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Spaghetti

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Posts posted by Spaghetti

  1. Honda Linked Abs For New Rider

    in Cornering and Techniques

    Posted

    I think the aversion to rear brake on track comes from two things - the fact that when the rear wheel is in the air, the rear brake doesn't work, and also the fact that an error with the rear brake in a turn can launch you dramatically in the air.

     

    ok, but so does an error with throttle control on a negative camber turn. Aren't most high sides due to throttle + handle bars pressure? We can do equally or worse damage with other controls than the dreaded rear brake.

     

     

     

    When braking heavily on the track on a full sport bike, there is very little weight on the rear tire, so putting the right amount of pressure on the rear brake to get some braking without locking it up takes a lot of attention, and that attention is usually better spent on other things.

     

    Yes, but the rear brake can be applied before the rear lifts.

  2. Honda Linked Abs For New Rider

    in Cornering and Techniques

    Posted

    I agree in a panic situation the rear brake is one of the easiest control to overdo. YellowDuc comments on learning front brake use are spot on.

     

    But I don't understand the rear brake aversion when riding on track. Even at the end of the straight, rear brake gives me an extra 10% braking power, no matter how much power goes to the front. Is it only fractions of a second in the end? Perhaps, but the gain in braking distance and bike stability improves my confidence. Yes, you have to learn how to use the rear brake and not overdo, like many other things riding a sport bike.

     

    As for the ABS, same thing. It's a question of measure. The problem is that most standard ABS controls are tuned for street riding. If you're on track you must be able to define the point of engagement of the electronics (relative to rotors, brake pads, asphalt quality, etc...). At the extreme, when the front wheel is about to lock why not to have an electronic support? It's like saying, I'm not riding with stock suspensions because they're terrible on track.

  3. Elbow Down Old Hat

    in Cornering and Techniques

    Posted

     

     

    Way back in 1987, MOTORRAD managed, at low speeds, 52 degrees of lean with a BMW K75 riding on Metzeler touring tyres. I'm sure the racing tyres of 25 years ago would tolerate more than that. What they wouldn't tolerate to the extent of modern rubber is additional forces at big lean. Current race rubber offer lots of grip for acceleration or braking even leaned to 50 degrees, back when you would more or less have to coast.

     

     

    So what this would imply is that today, with modern sport bike and entry-level performance tires (like Michelin Pilot or Dunlop Q3), we can reach a 60 degree lean with moderate acceleration/braking? I'm a bit skeptic because when I look at superbike races they visibly use less lean angle than motogp, I would say around 50/55 degrees maximum.

  4. Elbow Down Old Hat

    in Cornering and Techniques

    Posted

    The portion of the body with more weight is upper and head (plus helmet), not legs and butt. In this sense Ruggia weight positioning is not the most efficient (compare with Marquez upper body).

     

    What is impressive to me is how Ruggia was able to reach that kind of lean angle with tires, suspensions and frames of 20 years earlier.

  6. What Electronics Are You Guys Running?

    in School Questions/General Discussion

    Posted

    Thanks xpyrion it's very clear. It sounds like a good upgrade for the price, if using PCV. I wonder why the two products are not marketed together more often or sold together at a special price.

     

    A few more questions:

    - is the dyno still important? Let's say I change my exhaust, would the autotuner and a base map change be sufficient?

    - I heard a few cracks in my engine here and there, I imagine the autotuner could help improving combustion?

    - what should I tell my mechanic the target air/fuel ratio is? 13:1?

    - A smoother engine, a few more ponies, better combustion. What else did I miss?

  7. What Electronics Are You Guys Running?

    in School Questions/General Discussion

    Posted

    So I'm planning to install an autotuner with my current PCV. Just to clear any doubt, I was talking with somebody at the last track day who was claiming the autotuner needs a laptop at the end of the session to load some acquired data into the PCV? My understanding is that the autotuner is a sort of real-time dyno that adjusts the PCV mapping automatically while I'm riding.

     

    Timmer can you please confirm?

  8. Lap Timer As A Learning Tool

    in School Questions/General Discussion

    Posted

    I'm interested in a more sophisticated lap timer to improve my riding. I've been using Harry's laptimer on my iPhone for a couple of track days and it is quite good in showing track section speed, acceleration and breaking. I wonder what Speedangle and Moto-D GPS Next can do better for $500, other than the > 10Hz accuracy of course.

    - I like to check my riding after each session. Harry's laptimer makes it very easy since it's just an iphone app. Unless I bring a laptop to the track I don't think I can use Speedangle or GPS Next until I go back home. At which point I will hardly remember what happened during each session.

    - I would like to compare my riding with an expert rider data. So overlay my recording and the expert throttle/break/angle data to show where I'm losing time exactly.

    - Any other coach-like use I can make it of these lap timers or other devices please let me know.

     

    http://www.speedangle.com/

    http://www.motodracing.com/motorcycle-gps-lap-timer-start-next

  13. Rear Sets Benefits

    in School Questions/General Discussion

    Posted

    I'm debating whether to install rear sets on my 600cc, but I hear very different opinions on models and benefits. Prices varies wildly from $300 for Vortex to $600++ for Driven. I like the idea of the Sato racing concave foot pegs, designed to collapse in case of crash, a bit like R&G sliders.

     

    I hear the main benefit is to rise the height of foot pegs and avoid dragging on leaning?

    What's your experience?

     

    http://stores.sportbiketrackgear.com/Detail.bok?no=14799

    http://www.satoracing.com/rearsetstop.htm

    http://www.revzilla.com/motorcycle/driven-racing-d-axis-rearsets

  15. Patched Pavement Techniques

    in School Questions/General Discussion

    Posted

    I've seen a number of crashes happening on patched pavement corners (specifically first turn of the chicane 3 and turn 10 at NJMP), more so than other turns. In one case during an expert race I heard talking about a rider low siding on patched pavement.

     

    If you can't chose a different line, how do you approach patched pavement? Reduced lean angle? Lower speed?

  19. Inside Peg Weighting.

    in Cornering and Techniques

    Posted

    I think he's talking about anticipating the body position shift on a chicane or other tight series of corners. He doesn't do a good job of explaining how to use the handle bars in that scenario, which I think is critical, but I can see the body moving before working the handle bars on the corner change.

  24. Crashes At Phillip Island

    in Cornering and Techniques

    Posted

    At 1:32 in the video you can see Marquez front tire smoking right before the loss of grip and crash (go to 1:31, change the replay speed to 0.25, then quickly double click on the play button to advance one still image at the time). That looks more like a blocked front wheel than a tire problem. Bradl crashed into another bike. Crutchlow, at 1:25 in the still images you can see the rear tire almost lifting off the track, plus that odd leg position with the body upright while turing into the right corner (this guy should register at CSS and get his body position checked :D ).

     

    I think this was too much asking to the asymmetric tire on an extremely fast track, reason why some riders decided to go for the soft and slow down through the race. Those crashes don't look like bikes going at a slower pace to me.

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