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first compression lock up / fish tail

Discussion in 'New Riders and Riding Tips' started by Takamii, May 5, 2011.

  1. Okay so today did my first compression lock up - well not really a lock up more like a fish tail from changing down fast at higher speed limit

    back end fish tailed somewhat - kept the hands loose on the bars no panic and the bike straightened itself up

    interested experience though - can understand why slipper clutches would be good
  2. wait do you have another R1 or did this happen on a 250...
  3. On the new R1
  4. oh snap
  5. I did a small one today too, on Concord Rd. Meant to go from 4th->3rd and sort miss stepped and pressed it again not knowing the first try worked. Was small as I was braking anyway, and in a straight line.
  6. blip the throttle when you change down
  7. Oh I did, but still did a little lock-up since I must have been up near the limiter in second. I blame trying to keep up with Azama. He is a demon at weaving through traffic.
  8. Oh how I love my slipper clutch. In saying that though I try to still blip the throttle, I believe it's good riding practice and the more you do it in day-to-day riding, the more likely you will remember to do it coming in hot to a corner and trying to downchange without making the backend buck you off.
  9. excuse my ignorance but how does this assist ?
  10. i 'think' it helps match the engine revs to the new gear/speed you're travelling at and this avoids sudden hard engine braking. I could be totally wrong but that's how I see it. I'm practising it but really bad at it though lol. I think on the next practise session I go to I'll ask an experienced rider to just give a demo as by the time I blip I think I'm just to slow at down changing for it to work
  11. @carpetbelly - sounds about right :D
  12. Chirping the rear end on the Ducati with its dry clutch is a common thing. I tried blipping the throttle when going hard into twisty corners under hard brakes and one or two gears downshift. Well, if I didn't get that just right the clutch would bite hard and the bike would jump forward just as I was entering the corner, and that is not fun.

    So now I just tend to hold the throttle steady when I tweak the clutch for a downshift. That allows the engine to rev a little, but not so much as to make the bike jump forward once the clutch engages again. The dry clutch does make a big difference over a wet clutch. Oh, and I tend to downshift and brake late when playing on good twisty roads.
  13. That's it. ;)

    If you down-shift without blipping the throttle, when you let clutch out the engine needs to play catch up and you will often feel the bike pull up quite quickly/hard - depending on how quickly you let the clutch out of course.

    Blipping makes for smooth consistent and quick down shifts that wont pull the bike up so hard or cause the back wheel to lock (in most cases), and you can pull the clutch in, gear down and let the clutch out again in a blink of an eye.

    You should be able to do this while braking as well but it takes a bit of practise. A lot of people when trying to brake and blip at the same time pull the brake lever in with the blip which causes a bit of a bumpy ride. :D

    It's a good skill to have though. :)
  14. plus, blipping sounds pretty sexy especially in a tunnel/echoey city streets :D

    Though, it can be mistaken for Toolsmanship.
  15. #15 MONKEYMAN, May 6, 2011
    Last edited by a moderator: Jul 13, 2015
    me no have slipper clutch :nopity:

    just practice and repition like anything else, should combine with braking to slow as mentioned, neccessary on larger bikes imo if you go for a brisk play, not all would agree. but once you've got the feel for it, just smoothes everything out so beautifully.

    this will explain it much better than i can http://forums.superbikeschool.com/index.php?showtopic=848


    does sound like a lot of separate steps, but it's not, it becomes one very quick fluid motion, as shown here [URL="]
  16. What causes compression lock up is the crank cant catch up with the gear box. It was spinning fine and then you went down to far to fast and it cant spin up that fast. Or spin the fast in the first place. More revs, more exhaust gasses to pass, more compression. hence why it's not as common on a two stroke. Go the real proddies.
    And don't place to much faith in the slippers they fit std to road bikes. They can and do cause a heap of rear wheel tramp which sucks even more. Good slipper clutches are bloody expensive.
    One of the better systems I have liked is the Aprillia one. And it's nothing to do with a clutch. It leaves the exhaust valves open a smidge to lower the compression build up.
    Blipping the throttle will spin the crank up to match the added revs that changing down causes. But you have to get this right for it to work.
    It's not two sounds. As I so often hear. It's one sound and one motion when you get it right.
    R1's have a nice mid range punch. Use it a bit more and you will find it handles and corners a lot better too.