Author Topic: IMPRECISE HIGHWAY HANDLING  (Read 2935 times)

Offline China Greg

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IMPRECISE HIGHWAY HANDLING
« on: May 03, 2008, 01:23:54 AM »
!st Gen B12...

Riding my second 1st Gen B12, (last one I put 30,000 miles... this one now has 18,000).. I've noticed a very slight, imprecise feel to both of these machines at highway speeds. I've changed tires, adjusted head bearing torque, fork oil... and almost enything else I can figure.

Strange... just a very minor "looseness"  that makes it tought to really hold a firm line sometimes. Maybe just a design issue.... ?
Black '98 B12S, JE 1216cc bore kit, port work, Yosh RS3, Ivan jetting, drag bars, modified Corbin Gunfighter, Hyperpro shock, Racetech Gold valve kit, stainless lines, Wave rotors, polished wheels, fender eliminator, bar-end mirrors, NEP throttle lock, Adaptiv TPX radar detector...140K miles

Offline Cruisecontrol

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Re: IMPRECISE HIGHWAY HANDLING
« Reply #1 on: May 03, 2008, 07:29:11 AM »
Does your front tyre have a centre groove?

Offline pmackie

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Re: IMPRECISE HIGHWAY HANDLING
« Reply #2 on: May 04, 2008, 03:37:46 PM »
Hey Greg

I've never ridden a 1st gen, but normally I would have pointed you towards the rear shock, not enough rebound damping, or too soft a spring, or both. But, IIRC you've already got a 3rd party shock on board. Have you got the forks dropped?

All the 2nd gen's I've ridden are rock solid at speed. The only issue I've ever had is a slight bit of headshake decelerating between 75-65 km/hr (45-35 mph). This was on my 2G 600, with 120/60 Bridgestone fronts WITH a centre groove.

Moving to a 120/70 front (like the 1200) with no centre groove (Michelin Pilot Road and Bridgestone BT-021) cured the issue, even with a longer B12 shock and dropped forks.
Paul
2002-GSF600S, Progressive Fork Springs, B12 Shock,
SS Brake lines, EBC HH pads, Leo Vince Ex & Kappa bags.
Ex Bike Mechanic (late 70's), somewhat rusty
32 years in the Fuel/lubes industry(Retired)

Offline China Greg

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Re: IMPRECISE HIGHWAY HANDLING
« Reply #3 on: May 05, 2008, 01:07:43 PM »
I'm running Bridgestone BT-021's with no center groove.. (my second set). Actually the situation is most evident at SLOWER speeds: a TINY bit of looseness at SLOW speeds, like approaching stoplights, where it needs to be "tended to" slightly to keep a nice straight line. I don't think it's the head bearing adjustment (but I'll have to check that, as I just completed a 3000 miles trip).
But also on the Big Roads at speed, it takes a little effort to keep a really tight line. HAd the same problem with my prevous 1st Gen B12... especially after I added a used GSXR 750 shock, which is longer than B12 stock.
Black '98 B12S, JE 1216cc bore kit, port work, Yosh RS3, Ivan jetting, drag bars, modified Corbin Gunfighter, Hyperpro shock, Racetech Gold valve kit, stainless lines, Wave rotors, polished wheels, fender eliminator, bar-end mirrors, NEP throttle lock, Adaptiv TPX radar detector...140K miles