Aprilia RS660 Tech Discussion

Discussion in 'Tech' started by Monsterdood, May 2, 2022.

  1. Busdriver02

    Busdriver02 Well-Known Member

    I'm thinking the same now that I've let it sink in. The varying amount of drop in the aftermarket triple is definitely an additional variable. If someone were using a triple with no drop, that would probably do it.
     
    Monsterdood likes this.
  2. swetngblts

    swetngblts Well-Known Member

    Im thinking, pick your poison. Do you think theres limitations to retaining the stock triple? Geometry maybe? Clip ons? etc. Other factors included are the varying degrees in ones program. Some people may not ever have an issue with the same setup.
     
  3. Busdriver02

    Busdriver02 Well-Known Member

    This is a bit of thinking out loud, so by all means throw spears if I need to be corrected....

    Big picture to your question: I think the large drop uppers (if that is the direction your setup needs take you) are going to need a larger riser clip-on or fairing trimming. Based on measurements (see below) I'd think that after trimming the stock upper clamp, 1.5" clip-on risers should put the bars in the same rough place as 1" risers and the woodcraft/robem clamp.

    I would think all of what we've talked about falls into two categories: desired geometry and making it fit, with nizmo400r being correct, get desired geometry first, make it fit after that. Essentially you have a limited range of adjustment based on fork tube clamping surface, and you can shift that +/- range up and down by changing upper clamp drop. More drop = higher front end, less drop = lower front end. Extended fork caps and cartridge lengthening are other methods of shifting that range, or making the +/- range larger.

    Dropping the front end enough can run the front wheel into the radiator
    (others' experience here, this probably establishes the lower limit of adjustment once the rad is moved a bit)
    Moving the clip ons down quite a bit can create clearance problems with the fairing
    (with my setup-woodcraft upper, woodcraft 1" riser clip-ons, I gouged them with a nut on the bottom of the brake lever, which limits how far down I can position the levers)

    My nerdy engineering heart made me go measure stuff: Using the recessed thrust surface on the top of the stock upper as the reference plane and measuring to the top of the clamping section on the fork tube. The other drop numbers are derived from that based on observation and description, since I don't feel like taking anything apart.

    The stock upper has ~19mm of drop
    Robem has ~9mm of drop (based on description from the website: brings the upper to flush with the top of the fork tubes at stock front end height)
    Woodcraft has ~8mm of drop (based on the top of the fork tube being ~1mm below the top of the upper when I converted mine)

    Based on the internet pictures the Norton clamp looks to have no drop, which makes sense if it was designed to pair with the GP carts (w/ extended caps)
    The Melloti clamp appears to have a bunch of drop (no idea how much)
     
    swetngblts likes this.
  4. Monsterdood

    Monsterdood Well-Known Member

    I have the Spider top triple and have 5mm of fork tube showing ( HSBK recommended starting point based on Mazziato’s setup). I had my first laps on it today and the front tire just kissed the radiator guard. There is a 1” high X 1/2” wide shiny spot on the guard.

    I also was dragging my big boots too easily so I think I need to raise my pegs, raise the bike, or some combination of those (or train myself on a new foot position). Raising the bike a little would help address the radiator guard clash. I’m still thinking about what I want to do.

    In other technical news, the quick shifter wouldn’t work in my first session and I traced the issue to the shift lever having slop on the shift shaft and even with the pinch bolt tight, mine felt loose and would jiggle readily. The pinch bolt was all threads and I think a tolerance issue allowed it to jiggle. When it jiggles, I think it sends a noisy electrical signal from the shift sensor and the software shows a fault and disabled the Quickshifter. I replaced the bolt with one that has a shoulder on it, the shift link was significantly tighter and I saw no more faults and the Quickshifter worked great.
     
  5. Knarf Legna

    Knarf Legna I am not Gary Hoover

    Mazz holed the radiator guard and radiator at Road Atlanta with the forks 5mm below the Spider, we moved them flush and moved the lower mount for the radiator back and it's just kissing the guard now at full travel. The Arrow exhaust header clearance is a bit of a problem in moving the radiator back any more.
     
    Monsterdood likes this.
  6. Busdriver02

    Busdriver02 Well-Known Member

    No overheating at Chuckwalla. Highest temp before I called it quits was in the 102-ish range, only ever saw 3 chicklets.

    Based on my street bike almost overheating last year (113 degrees in stop and go traffic, the fifth chicklet came on) I'd guess the cooling system starts to struggle above 110. Checks with the MA overheats at the Ridge as well.
     
    mattys281-2 likes this.
  7. regularguy

    regularguy Always Krispy

    Don't trust the chicklets. We monitor water temp with AIM stuff. The bikes run hot and we have added a supplemental radiator. BK Corse has seen the same thing on the Trofeo bikes. I believe the Robem radiator will be available soon.
     
  8. Busdriver02

    Busdriver02 Well-Known Member

    The Robem rad being available would be preferable to the water pump.

    It's obvious that the stock cooling system is borderline in hotter environments. I'd be curious on the oil temp as well. I used to have a track prepped Boss 302 Mustang, coolant and oil temps were always a concern with that thing if you routinely used the additional rpm that is had over a normal coyote engine.

    In any event, do you know what the stock fan on temp is? The chicklets clearly aren't a temp gauge, but rather indicators and it appears that the fourth chicklet correlates to fan on.

    Hearing all the "this thing runs sooooo hot" that revolves around the two Italian manufacturers, I've always assumed they design around a higher running temp to get the heat rejection they need rather than a larger radiator.
     
    regularguy likes this.
  9. Monsterdood

    Monsterdood Well-Known Member

    Robem reminded me the water pump is not an approved modification for MA but the radiator is open to change / modify.

    On my first track day which went between 65-75F ambient air, I saw 174F in the Aim data. Not exactly a grueling test day though, but +110F to ambient as a reference point.
     
  10. TWF2

    TWF2 2 heads are better than 1

    Is that at Chuckwalla 100+ days? So far I had no issues.
     
  11. Busdriver02

    Busdriver02 Well-Known Member

    Phoenix. But same kind of crazy hot. I don't remember the exact temperature that I saw in stock form, just that it concerned me.
    I ended up with a GT500 fan/shroud, a setrab oil cooler, boxed radiator, and a venting the hood before I sold it.
    I don't know what they're running now for cooling but "DWVids00" and "Chris Wynne" YouTube channels are from two NASA AZ ST2 racers with Mustangs to give you an idea.
     
  12. TWF2

    TWF2 2 heads are better than 1

    You had 2012 I guess, my hood is vented stock. Usually I drive with oil temp on display and is been good. Don't think I will do any hot days, I may overheat before car :)
     
  13. Busdriver02

    Busdriver02 Well-Known Member

    Yep. The vents I used were much larger (also vented the front fenders, splitter, etc) than the stock ones on later years. I was mainly trying to get after front end lift. It just so happened to improve cooling.
     
  14. regularguy

    regularguy Always Krispy

    turn the fawking AC on poosey....
     
    Gino230 likes this.
  15. TWF2

    TWF2 2 heads are better than 1

    I would but windows must be down on track :)
     
  16. mattys281-2

    mattys281-2 Active Member

    i did my first ride on mine out at Chuck last weekend too. No problems, although I wasn’t paying particular attention to the temp as I hadn’t heard about the overheating tendencies. Mine stock cooling system with water wetter.

    that bike is a blast to ride, that’s for sure. Feels very sharp and light. I had a little bit of rear wheel slide between T5 and 4 with the TC turned down to 1, but nothing real sketchy.

    those things definitely need aftermarket rear sets, I was grinding the foot pegs and the rear brake lever on the first session.
     
  17. Monsterdood

    Monsterdood Well-Known Member

    My first day on the bike had me dragging my toes/boots everywhere. I have raised up the pegs on the spider rear sets and added some height to the suspension too. Double checked sag and added a little preload too.
     
    mattys281-2 likes this.
  18. mattys281-2

    mattys281-2 Active Member

    i ordered the Bonamici sets yesterday along with some other goodies. That little gal should be a little lighter with better clearance before the next trackday!
     
    Monsterdood likes this.
  19. Monsterdood

    Monsterdood Well-Known Member

    The Spider triple I’m using has an 11mm drop for reference. I ran the forks flush with the top of the clamp at VIR and the front tire just kissed the radiator guard. My radiator is within 1/4” of the Arrow headers I have so there’s no more room to give there. I wonder if the Dunlop front is a little larger diameter than the Pirellis the bike was undoubtedly designed for.

    I lengthened the rear shock (Ktech) to 310mm (+5mm from the shortest length) and the handling was okay but the bike wanted to run a little wide on corner exit and was a little harder to change directions. I feel like I want to lower the front end maybe 2mm but hate that I’d be getting that much more clash with the radiator guard.

    On the temperature front, the bike ran 187F-192F per the AIM data during qualifying at VIR. It was 83F and humid so the engine was +107F to ambient. In the race it got up to 210F with it being 83F out so +127F to ambient.

    With a 1.8bar pressure cap, the water should boil around 240F so I guess I had 30F of margin.

    Last question, does anyone know what the TC strategy is? Does it just back off the throttle smoothly or does it also cut fuel/ignition. I ran with TC on 1 and thought I felt it come on once or twice, but if it was the TC I felt, it was very smooth and barely noticeable (at my pace anyways).
     
  20. swetngblts

    swetngblts Well-Known Member


    IIRC i measured the ROBEM drop @ 5mm
     

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