Heavy Vibrations 90 - 100 kmh

I have a heavy vibration at 90 - 100 kmh. When i accelerate moderate up to that speed, it comes and then it dissappeares again after about ten to 20 seconds, over 110 kmh it's ok. If i accelerate at full throttel i don't feel it. I have new sprockets and chain, new rear tire, however, the front tire isn't so good, its quite worn.I've checked the swing and rear wheel bearings and they are good. There's no abnormal noices from the engine. The bike runs fine except from the vibration. Greatful for any suggestions.

Post edited by: JanTaliban, at: 2006/07/20 05:58

Post edited by: JanTaliban, at: 2006/07/20 06:00

How old are your tires? How many miles are on them? Old tires or high milage tires may still look new and have plenty of tread but they deform internally (treads separate from the carcass and you cant always see the problem)over the years and you'll get those "specific speed" vibes that come at one speed and go away at a higher speed.

they are not safe at this point since they may not vibe at higher speeds but could possibly blow out or blow chunks of tread off without warning. It's no fun going 90 mph and a chunk of tread blows off the tire...

JanTaliban wrote:

I have a heavy vibration at 90 - 100 kmh. When i accelerate moderate up to that speed, it comes and then it dissappeares again after about ten to 20 seconds, over 110 kmh it's ok. If i accelerate at full throttel i don't feel it. I have new sprockets and chain, new rear tire, however, the front tire isn't so good, its quite worn.I've checked the swing and rear wheel bearings and they are good. There's no abnormal noices from the engine. The bike runs fine except from the vibration. Greatful for any suggestions.

Post edited by: JanTaliban, at: 2006/07/20 05:58<br><br>Post edited by: JanTaliban, at: 2006/07/20 06:00

Ok I think you ansewred your own question. You have a bad front tire. On acceleration you are taking the weight and redistributing it to the rear. But the unasked questions are a little more serious. Why are you doing sportbike speeds on a LTD? My bro has a 750 LTD and the last thing I want to do is the ton+ on it. It's not a question of cc's either I don't want to do it on my 900LTD. If those speeds are important to you get a bike designed to do them safely or make sure your life insurance and cabinet of black market painkillers is full. I may take some flack on this but I don't believe the ltd's were designed to explore the upper reaches of speed. One thing the forks like to noodle. The bars put you in a position for pictures and not reactions. Hey everyone does a blast now and then If that's what you are talking about then cool! But 110+ on a 20+ year old bike, a LTD and with a bad front tire! Take another think on it

ambergrismooon wrote:

JanTaliban wrote:

I have a heavy vibration at 90 - 100 kmh.

...But the unasked questions are a little more serious. Why are you doing sportbike speeds on a LTD? .... But 110+ on a 20+ year old bike, a LTD and with a bad front tire! Take another think on it

Um, dOOd, 100KMH is 62.5 MPH .

Otherwise, a splendid answer as always...

Carry on.

Post edited by: Pterosaur, at: 2006/07/20 08:45

Yep! OK I've replaced the eyes and bought some more memory but they said the motherboard is still running a 286 processor so don't expect too much without a full brain transplant. KMH vs MPH.... Vegas oddsmakers have me as a favorite to screw it up again soon! Place your bets!

Sorry about my confusion but I still think it's your tire! What were we talking about?...........can this be caused by Chineese food?????

I will now proceed to entangle the entire area!

Also might wanna check the steering head bearings, if they are worn theres sometimes a bit of a wobble at mid speed. Allball makes a drop in replacement with tappered bearings and race.

mmmmm Chinese food.

How ironic, my least favorite boss ever has just accepted a new job in China. Good for him, that puts me, geographically speaking, about as far away from him as possible.

sorry for the thread heist. I just ate chinese food for lunch:laugh:

ambergrismooon wrote:

...Sorry about my confusion but I still think it's your tire! What were we talking about?...........can this be caused by Chineese food?????

Naturally, Gris knows, having once tried to glue together a bunch of old Lo Mein cartons from the back of his fridge into a tire...

:whistle:

Pterosaur wrote:

ambergrismooon wrote:

...Sorry about my confusion but I still think it's your tire! What were we talking about?...........can this be caused by Chineese food?????

Naturally, Gris knows, having once tried to glue together a bunch of old Lo Mein cartons from the back of his fridge into a tire...

:whistle:

isnt that the new chen -shing-chow-mein line?i hear they handle like a wet noodle!:whistle:

My bet is on your front tire being the source of the problem. I had this same problem on one of my cars (fine up to about 60 mph, vibrations through 68 mph, then smoothed out above 70 mph). Since it was under warranty I had the GM tech check out everything in the front end, and he said it was the tires. I didn't believe him, but decided to replace the tires anyway since I was going to be doing some traveling. Sure enough, the new tires cured the problem entirely. That was 25k miles ago, and the problem has not returned.

If it is not the tires, I bet on the front wheel bearings. Since you need to remove the front wheel anyway to replace the tire, I suggest you pick up a pair of bearings (available for about $10-15 per pair at any bearing supplier), and drop them in at the same time.

Thanks everybody for all your help. I will change the front tire Thursday next week. I get back to you with the result.

Post edited by: JanTaliban, at: 2006/07/21 04:53