Fz6 not riding straight, forks not in line with radiator.

[seanmhc]

I'm in a love hate relationship with my fz6 right now, everything about the bike is great - it's looks, it's practicality the amount of power and fun you can have on it. But most of the time I get on the bike i'm just not enjoying myself because I the darn thing feels like it doesn't want to ride straight. Not only does this make slow speed maneuvers more difficult, but it feels like it affects braking as the bike is 'skew' and general riding.

I started noticing this problem when I had my tyres changed, co-incidentally I swapped the stock exhaust out for a set of Dominator cans the night before. I'd only had the bike for a few weeks then so the problem may have still been here but I was unaware until I was riding on new rubber with an entirely different profile.

So when I'm riding it feels like the bike wants to go left. I find myself having to sit on the right side of my seat and apply pressure to the right handlebar to keep the bike going straight. Turning left is a breeze but turning right feels entirely un natural. When I'm sat normally I feel like I'm skew on the bike, my left hand feels further away than my right - If i look down at the forks it appears that the right fork is closer to the radiator than the left fork.. though by eye it doesn't look like the forks are twisted or bent. When braking I end up pushing more of my weight into my right handlebar and I have to really relax my arms and the handlebar turns to the right to 'straighten up' throwing my braking off all together.

From searching the net I thought it might have been the rear wheel alignment. Having made sure that's right.. giving up and riding with the wheel obviously pointing left or right - neither of which helped my problem it just made the bike want to slide round corners, then re-adjusting I've gathered it's not that. I've made sure my pressures are correct too knowing that can throw off a bike. The next thing I looked into was the steering head bearing, I'd noticed it had notched a little to the right and they were in obvious need of changing, I got a garage to do this as I wasn't confident in dropping the forks out - I hoped that by re-fitting them it'd hope to solve any issues with the forks being twisted too.. though stupidly I didn't ask as I was convinced at the time that it was the bearing causing the handlebars to move slightly to the right when riding straight throwing me off. Low and behold, this solved nothing.. (the handlebars turn much nicer now though).

When I was replacing my cans, I ended up fitting a new set of Givi arms as one of them on the right hand side was snapped. It took a lot of effort to line up the fixings and fit the box, almost as if the rear sub frame was out. There's also a nice set of scratches on the right of the topbox also the front right fairing screw mount has snapped between the two pieces which I noticed when trying to figure out what was vibrating at the front of my bike when I got it. This leads me to assume the bike has been down at some point whether dropped from stationary or moving I don't know.

The only other idea I have is that changing the exhaust might have adjusted the weight balance and taken some weight off the right side of the bike.. I'm not sure how this would make the bike not want to ride straight at higher speeds though as gyroscopic forces should counter this out, and it doesn't explain why the right fork appears to be closer to the radiator than the left and that I'm sat skew (even when I make sure i'm in the centre of my seat and upright) just to ride straight. I'm assuming something is bent, or something is out of alignment.

I'm starting to go crazy, I'm not enjoying the ride at all. I would love to take the bike to a garage and throw money at them so I can enjoy my ride again, but I'm not in the best of financial situations right now, unless I know exactly what needs doing and I buy the parts that's out the window for now. I'd love it if someone could help me out, or even come ride my bike and tell me I'm not going mad and imagining all of this because a bike not wanting to ride straight seems quite ridiculous in my head.

The bike is a 06 plate faired variant coming up to 20k miles.

I posted on the facebook page a while ago and it appeared a few other people had a similar issue but nobody has got to the bottom of it. I was hoping someone out there has, or could provide an explaination. I even tried drawing out the bike in an attempt to get my head around the physics of why this is happening, but I'm still clueless.

Hope someone can help!

 

[Motogiro]

:welcome: to the forum!
I remember a few member talking about the forks getting tweaked. I believe the remedy could be putting the bike on the center stand, loosen the front axle, lift the front and block the bike at the header. Carefully loosen the upper and lower triple clamps that hold the fork tubes. Re snug the front axle making sure the front wheel looks aligned with the triple. Re tighten the triples, put the front wheel to the ground and re tighten the axle.

Some of our other members will have an idea on this.
[MENTION=15974]FinalImpact[/MENTION] [MENTION=6338]TownsendsFJR1300[/MENTION]

 

[TownsendsFJR1300]

Plus 100^^ on Cliff's re-setting the fork.

Do NOT tighten the axle clamp bolt until pushing the bike up against a wall (or similar) and applying the front brake(several times). You want the forks to find their normal happy spot on the axle BEFORE you tighten it down. Do NOT force the right leg to match the distance the left one is...

As you suspect the bikes been down (and it sounds like it), as your messing with the fork tubes, try ROTATING the shiny inner tubes in the triple clamps to make sure NEITHER IS BENT. Rotating say 180 degree's, (or what ever), the lower fork should ALWAYS END UP at the same place.

While the nose is in the air, (I know you have new head bearings), double check (everything is still tight) the adjustment by gently pulling up on the front wheel(on the center stand). Your feeling for ANY play. There shouldn't be any. If there is, the mechanic may not have fully seated the race, torque down to proper spec's, etc.

The new muffler won't make the bike pull however, what I would do is loosen the main clamps for the exhaust and then loosen ALL FOUR rear sub-section torx bolts. (and their tight!!). Gently move the sub-frame back and forth (it may be sprung-tight to one side from the crash) until it find's it's happy spot and basically centers itself. Then torque to spec's... The top, left INSIDE nut is tight and hard to get to, but do-able.

IME, most times the bike goes down, the main fairing stay get's bent. (I'm on #3).

That will make the nose crooked and even a little bit, it's VERY OBVIOUS.
To check that, center stand the bike and sit on it. Steering straight, look directly forward and simply eye ball the nose if one side is higher than the the other, the fairing on one side is closer to the fuel tank than the other side.

Re-reading your 1st post, your handle bars may be bent. Kinda a PIA, but try removing them from the bike and set them on the floor.
It should be pretty easy to measure / see if one end is higher/lower than the other- At least rule those out..

PM sent as well.

FinalImpact will have more idea's on how to proceed as well..

Unless the frames bent, we'll likely get you going straight again, but please follow instructions to the letter...

 

[FinalImpact]

First confirm bars are straight. Put a straight edge across the clamp and measure back to the tips. Each side should be equal. Also confirm they centered and not pushed over to one side. Regardless if they are bent, it won't make it pull or drift.

As for the forks, loosen the lower triple pinch, loosen axle pinch and axle, stand in front of the bike, grab the bars and clamp the tire with you knees. Give the bars a good twist and take a look and see that the tire, triple and bars are aligned. Get the bike on its wheels and bounce it few time. Tighten all the bolts.

Anyone who's wrecked a dirt bike hard has done thisa time or two without loosening any bolts. Trees work well in place of knees too.

Also you could pull the fairing off in about 10min to get a better visual.

Of course all the inspections mentioned by Scott and Cliff are good too.

 

[TownsendsFJR1300]

Any updates?

 

[seanmhc]

I have a few updates here:

I was really busy over the Christmas period and have only just got round to having some time off to look at the bike, which has been mainly focused around giving the bike a good service, changing out tyres and replacing the chain and sprockets. I had learned to live with the lean albeit being a constant irritation and wanting to sell the bike every other day.

Anywho, so far what I've done:

As per above, reset the forks by loosening all the bolts from the lower triple and down, then compressing the suspension, twisting the front wheel till it was happy and torque-ing everything up. Ride seemed nicer but after a few days the issue was definitely back / unsure it ever went - I believe there must have been some sort of twist for it to feel temporarily better.

Checked the height of the forks coming out the top yoke with some calipers, made sure they were the same.

I have twisted the silver part of the forks whilst having both triple clamp bolts loose from my eye I couldn't see anything move.

Handlebars, I measured from each end to their clamp, adjusted them as they weren't exactly centred. Haven't checked for straightness as they look identical and I don't believe that's the issue... which will be explained in evidence below.

After all this having no effect I had a 'mechanic' friend of a friend come round to measure a few parts and have a look at the bike.

Things I / He noticed:

Front disks not centred in calipers, larger gap on one side than the other which is unusual

Very unusual front tread wear, originally believed to be camber wear - by the time the tyre was completely shot it was evident there was much more going on than camber wear. Basically looked as if I'd spent all my time riding clockwise around roundabouts and nothing else. I will try include a picture below.

When checking alignment, it looked as if the tyres were off-set from one another _ - and not parallel. Minutely but definitely notable.

From this we checked spacers in both front and rear tyres to make sure they were exactly as the service manual states. We checked front and rear bearings for play. We tried to add a washer to the front axle (on the left hand side as if you were sat on the bike) to push the wheel right - the axle wouldn't re-thread so we gave up on that.

When talking to someone outside of a local bike parts shop they posed the idea that the previous owner may have dropped the bike and tried to rebuild the forks and not balanced the air gaps and said I should get my forks re-built. As this is an expensive task I decided to make sure I'd exhausted all other possibilities first before spending money.

As my tyres were shot, I picked up a new set, this time opting for pilot road 4s. Replaced my chain and sprockets, made sure rear tyre was in alignment and wheels were balanced. No difference other than my bike was a little happier leaning into corners.

When coming back home from the squires egg run on Sunday my mate pointed out to me that from behind it looked as if my whole bike was 'sagging' / leaning a little to the right. He said it could have just been him as it was very minute but he said something looked off. This could perhaps make sense if my front tyre is off centred to the left, causing my bike to lean to the right a little, explaining how the wear pattern was just down the right side of the front tyre.

I'm still no closer to finding out the potential cause of this! I know with the fz6 the frame doesn't bend so easily, my (inexperienced) mind says there's something up with either - the head stock tube not being straight, the triples being bent or the forks being bent. I'd like to know what more experienced riders like yourselves think the problem lies within.


Edit: After re-setting the forks over and over the handlebar still looks as if it was turned slightly to the right, with the left side being further away than the right when riding straight.

 

[TownsendsFJR1300]

Sounds like, with the tire wear, your fork springs may be an issue.

As for the brake calipers: Yamaha Motorcycle Parts 2006 FZ-6 - FZS6V FRONT BRAKE CALIPER Diagram
their floating and should center themselves. If the grease in the boots is hardened up, non existent, that would contribute to that.

Yamaha recommends BRAKE SEAL REPLACEMENT every TWO YEARS. In reality, you can go much more than that.

For S&G's, go for a ride, maybe to 50MPH and stop quickly with the REAR BRAKE.. Now touch the front ROTORS and see if their cool/cold to the touch, they SHOULD BE. Old seals harden up, drag and will NOT center themselves if bad enough.

Just as a side note, I rebuilt my S2 calipers (twice as many seals as yours) several years ago. I can still (with the bike on the CC, scissor jack under the header lifting the ft wheel), easily get FOUR full rotations just by spinning by hand (as hard as possible). You should see close to one at least. If not, they need addressing..

 

[FinalImpact]

I'll be repeating myself but put a straight edge across the bar clamps and measure back to the tips. I'd guess they are bent from being down.

Lets talk about what it can/can't be and why.
1) bent bars or bars off center: the bike will drive and track straight (if the rider lets it), no impact on tire wear or bike lean angle (in most cases, again - rider influence). However it will make the rider very uncomfortable espicially if rider has a death grip on the bars. It will feel awkward and strange at all times especially when arms are at equal length. Corner tip and transition will feel uncomfortable.

2) Weak springs. No. It simply rides lower. This may impact other things but not tires, angles, rider position. The axle keeps the forks balanced. Granted it is not desired but it not the cause. And if your axle were bent to allow this, wheel removal would be a serious challenge!

3) Stem or triple being bent. Although possible, highly unlikely. The act of loosening the Top nut and using the forks to position the top triple self aligns the triple. If this off, inserting the axle is very difficult!

4) Rear wheel alignment. It can be off a considerable amount, like several degrees and have negligible impact on cornering or tire wear to all but a pro rider. The bike tracks straight even though the thrust line is askew. Even when off 4° the chain lets you know something is wrong as it vibrates.

5) Chassis twist... meaning if the rear wheel is 90° to the surface and the front wheels vertical angle is measured and found NOT to be the same angle as the rear, this could cause numerous rider complaints based upon the severity. I think the words "camber" a cage term were used earlier. Basically when both front and rear wheels are not in the same plane; i.e. both should measure and form a 90° angle to the surface when the bikes center line is staright up and down forming a 90° angle. Use a digital level from the rotor disc surface to verify this. Point it straight up for both tests. If the triple is pointed straight ahead the bike could be at any angle and the rotors should both measure the same angle. Make sense?

IMO if this bike hit hard enough to twist the chassis there would be other signs of damage and/or the PO would have been replacing several components. The bike would have been a total if insurance was involved.

Those are my thoughts. The two suspect items can be measured with common tools or cardboard squares if need be.

Let us know what you find!
Good luck!

 

[seanmhc]

I said I would attach photos with my previous post, I couldn't find any on my computer at the time, but I've managed to dig them out. Photos are all taken looking from front to back of bike.

Front tyre wear before replacing:


Brake caliper and rotor left:


Brake caliper and rotor right:


Spacer left (note gap between spacer lip and fork):


Spacer right (no gap between spacer lip and fork):


Left spacer can be moved when front axle is loosened up, but soon as seated by hand spacer gap closed on right but opens on left, photos taken when axel torqued up to 72nm.

Thank you again for your replys. I can't for the life of me figure out what could cause these gaps other loosening forks and twisting them as if they were bent they'd move the wheel side to side slightly but neither do.

I have undone the top nut, and this time the top clamp bolts + everything lower other than the lower triple clamp bolts, tried twisting left to right then bouncing the suspension to no avail.

I did also forget to mention that when riding, looking down at the clamps and the handlebar they both appear to be angled top left to bottom right (top yoke and bar together) when riding straight if that makes sense. sort of like this \ but at a much much smaller angle.

I will get round to checking the straightness of the bars, need to find a decent enough straight edge, and it appears I've left my spirit level behind at the patio I'm in the process of laying so I will need to rescue it in odrer to check the angles of both front and rear wheels.

Just wanted to make a post to point out the severity of my front tyre wear as everyone I showed hadn't seen anything like it.

Thanks,
Sean

Edit: In regards to brake caliper servicing, when trying to fit the washer on the axle we ended up removing the calipers in an attempt to thread the axle. Decided while they were off to remove the pads and retaining clips and give them a good clear of brake dust and grime in there, got the wheel from doing half a rotation to a good 3/4 even more if we put all our effort into it.

 

[TownsendsFJR1300]

Wow, that tire is bad and something quite wrong.

I'm not sure how your tightening the front axle. Below is from the shop manual.

The axle pinch bolt should not be tight initially. Tighten the axle to spec's.

Now, with the bike on the ground, grab the front brakes and push up and down on the handle bars.
That will center the disc's to the forks and the forks fall into their own "happy place". Now you can tighten the pinch bolt.


Now ^^^, is SOP, not counting any damage to the bike, etc. A bent axle, bad bearings, etc can throw everything out..

As for measuring between the forks and disc, if you have a pad thicker than the other side, that will throw #'s off and really doesn't mean anything


** Have you pulled the triple trees and checked bearings for wear, front end flopping about, etc??? If bad or too loose,
You'll be able to lift the wheel/forks while on the CC if the steering head bearings are loose / worn...






.

 

[FinalImpact]

As stated if the pads have different wear amount AND the fork leg is not drawn together the calipers will have a different spacing from the fork tubes. These are floating calipers and should freely move side to side with the pads out. And IF nothing is bent you CAN pull the forks together. If this causes the forks to bind then something IS BENT!

Back to the calipers; If they do not float, usually the inner pad will wear more than the outer and your brake squeeze will get mushy. But none of that has anything to do with the how it rides...

On that note; that front tire would have to be really low on air pressure to wear the side off.
What pressure do you run and how often do you check it? Under inflated tires can wear in strange ways. Even track bikes don't wear tires that bad. Unless you have the bike leaned over at a 45° angle doing thousands of circles about the roundabouts I just don't see this adding up.... Perhaps a compound defect coupled with low pressure???

What did the rear tire look like and how many km's on that tire?

Didn't you say something about the fairing being bent?
If so, it only takes about 10min to remove it and set it aside. Doing this removes the visual mind set of riding crooked. So if you have an area that is safe to take a short spin and not get fined, that may be an option as it lessons the perception in our mind that the bike is or is not riding true.

Also a straight piece of wood or strong cardboard could be used to compare bar sweep angles.

Perhaps take some pictures like these so we can see the alignment of all things?

Turn yours straight please....

@Motogiro Cliff, ever see a tire look like that?

 

[TownsendsFJR1300]

When the axle is tightened (not the pinch nut), the spacers won't spin.

The axle, bearings inside, wheel spacer, outer spacers, when tightened down, are all basically once piece..

For the OP, DO NOT PUSH THE FORK LEGS TOGETHER AS YOU TIGHTEN THE PINCH BOLT.
There is NO need to, goes against all logic and most importantly goes against how Yamaha want it done, (see above post from the YAMAHA SHOP MANUAL).

Agreed about checking/servicing the caliper to make sure their floating...

Re the possible bent fairing, it's a moot point even if it is BENT.


The UNEVEN TIRE WEAR is screaming at you, somethings mechanically wrong.
Plus the fact that the op feels the bike pulling / leaning to one direction.

Your skimming over obvious and IMPORTANT physical evidence...


The more I think about it, the more I would want to get inside the triple tree and check bearings and /or them being bent.

For the OP, is there any indication of the bike being involved in a crash??

 

[FinalImpact]

The two camps are devided and thats fine. If nothing is bent there is ZERO impact from pushing the forks together. Now if their natural position lands you with a big gap, something is bent.

That said, the FSM doesn't say to do a lot of things but people do them. Does that make it right/wrong? Not always.
Bottom line is it should have zero to no gap. If the gap is greater than a 1/2 mm, it indicates something is bent.

As for the tire, look at the contact patch when moving straight ahead with the proper air pressure. It is not much bigger than a thumb print. I'm just saying parts would have to be so damaged to get just that section of the tire to be the main contact patch. Now look at that tire; you would have to be WAY LEANED OVER to ever get that contact patch on the ground (one side of the tire) UNLESS the tire were low on pressure. The question now is to what extent the bike vs tire construction created that wear.

Fairing removal; agreed there is no impact to bike performance unless its changing the airflow significantly. But not all people are the same. Some have more/less visual acuity that can trick their brain into thinking the bike is leaning when in fact it is not but the visual impact changes how they ride. Now add in the possibility that the bars are bent and you have feeling and perception that the whole thing is a mess when it's simply playing tricks on the riders head. By removing the obvious hopefully we find what is less obvious.

If all items discusses here are put together on the same chassis it very likely does add up creating the effect the rider feels and is trying to compensate for.

 

[TownsendsFJR1300]

Remember, now with the new tire, it's still pulling to the side...

Between the one sided tire wear, pulling, something is not right. A bent fairing stay will NOT cause that wear.

And please do a CLOSE INSPECTION side's of bike, reg pegs, etc, anywhere that would show the bikes been down.

For the OP, find a reputable shop, have them test ride it and see what they say.
(We can only do so much thru a computer screen without hands on..)

 

[Motogiro]

Wow That is severe! I'm wondering if there is a problem with a fork spring being broken.Although it's hard to believe there would be that much flexing in the axle. The other suspect might be a twisted frame. I've never seen that type of wear on a bike. It's almost like the bike has been riding tilted while compensating with counter steering which may be a clue pointing toward a problem with the frame..

 

[Motogiro]

Also...check that the swing arm is proper relationship to the frame as well as rear wheel alignment.
Look at the front of the fender in relationship to the wheel. Is that actual or just the photo?

 

[FinalImpact]

I have to say no to spring fault. The only way the lower forks could be on a different plain is if the axles ends were bent.

From here: axle removal would be near impossible (tire just replaced. Not it.
Brake drag would be monumental. Not it.

We need more information. Lots more. A digital level from both rotors would tell us a good bit about the chassis alignment.