Will Someone Ride my Bike?

[jb1390]

LERecords - I am off work today and tomorrow, I can head up to glastonbury to meet you if you have a couple minutes, let me know.

My name is Jeff and my # is 860-367-four seven four four, call or text is fine.

 

[edgeofnj]

i'm not an expert either, but thought another way you could validate the steering tube is bent relative to the back of the frame is to point a laser pointer through the tube (or along the same axis) and see if it lines up with a laser level line aiming down the center line of the frame, from the rear. good luck and ride safe!

 

[Black_Cirrus]

I'm not a big fan of the "professionals" helping you with the problem. I would rather ride an identical model, etc., to get a comparison.

If you do take it to a professional, don't pre-mention any problem, just ask for an evaluation.

Ok I have to say your almost countering yourself there, your right Pros tend to have to work on several vehicle a day, and some of them are total junkers and some ride like a vault. That's why you need to tell them your concerns so they have an idea where to start cause they may notice a couple other things that you won't. Not sure if there is one in your area, but there are professional frame guys for motorcycles, saw them on tv, because even the high dollar racebikes get tweeked. But I'd be super careful to make sure he knows what he's doing.

 

[FinalImpact]

IMO 99% of the time a bent frame isn't going to make it shake. Bent wheels, bad tires, bad balance all attribute to a shake.

As for the frame, it won't bend much as it it'll crack being made of cast aluminum. However the aft section being steel will bend but it won't affect the ride it just holds the tail and seat. As you must have notice many parts of the frame are not symmetrical so it would be difficult to measure most sections.

Specifically what do you think is NOT true regarding the frames alignment? I am not talking about bent forks and a tweaked swing arm but feel free to mention them if they are. Rear wheel alignment will make it crab walk if its far enough out of align. Alignment won't cause a shake until its wrecked a set of tires by causing them to scallop.

Automotive shops have car guides that tell down to the 0.01" locations of alignment holes, alignment pins (gauge holes), suspension mounts, engine mounts, door openings, roof height, pillar angles, you name it - the whole X, Y, Z coordinates of all mounting points. The Book with this info would be priceless if you could find it. For a bike; as long as the HEAD mount aligns with the swing arm mount a basic 90 degree coordinate; the frame is likely intact as far as handling is concerned.
You have to independently check the forks, swing arm and rear wheel are in alignment though.

I'm trying to understand the hash marks and there meaning up above in relation to the carpenters level. It sounds as if you're saying the frame has a twist which effectively rotates the vertical axis of the head / triple clamp section from the horizontal section of the swing arm pivot which is effectively parallel to the earth via the center stand. Does this sum up the bikes condition?

And IIRC you also said that replacing the triple and the stem corrected some of this condition? This is just me, but I'd suspect the forks are the weaker link and whatever force it took to tweak the stem/triple clamps was pretty huge! Perhaps the previous repair had the forks replaced?

For what little its worth amongst this crowd - bad alignment of components does not make vehicles shake and vibrate. Too often "MULTIPLE" things are corrected simultaneously AND lead people to believe replacement of a bent part corrected the vibration issue yet in reality the bent wheel was also replaced and the tire/wheel assembly was properly balanced at the time of the repair. However the customer only remembers the frame being fixed / control arm being replaced and that fixed the vibration.

Same is true of vibrations on structurally sound vehicles. People bring them in with a vibration and find the shocks are not dampening effectively. They replace the dampening device and leave. It seems fine for while and then the vibration comes back as the customer tunes into the issue after the "wow, I got it fixed feeling is worn off". Often times the root cause is found to be a the rotating part; i.e. bent wheel, flat spotted tire, worn tire(s), out of balance tire/wheel combo and ONCE the condition is corrected - WALLA - the vibration is really gone.

I wish you luck in your quest to fix this. Hopefully the tweaked frame being replaced fixes all of the reported problems.

 

[jb1390]

The forks were definitely previously replaced when the bike was rebuilt-and yes Finalimpact I believe you summed up the condition of the bike/frame accurately.

I contacted several places about getting the frame straightened-and no one would give me a quote (even approximate) without seeing the frame. Even then, I'd be concerned that a die cast aluminum frame that has been bent, and then straightened, would crack eventually, leading to a safety issue.

A new frame costs roughly $1000, I put it up for sale thinking that I may be able to get a bike, without the dents, for around $4000, and if I can get $2500 for mine, it might not be worth the effort of the frame swap.

Before I decide anything for sure, I am curious if the handling issues are very minor-if someone else rides it, I'll know for sure. If it's losing significant handling ability, then I can proceed with whatever it is I'm going to do-maybe sell it, maybe do a frame swap.

 

[LERecords]

honestly, just knowing that it may have an issue is a total turn off to me... after all this chatter about this, i wouldn't even bother riding it and suggest you take it to someone with actual motorcycle mechanic experience and let them determine the next step. I understand you are a mechanic engineer, but your not a motorcycle mechanic (not downing on you at all) and honestly neither am i. you could have 100 people ride it and all tell you its fine, but a experienced mechanic might show you exactly what is wrong. i know your trying to do this cheap, but you cant put a price on your safety.

i tend to think that it is probably more than just the frame... and i'm sure a car backing over a bike would really f up more than what we have discussed. i feel bad for you purchasing this bike with undisclosed problems and you should look into the legal avenues (considering you were told that the frame was strait) to see if you can use the lemon law or such.

good luck to you, but if this seems like too much trouble, i would sell the bike quick and buy one that you know has no issues.

 

[jb1390]

I had a friend ride the bike yesterday (he doesn't own an fz6), and he said that if he hadn't known there was an issue-that he wouldn't have noticed anything was wrong. He was very impressed with the power (and, actually, the handling), and I don't think he even brought it north of 8K.

I am thinking that I will continue to ride it, keep the ad up in case someone wants to buy it, and buy another one in a year or two that I'd be really happy customizing to some extent, without the minor cosmetic stuff. I'm not too worried that there is a safety issue with riding it-I will check for cracks every once in a while, it's pretty easy with no fairings.

 

[FIZZER6]

I was under the impression that a cast aluminum frame would not bend but crack if bent that much.

The only bike I have ridden where the handlebars would shake at 50 mph if you let them go ended up being a bent front wheel rim. Chances are if a car ran the bike over the front wheel could be bent.

 

[jb1390]

They tend to crack, not bend upon collision, but that doesn't mean that it never happens. They won't bend as far as steel will before cracking, but they still will bend.

I wouldn't be shocked if the front wheel was slightly bent as well, causing the shaking. However, the bike rides good enough to use it for now, and hopefully sell it and buy another one without any issues and no dents in a couple years.

 

[UHcougarJohn]

Last time I had an issue with the front end on my fz it was a bad wheel bearing, you could try takeing the front wheel off and inspect it to see if the wheel is straight or if the bearings are bad.

 

[tyler2011]

A little far far for a ride but...

How worn is your front tire? When I bought my 05 FZ6 a couple years ago it had about 7000 mi and had the head shake if you let go of the bars but you couldn't notice it with just slight pressure on the bar. The tire had similar tread pattern. Stopped when I replaced the tire at ~9000. It's also prob time to replace if it's the original due to being 5yrs and prob more (Code stamped in tire as week and yr).

Might also be worth checking the head bearings, I checked mine at 16000 and were showing signs of moisture intrusion via some rust and pitting. Probably on this weekends to-do list along with an oil change and chain cleaning. Seems to be a common problem and may be avoided if repacked earlier than later.

My bike also will go left if you release the bars. I can shift on the seat slightly and it will go strait. Maybe an FZ thing or designed since it seem most will cruise with 1 hand on the bar.

 

[jb1390]

Out of curiosity-would someone (preferably multiple someones) please put a level on their rear tire, and (with the front tire pointing straight ahead), put a level on the front tire-and see if you can find any noticeable difference? I have heard before that frames are never "perfectly" straight, which makes some sense to me. It does seem like the amount they are off should not be easily detectable with a carpenters level, but maybe I'm wrong.

 

[MattR302]

jb - I sent you a PM with a local CT forum. Post up your question on that site, there's a bunch of riders that really know their $hit when it comes to bikes. I'm sure you'll have a bunch of local guys way more knowledgeable than me willing to help you out.

 

[FinalImpact]

FWIW: you might just string it and see where it all lands.
http://www.600riders.com/forum/how-tos/40463-how-string-align-your-rear-wheel.html

Do the math on a 1/32" of an inch (about the width of a hash mark on the swing arm). IIRC it ends up being a couple of degrees of thrust angle. So if the rear tire is off by a few degrees, its natural tendency is to go in the direction aimed. So if the front tire weren't there to "steer it back" at the end of a mile it would have been upwards of a hundred feet or more away from the desired destination. Meaning, a tiny bit off matters. On dirt bikes not so much. But on a street bike, it equates to tire scrub.

So working with what you have it still seems you wish to see just how bad the frame is tweaked.
Try this: On the center stand, get your smallest level in on the rear swing as close to the pivot as possible. Place small shims under the center stand to achieve perfection making the swing arm section level.

Using a plumb bob hung from the ceiling to form a 90 degree axis. Hang it such that you can get it parallel to the steering tube or the front forks. I know the forks rake angle is going to complicate this, but if you could compare the plumb bob angle to the steering head angle (maybe that line where the frame halves meet) you might have a better idea if the frame has an actual twist between the swing arm pivot and the steering head.

This line where the frame halves come together. . .

 

[ctbandit]

I could check it out f you want. Msg me.

 

[jb1390]

Update:

I recently finished a frame swap on the bike, and got new tires (the rear tire was showing cables).

The pulling problem is largely solved, but not gone completely yet. The measurements that showed the frame was bad are fixed, and measure correctly now, so I am confident that those particular problems are solved. However, I checked further into the forks because of the slight drifting issue that remains (no amount of aligning the front end, or aligning the rear tire makes it go away).

The upper forks (shiny section where they normally bend), has around .002" runout on each side when spun inside the lower fork. However, one lower section has around .050" runout, possibly more.

I am realizing that whoever "rebuilt" this bike did not fully inspect/replace everything that they should have. I am thinking that they found a bent upper, maybe even both uppers, and replaced just those pieces, instead of brand new forks.

So far on this bike, I have found a bent lower triple, bent frame, and bent lower fork. Let this be a lesson-DO NOT BUY A BIKE WITH A REBUILT TITLE, it is not worth the initial purchase savings.

That being said, I am committed to this thing by now, and I found a set of 2006 R6S forks on ebay that I bought. I just need to machine the spacers, and I should have them within a week with this whole thing solved I hope......and then I will have R6 forks

 

[jb1390]

On another note, my brother in law, Tom, is purchasing a 2009 FZ6, I am going with him to pick it up tonight. Looking forward to having another member on the forum, and a family member with a fizzer, so far in general I really like the bike-I've logged almost 5000 miles on it this summer.

 

[tom.gabriele]

On another note, my brother in law, Tom, is purchasing a 2009 FZ6, I am going with him to pick it up tonight. Looking forward to having another member on the forum, and a family member with a fizzer, so far in general I really like the bike-I've logged almost 5000 miles on it this summer.

No way! my brother-in-law has an FZ6 too. he bought some rebuild one and has had nothing but trouble trying to figure out what all the PO didn't fix.

 

[Signal 50]

I just saw this. I could also take a ride down if you need a hand. I'm in CT, but I think CTbandit and Mattr are closer.

 

[jb1390]

Nice, Tom.

Actually, the straight problems are now fixed, so I think I am set. Also, the addition of the R6 forks seems to have improved on handling. Corner speeds that used to seem like they were pushing the limits feel much more controlled now. With the new frame, tires, and forks it feels like a different bike.

Though I still kind of wish that I had bought a different bike (another FZ6), this whole process has proved valuable for education on the geometry of bikes in general, and I understand my bike a whole lot better than I would have if I had never had an issue.

The one thing that makes me hesitant to post that the bike is 100% fixed is a vibration at relatively high speed. Also, it seems like it clunks some in the front end over bumps (very mild), but I want to upgrade my steering head bearings (All Balls bearings on order). Tapered bearings seem like they would be much better and stronger for this type of application, so I'm going to throw them in there. If that doesn't solve it, then I think a tire weight fell off after balancing. Once that is resolved I will be happy to say the bike is at 100%-at least now it goes straight!