Jump to content
Smoother

KS16 2.5" (tire) modification. My experiences

Recommended Posts

FIRST IMPRESSION (ride one, Friday morning)

I'm not impressed.:(

Turning has become very strange and unnatural.  Let me try and explain it:

When turning the wheel tries quite hard to stay upright, putting noticeable pressure on the inside edge of my outside calf.  In addition, the nose of the wheel wants to fall into the turn; creating an alarming over-turn scare. I tried riding it for 20 or so minutes before I had to leave for the weekend.  But although I took my wheel with me to the coast, as I do every weekend, I was not happy.

I DON'T LIKE IT.

Edited by Smoother
  • Like 1
  • Upvote 1

Share this post


Link to post
Share on other sites

THIRD IMPRESSION (Ride three, Saturday Afternoon.)

Came back to the seafront after a charge.  Bumped pressure up to 40psi but soon found it too darty, so backed it off.  Discovered it was at 31psi again, but rode it anyway.

Experimenting with foot positions seemed to make a difference.  Experimenting with the way I execute turns, also made a difference.  Bending the knees/ankles differently, seemed to make a difference.  The standing up in corners, and nose-diving into corners was becoming less distinct, and less noticeable.

Lots and LOTS of turns, slaloms, 180s 360s figure 8s etc.  Lots and LOTS of experimenting with feet, knees, ankles, hips, (no, not the hips) and Its starting to feel good.

Higher speeds and bumps still create wobbles. :(

I LIKE IT.

Edited by Smoother
  • Like 1
  • Upvote 1

Share this post


Link to post
Share on other sites

FORTH IMPRESSION (Ride four, Brighton seafront, Sunday) 

31 psi seems ok.  Might try a little higher, but not so much that I'm pinging off every raised object that I run over. Things are starting to feel very normal.  I can't feel the wheel standing up in turns.  I can't feel the nose-diving into turns, and it doesn't feel darty.  I'm pulling off large, deep, slalom turns, one after the other, for miles. Keeping in time with my music, I'm having a great time.  Making adjustments mid-turn is easy and effortless.  The nature of my slaloms is more smooth and uniform than with the original Kenda tire.  I'm swooshing effortlessly through the thousands of people out for a Sunday stroll at the beach, Even their unleashed dogs, and wayward kids are no problem (mostly).  Honestly, I can't quite put my finger on it, but somewhere along the way, I've adjusted to a tire, that 2 days earlier, I was swearing I was going to have to remove.  It's not all strawberries and cream, however.  Bumps still create wobbles, and riding over rough terrain ( a series of bumps) is Wobble City. So the stability I was after is not there yet.  I'm hoping its something I'm doing that can be changed.

I REALLY LIKE IT!

Sometime soon I'm going to start where the blacktop ends and climb those grassy cliffs all the way to Beachy Head.

  • Like 1
  • Upvote 1

Share this post


Link to post
Share on other sites
47 minutes ago, Smoother said:

so I took some photos

Post plz.

Of the wheel+tire would be interesting, too.

Share this post


Link to post
Share on other sites
58 minutes ago, Smoother said:

SECOND IMPRESSION (ride two Saturday Morning)

So I started playing with the air pressure.  Initially, it was  31psi. (all pressures are approximate). I also tried it at 26psi. This seemed better, but I discovered that at 26psi, if I hit a bump (also known as a @Rehab1 :D), I got an alarming wobble.  Not wanting photos of my nipples censored by @Marty Backe I fought hard to not fly straight into a hospital bed. (Just kidding, it wasn't that bad, in reality, but a wake-up call, that stability wasn't any better yet). 

Bumps and nipples. @Hunka Hunka Burning Love I need some help over here!:clap3:

BTW I hope to drop off the motor to my friend this weekend. We have a non/ hydraulic press at work and my employees could not get the axle to budge.

Edited by Rehab1
  • Like 1

Share this post


Link to post
Share on other sites

Trim Lines 2

Gold markings are second or third trim lines.  Note that bottom shell outer half is currently separated from the inner.  I trimmed both shells (inner and outer) equally, then sculped the inner edge.  If I had to do it again, I would trim the inner and outer separately, trimming and sculpting only the inner to the tire, and then trimming the outer only where necessary.  Ribbed padding has been cut away to make way for the electric jigsaw.

Trim Lines 1

 

Edited by Smoother
  • Like 1
  • Upvote 1

Share this post


Link to post
Share on other sites
16 minutes ago, Smoother said:

Side ViewSide View 2

 

Great modification, it  kind of looks like a KS18 now the way the shell is cut away.   It looks good.  

  • Like 3

Share this post


Link to post
Share on other sites

Nice write-up - I hope you will continue to update us. I was impressed by the dramatically improved traction and handling, except for the wobbles. This reinforces my anticipation for the Ninebot Z and 4" tyre.

I'm baffled as to why you are experiencing wobble and instability after hitting small bumps, unless caused by a collision of the tyre and shell due to the close tolerances even after widening the shell. I trust that the Ninebot Z which is programmed and engineered for a wide tyre, will not exhibit this problem.

  • Like 3

Share this post


Link to post
Share on other sites
45 minutes ago, litewave said:

Nice write-up - I hope you will continue to update us. I was impressed by the dramatically improved traction and handling, except for the wobbles. This reinforces my anticipation for the Ninebot Z and 4" tyre.

Thanks. Don't get me wrong.  There's nothing wrong with the Kenda grip, it's just that this tire is almost a slick, so i was expecting it to slip and slide on damp grassy slopes.  I did get some sideways sliding, navigating the tire ruts on the trail but the orig. tire would have done the same.

 

45 minutes ago, litewave said:

I'm baffled as to why you are experiencing wobble and instability after hitting small bumps, unless caused by a collision of the tyre and shell due to the close tolerances even after widening the shell. I trust that the Ninebot Z which is programmed and engineered for a wide tyre, will not exhibit this problem.

I get wobbles with the orig. tire too.  My new tire makes no contact with the shell.  It could be me.  I'm hoping it's me.  Although, as we all know, wobbles exist and can be dangerous.  Of course, with a wider tire, there are more opportunities for parts of the tread to come into contact with raised parts of the path that are not directly under the central rib of the tire.  So if you run over a rock on the far right side of the tire ( a pebble that a thinner tire might miss) the wheel will want to pivot away from this rock, to the left, especially with high pressure/little give.  Then repeat this process on the left, and you pivot the other way.  I took a mud and rock path for about 1/2 a mile, and tried to go as fast as I could.  That's where I discovered Wobble City.  Also, I was aware of marked tram-lining.  When riding on a level surface parallel with another surface with a slight height difference 3 or more mm, and the wheel pulls hard to one side.  I almost never experienced this on my two 2.125" Kendas (14" and 16")  I would even tempt the tram-line gods by deliberately riding where tram-lining should be induced, nothing.  So watching out for possible tram-line scenarios has come back into my arsenal.  No biggie; don't ride on or near an obvious line going your way.

I would suspect that if the edge of a Ninebot Z tire runs over a raised object, it would tip quite markedly to the other side, especially as the large distance of the edge of the tire from the center, could produce significantly more leverage than a thin tire.  All the test rides are on finished, flat surfaces, or slickly produced promotional videos.  I wouldn't buy one without know how it handles irregular surfaces. (Not Ninebot bashing, I like the look of the Z, very mean looking)

Edited by Smoother
  • Like 2

Share this post


Link to post
Share on other sites
4 minutes ago, Smoother said:

I get wobbles with the orig. tire too.  My new tire makes no contact with the shell.  It could be me.  I'm hoping it's me.  Although, as we all know, wobbles exist and can be dangerous. 

In my experience, wobbles are likely if foot placement is too far to the front or rear. A small bump is enough to trigger the wobble.
 

11 minutes ago, Smoother said:

Also, I was aware of marked tram-lining.  When riding on a level surface parallel with another surface with a slight height difference 3 or more mm, and the wheel pulls hard to one side.  I almost never experienced this on my two 2.125" Kendas (14" and 16")  I would even tempt the tram-line gods by deliberately riding where tram-lining should be induced, nothing.  So watching out for possible tram-line scenarios has come back into my arsenal.  No biggie; don't ride on or near an obvious line going your way.

I was hoping that a wide tyre would better handle grooved surfaces, like trails with dried bicycle ruts that my 2" tyre would get caught in.

 

14 minutes ago, Smoother said:

I would suspect that if the edge of a Ninebot Z tire runs over a raised object, it would tip quite markedly to the other side.  All the test rides are on finished, flat surfaces, or carefully edited promotional videos.  I wouldn't buy one without know how it handles irregular surfaces.

I have wondered about this as well, but it won't deter me from buying the Z within a few months of its release, unless major defects are widely reported.

  • Like 1

Share this post


Link to post
Share on other sites

Another thing I noticed, was that occasionally and with no obvious warning or reason, the wheel would forceably want to be something other than upright (on a left to right basis), even though I had not directed it so.  I think this is a result of one side of the tire or other being pushed up by uneven ground on one side.  In other words the force pushing up (the edge of the tire in contact with the higher ground), is not directly below the force pushing down(ride'rs all up weight acting directly through the center of the wheel).  I also noticed this when riding a motorcycle with a wide rear tire.  When riding diagonally across a sloping driveway or edge-of-the-road drop off, I had to fight to stop the bike actively leaning towards the lower side of the road; sometimes quite un-safely.  I suspect riding a Nine Z diagonally across a slope would also create this, quite forceful, lean.  Even at 2.5" it is hard to counteract. I just end up riding with the wheel in its new "normal" angle until it rights itself, on more level ground.

Edited by Smoother
  • Like 2

Share this post


Link to post
Share on other sites

Nice mod and documentation. I've seen this done with the ACM too. Just couldn't get myself to hack up the shell like that.

~31-psi seems incredibly low. I run 65-psi on my KS14S and 45-psi on the ACM & MSuper. Basically I like to fill the tires to the max rating printed on the tire.

Just be aware that you increase the odds of getting a snakebite puncture when running your tire almost flat ;)

BTW, I appreciate you saving me the effort of having to censor more pictures. That @Rehab1 guy can keep someone busy with all his flashing :D

  • Like 3

Share this post


Link to post
Share on other sites

the pressure of 35psi is very normal on a 2.5". you should adjust the pressure to the weight (which is why you have a range) in most cases our weight is more than what could be ridden on the tires so most of the time we need to aim to higher pressures mentioned. p=F/A ... A is increased so p needs to be less. the IPS wheels (LHOTZ to Zero) I remeber they had a huge difference and I was kind of afraid reaching high pressure on the Zero thinking it might blow up which it never did and I think I was on 45+ psi. As being tubeless the walls are more rigid so the tube needs less pressure as it only needs to oppose the force down while a tube one will need more pressure to sustain the walls too (I might be wrong on the last as I am no expert but learning on tire technology).

As for the tire and wobble, I can understand that a more round surface might give you a feeling of a narrow wheel to which you need to adopt a bit (you're more like traveling on a rope now). There is also a factor of wearing the tire a bit (I was always suggested not to stress new tires for the first few hundreds of km (probably less on an EUC) on a car until they do their run-in period and get to their optimal state). Also is the rotation of the tire right?

Did you see improvement in turning at higher speeds and wider turns as you have to lean sideways a bit on those? I think there it performs better with more road hold and less risky to skids on turns from what I can think about.

I was also thinking that maybe the board didn't balance on closing it back. Did you try to hold it steady on flat and see if the wheel pushes more/less forward/ backwards when not loaded? If so maybe a calibration might help.

Well done for the job, that new tire really looks nice :) and even the wheel have a new look now... you're making me want to experiment on my i5 here but that doesn't have the room for changes as you have on your KS. I need to dig deeper for a perfect different road type tire while trying to achieve something new, but will definitely have to wait for now (maybe mid 2018)

  • Like 2

Share this post


Link to post
Share on other sites

Awrsome mods and documentary of the process.  @Smoother! Doesn’t it feel great to create a unique wheel? A little slicing and grinding and presto you have your own signature wheel.  Your.a brother from a different mother.  :)

Edited by Rehab1
  • Like 2

Share this post


Link to post
Share on other sites
10 hours ago, Smoother said:

SECOND IMPRESSION (ride two Saturday Morning)

So I started playing with the air pressure.  Initially, it was  31psi. (all pressures are approximate). I also tried it at 26psi. This seemed better, but I discovered that at 26psi, if I hit a bump (also known as a @Rehab1 :D), I got an alarming wobble.  Not wanting photos of my nipples censored by @Marty Backe I fought hard to not fly straight into a hospital bed. (Just kidding, it wasn't that bad, in reality, but a wake-up call, that stability wasn't any better yet). 

I was feeling a bit more comfortable on flat, level paved or bricked surfaces, so I took to the hills, literally.  When the west end of Eastbourne (Sussex, UK) promenade runs out, the grassy slopes and chalk cliff leading to Beachy Head (famous lighthouse and popular suicide jump off cliff), begin.  My new tire, being somewhat of a slick, I was curious, and apprehensive how it would handle moist grass and soft mud, on slopes.  Initially, it was pretty good, so I attempted a challenge; a steep damp grassy slope which was about 15 feet long but steep enough that I couldn't see over the top of it.  I rode with my arms outstretched, expecting a face plant at any second, but, no, nothing!  It made it no problem.  So I got more adventurous and climbed more grassy slopes.  Soon I was a few hundred feet above sea level (having started near sea level).  It handles everything just fine.  I was impressed. But, my battery was at 40% and the car was all the way at the other end of the seafront, with some hills in the way, so I took some photos, and headed home; even though I wanted to climb some more. Even descending on damp grass over soft mud, to sea level was a non-event. 

I'M STARTING TO LIKE IT.

IMG_1001

Part way to Beachy Head.  Town of Eastbourne in the background. The path I took to get here is below the white tower block, but the path turns to wet soft grass as the path disappears below the hill.

IMG_1002IMG_1003IMG_1005

This is the way I came up.  Look carefully on the right of the path, in the mud.  That's my tire track.

hmm good that you could find a tire :)  but i think 20-30 psi.. that is alarmingly low :o but i just read it was tubelsess.. but i still think 20 psi pretty damn low i mean does the tire even old out properly??? :D 

Edited by Shad0z

Share this post


Link to post
Share on other sites
1 hour ago, Rehab1 said:

Doesn’t it feel great to create a unique wheel?

Yeah, right up until some Californian is photoshopping your nipples. :facepalm:

  • Like 2

Share this post


Link to post
Share on other sites
16 minutes ago, Smoother said:

When quoting a post, take the time to remove the unnecessary parts to your response; in this case, all the photographs, and 60% of the text.  It just makes things neater.   See how I only quoted the part of your post I was replying too? 

ah thank you.. i will do that ;) 

so you have experience with tyres.. always a good thing. . . dont you get tyred? :D

Edited by Shad0z
  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×