so i was out riding around last night, and my buddy wanted to see how his trans-am would do against my bike. we hopped on the highway to do a quick run, and right around 100mph i go from asphalt to a concrete bridge. im guessing i hit the gap between the two and the front end of my bike starts a really nasty wobble and nearly threw me off at over 100mph!!

so when we pull off the highway, my buddy is freaking out because he thought he was gonna be scraping me off the road. he says he doesnt know how i didnt go down because my rear wheel wasnt even on the ground. he told me that i was entirely on the front wheel with that nasty headshake.

has this happened to any of you guys? i mean i really dont think it should have been that bad. i havent really messed with any of the dampening or rebound on the bike since i bought it, but im thinking i should after that near accident.

 

Worry less about your damping and rebound and more about the family van that you and your buddy could have crashed into...kinda like the one my wife drives with our two kids.

 

hmmm...i know what you are getting at man. yeah it was reckless, but the highway was dead when we got on. when i posted this thread i was looking for advise not a lecture. i have a daugher of my own, its not like i go out riding to cause problems and take lives.

anyways...this same thing happend with my bike last fall riding back from work on the interstate. my co-worker was following me, and i hit the transition between the road and bridge. he said that the rear wheel came off the ground, but i didnt get any headshake that time.

 

Is the separation of the bridge and the asphalt at different height levels? If you think about the physics, speed and consider the angle measurement of the flux capacitor and the gravitational pull, at about 100 MPH, if the ground of the bridge (after the road separation onto the bridge) is lower, than it is possible that you wen't from two wheels to one wheel (to be on your front).

Well, it was just a thought!

But seriously, at that speed, if you are leaning forward onto the tank and if your body is slightly off of the bike to maintain stability and to be behind the windshield to reduce windsheer, then it is probably possible that at that speed, and if the ground is at different heights than the bridge (bridge being lower than the road) evern by just an inch or so, could cause these results.

I don't know about damping and rebound adjustments, so maybe someone else cold chime in.

 

Thats good to hear porter. Because I'm not in the mood to give lectures about stupid highway racing regardless of traffic conditions.
You seem smart enough, keep your daughter in mind next time you race, what she will have deal with growing up without a father because daddy wanted to have a little fun with his fast motorcycle.

 

yeah me too. and trust me, she was the first thing i thought of after that whole ordeal. as much as i can't live without her, she couldn't live without me.

oh and later that night i came to find out that a guy i rode with once wrecked his bike and died on the scene just earlier that evening.

 

Its always very sad to hear that one of the motorcycle community has had an accident and passed on, but it makes me even more furious to hear about illegal street racing.
Its not tolerated in this forum and I'm sure many will agree that its not a topic worth bragging about.
I'm glad to hear that you came unharmed from the event and I hope you will hear us out when we say to be smart and ride safely.

Done.

 

come on man, seriously? i didn't start this thread to 'brag' about street racing. if i would have known i was going to catch hell i would have left it out. all i wanted was suspension advise, but i get you who wont stop giving me hell about a choice i made regardless of whether it was responsible or not. and to say that street racing makes you 'more furious' than hearing a fellow rider has passed due to an accident is pretty backwards to me dude.

 

Glad to hear you are ok. If you happen to have a clymer manual, it tells you what your settings should be to be at stock. I took mine back to stock (previous owner had them way out of whack) and then about a half turn harder all the way around. Itis more personal preference and what works for you, rather than a perfect setting. If need, I guess I could post the settings to put it back to stock.

Joey, I see your reason for concern and it probably isn't the smartest judgement on his behalf. But I dont see the difference between runnin next to a car on the highway, and opening it up on a empty piece of interstate. Both are reckless, but if you tell me that youve never opened up your bike, or exceeded the speed limit, Id say your full of shiat. We all have done it at some point. I come here to read and share things about my bike, not read someone's personal oppinion or belief's about what is smart or not smart. You are right though.

 

I'm still pretty green... but I believe these links might help you with the wobble situation... if it is what I think you are saying it is... then it can happen with any suspension set up provided the right harmonic feedback is recieved...

http://en.wikipedia.org/wiki/Speed_wobble

noting
"Wobble or shimmy begins when some otherwise minor irregularity accelerates the wheel to one side. The restoring force is applied in phase with the progress of the irregularity, and the wheel turns to the other side where the process is repeated. If there is insufficient damping in the steering the oscillation will increase until system failure. The oscillation frequency can be changed by changing the forward speed, making the bike stiffer or lighter, or increasing the stiffness of the steering, of which the rider is a main component.[1] While wobble or shimmy can be easily remedied by adjusting speed, position, or grip on the handlebar, they can be fatal if left uncontrolled.[3]"

also, this might help... just a lil more info on the physics involved..

http://www.msgroup.org/forums/mtt/to...?TOPIC_ID=2234

anyway... I guess the point is...when you hit the seam between the asphalt and the concrete the forces may have resonated through your suspension