warped discs (and other things).. options for replacing

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fatfreddy000
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warped discs (and other things).. options for replacing

Post by fatfreddy000 »

just took my bike in to get the front wheel puncture sorted (full pressure to totally flat= 15 hours ish)
turns out its coming from the bead. could be just shitty old paint or contamination but theres a few dings in the rim too and the tyre's a bit old and has a gash in the side (somehow i brought it with a new MOT!) so looking for a cheap front wheel now and will get a new tyre to go on it and bearings i guess..
while it was there they noticed at least one of the discs was warped so also looking for cheapest decent pair of discs i can find.
are the Chinese eBay ones really shite or any good at all?
otherwise i shall be going second hand as my wallet is rapidly emptying (as expected) on putting right a catalogue of horrors..
if anybody has a wheel with discs in good condition possibly with a tyre on or just a wheel or discs let me know if the price is right. I'm eager to get this all sorted promptly..
in addition I've gotta do the headset bearings and maybe new fork springs..
whole front end needs sorting really..
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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fabiostar
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Re: warped discs (and other things).. options for replacing

Post by fabiostar »

iv used chinese discs on my previous bike and i had no problems with them. they used to be proper shite but the quality seems to have got much better of late.
the older i get,the faster i was :lol:

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Cadbury64
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Re: warped discs (and other things).. options for replacing

Post by Cadbury64 »

In my own experience a buckled disc is usually caused by a bend in the aluminium carrier, not the disc itself. If that is the case, then you may have some success gently prying the carrier (not the disc!) in or out to correct it. I've done this myself on my VFR800, using a dial indicator gauge and a pry bar, and got 99% of the buckle out. I suspect most warped discs are caused by an impact to the disc e.g. during wheel removal or tyre changing, rather than caused through use.

Of course if the discs are worn, then replacement is the correct option.
1997 VTR1000F, 2009 ST1300, 2001 FJS600

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fatfreddy000
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Re: warped discs (and other things).. options for replacing

Post by fatfreddy000 »

Cadbury64 wrote:In my own experience a buckled disc is usually caused by a bend in the aluminium carrier, not the disc itself. If that is the case, then you may have some success gently prying the carrier (not the disc!) in or out to correct it. I've done this myself on my VFR800, using a dial indicator gauge and a pry bar, and got 99% of the buckle out. I suspect most warped discs are caused by an impact to the disc e.g. during wheel removal or tyre changing, rather than caused through use.

Of course if the discs are worn, then replacement is the correct option.
i will check the thickness with my calipers in the morn.
if they are well ver 3.5mm i will give that a go, thanks,
in the mean time I've been researching and found some good cross ref info on here.
seems that cbr900rr fireblade discs will fit from mid- late 90's bikes.
I've sourced a couple of pairs on eBay from this model and 1 pair from a vtr1000 all around £80 delivered.
I'm just waiting on the sellers to respond confirmation of them running true and their remaining thickness and then if i can't sort more i'll close the best.
thanks..
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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fatfreddy000
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Re: warped discs (and other things).. options for replacing

Post by fatfreddy000 »

fatfreddy000 wrote:
Cadbury64 wrote:In my own experience a buckled disc is usually caused by a bend in the aluminium carrier, not the disc itself. If that is the case, then you may have some success gently prying the carrier (not the disc!) in or out to correct it. I've done this myself on my VFR800, using a dial indicator gauge and a pry bar, and got 99% of the buckle out. I suspect most warped discs are caused by an impact to the disc e.g. during wheel removal or tyre changing, rather than caused through use.

Of course if the discs are worn, then replacement is the correct option.
i will check the thickness with my calipers in the morn.
if they are well ver 3.5mm i will give that a go, thanks,
in the mean time I've been researching and found some good cross ref info on here.
seems that cbr900rr fireblade discs will fit from mid- late 90's bikes.
I've sourced a couple of pairs on eBay from this model and 1 pair from a vtr1000 all around £80 delivered.
I'm just waiting on the sellers to respond confirmation of them running true and their remaining thickness and then if i can't sort more i'll close the best.
thanks..
just popped out and checked and both rotors are about 4.15mm so within limits.
thats got me wondering if i should replace them..
i can't actually see any distortion while spinning the wheel and watching the space between the rotor and the fork leg but the garage i went too assured me they were warped on some grounds- maybe the brakes were binding for part off the wheels rotation..
i will need to get them off for further inspection, and to change the knackered leaking tyre anyway but I'm waiting on a pair of paddock stands to be delivered from abroad at present so i guess shell just be off the road for a bit :thumbdown:
at lease ill have more of a chance to crack on with my epic list of jobs to do :thumbup:
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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fatfreddy000
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Re: warped discs (and other things).. options for replacing

Post by fatfreddy000 »

fatfreddy000 wrote:
Cadbury64 wrote:In my own experience a buckled disc is usually caused by a bend in the aluminium carrier, not the disc itself. If that is the case, then you may have some success gently prying the carrier (not the disc!) in or out to correct it. I've done this myself on my VFR800, using a dial indicator gauge and a pry bar, and got 99% of the buckle out. I suspect most warped discs are caused by an impact to the disc e.g. during wheel removal or tyre changing, rather than caused through use.

Of course if the discs are worn, then replacement is the correct option.
i will check the thickness with my calipers in the morn.
if they are well ver 3.5mm i will give that a go, thanks,
in the mean time I've been researching and found some good cross ref info on here.
seems that cbr900rr fireblade discs will fit from mid- late 90's bikes.
I've sourced a couple of pairs on eBay from this model and 1 pair from a vtr1000 all around £80 delivered.
I'm just waiting on the sellers to respond confirmation of them running true and their remaining thickness and then if i can't sort mine out i'll close the best set.
thanks..
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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fatfreddy000
Posts: 186
Joined: Thu May 04, 2017 6:02 pm

Re: warped discs (and other things).. options for replacing

Post by fatfreddy000 »

fatfreddy000 wrote:
fatfreddy000 wrote:
Cadbury64 wrote:In my own experience a buckled disc is usually caused by a bend in the aluminium carrier, not the disc itself. If that is the case, then you may have some success gently prying the carrier (not the disc!) in or out to correct it. I've done this myself on my VFR800, using a dial indicator gauge and a pry bar, and got 99% of the buckle out. I suspect most warped discs are caused by an impact to the disc e.g. during wheel removal or tyre changing, rather than caused through use.

Of course if the discs are worn, then replacement is the correct option.
i will check the thickness with my calipers in the morn.
if they are well ver 3.5mm i will give that a go, thanks,
in the mean time I've been researching and found some good cross ref info on here.
seems that cbr900rr fireblade discs will fit from mid- late 90's bikes.
I've sourced a couple of pairs on eBay from this model and 1 pair from a vtr1000 all around £80 delivered.
I'm just waiting on the sellers to respond confirmation of them running true and their remaining thickness and then if i can't sort mine out i'll choose the best set.
thanks..
just popped out and checked and both rotors are about 4.15mm so within limits.
thats got me wondering if i should replace them..
i can't actually see any distortion while spinning the wheel and watching the space between the rotor and the fork leg but the garage i went too assured me they were warped on some grounds- maybe the brakes were binding for part off the wheels rotation..
i will need to get them off for further inspection, and to change the knackered leaking tyre anyway but I'm waiting on a pair of paddock stands to be delivered from abroad at present so i guess shell just be off the road for a bit :thumbdown:
at lease ill have more of a chance to crack on with my epic list of jobs to do :thumbup:
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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Wicky
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Re: warped discs (and other things).. options for replacing

Post by Wicky »

Try working on the brake disc bobbins in case they've got seized.

https://www.youtube.com/watch?v=1qoPqN2GBdw

As brakes on a 150mph bike are quite important it might be worth considering refurbishing calipers, cleaning any corrosion in seal grooves, new dust and fluid seals, cleaning / polishing up / replacing the pistons, replacing old hoses with braided hoses and new fluid.
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fatfreddy000
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Re: warped discs (and other things).. options for replacing

Post by fatfreddy000 »

Wicky wrote:Try working on the brake disc bobbins in case they've got seized.

https://www.youtube.com/watch?v=1qoPqN2GBdw

As brakes on a 150mph bike are quite important it might be worth considering refurbishing calipers, cleaning any corrosion in seal grooves, new dust and fluid seals, cleaning / polishing up / replacing the pistons, replacing old hoses with braided hoses and new fluid.
i agree, rear brake certainly need refurbishing with seals and fluid at least maybe a piston too
front and rear brakes have newish good ridge braided hoses and fronts seem to be working well but i will change fluid and give them a thorough look over as a minimum.
once the wheels off i will check the rotors and carriers for signs of distortion.
the bobbins have no movement- how much play should there be?
“If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish.” Biologist Jonas Salk

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Cadbury64
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Re: warped discs (and other things).. options for replacing

Post by Cadbury64 »

There won't be much freeplay but the bobbins do need to be free to spin in place. Fit a suitable nut bolt and washers through the bobbin and snug up, then you should be able to rotate the bobbin with a spanner. Squirt a bit of brake cleaner at it to flush the crud out and free it up.

I'd also suggest cleaning the disc surface with a Scotchbrite pad to remove any old pad material or corrosion.
1997 VTR1000F, 2009 ST1300, 2001 FJS600

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