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i have run into that problem once coming off the freeway using both brakes i started getting this horrible shudder through the handlebars; i release and braked again and it was gone, i read a thread on it a while back dont know if anyone has found a solution yet though so I started fiddling to recreate it when walaa. i can now do it (not as hard, but enough to cause a problem for an emergency brake) it will begin to shudder when i use front brake only and seems to start when the forks reach near the end of their travel in a normal brake dive. over and over and over again. this is after i was riding for bout 25 minutes worth of city miles. if i can recreate this consecutively then i think im going to have a visit with the yami dealer.
 

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I'm experiencing the same thing. Feels like really fast ABS pulsing, but with a good up & down vibration on the handlebar to boot. Seems to happen mostly when I apply brakes while the bike isn't going very fast (<10 mph), and/or when not steering exactly straight. Just started happening around 1750 miles. Never a problem before then. Let me know if you get any further clues from your dealer or elsewhere.
 

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Keeps getting worse for me

Kneedragger said:
I'm experiencing the same thing. Feels like really fast ABS pulsing, but with a good up & down vibration on the handlebar to boot. Seems to happen mostly when I apply brakes while the bike isn't going very fast (<10 mph), and/or when not steering exactly straight. Just started happening around 1750 miles. Never a problem before then. Let me know if you get any further clues from your dealer or elsewhere.
Dang. Now it seems to happen everytime that I ride my bike (2400 miles on it now). I still haven't hit the front calipers / discs with brake cleaner yet, so I'll try that next. I went for a 15 mile ride tonight through the country, and it was vibrating on about one out of every three stops. Quite annoying. It was only happening when I was just about stopped, and didn't matter if I was on level, uphill or downhill. It vibrates badly enought to make the windshield rattle. If I can keep duplicating this, I may also contact the dealer.
 

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Me too. Yesterday at only 30 MPH and fairly moderate straight braking. It appears to be resonating which means that there is something loose and undamped. It does not seem to me that it is the same as the groaning you can get from car brakes, but more like the whole fork is vibrating. Can't wait to hear about the cause, and the fix.
 

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I'm another person you can add to this list. It has only happened to me once, but it was so weird... and I remember someone on here talking about it before. I will be awaiting some kind of solution, I was only going about 20 at the time, and it didn't to it again since... some 150 miles ago...
 

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happened to me too, though not as violently as the first time. It seems to happen in the beginning of a ride, when you get on the brakes pretty hard...
 

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More data points

IronChefCJP said:
happened to me too, though not as violently as the first time. It seems to happen in the beginning of a ride, when you get on the brakes pretty hard...
I went out for a 60 mile ride last night and it was happening all of the time. I started looking at the speedometer when it was happening, most of the times is started at about 17mph, and a couple of times it started at 20mph and 21mph. Odd stuff. I suppose that I should look to see if any bolts are loose.
 

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Our bikes are made with alot of cost saving parts. Heance why they were $6K. Not the price of the R6 or even better R1.
 

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jrevans said:
I went out for a 60 mile ride last night and it was happening all of the time. I started looking at the speedometer when it was happening, most of the times is started at about 17mph, and a couple of times it started at 20mph and 21mph. Odd stuff. I suppose that I should look to see if any bolts are loose.
I know that I questioned this at one time, but I have to agree that it is some kind of consistent problem. I have been reading everyone’s comments, and decided to inspect my bike to see if I could find anything unusual (and I still have NOT had this problem).

First stop was the front brakes. Checked torque on fasteners as I went along, nothing loose. Correct brake fluid level. Removed all pads, measured thickness and inspected, no problems. Removed each caliper slide pin, no rust, adequate grease present. All of the guides and spacers were in place. No air in brake lines. Disc carriers bolts are all there and torqued correctly. No disc warpage. I feel confident that my brakes are safe and working properly.

I looked at the front suspension next. It does seem that that they compress too easily, so I did some measuring. With the bike on the center stand I placed 2 Ty-Rap’s around the fork tubes. Just sitting on the bike (210 lbs.) compressed the forks 1 ¾”. I then left them in place for 10 days and went about my normal riding routine. After this time, with no panic stops (and avoiding the triple jumps!) the forks had traveled a maximum of 4 ½”. The repair manual gives a maximum available travel of 5.12”. I feel that this is not as it should be, and that the fork springs might be losing their preload rate, causing erratic compression and/or rebound force. I wish that I had measured this when it was new, but maybe one of the new owners here can make a quick measurement of their forks using a similar method to mine.

Back in this post , ozfz6nguy said that his bike handled great after replacing the front fork springs. If you ask me, I would say that that is most likely the cause and that fresh oil and new springs are in order. However, I am going to install an air pressure setup on my existing suspension, and see if a minor amount of compressed air stops the diving. I will take pictures and keep a running parts list to let everyone know how it turns out.

Keep up the discussion, everyone.
John
PS- Yes, I admit that I can learn something new, too…
 

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WD40 may have done the trick!

Kneedragger said:
I may try the WD40 they suggested. But perhaps new springs are the real answer.
I liked that sound of their reasoning, and when I looked at my rotors today, sure enough, the floaters were slightly rusty. I carefully applied a small amount of WD40 to each floater on both discs then when for a 15 miles ride. No shaking what so ever. I didn't ride it too far, but it was doing it very frequently before. Hopefully that is the solution that we're looking for. :)

Thanks for pointing out that thread, and I recommend others try the WD40 trick.
 

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Keep tires properly inflated!

One more factor I'll add to this problem -- underinflated tires. Before applying WD-40, I first checked my tire pressure and found it was 4 lbs short in each wheel! So I decided to try a little experiment and just pump the tires; no WD-40. Proper pressure restored and 25 miles later, the bad shaking is completely GONE. I did get a tiny shake on one stop but nothing like what it used to be. So, keep those pumped up (33/36). Now for some WD-40...
 

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Update to front suspension mods


Back in September I had every intention of installing an air setup for front preload adjustment. However, I got a great price ($100) on a pair of RaceTech springs, part # FRSP S362795. I fabricated the spacers @ 8.875 long, giving me 3/4”-7/8” static fork sag. I did not change the oil type or volume.

Since doing this about 3 weeks ago, I have not had the radical diving during normal braking that was common before, and the steering feels very tight in the turns. I am happy with this mod, and recommend it to all. Just be sure to select the correct spring rate for your weight and riding style.

John
 

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I had to re-WD40 my rotor floater buttons

Two nights ago, I went for a ride and wouldn't you know it, but I was getting the "shaking while braking" effect again.

So, to prove to myself that the WD40 did the trick last time, I squirted the floater buttons again and *poof*, the shaking is gone.

I wiped up the excess WD40 and let it sit for a while, then cleaned the rotors up with brake cleaner.

Brake cleaner if your friend. :)

(plus it does an awesome job of taking chain lub off of the rear wheel. Just try not to get too much on your tire.)
 

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Moldmaker said:

Back in September I had every intention of installing an air setup for front preload adjustment. However, I got a great price ($100) on a pair of RaceTech springs, part # FRSP S362795. I fabricated the spacers @ 8.875 long, giving me 3/4”-7/8” static fork sag. I did not change the oil type or volume.

John, why did you make new spacers? How long are the stock ones? I figured the springs would be made to a length to work with the stock spacers. What is your weight? I'm 190# and the site said to go with 0.917kg springs. Would you go with 90 or 95? Also, the stock oil is 5W (US 01), & Racetech suggests 15W.

I'm not doing the change yet, as I'm still waiting to see if Yamaha bellies up to the bar. Tech Support has said that the stock spring rate (.80) is to soft. They haven't answered the question of what to do about it.
 

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dalebowgren said:
John, why did you make new spacers? How long are the stock ones? I figured the springs would be made to a length to work with the stock spacers. What is your weight? I'm 190# and the site said to go with 0.917kg springs. Would you go with 90 or 95? Also, the stock oil is 5W (US 01), & Racetech suggests 15W.
New spacers are required as the RaceTech spring length is about 3.625" shorter than stock. With my weight about 215#, I went with the .95kg rate. I purposely kept the oil level and viscosity unchanged to see how the preload rate was for me before I fine tuned the rebound characteristics.

I am going to make another set of spacers .250” shorter and try them before I settle on the final preload value. The bike is just a bit firm around town and over concrete expansion joints on the freeway. I will update when I’m finished.
 

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Has Yamaha been any help?

Curious what your dealer / Yamaha has said about this problem. My dealer originally reported that the Yamaha tech said to adjust the preload, as it's too soft from the factory. When I asked how he intended to do that, the dealer said he wasn't very familiar with this bike. Talking to customer service multiple times finally got them to agree to send their service rep out to look at the problem. They didn't appreciate it when I told them that their service rep must be living in a cave, if he didn't know about this problem. I'm not an engineer but I read on one of the threads an analysis, that suspension is the likely culprit. Anything you do to the brakes will temporarily stop the problem. Sanding, WD40, differently braking style, different rider weight are all temporary fixes that change the frequency of braking occillations that the suspension must absorb. I'm now of the opinion that John is on the right track. However, I don't see why Yamaha hasn't come up with a fix. Further, since all the American bikes sold are still under warrantee, I don't see why we should have to pay a dime to fix this problem.
Customer service went so far as to say that it is not a problem and therefore there is no fix! Maybe they are just hoping that we all would rather ride than have the bike in the shop for ever while they figure out the least costly method to fix it. $250 for race tech set up isn't going to break me but now I'm angry. I intend to get Yamaha to fix the problem, at their expense, even if it's at my inconvenience.
 

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FZ 6 Shaking Under Brakes

I have purchased a FZ 6 N in Australia and it seeems to have the same problem. I am heading down the same path and trying to get the dealer to fix this problem. So if anyone get any results from Yamaha please advise. :)
 

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Hi guys, wow this is somewhat dissappointing news...I am kind of anal about my bike and knowing that it has such defect on the brakes/suspension makes me ponder. Needless to say that for the price of the bike we get a great deal but still don't like to play with ANY type of brake or suspension issues. My bike has 1650 miles and I am paranoid that this will happen. If it does and Yami does not respond I will be exchanging it for something else. It hurts but what can I do?

Your opinions will ge greatly appreciated it and by the way if you had the money would you exchange your bike for a R6 or a FZ1?

Let me know...

Have a great night/day/week and ride safe!!!
 

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I guess I'm one of the lucky ones. My 04 FZ6 has just under 27,000 miles on it now and I haven't had any of the brake shaking problems yet. My front end is getting rather soft however. I love my bike enough that I'm going to fix the problem with the R6 fork/brake mod, but I'm wondering if any of you have checked the steering head/bearings for any looseness. My friend's bike (not an FZ6) was suffering this type of shuddering under braking and when I put his bike on the center stand and had him sit on the passenger seat to lift the front wheel, I was able to grab the bottom of the forks and wiggle the whole assembly slightly. After removing, greasing, and reassembling the steering head bearings the problem is gone. Just a thought. It would be nice if Yamaha would take some responsibility and redo our forks under warranty. The fork springs are seriously soft from the factory.
 
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