2018 Aprilia RS4 50 Euro 4 Upgrade Project

[Berkeley]

Last week I measured the castle nut on the RS 50, and posted it in the thread on castle sockets.

Could you measure the new RS castle nut, and post those dimensions?

Hey Tora, Here are the measurments of the RS4 50 Castle Nut.. I should have measured this before ordering the RS one!!!

[toratora]

Hey Tora, Here are the measurements of the RS4 50 Castle Nut.. I should have measured this before ordering the RS one!!!

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Only the center photo measurements will be valid. The other two are employed using the inner measuring tool, and thus will be off by some amount. If you cannot get in there one option may be to order a spare nut from EasyParts (10€).

Also, if you take the weight off everything there’s not a lot of force holding that nut in place. You can use other tools to spin it around. The threads are standard so turning it counter clockwise will remove it.

I didn’t realize it until reading this post that the older RS employs a different design.

[Berkeley]

thanks tora,

The inner diameter of 27mm(approx) turned out to be the same as when i measured it on pg37 using the outer measuring tool. so should be just about there though.

ill have a hunt for that tool and ask the dealer as well , Dont know what they would change this nut diameter? maybe so you would have go to the dealer service center and get any work done there!!!

If i dont get any joy then will employ the screwdriver and hammer ( trying to avoid any damage) and if the other nut fits then will order it from easy parts.. cheers!!

[toratora]

There are a number of circlip/snap ring, angled needle nose pliers out there that should be able to do the job.

The trick is to remove all weight/force from the system making the nut easy to turn.

[Berkeley]

hey tora, tried those.. no luck.. I went to the dealership 3 times and each time gave me one that didn't fit ( even though i gave them the dimensions) saying that GB motorcycles has made a custom one.. so ill let you know if it fits.
cheers

[Berkeley]

So we stripped the front end of the bike today.. and amaya got involved...... made her do everything so she learns how to take it apart and then assemble again.

I must say the front headlight was 30 euros more then 3 months ago?? how I dont know but I will ask them. It just seems ridiculous that you cant just change the lens only .



Now moving onto fitting the gear changer I followed the instructions, read the wiring manual (which didnt seem to add up to the actual bike) as some terminals in the manual said they were blank when in fact they did have a wire in there??









I put the wires in the back of the dashboard connector just to see if it worked and all i got is a lit up screen but no flashing or N coming up when the key is turned and or started.

has anyone got any ideas why?

Is it because the dashboard isn't connected? Is it because the bike is stationary so not giving a reading? Is it not showing up because there is no chain on the rear sprocket stopping it from spinning in neutral?? if anyone's got any ideas pls fire them over, or know how I can go about error finding or steps I can take in solving this cheers

[toratora]

I don’t think that gauge is comparable with these bikes. The tach sensor wire is analog, so it’s not going to generate a digital signal. There is a neutral switch that reads the shifter barrel, but they want to take a signal from the lamp, and there isn’t one on this bike since it’s built into the dash unit. As for the speed indicator it's simply an analog pulse that get’s sent from the sensor to the clocks. There are no outputs to which the gauge could connect.

As for turning the Castle nut. There really shouldn’t be on pressure on it. The bike is new enough that it shouldn’t be corroded, or seized. If the shock is removed, and the weight is taken off of the swing arm you should be able to turn the nut. Maybe tap the other side of the spindle with a soft hammer to loosen things up.

[Berkeley]

I don’t think that gauge is comparable with these bikes. The tach sensor wire is analog, so it’s not going to generate a digital signal. There is a neutral switch that reads the shifter barrel, but they want to take a signal from the lamp, and there isn’t one on this bike since it’s built into the dash unit. As for the speed indicator it's simply an analog pulse that get’s sent from the sensor to the clocks. There are no outputs to which the gauge could connect.

As for turning the Castle nut. There really shouldn’t be on pressure on it. The bike is new enough that it shouldn’t be corroded, or seized. If the shock is removed, and the weight is taken off of the swing arm you should be able to turn the nut. Maybe tap the other side of the spindle with a soft hammer to loosen things up.

Thanks tora, much appreciated! I will lift the front forks and spin the wheels to generate a speed as in the manual it says that it may not register when stationary..( just to rule that out) and maybe try another ground connection again just to check

Here is some more info below about compatible bikes and how to get a signal.. maybe theres something in there??.. but nothing more on their site.

just glad i tested it before and decided to call it a day before cutting any wires.



Cheers

[toratora]

From reading the documentation I can say the Koso gear indicator wont work on the RS50. This device was made for 15 year old four stroke bikes with ECUs. These little bikes don’t really have ECUs. They have a CDI, and that’s about it.

[Berkeley]

thanks tora, at least it will save me the hassle of trying to find a solution with it.. time to put the bike back together now cheers