70-80 MPH and over fish tail feeling

[Ronny]

I have a 2005 FJR with 7000 miles on it. Running empty bags on the highway and no trunk it has the feeling that the rear end is fish tailing. I have checked the front end and torqued the headset, checked the rear end and torqued the swingarm, rear axel. I recently replaced the original tire and put Continental Road Attack 2 tires on it. The bike just feels squirmey like it is getting close to a speed wobble. Anyone have this problem and know what it could be? Any help would be appreciated. tia, Ron

 

[Geezer]

Well, if the problem started after you put on the new tires, I'd look there first. Maybe you got a bad one.

 

[flapsup]

I don't know you and I don't want to insult your skills, so here's a few things to think about:

I see that you checked a lot of stuff, but you didn't mention tire pressure. 40 front, 41 rear?

How many miles on the new skins? Is this your first set of brand new tires?

Are the beads on the new tires fully seated?

Why does your '05 only have 7,000 miles on it?

Suspension settings too soft or way too hard?

Any front end work done lately like pulling the fork legs off? Might be out of alignment if they were reinstalled badly.

Are you testing on rain-grooved pavement?

Don't forget to try to correct just one thing at a time so you find out for sure what the problem is. If you fix two things, you won't be certain which one fixed the problem.

 

[TheZsdad]

Could the tire/tires be on backwards i.e. rotation?

 

[mcatrophy]

I have a 2005 FJR with 7000 miles on it. Running empty bags on the highway and no trunk it has the feeling that the rear end is fish tailing. I have checked the front end and torqued the headset, checked the rear end and torqued the swingarm, rear axel. I recently replaced the original tire and put Continental Road Attack 2 tires on it. The bike just feels squirmey like it is getting close to a speed wobble. Anyone have this problem and know what it could be? Any help would be appreciated. tia, Ron

How many miles on the tyres? It takes 50-100 to get them properly gripping the road. And make sure you are measuring your pressures with a known good measurer.

Could the tire/tires be on backwards i.e. rotation?

Think that only affects water clearing.

 

[RaYzerman19]

Normally, this can be caused by tire pressure too low, suspension set on soft for your weight, and if you have a top box. I would start with tire pressure and dialing in the suspension from the stock settings, especially if you feel any instablity in the twisties.

 

[ionbeam]

Other things to check are the rims for lateral and radial run-out (bent rims) and verify the forks are true and straight. How much of the fork tube is sticking above the top of the triple tree? Does your FJR have stock dog bones? As mentioned do check the tire pressures with a known accurate gauge because a low rear tire acts much like what you describe.

 

[CAJW]

Well, if the problem started after you put on the new tires, I'd look there first. Maybe you got a bad one.

+1 on tires. A brand new set of Dunlops once sent my 97' ST1100 into a wobble (fish tailing) at speeds anywhere over 60. A tire change to Bridgestones fixed it.

 

[Ronny]

I don't know you and I don't want to insult your skills, so here's a few things to think about:

I see that you checked a lot of stuff, but you didn't mention tire pressure. 40 front, 41 rear?

How many miles on the new skins? Is this your first set of brand new tires?

Are the beads on the new tires fully seated?

Why does your '05 only have 7,000 miles on it?

Suspension settings too soft or way too hard?

Any front end work done lately like pulling the fork legs off? Might be out of alignment if they were reinstalled badly.

Are you testing on rain-grooved pavement?

Don't forget to try to correct just one thing at a time so you find out for sure what the problem is. If you fix two things, you won't be certain which one fixed the problem.

The bike isn't ridden too much because I race bicycles and don't ride too much after doing training of 300+ miles per week. Now that I am older and slowing down, I am starting to ride the M/C more, I have about 1000 miles on the new tires. the bike did it a little (not much)with the original Bridgestones on it. I had read the Contis worked well for these bikes. I have 36 psi in front and 42 psi rear. Arrow rotation is correct. I did notice it is more apparent on asphalt roads and not on concrete too much. Would low profile tires such as these cause such a thing? I have the suspension (front and rear) at medium and the rear lever on soft. I only weigh 145 lbs.

 

[Ronny]

Other things to check are the rims for lateral and radial run-out (bent rims) and verify the forks are true and straight. How much of the fork tube is sticking above the top of the triple tree? Does your FJR have stock dog bones? As mentioned do check the tire pressures with a known accurate gauge because a low rear tire acts much like what you describe.

Everything is stock and original except the tires. Bike is clean and always garage kept. I did put on some rear lowering links, I lowered the bike about 1 inch. Inseamed chalenged at 30" inseam.

 

[Ronny]

Well, if the problem started after you put on the new tires, I'd look there first. Maybe you got a bad one.

+1 on tires. A brand new set of Dunlops once sent my 97' ST1100 into a wobble (fish tailing) at speeds anywhere over 60. A tire change to Bridgestones fixed it.

I guess this is a possibility. Are tires warranted or do I just get a new one and try another to see if it solves it?

 

[03HiYoSilver]

Ronny,

You also need to check your Tires Pressure at least 1X week. Even when they have 15-20 lbs/Air, you CAN'T see it.

As little as 3-4 lbs down makes a BIG difference.

 

[Ronny]

Ronny,

You also need to check your Tires Pressure at least 1X week. Even when they have 15-20 lbs/Air, you CAN'T see it.

As little as 3-4 lbs down makes a BIG difference.

Would 36 front and 42 rear be recommended? That is what i have read.

 

[Donal]

The bike isn't ridden too much because I race bicycles and don't ride too much after doing training of 300+ miles per week. Now that I am older and slowing down, I am starting to ride the M/C more, I have about 1000 miles on the new tires. the bike did it a little (not much)with the original Bridgestones on it. I had read the Contis worked well for these bikes. I have 36 psi in front and 42 psi rear. Arrow rotation is correct. I did notice it is more apparent on asphalt roads and not on concrete too much. Would low profile tires such as these cause such a thing? I have the suspension (front and rear) at medium and the rear lever on soft. I only weigh 145 lbs.

I would say your front pressure at 36psi is a bit on the low side. The recommended pressure is 39 psi and some go higher than that.

Don

 

[03HiYoSilver]

...I would say your front pressure at 36psi is a bit on the low side.

The recommended pressure is 39 psi and some go higher than that.

Don

Like he said, about 39-41 lbs works better and reduces Cupping etc...

 

[not2shabby]

Other things to check are the rims for lateral and radial run-out (bent rims) and verify the forks are true and straight. How much of the fork tube is sticking above the top of the triple tree? Does your FJR have stock dog bones? As mentioned do check the tire pressures with a known accurate gauge because a low rear tire acts much like what you describe.

Everything is stock and original except the tires. Bike is clean and always garage kept. I did put on some rear lowering links, I lowered the bike about 1 inch. Inseamed chalenged at 30" inseam.

If you didn't lower the front end too, this could be the problem. I'd try sliding the fork tubes up in the tripples about 5mm and go for a test ride.

 

[Ronny]

It has me stumped. My old "73"Kawa Z900 went straight, My "84" Kawa went straight, my Goldwings went straight but they all just handled bad in twisties.

I have cruised at 120mph with this FJR before at 2400 miles on odometer w/original tires and it went straight. I remember it starting fishtailing at about 5000 when the tire was getting flat across the middle. It must be the new Contis.

I will try 40 psi Frt.- 42 psi Rr then, I hope that works, If not, back to Bridgestones.

Thanks all for all the advice. I'll let you know.

 

[ionbeam]

If you didn't lower the front end too, this could be the problem. I'd try sliding the fork tubes up in the tripples about 5mm and go for a test ride.

Thanks not2, that's where I was going with that comment. Lowering the rear alone changes the steering geometry and makes the bike slightly more unstable.

There are many good tires besides the OEM tire. Do a search on tires, you should find a life time of reading :lol:

 

[Fred W]

I hate to contradict my friend and mentor Professor ionbeam, but while lowering the rear end will alter the steering angles, that change will actually improve the straight line stability (at the cost of slower steering) . I don't think that the lowering links would be the cause of his wobbling woes unless it also did something negatively to the aerodynamics.

Of course, I could be wrong. It has happened a time or two before.

And to the OP, yeah, 36 is way too low for the front tire. 40 should work fine as long as you haven't already cupped the front due to the low pressure.

Also, you didn't mention, what windshield are you running?