King Song S18 Discussion

[enaon]

9 minutes ago, ffontana said:

Now I have all my cells glued together to avoid vibrations.

me too, I am not saying it s not a problem, I just say it is not always the same one, I have seen many type, damage on the measurement circuit due to the plastic ring bending the battery case on old bms is very common too.  

[Tawpie]

Thank you so much @ffontana. I'll get the packs to a repair shop.

[NewB]

September 2022 s18 SE (molicel version). Has anyone heard anything about the availability of the latest batch of s18 molicels? It is listed as being available late September, but I understand timelines slip. I am not sure how often ewheels updates their website listings, but I would think it would be an invaluable service to update them as information becomes available (but maybe they already do).

I reserved one on ewheels.com but do not want to bug them if someone on here has already done so.

[OldFartRides]

Wow, looks like I’ll be tearing mine down this winter for battery safety inspections/ preventative measures….

[Ksmack]

I’ve now put on about 1500 miles on my S18 and have recently started getting wobbles when braking hard or going down steep down hills (think mountain roads) at around 18+ Mph. The wobbles have only recently started after I updated to the latest firmware. Has anyone else seen this?

 

More background: I recently had an angle cutout at a pump track because of a bug in DarknessBot. While trying to diagnose this, Kingsong told me to upgrade my firmware. I did this, checked all of the bolts on the axel, pedal hangers and suspension, and then recalibrated the wheel. Now whenever I ride these steep inclines the wobbles kick in severely and it is a struggle to not get tossed of the wheel. I’ve never experienced wobbles of any kind before this, so I am puzzled. 
 

I’ve got pads on my wheel, I have a K66 tire that is well aligned (I’ve varied the tire pressure quite a bit bit that doesn’t seem to affect the wobbles), I’ve played with the pedal angles and my foot placement. I have pads on the wheel. 
 

The three things that have changed are: 1) I had the slow speed crash. 2) I updated the firmware. 3) I added the Nylolove pedals about the same time (which feel awesome). The wobbles are really perplexing. 

[Funky]

2 minutes ago, Ksmack said:

I’ve now put on about 1500 miles on my S18 and have recently started getting wobbles when braking hard or going down steep down hills (think mountain roads) at around 18+ Mph. The wobbles have only recently started after I updated to the latest firmware. Has anyone else seen this?

 

More background: I recently had an angle cutout at a pump track because of a bug in DarknessBot. While trying to diagnose this, Kingsong told me to upgrade my firmware. I did this, checked all of the bolts on the axel, pedal hangers and suspension, and then recalibrated the wheel. Now whenever I ride these steep inclines the wobbles kick in severely and it is a struggle to not get tossed of the wheel. I’ve never experienced wobbles of any kind before this, so I am puzzled. 
 

I’ve got pads on my wheel, I have a K66 tire that is well aligned (I’ve varied the tire pressure quite a bit bit that doesn’t seem to affect the wobbles), I’ve played with the pedal angles and my foot placement. I have pads on the wheel. 
 

The three things that have changed are: 1) I had the slow speed crash. 2) I updated the firmware. 3) I added the Nylolove pedals about the same time (which feel awesome). The wobbles are really perplexing. 

All mental..  Maybe you got "scared" after that crash and now don't trust the wheel.

Try recalibrating the wheel again. Put it on stand, so it's all even/leveled..

Did you put the K66 recently? You changed the pedals - which may have little bit different angle and what not. (Even little bit, can change whole game.)

[Ksmack]

1 hour ago, Funky said:

Did you put the K66 recently? You changed the pedals - which may have little bit different angle and what not. (Even little bit, can change whole game.)

I’ve ridden the K66 for about 800 miles so far without problems. I’ve got the tire well centered and balanced (no tire wobble). 

I’ll try some more pedal angle settings to see if that improves things. 
 

(The funny think about the crash is that now I feel more confident on the wheel! I think I’m just glad to experience/get my first cut off out of the way). 

Edited September 20, 2022 by Ksmack

[The Brahan Seer]

2 hours ago, Ksmack said:

The wobbles are really perplexing. 

Only other thing I would check is the play in the wheel. If you grab it and try to move it side to side. Any noticeable play? I haven't updated to the new firmware. The forces exerted by braking might be causing something to twist or go out of alignment maybe check axel by removing the bolts and reinstalling (broken bolt?) that might not be picked up depending how you checked the bolts. Very odd indeed. Sorry this isn't much help.

[Ksmack]

2 minutes ago, The Brahan Seer said:

Only other thing I would check is the play in the wheel. If you grab it and try to move it side to side. Any noticeable play? I haven't updated to the new firmware. The forces exerted by braking might be causing something to twist or go out of alignment maybe check axel by removing the bolts and reinstalling (broken bolt?) that might not be picked up depending how you checked the bolts. Very odd indeed. Sorry this isn't much help.

I actually realigned the tire and checked all the axle bolts/retightened everything. Still no bueno.

[The Brahan Seer]

@KsmackDo you experience the same issue if you lock out the suspension?

Edited September 20, 2022 by The Brahan Seer

[Ksmack]

11 minutes ago, The Brahan Seer said:

@KsmackDo you experience the same issue if you lock out the suspension?

I haven’t tried that. I’ve got a Rockshox shock on. I can’t completely lock out the suspension, but I can stiffen it quite a bit. I’ll do some testing this afternoon and try it out. 

[5Cauac]

Loose suspension definitely compounds wobbles. I also did not see a mention on tire pressure. Low PSI also will contribute greatly to wobbles.

 

 

[Funky]

23 minutes ago, 5Cauac said:

Loose suspension definitely compounds wobbles. I also did not see a mention on tire pressure. Low PSI also will contribute greatly to wobbles.

Didn't low PSI remove wobbles? High PSI would feel like riding on knife edge, resulting in more wobbles. (At least for me at lower psi wheels feels more stable.. At beginning i could not go over 28psi at all. Now i can ride 35 without any issues. I personally still like ~30.)

 

He did mention: (I’ve varied the tire pressure quite a bit bit that doesn’t seem to affect the wobbles)

[5Cauac]

@FunkyYou are absolutely correct on the tire PSI. How embarrassing, my apologies. Don't know why I had that reversed.

The soft suspension however...........

[Ksmack]

I typically run my wheel at 30-34psi if I’m going to the bike park or going down stairs. I’ve never had wobbles at these pressures before. I lowered the tire to 27 psi, but still get wobbles. I’m 200lbs including gear. 

[Ksmack]

42 minutes ago, 5Cauac said:

 

Loose suspension definitely compounds wobbles. I also did not see a mention on tire pressure. Low PSI also will contribute greatly to wobbles.

 

 

What do you mean by loose suspension? Do you mean are all the bolts on the linkages tight, or do you mean is the suspension locked out/stiff? The bolts are snug on the suspension (I don’t want to over tighten them and introduce friction). A while back I also fixed my suspension by aligning the sliders in the tubes so there isn’t any friction (following the suspension overhaul tutorials). It is much smoother now. I wonder if that could be contributing to the wobbles?

[5Cauac]

4 minutes ago, Ksmack said:

What do you mean by loose suspension? Do you mean are all the bolts on the linkages tight, or do you mean is the suspension locked out/stiff? The bolts are snug on the suspension (I don’t want to over tighten them and introduce friction). A while back I also fixed my suspension by aligning the sliders in the tubes so there isn’t any friction (following the suspension overhaul tutorials). It is much smoother now. I wonder if that could be contributing to the wobbles?

Sorry, what I meant was a really soft suspension. This is why the suggestion of locking it out was mentioned. You may also want to play around with your foot positioning and /or posture while riding. Having your feet positioned too much to either the front or back of the pedal will effect your center of gravity. Set up a camera to view youself from the side as you ride or pay attention to your shadow. If you see you are leaning too much forward or back that is contributing to the the wobbles.

 

[Tawpie]

And you mentioned just changing pedals—the Nylonoves are a teeny bit different than stock. I'd try different foot positions etc. (I recently got a set and yes, they're very fun to have, I'm not certain they're "better" than my Fish inserts, but they sure do look swell!)

[Ksmack]

tldr; A combination of changing the pedal tilt angle to 1 degree backwards, setting the shock to the slowest compression for a firmer ride, and changing my body position slightly seem to have fixed/dramatically improved things.

Thanks for all the suggestions. I went to one of the major paved hills (the NCAR building in Boulder, which is about a mile long with a very steep incline that bikers love to ride up and down) to do some testing. All tests were done at 27.5 psi. I realized looking at my notes that my previous tests were done between 29-34 psi. For each test I also was carving as riding and my right foot was slightly ahead of my left foot.

Test 1: My default riding setup. Pedals set to tilt 1 degree forward. Suspension not locked out (fast compression). At the steepest part of the incline as soon as I went past 23 mph I started to get wobbles. At the bottom I braked hard and also got some minor wobbles. Still, it wasn’t as bad as when I had the tire at higher pressures (30-34 psi). Lowering the pressure to 27.5 psi helped.

Test 2: Set the pedal tilt angle to 1 degree backwards. Everything felt more stable at speed on the steeper descent. Started to feel very slight wobbles wanting to start at 25 mph this time. It was easy to dampen them.

Test 3: Kept the pedal tilt angle at 1 degree backwards. Locked the suspension out by setting it to the slowest compression/fastest rebound. The suspension still works, it just reacts much slower. This time I didn’t have any signs of wobbles while going over 25 mph.

Tests 4-6: Experimented with body positions and tried to move my body a bit more forward. This was made easier by having the pedals tilted back. Felt much more stable and was able to ride the final run the whole way down at 27 mph (I’ve got my tiltback at 28 mph). Carving gave my legs a good workout!

I think I may have to tilt the pedals back a bit more if I’m going to tackle even steeper inclines for the time being. Looking over my old logs, I have been doing the steeper inclines quite a bit slower, so I think it is a matter of getting the muscles and body position right. I don’t often do steep descents like that, so I haven’t practiced it much. It is exciting to have some new skills to work on! I haven’t had speed wobbles since my beginning days on the 16X.

Thanks again for all the help and suggestions.

[The Brahan Seer]

@Ksmack Its good to know you have found the solution. As you learn the new muscle memory and get used to the changes you made you will be able to adjust everything again to your liking. Thank you for sharing your insights with us. This is useful to know that despite our experience, making changes can make a big difference to our riding skill. Until we get used to it again.

[Tawpie]

What with my battery problems putting the wheel out of commission, and having to take it 70% apart for the new packs (molicels), I decided to do suspension maintenance. I'm the second owner, and while the suspension has always worked really well, it has more stickshun than I like and I've never had it apart to see if everything was ship shape or not. It's got roughly 1500 miles on it, mix of street (previous owner) and blue trails—I don't jump cuz I can't afford to break myself. Here's what I noted:

1. With the skins off and the batteries installed, it looks like a master with a double slider. It didn't need to feel so wide, did it? And why isn't there an XL version yet?
2. 8 of my bearings are going to get replaced. They're not "bad", but they have a definite catch in them like one of the bearings or the race is flat spotted. These are the ones in the center pivots, there are two in each pocket.
3. Some of the stickshun I have (the reason I think it can be better) is because of the shock's top and bottom mounts. The binding posts that hold them on are a teeny bit short so when you clamp down the bolts it squeezes the bushings into the shock. The bushings are made of some hard+slippery plastic (Delrin?), but there's quite a bit of static friction. I'm going to put in shoulder shims so the clamping force is born by the binding posts and see how that works out.
4. No split washers, no broken bearing seals, no broken bearings, no metal-to-metal interference. It all looks real good.
5. With the suspension disconnected, there's still a fair amount of stickshun in the sliders. The linkage wasn't helping but it's not the main cause... it's not like the sliders are misaligned, once they get moving they move easily but getting them to start moving is less than ideal. I'm going to have to noodle on that—hints are appreciated! I wonder if there's phnee† inside the sliders, the dust seals are kind of a joke.
6. I'm going to add hard foam padding around the two bosses on the inner shell that can dent the front battery boxes. When it's done I'll post pictures.
7. I doubt I'll open brand new battery packs to add glue to the cells even though I probably should. Maybe when they're out of warranty in 6 months but for now...

So far, nothing terrible!

 

† phnee: n. f'-nē Goobers or other yucky substance of unknown origin.

Edited September 23, 2022 by Tawpie

[NewB]

That is actually heartening news! I ordered one of the upcoming batch of molicel s18s from ewheels and was wondering what I would have to do to make it smooth. Based on your experience, I at least know what to look out for. Given that I weigh all of 130 dripping wet with clothes on, I want as little binding as possible. Thank you for the post, and keep us updated!

 

[Ksmack]

8 hours ago, Tawpie said:

With the suspension disconnected, there's still a fair amount of stickshun in the sliders. The linkage wasn't helping but it's not the main cause... it's not like the sliders are misaligned, once they get moving they move easily but getting them to start moving is less than ideal. I'm going to have to noodle on that—hints are appreciated! I wonder if there's phnee† inside the sliders, the dust seals are kind of a joke.

For me I had to loosen the outer axle bolts. I loosened all four outer bolts until they were no longer snug and checked to see if the suspension moved smoothly (no hitches). The bottom shock pin needs to be disconnected. I started tightening the bolts one by one, checking if the suspension kept moving smoothly. For my wheel on the right side (non motor cable side) it was the back outer bolt that needs to be kept looser and the front one can be tightened. On the right side it is the front bolt that needs to be slightly looser and the back one can be tightened. Of course it could be different for you. 
 

I was surprised at what a big difference this makes on the small bump sensitivity when I got it working. 

[enaon]

5 minutes ago, Ksmack said:

For my wheel on the right side (non motor cable side) it was the back outer bolt that needs to be kept looser and the front one can be tightened. On the right side it is the front bolt that needs to be slightly looser and the back one can be tightened.

having the bolts loose it not a good solution I think, it just means that you should shim it. 

[Tawpie]

1 minute ago, enaon said:

having the bolts loose it not a good solution I think, it just means that you should shim it. 

Is there a torque spec or recommendation for the axel bolts? I have a thing about torquing bolts that keep important parts on...