Notes on Changing KS16S inner tube.

[DaveThomasPilot]

Just wanted to mention a couple of things I noticed when removing the inner tube from my KS16s.

I watched the two videos below.

Justina's video only showed removing the six bolts above the pedal on one side.  You have to remove them on both sides.

Neither video showed the star washers that are between the plastic shell and the "pedal bracket".  I couldn't figure out a way to remove them after removing the screws.  They'll just fall out when you tilt the wheel vertical to remove the plastic housing.  

They went everywhere.  I found all but two--I'm hoping they fell down between the rim and tire and ended up in the tire (I haven't removed the inner tube to check yet.  It's going to be a real hassle trying to get them back in.  Maybe I'll glue them to the inside of the housing.  Any suggestion would be appreciated.

When I removed the six screws from the pedal bracket, I heard a loud snap after partially backing the screws out.  Turns out the plastic was hanging on the screw and pulling it up as the screw loosened.  It would finally come loose and slap back down on the bracket.  That was the snapping sound.

But, I I got a small crack around one of the holes.  

If I do this again, I'd loosen ALL the screws before completely removing any.  That way, I could slide the wheel/pedal bracket around to get the screw perfectly centered in the hole.  This should eliminated it catching when the screw is backed out all the way.

  Finally, there are two cables from the wheel/motor that need to be removed, not just one.

When I removed the second, a got a very loud and annoying beeping and a voice saying something I really couldn't understand.  I silenced both by pushing the power button (I have no idea how the power got turned on).

 

 

 

[mrelwood]

Good points. I didn’t watch the videos, but one thing to note also is that when pulling the motor assembly in and out of the shell, you have to pull the shell sides apart to make room for the motor cables. Otherwise they will strip very soon, or even immediately.

[DaveThomasPilot]

So, maybe my KS16s is a little different than yours, mrelwood.   On mine, there's a channel for the cables so I didn't really have to pull the shell apart to make room. 

I gotta say, the KS16s is much better than my 14C in regards to cable routing.  The 14C was a real pain to tuck the cables back in--and there was a big cap whose leads were sure to break after disassembling the wheel a few times.

Putting the tire back on was much easier than getting it off, probably because I used liquid soap as a lubricant.  Thanks, EUC forum!

I tried fixing the inner tube (hey, Marty says he always just fixes the inner tube!).  But, while one "snake bite" was obvious, I wasn't at all sure that I hadn't damaged the inner tube when I took it off.    Then, I didn't have the tire levers and was using a big, flat bladed screwdriver.  I saw one puncture I think I made taking it off, but I was worried there might be another.

Or, that when I was trying to ride with a flat, I didn't damage the tube in more than one place.

Somewhere I read you can't inflate the patched tube outside the tire--there isn't enough support to hold the patch.  Sure enough, when I tried inflating it, the patch blew out.  So, I patched it again, and reassembled the tube in the tire, in the shell.

Sure enough, the tube still leaked.  I'd already ordered another tube from eWheels, so I decided it wasn't worth the hassle to keep putting the tube in the tire before inflating to make sure I'd fixed all the punctures in the tube.

I think all the tube damage was because I tried riding with too low pressure.  I'd ridden the tire a few miles the previous week.  The tire couldn't have been flat then, or I would have noticed it.  Next time I tried riding it, I went 20 or 30' before I realized it was totally flat.  So, that's  when I probably messed up the tube.

Anyway, the main lesson I learned is to not just jump on the wheel and go.  Make sure the tire isn't really flat first...

Hope this helps someone else.

[mrelwood]

4 hours ago, DaveThomasPilot said:

there's a channel for the cables so I didn't really have to pull the shell apart to make room. 

That is surprising, great progress KingSong! Mine is from early 2017.

Riding at 30PSI indeed makes the tube quite prone to getting damaged. It is also common that the tube or the valve leaks slowly, so the pressure should be checked every week, no matter how little one rides. A pressure gauge costs less than $10, and I think it is key to a consistently comfortable ride as well.

Steel reinforced plastic bicycle tire irons were also about $10 for a set of three. Using a screwdriver is a certain way to scratch or damage the soft aluminium rim, and a likely way to damage the tube as well, as you now learned.

[Smoother]

On 5/23/2019 at 7:22 PM, mrelwood said:

Good points. I didn’t watch the videos, but one thing to note also is that when pulling the motor assembly in and out of the shell, you have to pull the shell sides apart to make room for the motor cables. Otherwise they will strip very soon, or even immediately.

Indeed.  Mine stripped the first time, right down to the wire.  Had to use electrical tape to re-protect it.

To make sure it never happens again I cut out the piece of plastic between the two rows of three bolts.  It serves no purpose.  The case is still fully supported and secured to the pedal hangers.  Theres a picture on my 2.5" modification thread  I'll look for it

@DaveThomasPilot said " On mine, there's a channel for the cables so I didn't really have to pull the shell apart to make room. "  Only just read this.  So King Song is copying my ideas now?  Good!  Someone has to show them the way. 

[DaveThomasPilot]

I should have taken a picture before I put it together.

The inside of my shell has extrusions that (best I can recall) were about 1/2".  They ran just outside the screw holes up past where the cables egress.  Those extrusions keep the sides separated.  There was no interference with the cables when I slid the shell off then back on.

A similar mod would be to glue shims on the inside of the shell just outside the nuts.  Then you wouldn't have to cut the plastic shell.  But cutting the plastic seems like it does the job too.

[Ignacio Azcorbebeitia]

Hi my problem is: the valve touch the cover.

The alligment is ok. 

 

[mrelwood]

On 6/3/2019 at 3:28 AM, Ignacio Azcorbebeitia said:

Hi my problem is: the valve touch the cover.

The alligment is ok. 

Either the tube has rotated a bit or the valve is bent.

1) Press the valve firmly towards the rim. If it doesn’t stay down:

2) Empty the tire completely. While squeezing the sides of the tire together, rotate the tire in relation to the rim, to the opposite direction that the valve points at. Meaning, if the valve is an ”L.”, rotate the tire <=. Then fill the tire, and be careful not to pull the valve away from the rim too much.

If neither trick works, the valve has been straightened too much, and the inner tube must be replaced.

[Smoother]

Yes @Ignacio Azcorbebeitia that can happen.  The interface between the rim and the valve step is not well designed, and the inner tube is not well designed either.  At best, the whole situation is a compromise.  I understood what @mrelwood was saying because I've been there before.  Otherwise, it's a bit hard to describe in writing.  Here's my version:

Let most of the air out

Break the bead (tire to rim grip) on both sides.

Spin the tire around the wheel rim one way and then the other, and observe the valve as you do so.

Note which direction moves the stem in the direction that solves your problem

Maximize that effect while re-inflating the tire.  Keep monitoring the valve and physically force it inwards (away from the body) while you inflate the tire

Test by hand rotating the wheel past all parts of the shell it comes close too

If there is still contact, do it again, only better.