Re: KTM RC 390 Ownership Experience

Hows the bite compared to old stock ones.

Re: KTM RC 390 Ownership Experience

The difference is night and day, upgrade highly recommended

Re: KTM RC 390 Ownership Experience

The Bybre Calipers are based of the P4 Big Brembos but downsized for use in smaller bikes and scooters. The Brembo calipers have a span of 100mm or 108mm but the Bybre units are only 80mm. So if any of you had hopes of chucking on some monoblocks you'll end up spending quite a bit more for the mounts becase of the span difference.

Also most of the 4 pot calipers have a larger piston for the first pair and a slightly smaller pair for the rear, I still have no idea why but all the four pistons on the Bybre units used on the KTMs are the same size. This could also be the possible reason the stock brakes need a lot more pressure to activate.

The stock 28mm pistons and Orings which I received are almost exactly the same as the ones on older generation Brembos including the lip on the smaller Orings. Not sure if the official Brembo site will still sell them.

Some more not so interesting things I came across, looks like the Bosch ABS system had the tendency to get an air bubble if the system is bled incorrectly, which is all the time since you require a vaccum pump to do it the correct way. The bright side is if you slam in the brakes a couple of time it releases most of the air. Easier for me to notice because of the clear reservoir and tube.

Re: KTM RC 390 Ownership Experience

A few of you guys had dropped me PMs asking how Hatsumi looked, so here she is...

List of Parts removed:
- Side grab bar
- Sari Guard
- Tire Hugger
- Rear footpegs
- Stock footpegs, foot controls and holders

List of Fluids:
- Bosch 600 DOT 4 Brake Fluid
- Motul Motocool Coolant
- Motul 7100 Engine oil

List of Upgrades:
- Heavier clutch springs (up by a ratio of. 75)
- Upgraded Valve springs to allow better spring rate at full throttle/redline
- MGP Rearsets
- K&N KT1211
- Brembo RCS19 Master Cylinder
- Brembo Clutch perch and clutch lever (meant for CBR600)
- Custom Quick Throttle
- FactoryEFX Tank Grip Pads
- Pirelli Diablo Rosso II
- DID sprockets

I have been working on her for for quite sometime and there is still a lot work left to do. Custom tail tidy, Werkes exhaust, custom triple tree, rear suspension upgrade(Ohlins or JRi) and a couple of other minor upgrades are in the works.

Re: KTM RC 390 Ownership Experience

Good piece of tid bit, checking the air bubbles through the clear tube. What were the effects that you observed when there is an air bubble in the hydraulic unit, how negatively did it affect the braking or feedback if any.

Cheers!
VJ

Re: KTM RC 390 Ownership Experience

You actually don't notice it most of the time, I can't explain lever feel because each person has different preferences but I will try.

I like my lever to be firm and progressive. If the lever is grabby or soft I can't gauge how much pressure I need to place on the lever while braking for a corner. Again most people won't notice because it isn't so apparent in the city riding where you're hardly ever using 100% of the braking available.

With the air in the ABS system, I never felt the firmness at the lever, it had all the symptoms of air in the system but regular bleeding using a bleeder bag/hose never seemed to resolve it. The issue would get worse when the system was functioning at higher temperatures on the track, the lever would sometimes be firm and sometimes be soft and sometimes collapse all together. This was because the air would compress but not enough to activate the ABS

I spoke to Kruger on the 390 forum and he helped me in diagnosing the issue. Even when we left the ABS switched on for the track we were never ever braking abruptly enough to engage the system so the air just stayed in the system and further because we were bleeding the brakes with the ignition turned off, the ABS system wasn't active during that time.

Anyway his solution was to remove the ABS system completely which after I told him that I still have to get the bike to the track and the 40km odd ride had enough of idiots on the way, he asked me to find a nice open road and basically slam on the brakes as hard as I good once I was up to speed to engage the ABS. This worked, after the first couple of brake checks I saw a few bubbles rise into the reservoir.

Almost immediately the lever feel improved and was much firmer, even the braking effort was reduced.

In short if you slam on your brakes all the time, you most probably don't have air in the ABS system, if you are one of those almost never gets the ABS to activate and feel like there's air in the system but bleeding doesn't resolve it, you most probably have air in the ABS system. We were joking about it as getting punished for not using the ABS.

Re: KTM RC 390 Ownership Experience

I can relate to the sentiment mate. So, my guess would be this wouldn't happen unless the brakes are bled and or improperly bled. Say, I don't think this happens unless one replaces the brake fluid and a job not so well done, when the air enters inside the system. Now, the other side of the coin would be, since you've mentioned the point of ABS turned off, is it a good idea to bleed the system with the ignition on so that the ABS unit is alive during the bleeding process? Can that be a cause of bubbles in the system in the first place.

Cheers!
VJ

Re: KTM RC 390 Ownership Experience

Yes and no, ABS systems need to be pressure bled or vaccum bled and the SVCs don't have either so almost every KTM out there will have air in the system. The suggestions I was given will help a little but not remove the air completely

Re: KTM RC 390 Ownership Experience

Love how you've done up the RC! A quick question though, how are the pirelli's compared to the m5's?

Re: KTM RC 390 Ownership Experience

These are H rated so compared to the W rated Metz they tend to slide a bit more. If you want to do a side by side comparison with H rated Metz then these are definitely better. Better wear pattern and the slide is more predictable. I can't comment much on the life of the tire because we use them on the track and by the 4th or 5th track day we have to change tires.

RC390 Side stand error( Brass nut missing/broken)

Hi, I have a rc390 2017. The side stand sensor is broken. The fault is that the brass nut attached to the side stand(which touches the plate when retracted) is fallen off somewhere. The bike is now stalled. The sensor is not in the same place as the older models so I can't by pass it. Has anyone faced the same issue? On older bikes maybe? How do you suggest I fix it? The stand is too tight to remove. Oh, the end of the nut is still stuck in the groove. so got to remove that as well. Let me know what my options are.

Re: RC390 Side stand error( Brass nut missing/broken)

am not sure how the new rc390 is wired up.
on the older ones you could use the bypass plugin (sold by one Mr.Dhaval Mahidharia) or call up your service center (they also have a similar device that will bypass the sensor).
some folks on in other countries have said that you could short out two of the pins on the sensor connector using a wire or a 10k resistor (which is probably what these bypass plugins are doing).. never tried it.

your best bet would be contact your service center and ask them if its possible to bypass the side stand sensor like on the older versions (or if they have another solution) if so borrow it and use it to get the bike to the svc and then replace the required parts.

Here is a link i found from another forum:


can you a post a pic of the wire/connector going up from the side stand sensor (usually tied to the frame with a zip tie above the side stand area)

or maybe simply weld a bit of metal to the broken part so that it touches the plate when retracted ?

Re: RC390 Side stand error( Brass nut missing/broken)

How far is svc?

Like mine is 2km away. In past, they have fixed my bike at my home also. You can try that.

Or go to service center and ask them how do you bypass it so that you can bring bike to them. ✌️

Re: KTM RC 390 Ownership Experience

Saw this process of vacuum bleeding on a ZX14R at Kawasaki yesterday. Man it was fun to watch it.

Does it does some difference to current setup?
I can ask guys at Kawasaki to do it in my RC. [emoji23]
They have all the high end machines.

Re: KTM RC 390 Ownership Experience

It should definitely help with the lever feel, if you can get the Kawasaki guys to do it for you then definitely go for it