front end shakes under heavy braking

[fazer.rider]

the shakes aren't severe. in fact it's very subtle but just wondering what's causing it and if it's normal. regular braking there's no shake. it shook when i had to slow from 40mph to 0 in 3+ seconds.

 

[Fz6Sa]

I'm thinking of the discs, - if your brake discs are are not perfectly flat, - you will experience some shaking.
Or if your break calibres don't break evenly I guess the symptom would be shaky as well.

Check the discs and the break pads, - if they seems OK, - check for air in the break system/fluid.

 

[oso2k]

the shakes aren't severe. in fact it's very subtle but just wondering what's causing it and if it's normal. regular braking there's no shake. it shook when i had to slow from 40mph to 0 in 3+ seconds.

I've noticed a similar sensation on the my 05 FZ6 both when I had the OEM forks and now that I have the R6 forks. Some have suggested this sensation is related to the steering stem ball bearings.

 

[YamaSpeed]

I have had this happen to me as well. I think that the calipers just need to be cleaned and greased (dust build up). I am not sure of this. But I will be pulling my brakes soon to service them. when I do I will grease them up with anti-seize.

 

[SovietRobot]

Honestly, under heavy braking, anything can cause the shake.

Warped rotors, unevenly worn pads, calipers, air in the system, tire balance, wheel bearings, head bearings, a loose pinch bolt, etc.

 

[dako81]

How much do you weigh? Could be some sort of death wobble from the front end compressing changing the rake angle or whatever.

 

[abacall]

I vote for a loose steering head. Either bearings need to be replaced (common issue here) or something is just loose.

 

[CravenMoorhead]

There have been some posts on this product that may be helpful to the poster:

Yamaha FZ6 2004-2007, Yamaha - SuperBrace - The Ultimate Fork Stabilizer

 

[bmccrary]

100 bucks says its your lower tripple tree has lossened up.

Pull the bars off, remove the large chrome nut and pull the upper tree. Then take a spanner wrench and tighten up the nuts that pull the lower tree into the frame. While your at it, go ahead and pull the lower tree out. Clean and re-grease the bearings if needed.

-bryan

 

[fazer.rider]

i jammed on the brake again, to a point where the rear tire fishtailed a bit. weird, i didn't feel the shakes this time.

 

[wrightme43]

Are the floater pins on your rotors corroded up or dirty?
Have you recently cleaned and degreased with brake clean both rotors?

Sometimes pulsation is caused by a uneven or unequal layer of brake pad material attached to the rotor.

It could be any of the things above, I just wanted to toss another option into the mix.

Steve

 

[jrevans]

Are the floater pins on your rotors corroded up or dirty?
Have you recently cleaned and degreased with brake clean both rotors?

Sometimes pulsation is caused by a uneven or unequal layer of brake pad material attached to the rotor.

It could be any of the things above, I just wanted to toss another option into the mix.

Steve

Dirty floater pins on the rotors were the cause for me. I did a back to back test: Had the shaking happen half a mile from home. Cleaned the floaters with brake cleaner and put a tiny drop of WD40 on the floaters, went back out and the shaking was gone.

Here's a link on the other forum:
Freaky jitter in front brakes - Page 2 - Sportbikes.net

 

[leetaylor742]

100 bucks says its your lower tripple tree has lossened up.

Pull the bars off, remove the large chrome nut and pull the upper tree. Then take a spanner wrench and tighten up the nuts that pull the lower tree into the frame. While your at it, go ahead and pull the lower tree out. Clean and re-grease the bearings if needed.

-bryan

Hello from the UK...

Sorry to dig up an old post but I wondered if anyone could expand on tightening lower tree on FZ6?

I have been searching archives to work out what is causing slight clonk through bars when pulling up sharp (I dont really feel until quite slow and release the brake a little)

I have had head bearings replaced as I thought it was them with tapered type (within last 2k) and are pretty confident that its not them and fork oil replaced with 15w around same time.

It definately feels like its around the area of the head bearings/lower tree so when I saw this post I thought this would be worth a try... is it as simple as it sounds in this post - pull bars, remove large nut and pull of the top yoke? do I need special tools to tighten these bolts? I'm not scared to pull apart but would rather only do it once so if I need something specific then i'll sort that first?

Anyone have any other ideas if it isnt this?

Cheers

Lee

 

[leetaylor742]

No ideas?

Lee

 

[TownsendsFJR1300]

Hello from the UK...

Sorry to dig up an old post but I wondered if anyone could expand on tightening lower tree on FZ6?

I have been searching archives to work out what is causing slight clonk through bars when pulling up sharp (I dont really feel until quite slow and release the brake a little)

I have had head bearings replaced as I thought it was them with tapered type (within last 2k) and are pretty confident that its not them and fork oil replaced with 15w around same time.

It definately feels like its around the area of the head bearings/lower tree so when I saw this post I thought this would be worth a try... is it as simple as it sounds in this post - pull bars, remove large nut and pull of the top yoke? do I need special tools to tighten these bolts? I'm not scared to pull apart but would rather only do it once so if I need something specific then i'll sort that first?

Anyone have any other ideas if it isnt this?

Cheers

Lee

I would put the bike in the center stand and get the ft end up in the air (sizzor jack, etc under the header). Pull/push the forks/front tire checking for ANY FREE PLAY. You also want to check for smoothness when turning from lock to lock. Any roughness, I'd pull the entire triple tree out as the bike is known to get water in there and rust as yamaha was cheap with the grease when assembling.

If there is play, depending on the mileage you can either do a full service (R&R the triple tree, re-grease, if worn out, replace the head bearings).

If it just needs an adjustment, slightly loose, yes, pull the top yoke.

I believe their a lock washer(with a tab). Remove that and tighten the large nut a very small amount as it doesn't take much to wear down/loosen up. Re-check for slop/looseness (especially after re-tightening the top triple).
Re-assemble.

Good luck