Odd handling, front end issue!

[RDly]

Hi again, I recently posted a question about rear wheel alignment since my bike was handling pretty strange and have found that to be ok. The reason for asking is that my FZ6 has completely different characteristics between left and right handers.
After confirming the rear wheel was aligned ok I turned my attention to the front end and checked the forks and yokes/triple trees were set-up correctly. Everything appears to be as it should be but the bike still doesn't handle as it should.

Let me explain:

Riding straight ahead I can detect a slight pull to the right, I can counter this no problem and it doesn't really bother me. However, left turns are a dream and the bike is precise under any power load, the problem arises when I attempt a right hander and the front end feels like it's oversteering. This is particularly nasty at low speeds, especially roundabouts with the front end attempting to dive under itself!

The forkes are equal length in the yokes and straight, the tyre pressures are ok 33F/36R and the only thing I can think of is the original Dunlop tyre is the cause.

Does this ring a bell with anyone else?

Thanks.

P.S. I've been riding bikes on the road for the last 35 years, but this is a ****** mystery

 

[LERecords]

ok.. some things you may or may not have looked at..

-are all your wheel weights there??
-are they located centrally on the rim (instead of on the far sides)
-did you try to see if the front AND rear wheels are aligned properly (there is how to's on how to check this, i have always done it with the 2 string method)
-are the tires (both front and rear) in good condition (flat spots, cupping... you may want to put the bike on the center stand and run your hands all over the tires, you "should" be able to feel if there is something off

thats all i can think of for extra things to check. my money is on that you need new tires.. btw you may have to replace not just the front, but the rear to if they have cupping or flat spots.. sucks but cant put a price on safety... good luck :thumbup:

 

[von_trippenhopf]

I had some front end 'oddness' a little while back, turned out the headstock bearings were getting tighter, whoever did the bearings last time missed out the washer between the two nuts on the stem. I'd checked for slack, but not tightness so I hadn't noticed the steering was gradually tightening up. Made for a few interesting moments until I sorted it!

 

[FZ6-ZN]

My guess is the fork stanchions are slightly twisted in the triple clamps.

Loosen the two bolts on the under bracket, hold the front brake and bounce the front suspension a few times and re-torque to two bolts and you should be ok.

FZ6-ZN

 

[RDly]

Thanks for your replies guys. I have gone through the basics and beyond. The forks are straight as is the back wheel, the wheel balance weights are original Yamaha. The headstock bearings are free with no high/low spots.
I'm beginning to think it's a tyre problem since it's a 2003 bike with only 2700 miles on the original Dunlops that may or may not have seen their usuable life gone by some 4 years ago!

What is really odd is the difference between right and left handers, the tyres can't be responsible for such a difference, or can they?

 

[LERecords]

What is really odd is the difference between right and left handers, the tyres can't be responsible for such a difference, or can they?

well, they can be if they have flat spots on one side or the other.. same goes for cupping.. i didnt realize that the tires were that old.. not to say that its definit that they are the problem, but i would be leaning more toward them then anything else.. any chance to you could take it to a shop and have them look at the tires at least???

 

[RDly]

i didnt realize that the tires were that old.. .. any chance to you could take it to a shop and have them look at the tires at least???

I was thinking along the same lines, perhaps a second opinion is what I need, but for sure it's not right and although I'm an old git I do know what feels right and this bike is a complete nightmare!

 

[rsw81]

The tires could certainly be causing this problem, not to say this is definitely the case this time around. If the previous owner of the bike didn't maintain proper tire pressure and/or wore the tires unevenly (for various reasons), you could easily get different lean characteristics which each directioned turn. Considering the age of the tires, I'd just replace them if I were you.

 

[Naykid]

Disregard the rear marks for aligning the rear wheel. String both wheels like the previous member told you to do. That will tell you what is wrong. If you don't know how...google it.

A tire will not cause your problem. Only a bent frame or an out alignment rear wheel will do that.

 

[JAZZ-n-FZ6]

This may sound ridiculous, but are you sitting on your bike straight? If you are sitting more to one side it, it will cause you to turn slightly. Just a thought.

 

[RDly]

Disregard the rear marks for aligning the rear wheel. String both wheels like the previous member told you to do. That will tell you what is wrong. If you don't know how...google it.

A tire will not cause your problem. Only a bent frame or an out alignment rear wheel will do that.

Righty ho! Stringing it is, i'll have a go later after work.

Incidentally, i rode to work in the wet today and it was 'interesting'. Absolutely bugger all feedback from the front end, I may as well have been riding on ice for all i knew!

 

[RDly]

This may sound ridiculous, but are you sitting on your bike straight? If you are sitting more to one side it, it will cause you to turn slightly. Just a thought.

Excellent, that made me larf

 

[Motogiro]

This may sound ridiculous, but are you sitting on your bike straight? If you are sitting more to one side it, it will cause you to turn slightly. Just a thought.

Not ridiculous at all!
Take it a step further and make sure your sub frame is aligned. A tweaked sub frame that's off center will give you uneven weight distribution hence a difference in right and left turns. Maybe take a string and tape it dead center to tree and tape it dead center to you tail section. The string should reside dead center on your tank. If not your weight is not centered on the bike.

 

[RDly]

Ok, I think I have figured this out and it's not surprising really. I arrived home from work today and felt the front tyre. The left side was a lot warmer than the right. I then strung it up and the wheels are exactly aligned, so no issue there.
I then thought about the odd warming of the tyre and came to the conclusion that the left is warmer due to greater friction/grip.
When I was stringing the bike I noticed the right hand side of the tyre is discoloured brown, it wasn't like this when I bought the bike but has since appeared.
Again I thought about the old fella I bought it from and he left it on its sidestand for the last seven years, barely moving and exposed to the sun under a lean-to. Then the penny dropped ........ It's UV damaged

Time for new rubber, I'll trawl the forum and see what people rate as a decent replacement, but for now I would like to thank everyone for their input :thumbup:

Horrible brown tyre pic below!!

 

[rsw81]

Ok, I think I have figured this out and it's not surprising really. I arrived home from work today and felt the front tyre. The left side was a lot warmer than the right. I then strung it up and the wheels are exactly aligned, so no issue there.
I then thought about the odd warming of the tyre and came to the conclusion that the left is warmer due to greater friction/grip.
When I was stringing the bike I noticed the right hand side of the tyre is discoloured brown, it wasn't like this when I bought the bike but has since appeared.
Again I thought about the old fella I bought it from and he left it on its sidestand for the last seven years, barely moving and exposed to the sun under a lean-to. Then the penny dropped ........ It's UV damaged

Time for new rubber, I'll trawl the forum and see what people rate as a decent replacement, but for now I would like to thank everyone for their input :thumbup:

Horrible brown tyre pic below!!

Everyone has their own opinion about tires, and a lot of it has to do with riding style and preference. I do a lot of commuting miles with a touch of canyon runs mixed in, so I really like the Michelin Pilot Road 2's. Get's great distance on the tires and is very grippy on the sides.

I don't want to start a whole tire debate here, so perhaps it would be best to just do a search and read what other's have already written.

 

[deeptekkie]

Ok, I think I have figured this out and it's not surprising really. I arrived home from work today and felt the front tyre. The left side was a lot warmer than the right. I then strung it up and the wheels are exactly aligned, so no issue there.
I then thought about the odd warming of the tyre and came to the conclusion that the left is warmer due to greater friction/grip.
When I was stringing the bike I noticed the right hand side of the tyre is discoloured brown, it wasn't like this when I bought the bike but has since appeared.
Again I thought about the old fella I bought it from and he left it on its sidestand for the last seven years, barely moving and exposed to the sun under a lean-to. Then the penny dropped ........ It's UV damaged

Time for new rubber, I'll trawl the forum and see what people rate as a decent replacement, but for now I would like to thank everyone for their input :thumbup:

Any tire can sustain U/V damage but I too had a set of Dunlops a few years ago which turned brown. Radials on bikes are fantastic, but when they're not right they can cause weird handling problems, even when everything on the bike is right. I hope this solves your problems. Take care and safe riding.