RMZ250 (hard)enduro build

[Balgaroth]

If your disc is dished "in" then I'd replace it even if it's still above max thickness. There are super cheap discs on Aliexpress nowadays, just get a nice matched set front and rear and plop in.

They also sell caliper rebuild kits, but I see you've actually replaced the pins. Greasing them properly and reassembling clean makes a huge change to how the caliper slides and works.

For the screws on the reservoid, it's not technically required to remove the cap to back out the pads - as long as the lever "preload" screw isn't set too tightly, it should be possible to push the fluid back in the level resting position. If the set screw is set too far, it could technically be blocking the return orifice, although I'm not sure if that's realistically possible. Always easy to try out by checking if the lever has freeplay. Even with a stuck piston trying to push the fluid back should push the piston out and allow the extra fluid to overflow into the reservoir chamber.

The lever resevoir was 100% too full, I tried very hard to push the pistons further, to the point that some fluid escaped the reservoir, thankfully it seems that the membrane let some fluid out but isn't torn.

As for the disc on the picture it was brand new when I also changed the pins and the pads. I was expecting it to have to bed in but the pictures were taken after 40min/30km of MX riding, and the inner side of the disc is still not matched with its pad. Very disappointed, especially since I replaced the caliper pins in order to improve feel and make sure the disc and pads would be better aligned in the hope they would wear mire eavenly.

 

[Balgaroth]

Some new update, mostly bad news but some good too.

Last weekend I went for a MX session on a local track, it was bone dry and tye ground was rock solid. It was definitely a change from the last 2 sessions in deep mud. I was pleasantly surprised by the battery level that dropped significantly less than in the mud. I was kind of expecting it but it was nice to have some confirmation.

The day was pretty warm, nearly 30°C, the battery picked maybe 1 or 2°C so basically nothing. Regarding the motor and controller, both got as warm as during the mud session (60/40°C) but considering that the ambiant temp was nearly 10°C this is actually good and in any case the temps are well within the limits.

I also borrowed a generator from a friend to test battery recharge. I wanted to confirm if his generator size was enough for my charger and to see how much I could get in a short duration. After the first run I plugged it in and in 20min I managed to get 8% back, while I drained roughly 10% during the first session. The battery temp didn't change either so it means I should be able to get full MX days with that setup.

Now that's where the good news stops ... At the end of the second session all was good until the power went off all of a sudden. It wasn't a limp mode like when I am hitting the low V limit, I could twist the throttle in every way and nothing would happen. After a few secs it would come back like nothing happened and without me doing anything. I went to the pits to check temps, charge, etc and all the numbers were as stated before. I waited a little bit and went back to ride in the daily mode but the problem kept in happening, mostly when accelerating hard exiting corners. I even tried with the Eco mode and got the same issues. Because the only modification since last time was that I installed a reverse button on it and activated the function in the app I decided to disconnet the button, deactivate the function and go again. Same happened. After that I tried to do some starts with the phone connected and visible to see if any message error would pop or if the bike was turning off but again, couldn't see anything. I went home pretty disappointed and baffled.

Because of the race this weekend I changed the ON/OFF switch. Initially I put it on the tank cap but it isn't allowed for racing so I replaced it with another one on the handlebars. I am wondering if this could be the issue but since the app remains active and connected to the controller, even when it is "dead" I am doubting that. When rewiring the old switch to do some A/B testing later today I found that my throttle wiring plug was not fulling clipped in. I guess it could be the issue and explain why the issue got worse and worse as it kept on moving out of the female plug. I wasn't looking for this either when I disconnected the reverse switch. Now I need to go test the bike this evening to make sure it works otherwise I will take the 125 for the race.

I also had to make a chain guard so the bike is race legal, I reused the one from the ICE and made some backets to attach it. It isn't super pretty but it should work, to be tested this evening too.

 

[bananu7]

I found that my throttle wiring plug was not fulling clipped in.

Dunno if you did that already, but I replaced the generic white plastic plugs with waterproof Sumimoto ones, they seem much more reliable.

 

[Balgaroth]

I

Dunno if you did that already, but I replaced the generic white plastic plugs with waterproof Sumimoto ones, they seem much more reliable

I also replaced them, I am using these:


I got a chance to test the bike today, I got to ride 10m before the problem happened again. Every time the bike shuts down it only works again after I stop completely. I tried a few timed before unplugging the handlebar switch and plugging the previous switch back in. After that the bike worked for 1h without any issues. So it turns out that the ignition switch was the culprit. I will get a kew handlebar switch, I saw a waterproof one rated for 60V on Aliexpress, surely it can't be any worse than the one that failed.

The issue appeared once later but that was a different situation, basically when doing a pivot turn and letting the front end slam back to the ground cause a momentary glitch. I had the issue once in the past on a log hop that went very rough. Not sure if this is also a switch issue or something else. I will start by installing a new handlebar switch and go from there.

 

[Balgaroth]

First race done, no drama with the old ignition switch the bike worked flawlessly all day long. They put me in ye 125MX category and I can safely say that this bike is way faster as I am not a good rider, never did gate starts and took 2 out 3 holeshot lol. After than the young guns passed me left right and center lol. I recharged the bike at lunch, autonomy was never an issue but without the lunch recharge it would have been, maybe not so much in dry conditions but this time it was a mud fest all morning.It dried up to "playdoo" level in the afternoon which was nice.


I wired my reverse switch to be used as an ignition switch too in case the old switch gave up, I will use it from now on to see if this is reliable or not.


Next up I will need to take care of the rear brake system and then soften the suspension a little bit. Considering how good of an MX/Prairie bike it is I think I will go with a GP enduro style of suspension rather than hard enduro as initially planned to keep some versatility.

 

[Balgaroth]

It's been a while since I updated this thread but the bike is riding at least once a week, 2 if I have time and so far all seems to hold up. Few updates thought:
- Last ride my map switch died, and I am sick of the ignition flip switch as I sometimes catch it and turn the bike off (in tech enduro situations). Yesterday I ordered some new switch and will improve this. The ignition will be a push button, the map switch will be nested in tye airbox to be accessible but without risk of changing the map inadvertedly.
- I also order a 96-12v converter, in winter it will allow me to run a light directly from the bike battery, in summer I will use it to run a fan to cool down the controler on tech climbs with no airflow. I don't want a complicated wiring and a bike with loads of accessories everywhere, this should keep it streamlined.
- I made a skid plate with 8mm HDPE plate, so far it seems to be working well, I will post pictures next time and more info.
- I also strapped down my battery with a rachet strap, it seems that despite some foam in the gutted tanks to push the battery down, it was still moving around (battery stand have some marks).
- I did my first oil change 2 weeks ago, the bike had roughly 300km of enduro and MX, roughly 40hr of riding. Considering that the oil has a very limited job I wasn't impressed by how it looked, so I flushed the gearbox with a little bit fresh oil (you can see it in the tray). Not sure if the gearbox is just not well sealed or if the oil was trash. I put some fresh quality oil, we will see how it goes from now.

 

[Balgaroth]

A few updates:
Regarding controler setup, I recalibrated my throttle to have a lot less dead throttle at the start and to have the max voltage setup at the vert end of the throttle travel. Previous end calibrations was done to avoid whiskey throttle when shaken hard during some downhills and whatnot, and to make sure I was getting all the power. This ended up being annoying as I had to make a lot more wrist movement for small wheelies and pivot turns. Also the reduced usable throttle travel meant it was snappier and sometimes missing fine control. I also turned off PC13 Race setup so now I am only using Eco8, and Line throttle parameters.
I also did the switch to PID AN10, redid a autolearn. Since I made all these changes at once I can't pin point which contributed the most but the bike is a lot smoother and power is easier to control. Also, I didn't get any Hall sensor error last ride and it was not for the lack of hard riding with pivots, river bed climbs etc. So it seems that the AN0 setting was causing the issues, but time will tell. Also, I managed to ride in 80% mode most of the ride, even in the rocks. Before it wasn't possible and the motor was stalling even in 100% mode. It could simply be because I am used to the bike more but if it was the case I wouldn't feel the difference I guess.Very happy overall, the bike is not as linear as a Stark EX but to be fair I don't like how soft they feel (at least in 30/40hp modes), the current setup is kinda in between the stark and my previous setup which suits me well.

Yesterday evening I also did some hardware modifications. Installed a light in the number plate, installed a 96-12v converter wired on my previous ignition switch in the petrol cap which I can't use anymore as it does not fit the racing rulebook. The light is connected with a plug, like that in summer I will disconnect the light and instal a fan on the controler which will be easy to switch on when riding slow stuff. I placed the converter inside the gas tank.




I replaced the ignition flip switch with a push button in order to not turn off the bike inadvertedly (happened a lot in tech enduro situations).


I also installed a new map switch which is hidden in the airbox wall in front of the shock. You can easily acces it if you want to change map but the is no way you could switch map inadvertedly, which also happened with the handlebar flip switch. Now it's going to be time to test all these mods.