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R6 trackbike Caliper in contact with disk


fastfox

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Hi peeps.

Got abit of problem with my 01 R6 trackbike.

Ive noticed that one of the front caliper housings has been in contact with the brake disc.

See pic

DSCF2941.jpg

I dont how or whay this is happening. I`m wondering if the right hand fork tube is bent (right hand as you sit on the bike)

I brought the bike as a trackbike and i know its been a track bike for most of its life.

The only thing i can think of its some how bent, when ive strapped its down to my bike trailer.

Ive also noticed that the Flanged end of the axel comes all the way though the fork tube and pushes the spacer away from the fork leg.

See pic

spacergapwithrimfitted.jpg

spacerfitted.jpg

Anyone know of any ideas to over come this problem.

The disc is only just in contact with the caliper. Do you think it would be safe to simply use spacers between the back side of the disc and the wheel hub?

Cant really afford new fork tubes.

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Is the fork damaged where the spindle slides through?

I can't see a bent fork causing that unless it really fucked. It would have to be bent between the caliper mounts and spindle hole. Unlikely.

I'm just trying to understand how the spindle pulls through the fork lower.

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Is the fork damaged where the spindle slides through?

I can't see a bent fork causing that unless it really fucked. It would have to be bent between the caliper mounts and spindle hole. Unlikely.

I'm just trying to understand how the spindle pulls through the fork lower.

Nah. no damage visible. wondering if ive somehow twisted something when ive ratcheted the bike down to the trailer.

The spindle pulls all the way though cos there is nout stopping it. My mates R6 is the same set up.

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This might be a daft answer, but here goes.... Are the pistons in the caliper moving freely? If one side have seized, then could the other pistons be pushing the disc over when the brakes are applied?

Hi bud. Nope its not a daft answer. Its the first thing i thought myself.

All pistons moving fine plus the calipers are monoblock and dont slide. Even if i put the caliper in with no pads and with the pistons pushed all the way back, there would still be contact.

Rightly or wrongly, ive now used split washers between the face of the hub and the underside of the disc which now centralises the disc in the caliper.

What i did notice when i took the disc off the hub was that two of the bolts were different sizes. (never had the discs off before) Closer inspection of the holes shows that there has been damage from cross threading and it looks like a helicoil has been used to repair the threads. I`m wondering if the face on the bub have been taken back or machined so that the helicoil bites new thread into virgin metal.

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yeah point taken, but i took the view that if the brake binds against the caliper it would have pretty much the same out come.

Ive just spring washers. The ones with the off set split so that when you screw down against them, they in turn push back against the bolt. Ive also ensured that there is plenty of shank/ flange going though the disc holes.

Ive also used a toque wrench to make sure ive achieved the correct tightness.

What do you think?

The washers them selfs are about mil thick at most.

Just gives me the clearence.

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Sounds like the wheel then, so eskip for a replacement. As said above, it's just not worth risking it with brakes.

Unless your superman using lorry straps, you've not done it securing it in a van.

Thats a shit way to hold the spindle in place...make sure the pinch bolts are in and tight!

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Hmmm

1) I'd be worrying about the washer route to clearance the way you have done it. If no other solution can be found, put two plain ground washers between the caliper and leg. Use plenty of loctite. It is however a 'bodge' route to free running, and I'd strongly advise some more investigations - the problem is probably quite simple.

2) are they R6 blue spots? Lore says all these things 'bolt straight in' can casting marks be checked to double check they are the correct ones for the model. A differnce in casting/machining sizes could cause this.

3) check you have the correct wheel spacers, from the right year, installed in the right side. I suspect this is the reason. Just possible one has been swapped inadvertantly in the bikes many tyre changes.

4) check its got the right wheel bearings, and they are correctly seated. This is another cause, due to incorrect assembly. Possible, and easy/cheap to check.

5) check in has the correct bearing inner support tube between the bearings, one too long could cause this.

6) Failing this, some material could have been removed from the caliper bosses on the inside. Can't see a reason for this, even if they have been helicoiled etc.

7) silly/unlikely other reasons could be... legs swapped to wrong side then hacked about to fit (very unlikely) two legs off the same side (also v unlikely). Wrong spindle. Bent yoke is possible, bent leg less so.

Does the clearance problem occur on both calipers or only the one side?

If the above reveals nothing the bike should be condemned. Send it to me, I will look after it ;)

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Hmmm

1) I'd be worrying about the washer route to clearance the way you have done it. If no other solution can be found, put two plain ground washers between the caliper and leg. Use plenty of loctite. It is however a 'bodge' route to free running, and I'd strongly advise some more investigations - the problem is probably quite simple.

2) are they R6 blue spots? Lore says all these things 'bolt straight in' can casting marks be checked to double check they are the correct ones for the model. A differnce in casting/machining sizes could cause this.

3) check you have the correct wheel spacers, from the right year, installed in the right side. I suspect this is the reason. Just possible one has been swapped inadvertantly in the bikes many tyre changes.

4) check its got the right wheel bearings, and they are correctly seated. This is another cause, due to incorrect assembly. Possible, and easy/cheap to check.

5) check in has the correct bearing inner support tube between the bearings, one too long could cause this.

6) Failing this, some material could have been removed from the caliper bosses on the inside. Can't see a reason for this, even if they have been helicoiled etc.

7) silly/unlikely other reasons could be... legs swapped to wrong side then hacked about to fit (very unlikely) two legs off the same side (also v unlikely). Wrong spindle. Bent yoke is possible, bent leg less so.

Does the clearance problem occur on both calipers or only the one side?

If the above reveals nothing the bike should be condemned. Send it to me, I will look after it :thumbsup:

yeah, bollox to it. you can have the bike :-)

Yes the problem is only on the one caliper. They are blue spots and the correct caliper for this bike (all years 99-02 are the same). Ive had a few R6`s over the years. The spindle is correct. (there also the same from 99-02)

Its really weird because everything looks strait and true. Also i have a wet rim with discs and have the same problem.

I have already ordered a secound set of spacers. (again the same for years 99-02) and they are all the same.

Its got to be the for hasn`t it?

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You could check the fork by taking both calipers off then measurin g the thickness of the bosses that mount the calipers. AQlso check the inside edges are as they should be, ie no metal removed.

Are the disks symetrical? If one was on back to front (eg post wheel change) could this cause it?

I'll be around next week with tthe van, you'll need topay me totake it away though... price of scrap... not work being in this game (sucks teeth)... :tumbleweed:

;)

If that doesn't work.... it must be a grey import sir :(

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You could check the fork by taking both calipers off then measurin g the thickness of the bosses that mount the calipers. AQlso check the inside edges are as they should be, ie no metal removed.

Are the disks symetrical? If one was on back to front (eg post wheel change) could this cause it?

I'll be around next week with tthe van, you'll need topay me totake it away though... price of scrap... not work being in this game (sucks teeth)... :tumbleweed:

:icon_blackeye:

If that doesn't work.... it must be a grey import sir :eusa_whistle:

Dude, if you have a hitch on ya car i`l though in the trailer and pay the fuel

Wiill check the fork bosses. you never know, although this is a new problem thats happened whilst ive had the machine. Possibly something ive fucked up.

If it is, i dont understand what ive done. I`m pretty good with the spaners. Dont get me wrong, i`l never work for GSE-airwaves, but i cant change wheels, brakes, chains, electrics and do must things bar 4 stroke engine work. Its bugging the arse out of me.

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I'm watching this with interest as I've a 94 cbr6 steelie with a full 95 front end on it and it has exactly the same issue with one of the caliper mounts where the disc rubs on the inside of the disc, the other lines up perfectly :lol:

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How are you bolting up the front wheel?

If you are doing things in the wrong order it is possible to pull one fork leg inwards.

You need to torque up the axle and clamps and then the calipers and then release the torque on the axle and apply the brakes a few times and bounce up and down on the front suspension to centre the wheel and then re-torque the axle and releas and re-torque the clamps.

On ohlins equipped Aprilia's and Ducati's it is possible to prevent the front wheel from spining freely by not doing this procedure, could be you've got something similar.....

+1

It's possible to wedge the forks on the bottom of their stroke on a 954 fireblade if you torque the axle up first before the fork clamps, as it nips the fork lowers inwards...

I nearly ended up in the carpark at Nutts Corner via a tyre wall learning this the hard way..

-John

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How are you bolting up the front wheel?

If you are doing things in the wrong order it is possible to pull one fork leg inwards.

You need to torque up the axle and clamps and then the calipers and then release the torque on the axle and apply the brakes a few times and bounce up and down on the front suspension to centre the wheel and then re-torque the axle and releas and re-torque the clamps.

On ohlins equipped Aprilia's and Ducati's it is possible to prevent the front wheel from spining freely by not doing this procedure, could be you've got something similar.....

Hi.

To be honest, ive not been doing that.

(feel abit of a twat now) Ive been putting in the wheel spindle and doing it up lightly to start. Ive then been putting in the calipers and toqueing them up

Ive then dropped the bike off the front paddock stand and then using a toque wrench to crack it up the rest of the way.

I then do up the single clamp.

Ive always done it this way on every bike ive had...

Do you think due to the ammount of rim changes ive tweeked the forks out?

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I too have always nipped up the spindle then the pinch bolts and then the caliper/or mounts up, and have never had any problems with alignment? :eusa_dance:

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I too have always nipped up the spindle then the pinch bolts and then the caliper/or mounts up, and have never had any problems with alignment? :eusa_whistle:

To be honest, i dont know how it can be done anyother way.

If i do up the pinch bolt before the axel then how can you even do up the axel??????The axel is being pinched.

plus with the axel flange being smooth with no lip on it, it would just pull though anyway

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fastfox - with respect can I suggest now might be a good idea to check the owners manual for your model (assuming you don't have one already, e-bay maybe?) or that £20 on a Haynes manual might be money well spent? I don't know much but I know brakes are one area where it's not worth messing about :)

For example the procedure for my RSV-R is a bit weird (basically what millemille has described above), but it's simple enough to follow the destructions in the Haynes manual every time and make sure everything is torqued up just right :wub:

Hope you get it sorted - cheers,

Matt ;)

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What torque should your front axle be tightend to?

off the top of my head 80nm. but thats off the top of my head

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fastfox - with respect can I suggest now might be a good idea to check the owners manual for your model (assuming you don't have one already, e-bay maybe?) or that £20 on a Haynes manual might be money well spent? I don't know much but I know brakes are one area where it's not worth messing about :D

For example the procedure for my RSV-R is a bit weird (basically what millemille has described above), but it's simple enough to follow the destructions in the Haynes manual every time and make sure everything is torqued up just right :thumbsup:

Hope you get it sorted - cheers,

Matt ;)

Got both a owners manual and a Haynes, dude. Owners doesn`t say anything about wheel removal and the Haynes doesn`t describe refitting the rim as described in this thread. Just says something along the lines of "refitting is the reversal of removing" :icon_salut:

But ya right in what you say. Haynes manuals are fecking ace

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If you loosen the pinch bolts in the yokes and on the wheel spindle ( with the bike supported , obviously ) and rotate the fork stanchion you will be able to see if the end of the fork moves in or out on the spindle , if it does then you have a bent fork

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off the top of my head 80nm. but thats off the top of my head

close, it's 72nm I think

I'm guessing your R6 should be similar procedure too, in fact the front wheels for the early R1 and R6's are interchangeable.

On the R1, the goes through the wheel from the RHS fork leg and screws into the LHS fork.

Tighten to correct torque, then tighten pinch bolt on RHS fork leg. Fit calipers and torque to 40n/m

I don't think you should be able to pull the non-threaded end of the spindle through the RHS fork leg like that.

Are you completely 100% sure you've got the correct spacers, in the right places?

edited to add:

this may help - think it is the correct vintage http://www.yzfr6.net/manual/R6_manual_chasis.pdf

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If you loosen the pinch bolts in the yokes and on the wheel spindle ( with the bike supported , obviously ) and rotate the fork stanchion you will be able to see if the end of the fork moves in or out on the spindle , if it does then you have a bent fork

Thanks. Will give this ago. Was thing of spinning the stanchion 180 degrees then if the problem moves to the otherside of the same cailper then i defo have a bent fork.

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close, it's 72nm I think

I'm guessing your R6 should be similar procedure too, in fact the front wheels for the early R1 and R6's are interchangeable.

On the R1, the goes through the wheel from the RHS fork leg and screws into the LHS fork.

Tighten to correct torque, then tighten pinch bolt on RHS fork leg. Fit calipers and torque to 40n/m

I don't think you should be able to pull the non-threaded end of the spindle through the RHS fork leg like that.

Are you completely 100% sure you've got the correct spacers, in the right places?

edited to add:

this may help - think it is the correct vintage http://www.yzfr6.net/manual/R6_manual_chasis.pdf

Thanks monkey.

Yes, i have the spacers in the right place.

I even brought some new ones in case the spacers wasn`t interchangeable across years (99-02) as i thought.

Ordered some for a 01 R6. They are the same. Ive even measured them with the vernier calipers and they are bob on the same (all but the width of a flys fore skin) All four spacers are the same.

Also, ive now fitted the wheel as per the instructions given in this thread. ...I still have a problem. I tried it a few times. I guess maybe doing it wrong over and over, i may of damaged it.

I`d also just like to add a big thanks to everyone who`s been helping me out on this one, so far!

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Right. Span the stanchion but it only made a small diffrence.

What i THINK is happening is the sliders are twisted due to a aftermarket mud guard (Fender if ya from the states).

Ive span the stanchions and adjusted the mudguard. Ive taken the spacers out from behind the disc and i seem to have clearance between the caliper and disc! Bonza!

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How on earth is a mudguard able to twist the fork legs?????

Its a very tight fit and it looks like its pushing the forks apart from where the mudguard mounts at the back.

I was suspious when i spotted that the disc seems of been in more cantact with the caliper at the leading edge than the trailing edge.

If i remove the guard, the caliper lines up with the disc

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Are you really suggesting that a plastic/fibreglass/carbon fibre mudguard is able to exert more force on the fork leg than the metal axle and metal fork leg clamped mecahnical joint can resist?

When you do up the clamp at the bottom of the fork leg that should make a solid mechincal joint between the axle and fork leg and rigidly orientate the axle cente line perpendicular to the caliper bracket face, there should be no conceivable way that this can be moved by the mudguard!

Think for a minute about what happens when you apply the front brake, the clamping force exerted by the calipers on the rotating discs will try and in turn to twist the fork legs inwards. This is stopped by the axle/fork leg mechanical joint.

If, on your bike, the mechanical joint is so poor as to be unable to resist the twisting exerted by the mudguard then what the hell is happening when you brake?

IMO you've got another problem there....

Ok, `spose you`ve got a point if ya put it like that.

All i know, where the mud guard mounts at the back of the fork slider, its tighter than a camels arse in a sand storm and pushes the two mounting points away from each other slightly rotating the sliders on the stanctions. This (appears at least to me) to inturn bring the caliper into contact with the disc.

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Ok.

Do a simple experiment.

Remove the front mudguard, remove the front wheel and calipers etc.

Clamp the front axle up in both the fork legs without fitting the front wheel. Don't worry about torquing the axle up, just spin it up and then clamp it with the clamps at the bottom of the fork legs.

Measure between the faces of the caliper mounts.

Fit the mudguard.

Re-measure the gap between the faces of the caliper mounts.

Did fitting the mudguard actually cause the caliper mounts to move, relative to each other?

If yes, then your fork slider/axle mechanical joint is fucked.

If no, then that's not your problem.

Right done this. Ya right. no change that i can detect with a tape.

Took the Axel out and rolled it over a mirror (smoothest surface i could find). There is a very slight (and i do mean slight) bend in the Axel. I recon less than a mill

Do ya think this could some how effect things? Its so slight though. Its on the threaded end which is the opposite side to the problem.

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I think you've just found your problem!!!!!!!

The straightness of the axle is essential in keeping the fork legs/calipers/discs in alignment.

If the axle is bent then the fork legs will be twisted in relation to each other and probably what is causing your problems (I suspect still combined with pulling the fork legs in toward each other with the order in which you tighten up the axle and clamps)

Get a new axle and see what happens then.

cheers will do

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