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Discussion Starter · #1 ·
My 2003 R6 fork has some weird looseness that is felt when braking. It is very noticeable when sitting on the bike, walking it forwards and applying the brake a little now and then - tapping the brake.

I know it sounds like the steering head bearings are loose, but, when I have the bike on the stand, the fork is rock solid - no play at all. The two locking spanner nuts underneath the triple three are also nice & tight.

It feels like it's from within the fork, as if the looseness comes from some play inside the fork tubes.

Please advice!
 

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Stunt Rider
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^this.
 

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"The Dude abides .. "
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missed the part where he said he has floating rotors.. does he have floating rotors ? I have never seen an R6 stock rotor with buttons that would move, even with a lot of miles..

as rc51 said, ya can't check steering head play with the bike on a front stand. Need to somehow support the bike from further back with no weight on the forks/steering head.

you do not want the steering heat overly tight.

that said, with the forks fully extended, there will be a tad bit of play from inside the forks. Excessive play means the bushings are worn, but even new, there will be some.
 

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Make good choices.
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How's the weather at your place?
Just lovely, thanks.

missed the part where he said he has floating rotors.. does he have floating rotors ? I have never seen an R6 stock rotor with buttons that would move, even with a lot of miles..
Don't they all have floating rotors? All the stock rotors look like this: picture
 

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"The Dude abides .. "
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Just lovely, thanks.



Don't they all have floating rotors? All the stock rotors look like this: picture
floating rotors allow the ring disk to have free movement, independent of the rotor carrier. You can literally wiggle the ring on the carrier from side to side.. Braking makes a rotor like this and possibly others, Brembo and EBC rotors are typically "semi-Floating" rotors.. There is a spring washer located on every rotor button, that keeps the ring from rattling back and forth freely, but will allow the ring to self-center on the button when needed..

on brembo rotors ($680+ a pair) and likely other brands, you can remove the snap ring on the back side of each rotor button, and remove the spring washer. This converts the rotor to a fully floating rotor.. they literally "jingle" around the pits when riding at a slow pace.. most leave the spring washers in place. Having snap rings allows you to replace the ring or carrier, instead of buying an entire rotor/carrier assembly if needed.

Stock r6 (or honda, suzuki or R1) rotors are not floating, or semi-floating rotors. The carrier and ring are secure, you can't move em. GIve it a try on your bike by pushing on the ring.. it won't give. A fully floating or semi-floater will allow the ring to give some if you push on it from the side.
The buttons are simply a method of attaching a rotor carrier, to the disk. The buttons are pressed on. SOME people dremel the washer out from the stock button, and this converts the rotor to a floating rotor.. but very very few people bother with this. (i honestly can't remember the last time i saw that in fact..) The current 310mm OEM r6 rotors are darn good.
 

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I eat what my R6 cooks!
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missed the part where he said he has floating rotors.. does he have floating rotors ? I have never seen an R6 stock rotor with buttons that would move, even with a lot of miles..

as rc51 said, ya can't check steering head play with the bike on a front stand. Need to somehow support the bike from further back with no weight on the forks/steering head.
I picked up a motorcycle/atv lift from sears and just slide it under the headers. I raised the back end up with my rear stand, and then just jacked the bike up by the headers. It worked perfectly.

Link to the lift I used:
http://www.sears.com/craftsman-moto...1x000001&kpid=00950190000&kispla=00950190000P


edit: Only other thing I could think of it being is if your fork seals were blown out a long time ago and you have rode it until there is almost no oil in there and the forks are just sticking when they are compressed. I would really lean towards your steering head bearings, though.
 

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Discussion Starter · #13 · (Edited)
Hi people - thank you for your quick replies!

OK, I'm danish, so my english can be a bit off now and then. When I said on a stand I actually ment, lifting up the front. So I have had the front off the ground with no weight on it. That's why I'm so sure that the bearings are fine. They are also only about a year old (special bearings bought from allballsracing.com)

I took the fork legs apart, looking for the cause, but other than a bit too little oil, my un-trained eye didn't find anything.

Also, I should have mentioned that the fork is mounted on an old 1977 Honda. On top of this, the rotors are from a 1996 Honda CBR 600. Here's a link to the whole build (lotsa photos) and here a quick photo of the set-up:



LOOSE ROTORS
I will check up on the loose rotor theory.

BUSHINGS
Worn bushings sounds like a likely cause of the looseness. Which bushings are they? Are they featured on this:



(Taken from here: http://www.cmsnl.com/yamaha-yzf-r6rrc-2003_model11251/partslist/ - looks like that's the one I have)

Thanks again for all your replies and help :)
 

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Meh
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I have no idea about your fork problem, but your mutant Honda looks awesome! And you're English is excellent. Way better than any of our Danish, I'm sure.
 

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"The Dude abides .. "
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Huh, I always thought those buttons allowed the rotor to move side to side.
go try pushing on the ring of an oem rotor, or any rotor without a spring washer on the back side. It wont' move at all on the carrier.
 

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"The Dude abides .. "
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and just to reiterate.. even brand new forks will have a little movement when when the forks are fully extended, and you pull on the bottoms when the bike suspended on a front stand (by the lower triple, not by the bottom of the fork tubes).
Don't rush out to buy a bunch of new bushings if you find this the case.. Next time you have the forks serviced, as your tech to look at the bushing surfaces. Or if you are a DIY kinda person, inspect them on the next fork service.
 

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nom nom nom nom nom nom
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An easy way to see if it is the rotors (or anything else on the brake system) is to put the front end up against a wall and push the bike into it with the bars. See if you get the same feeling when it is the wheel pushing back vs being stopped by the brakes.


One thing to remember though: There are a couple different places where there will be some, very minimal normal play. When you add all the little bits of play together, it will seem like a lot. The steering head bearings will have play at the top and bottom. The forks will have play in both top and bottom bushings. The bearings will have play between the inner and outer races. The brake rotors will have play between the carriers/buttons/discs. The pads will have a little bit of play in the calipers.

Lots of very very little stuff by itself. Also remember that when you have 0.05mm of play at the steering head, the movement at the axle three feet away will of course be much greater.


Another thing to consider: When the bike is on the ground, all the weight of the bike is pushing the front wheel forward, when you hit the brakes, the wheel is getting pushed back (both relative to the bike itself). You are jumping from one end to the other in terms of the play in the forks and steering head. Another reason why it is so noticeable.
 

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Make good choices.
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go try pushing on the ring of an oem rotor, or any rotor without a spring washer on the back side. It wont' move at all on the carrier.
Oh yeah...I did this...you were right.

Clearly they are designed to just look like floating rotors sitting on the showroom floor and I fell for it hook, line, and sinker.
 

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Reads the rulez
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That bike is awesome. I want it!!!
 
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