Since the addition of the R6 forks 2 seasons ago (2012-02), in that 1st season I had one event of down hill corner braking where the nose went into a ballistic chatter that had me on the double yellow at high speeds and the only means of stopping it was letting off the brakes. However, it never repeated for 10 months (End of 2012) so I wrote it off as a conditional.
OK - so from March of 2013 to June, I've ridden allot of the same roads. I did change tires and had the chatter thing happen on a road I ride more often. I've been back and sure enough I can repeat it! The area has a pronounced washout/ripples/divets/bumps where everyone brakes before this corner. OK - i can accept that where the road is abusive it could put the ball in play. But now, its an upward trend happening about 5 times tonight which is an all time record. One of those events nearly got me in trouble and this time I couldn't see anything in the road bump wise.
- tires good, S20s
- brake fluid - DUE, ready for bleeding
- Forks, no leaks, but two years on fluid. They are due for a fluid change.
Before she gets parked for the winter, I'll at least do the brake fluid and see if I get a run in to duplicate before weather turns (its imminent). My gut instinct says its a combo of all things. Conditions, tire pressure, fork damping, and brakes. Its still running the OEM pads from 08. They have life but, maybe they need swapped. Rotor surface looks just as it has.
I'll keep you posted as to what I find. And lets not exclude the back of the bike. No changes anywhere, but I suppose it could factor into this also.
Anyone else have chatter issues? Only saw one thread on the issue...
EDIT LIST:
*****************************
ACTUAL CHANGES / PROGRESS REPORT SNIPIT...
*****************************
NOTE: N/C = No change to performance
2014-01-05 (N/C) Dump Fork oil (10wt --> 7.5wt), measure and reset SAG, Clean calipers & bleed brakes, verify rotor deflection.
2014-04 Riding season under way!
2014-04 to 06 Minor improvements with increased Tire pressure. Played with lots of values front and rear.
2014-06-20 (N/C) New brake pads installed and bled brakes again.
2014-06-29 Improved! Synchronized rebound damping on both forks, decreased rear sag, increased rebound rate.
2014-07-26 New 016 Pro front tire. Too soon to tell. Verified rotor trueness after install.
*****************************
JJD952
OK - so from March of 2013 to June, I've ridden allot of the same roads. I did change tires and had the chatter thing happen on a road I ride more often. I've been back and sure enough I can repeat it! The area has a pronounced washout/ripples/divets/bumps where everyone brakes before this corner. OK - i can accept that where the road is abusive it could put the ball in play. But now, its an upward trend happening about 5 times tonight which is an all time record. One of those events nearly got me in trouble and this time I couldn't see anything in the road bump wise.
- Key takeaway: this only happens going downhill, braking HARD, on rough surface, and leaning. Remove ANY of ONE factor and it never happens! That said it seems to be a tire loading issue making the tire dribble and the suspension bouncing in unison with the tire (aka "Rubber Ball"). It IS NOT a Brake issue but a loading/weight transfer issue when the brakes are used hard!
- Goal --> Change one thing at a time and try to reduce or eliminate the headset dribble!
- tires good, S20s
- brake fluid - DUE, ready for bleeding
- Forks, no leaks, but two years on fluid. They are due for a fluid change.
Before she gets parked for the winter, I'll at least do the brake fluid and see if I get a run in to duplicate before weather turns (its imminent). My gut instinct says its a combo of all things. Conditions, tire pressure, fork damping, and brakes. Its still running the OEM pads from 08. They have life but, maybe they need swapped. Rotor surface looks just as it has.
I'll keep you posted as to what I find. And lets not exclude the back of the bike. No changes anywhere, but I suppose it could factor into this also.
Anyone else have chatter issues? Only saw one thread on the issue...
EDIT LIST:
*****************************
ACTUAL CHANGES / PROGRESS REPORT SNIPIT...
*****************************
NOTE: N/C = No change to performance
2014-01-05 (N/C) Dump Fork oil (10wt --> 7.5wt), measure and reset SAG, Clean calipers & bleed brakes, verify rotor deflection.
2014-04 Riding season under way!
2014-04 to 06 Minor improvements with increased Tire pressure. Played with lots of values front and rear.
2014-06-20 (N/C) New brake pads installed and bled brakes again.
2014-06-29 Improved! Synchronized rebound damping on both forks, decreased rear sag, increased rebound rate.
2014-07-26 New 016 Pro front tire. Too soon to tell. Verified rotor trueness after install.
*****************************
JJD952
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