kagenin said:

Just finished up with the tire swap

How does it perform onroad and offroad?  Do you have photos/videos of it on your S18?

[Kagenin]

I don't have any videos of myself yet on it, but here are at least two youtubers sporting the IRC TR-1 in 2.75-14 on their S18.

https://www.youtube.com/channel/UCwyv4kBOPCgGafEz0Q6xcUg This guy is in Japan, but has English subs on all his vids.

https://www.youtube.com/channel/UC0ZXwihNHKtC2WDq1adHLeg This guy is in NorCal like me.

EDIT:  I just noticed how similar it looks to the Kenda K262.  Makes me wonder if Kenda is buying them from IRC to re-brand (or the other way around).

Edited April 24, 2021 by Kagenin

[phillybinchi]

Thank you @fbhb for this post! I finally got the time to fit the CST 6004 on to my S18 and you weren’t kidding about the level of accuracy it takes to get it to fit lol! It took about 4 tries getting the beads properly seated and tire inflated and about 3 tries to get correct shim placement on the axel to get the wheel centered. But let me tell you it was worth it!!! The wheel feels so planted and stable. Thank you again for all of your work on this post! 
 

https://flic.kr/p/2m5ngNr

[fbhb]

6 hours ago, phillybinchi said:

But let me tell you it was worth it!!! The wheel feels so planted and stable

Obviously I already know how you now feel about this tire on the S18, as I think the wheel behaves so well in pretty much every situation imaginable with the CST 6004 fitted. Stability, nimbleness, precision cornering, grip, wear resistance - the list goes on and you will definitely get to experience the S18's handling at it's best as you get more and more accustomed to it.

As you acknowledged, it does take some work and precision to get it centred and running without rubbing, but the pay off is truly remarkable!  So glad you put in the extra effort, you'll really be enjoying the S18 so much more from now on!

Edited June 14, 2021 by fbhb

[fbhb]

Link below is to a mod to remove the excess material of the slider tubes, protruding below the pedal hangers, that can cause the S18 to cut out if caught on/clipping a rock:

Edited August 28, 2022 by fbhb

[fbhb]

I have edited my original post on page 1 today 24/09/2022 to include some refinements I made recently to the S18 slider stiction issues and also in answer to queries asked in the general: King Song S18 Discussion

 

[GerardBu]

Wooow nice job but i think most of us can't do this type of tuning 

[Marcoz]

Hello, your post on S18 weak points is awesome!

Just a question: I'd like to buy a CST C6004 or a C186 for my S18:

- Can you confirm that no mud fender cut is needed with both of those tyres?
From CST site the C6004 seems to have a 20" external diameter and apparently there's no clearance enough to make it fit with native S18 mud fender...
Wouldn't be the 2.5-14 (19.4") version better than the 2.75-14 (20") version for a wheel that was born with a 2.5" with and 18" large tyre?https://www.csttires.com/int/tire/c6004/

- With an off-road tire maximizing the width (2.75") and diameter of the wheel (20"), wouldn't you risk a rock picked-up between two wedges of the tire to block the wheel when it gets stuck below the fender?

- With a 20" tire wouldn't the torque of S18 be too sacrified when climbing on the mountains, considered its limited power?

Thanks a lot for your recommendations!

[fbhb]

11 hours ago, Marcoz said:

Just a question: I'd like to buy a CST C6004 or a C186 for my S18:

- Can you confirm that no mud fender cut is needed with both of those tyres?

I can ONLY speak of the CST C6004 fitment, as that is what I initially installed on my S18 with many photos posted here on page 1 actually showing the 2.75-14 tyre/fender clearance once fitted and it was indeed achieved without any modification to the fender.

I do however state clearly in the text, that with the CST C6004 in 2.75-14 the motor has to be very well aligned so as not to rub and ALSO in a more recent Edit: 24/09/2022 I go on to explain how to rectify the King Song manufacturing issues that cause the well-known wheel/motor mis-alignment problems!

When I initially installed the CST C6004 I would use the S18 mainly on sealed roads (90-95%) with some very occasional light, smoother trails where the tyre performed well enough, but it could drag small stones through although never anything that got caught. Should it be that your main aim was to ride with the CST C6004 on trails frequently, then the 2.5-14 would be a very wise choice for the additional fender clearance it offers IMO.

I now dedicate my S18 100% to trail riding, but with this in mind swapped out the CST C6004 for the IRC TR-1 which although the TR-1 is also 2.75-14 and it being a knobby it actually has much more side clearance (also smaller outer diameter) than the CST, so performs extremely well All round and perfectly offroad (on road too for me)!