Yamaha YZ450F

[j bjork]

Tubeliss is nice for hard enduro as you can run low pressure without getting pinch flats or the tire moving on the rim.
But not getting flats? I have had several flats with tubeliss. I think twice by getting holes in the tire, but most of the times leaks in cracks around the knobbs. I think I have posted about some of the times in the 250 thread, I have probably just used the tubeliss wheel twice or so on this bike.

 

[j bjork]

The previous post looks like I am talking to myself, but it was actually a response to the post before..
Anyway, here is a tire I ran on tubeliss a while ago:

To the left is a repair from a flat, that looks like rope sticking out of the tire.
You can also see a lot of cracks around the knobs, those kind of cracks can be enough for a leak sometimes.
To the right you can see a knob that has broken off, exposing the cord in the tire.
That very often mean a flat, but I think this one actually still held air.

The problem is these tires that are made for tubes have very little rubber on the inside of the cord, so they easily leak if the cord gets exposed from the outside. A little crack is often enough

 

[bananu7]

A little crack is often enough

I run my tubliss with latex sealant inside - that could help with small cracks. That tyre is way past overdue, though... I kinda get wanting to use tubes for training to run the tyres to the very end.

 

[j bjork]

When you have sealant in the tires, isn't it a sticky mess when you change tires?
Not that the mousse grease is very funny when changing tires either

That tire was rather well-done when I changed it, but they don't have to be to be problematic.
This tire I have now haven't done many hours:

It wouldn't leak as it is now, but already it is loosing knobbles.

Not as bad as this though:

I cleaned up the wiring a little while ago.
The wiring from the electronic box looked like this:

And I changed it to this:

However, I made a mistake. And it took me a while before I realized the significance of it.

Thing is, I haven't dared to run the display on the built in 5v from the controller since it broke and I had it repaired.
Instead I ran a 12-5v converter from the built in 12v on my other controller while this bikes controller was away for repair.
However, when I got it back the built in 12v wasn't working.
So I had to run my 12-5v converter from my external 12v converter, but that is isolated. So neither + nor - has any contact with battery + or -, while the controller's built-in converter has common ground.

I could have connected 12v- to B-, but I don't want to be in contact with either when pushing buttons or whatever and it worked anyway.
Back to the problem, I mixed up B- and 12v- in the connector when I changed the wiring:

I planned to draw a better diagram before posting, but it doesn't seem to be happening
So I noticed that the reverse didn't work, that is the relay in the middle. To the right you can see T14/10 that should be 12v-, but instead was B-.
In the messy part in the top to the right you can see T14/1 that was supposed to be B- but instead was 12v-.

I figured out what the problem was, and fixed it.
Then I noticed the display didn't connect to the controller. Measured the can signals from the controller with an oscilloscope and didn't get anything.
Changed controller, got signals but still no connection

Measured signals on the display, but only got interference. No ground voltage or anything.

Eventually it hit me, I sent battery voltage trough the relay coil (top left), so very low current but still, in to the 12v-.
So before that I had 12v- and B- floating with no real voltage difference at either end of the can bus. B- connected to the controller and 12v- connected to the display.
Now I had a leak from B+ in to 12v-, so it could be up to 100v or so difference between the two

And it resulted in a broken display and controller

 

[bananu7]

When you have sealant in the tires, isn't it a sticky mess when you change tires?

I only use very little, I don't see a point of flooding it more than necessary. I think for the rear I used just 80ml or something like that. And unfortunately until I fix the bike the tyres aren't really getting used...

And it resulted in a broken display and controller

Oh no! Which one was that? Is it completely dead?

 

[j bjork]

The can bus is dead on both display and controller, except from that they both work as far as I know.
I could try rx-tx instead, but then I loose reverse and I don't want that.

So I ended up changing the controller to the old one from the other bike, wire back the 12-5v converter to the built in 12v (that works on that controller) and changing pcb in the display.

 

[j bjork]

Another change I have done, I had this fastener for the seat:

Sure worked, but could hurt if you slipped on the foot pegs and sat down hard and a little to the side for example.
So now I made this instead:

I didn't have a suitable washer, so I cut out a piece stainless steal sheet and turned it round in the lathe.
Turned out pretty good I think

Had to modify the bracket a bit, but it seems to work fine now,

 

[j bjork]

I had a little mishap on the latest ride, I heard something rattling a little but didn't understand or saw what it was. So I thought it was just the chain or sidestand maybe.
Then after a while there was a clear bang.
At first I thought it was a slightly larger stone thrown off the tire, but then it hit again.
I stopped and checked, but didn't see anything.

Later I realized I had no reverse. No horn either
Looked more when I changed batteries, and saw that I had lost my dc-dc converter

I knew where I was when I heard the bangs, so I went back and looked:

Found it, it had lost some fins and the wires were ripped out of the connector, but it still works

I suppose this is the ratling..

 

[j bjork]

I was an official at a competition this week that consisted of several short courses. Once we had built the courses we also got to test them to see how long they took to run, as well as run up tracks so they were easier to follow.
Some of them were on fields with straits and corners, so more or less full throttle, full brake, then full throttle again.
In those conditions I loose power after a while, so I logged to see what was happening:

I have mainly thought it was motor temp, but maybe not.
This is controller temp, and it starts reducing phase amps at 65 degrees.
The motor is also rather tot at 90 degrees, but id doesn't start reducing until 130 degrees.

Here is one more with motor temp.

 

[j bjork]

It has been a hard weekend riding, first a race on Saturday that went ok.
Nothing really bad or really good, but had big problems with arm pump. After the race that lasted about 1hour 17min for me, it turned out that I finished 14 seconds after another club member
I sure could have made an extra effort for those damn seconds if I only knew.
We were not in the same class, so it didn't really matter. But still, it would have been nice

Then I thought that was a little bit too little riding for one weekend, and went for a practice today (Sunday).
I felt rather worn, but it went pretty good except that I dropped the bike in a climb up a hill with decent sized rocks on the first lap and bent the right radiator a little.
Then on the 6:th lap I went down harder when I lost front wheel traction and bent the left radiator badly

Left radiator

The right one is not too bad.
But this is the second time I am striating that one out

This bike is so fragile with those sensitive things sticking out to the sides,
the old bike sure was a lot tougher.

 

[bananu7]

I've put radiator braces on my EXC when I noticed that that after a few falls they're decidedly not rectangular anymore. It's been all good since then - maybe you could consider adding some form of protection there? I don't have full cages, just bars and plates on the outside.

 

[j bjork]

Yes, I think something is needed for protection. The radiators are very light, but not very sturdy..
Here they are after a little straightening:

The right one

And the left one.
I ran in to a problem though, I got a little crack when I was working on it.
They are alu, and soldered. I cant weld them when they are soldered, so I tried soldering too. But wasn't very successful.
I ended up gluing with the black goo in the picture

 

[j bjork]

It seemed like the angle of the lower connection wasn't right when I mounted the radiator.

I tried to adjust, but I bent too hard
I decided to just skip it, and only use the right radiator.
That is the one with the radiator cap anyway.
I tried to find plugs, but ended up printing them in tpu:

They turned out to not seal very well, so I had to use some sealant as well.

But on to something else, I finally got a nice package:

I will start testing them now, and hope I will be able to finish the battery before "stångebroslaget" (big Swedish race) in the start of July.

 

[j bjork]

My tpu plugs leaked, at least one of them
Went to the tried and true "short tube with alu plug"

Not as elegant, but it will have to do.

My battery testing is progressing more or less:

The cells seem excellent
All cells I have tested have delivered over 5Ah.
The testing however, isn't going as smooth as I hoped.
One time channel 2 had a nervous breakdown:

What you see here are 10 cells being charged, up to about 4,1v they are about equal.
Then the voltages just starts jumping around
It stopped charging when it happened, so no harm done to the cells I think..

It also seems like the cells are more equal in voltage than the reading on the charger.
I did a manual calibration where I moved one cell between all the slots and adjusted so they were equal down to the third decimal place, but then they showed more spread than before when I put in cells in all slots

It seems it can show up to 0,01v wrong, and often 0,005v wrong in some slots.

 

[harrisonpatm]

My tpu plugs leaked, at least one of them
Went to the tried and true "short tube with alu plug"

Not as elegant, but it will have to do.

My battery testing is progressing more or less:

The cells seem excellent
All cells I have tested have delivered over 5Ah.
The testing however, isn't going as smooth as I hoped.
One time channel 2 had a nervous breakdown:

What you see here are 10 cells being charged, up to about 4,1v they are about equal.
Then the voltages just starts jumping around
It stopped charging when it happened, so no harm done to the cells I think..

It also seems like the cells are more equal in voltage than the reading on the charger.
I did a manual calibration where I moved one cell between all the slots and adjusted so they were equal down to the third decimal place, but then they showed more spread than before when I put in cells in all slots

It seems it can show up to 0,01v wrong, and often 0,005v wrong in some slots.

I feel like none of those voltage differentials are too far off, and it only happens over 4.1v.

 

[j bjork]

That oscillating is not normal, the charger even sensed it was something wrong and stopped charging.
Here is a normal charge curve:

The riding went well last weekend, amazing time for 2 laps for me:

30,6min, a little over 15.30 for each lap.
I think my best time is about 15.18, for one lap before.

However, I lost the 12v from the converter.
It seems like it is the converter itself that broke

 

[j bjork]

It wasn't just the 12v converter that broke last weekend:

Had another flat on the first lap again too
I'm not sure what to do. If I should keep changing tubes, get a 19" mousse, or maybe just stop trying to run a 19" wheel in the woods.
The front tube just keeps surviving though. I am just waiting for a flat, so I have an excuse to change the tire.
But it just doesn't happen.

I did an amazing race this weekend
The race was at a very rocky and miserable track, and it started raining a day before the race and just continued in to half the race or so.
I decided to run my super soft rear tire, and take a little chance by running tubliss instead of mousse.
I think it was a smart move, the track was a bit slippery, and there were a few rocky climbs.

I thought I did alright, had some problems with arm pump on the second lap, so I had a hard time keeping speed up, keep a strait line, precise throttle control and such things. On third lap I had problems with the (thumb) brake sticking.

I was surprised though that I passed several riders on every lap (about 3 or 4), and I don't think I was passed once
Anyway, when I checked the results, I finished third total in my class

And the times.. I was about 55 seconds from first, and about 1:30 from fourth..
1,2 and 4 was from the the club that arranged the race, so it was their home track.
Nr 5 was from my club, and I think 4:30 or so behind me

The ones that I actually compete with (same age group from my club) was something like 20 minutes behind on a 1 hour race

 

[j bjork]

Trying to make some progress on the battery build:

I tried to print these spacer sleeves standing in ABS first, but eventually they became PETG lying down..

And poison green

cut sheets..

 

[j bjork]

It worked rather well to just give the sheets a few small 10 joule spot welds to hold them together:

Welding..

I have problems with consistent welds. When I test weld with 170 joule it sticks really well:

But I have noticed that it is not always the case on the battery

 

[Zambam]

Why did you not go with Wellgo this time round? Are you not concerned with hand drawn square's accuracy on the the + battery terminals?

 

[j bjork]

I think one big thing is the connection between the copper sheet and cell, so I started putting my templates I used to cut out the sheets under the cells:

To get an extra push up against the copper.

I hope this will work..
The plan is to be able to put a plastic sheet in between and fold one half over the other.
There are basically no room for error, there are several holes for screws that needs to line up.

 

[j bjork]

Why did you not go with Wellgo this time round? Are you not concerned with hand drawn square's accuracy on the the + battery terminals?

I guess I wanted to try something else.
I think, as I have very short distances from cell to cell, the connections to the cells are more important than having thick copper between cells.
So now I have 0.25mm copper sheets instead of 1mm copper plates and maybe 0.05 copper connecting to the cells.
But I cant say for sure what is best, as the thin copper path is very short on the wellgo plates.

Something I do know is I will save some weight and room. The pack should be about 5mm thinner and maybe 1,5kg lighter
(I think the copper plates weighs about 2kg, but it should be here in the thread somewhere)

 

[j bjork]

And yes, aiming is a bit worrying
But I can also see a little of most cells, that also helps with judging how well my squares line up.

 

[TPEHAK]

A few layers of fish paper probably will work better for insulation than a plastic sheet (plastic can creep, crack and so on). But the best is to use a thin fiberglass board for insulation.

 

[Zambam]

I have problems with consistent welds.

You have 0.25mm copper to the cells. What is the top layer, material and thickness?