Aprilia RS660 Tech Discussion

I think 483mm and 310mm are right in there. I have heard of some running a little higher n the rear. With your stiffer springs, I think you may want a little more rear ride height or maybe lower the front a little. I would guess the sluggish steering is the front riding high through the corner. There is also the matter of how hard and deep do you trail brake but once you roll on the throttle, the bike won’t hold the line when the front is too high or the rear is too low. Raise the rear unless you feel the rear spinning up and then lower the front instead.

 

We have suspension potentiometers Front and Rear, so we have loads of data. It's kind of neat to see back to back runs and what your changes do to the bike. For example, bottoming the fork under braking with the .925/10mm preload. 11 bar brake pressure. Also, the fork is sitting around 43mm off the throttle, trying to transition Left to Right in turn 4. Change was .975 spring rate with 7mm preload. This lowered the fork 2-3mm off the throttle, and I still am on the bottom with 11 Bar brake pressure but for a smaller period of time. Also, with the fork stiffer, the rear comes up under braking so that becomes the limiting factor.

Suspension guy told me, he likes to see around 55mm average stroke over the whole lap- we are sitting around 38 so quite high. My thought was more spring and less preload will fix that. May have gone too far with the spring, but I'm going to test soon and try a bunch of different things. I like the Bitubo cartridge setup, spring changes are a snap.

It's fun to play with, but at the end of the day the rider makes the difference. I'm in the ballpark now with my baseline so the rest is just tinkering.

 

Hey @Gino230 you probably know this, but when we first started I didn’t. You don’t need the same size spring in each side, so you can fine tune changes by only changing one spring.

 

Very cool with the suspension data! Maybe one day for me… I would say you are running a little stiff. Softer is more traction in general but then you get more attitude changes and suspension effects as it gets softer. At “our” speeds, we can probably go a little softer and then as lap times come down, add in some more stiffness.
Do you have real time anti-squat calculated data? I think that is a key part of the suspension data is understanding where that swingarm is on corner exit for each corner and then finding the right balance to get the best average for the critical corners.

 

Yes that's what we do. The bike came with an .80 and 1.05, so I got a .9 and 1.0 which would give me almost all the possible combinations!

Don't forget I'm 195lb in my boxer shorts. vs. your svelte 185. The data guys were talking about suspension velocity- especially the rear. Since there's no link, you generally have a very narrow spring range that works. Too much preload and it will be topped out all the time and very likely to spin the tire. Compression valving can be fine tuned also. One problem with not having a linkage is if you introduce abrupt input into the shock (softer spring and hard on the gas at corner exit, for example) it gets shoved down in the stroke and then it takes a few seconds to stabilize.

I am not very good with Aim RS3 yet, but I think those calculations would be easy to put into a math channel?

Like I said, fun to play with, but the majority of the work has to come from the rider!

 

Suspension velocity analysis is already available in the RS3 Suspension Analysis Layout.

 

What wheel base are you running?

 

Unrelated post to the above conversation.

Awhile ago I posted this thread (before I knew this thread existed) looking for brake pressure channels out of the stock ECU.

I have a fleet of RS660's that are still running ABS modules for a data driven racing school. Basically providing the kind of 1:1 (or 2:1 in this case) attention that I provide to my Superbike rider throughout the season, but in a classroom setting and available to someone outside of the professional paddock for the first time that I know of.

In the large order to AIM, I got 15 Solo 2 DL's and 15 SmartyCam 3 Sports, along with 10 sets of ACC + Brake Pressure transducers + tubing/banjos + assorted wiring.
I was not looking forward to installing, bleeding, and then eventually removing all of that equipment on the fleet.

After doing some digging and CAN sniffing on the bikes, I found that the RS660 uses the same ABS brake pressure protocol as the RSV4 despite using different manufactures for the actual ABS pump itself (Bosch for RSV4 & Continental for RS660). Thankfully Aprilia keeps many of the CAN protocol ID's standardized across their Euro 5 RS models.

After realizing this I was able to throw the RSV4 Solo 2 DL V2 profile on the RS660's and it was successfully capturing brake pressure from the stock ABS unit for front and rear pressure. Although it blends both brake pressure channels so it is unable to distinguish between front or rear inputs, you'll have to look at the data channels for front/rear brake brake switch to distinguish between the two, but if both are being used simultaneously it'll blend the pressure values.

I shared my findings with AIM and I'm working with them to release an updated version of the RS660 Solo 2 DL protocol that includes brake pressure for anyone with the logger/bike in the future.
It won't be of much help to many people, since anyone who would bother putting a Solo 2 DL on their RS660 likely has ABS deleted, but it made an incredible difference for my unique use case running a racing school. No ETA on that protocol being released by AIM, we're still doing some testing on it, but the RSv4 protocol works at the moment for capturing that and other channels not in the RS660 profile.

I got to test it last week at the Aprilia Racer Day and threw Miguel Olivera on a bone stock RS660 around COTA that only had a set of SC1 slicks and he did a 2:25.
AIM and I collaborated to post the video if you're interested in seeing it, I told him to send it and he obliged.

https://www.instagram.com/reel/C55-JHLrBrz/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==

 

^^ got that on youtube?

 

Not yet. I can upload it when I get home without the music or cuts.

 

what kind of race tire life everyone getting? Can you make it through multiple weekends on a rear or are they shot after one?

 

That's a great video showing the need for an accessory radiator. A cloudy 74F day and the water temp reaches 212F.