Ken 12r
Novice Class
Posts: 86
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posted August 30, 2011 01:18 PM
Zx12r Brake Discs.
After testing the Turbo 12 out to 219.1 mph at Elvington last week a new problem has presented itself.Stopping my bulk (250 lbs)from that speed before running out of track.
Current set up is Harrison billet 6 pot calipers which I think should be up to the job,clamping on stock discs.
I dont want wavy discs,had them did not like them and have seen several crack.
I would like brembos but they dont seem to be available anymore.
I will probably try the PFM iron rotors if they still make them and I can order a set.
Anybody else got any ideas ?? other than get back on the diet.
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www.uklandspeedracingassociation.co.uk
  
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Shane661
Needs a life
Posts: 11494
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posted August 30, 2011 01:34 PM
How much distance to stop?
How about the Galfer full floating Superbike rotors? Other than that, EBC makes some.
My Braking brand rotors turned all kinds of colors stopping from the low 180's at Maxton in just under 1/2 a mile, but did not warp. Still, I would probably choose something else to try next.
Shane
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shiphteey
Needs a job
Posts: 2529
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posted August 30, 2011 05:59 PM
Ken, I was able to get my 12 stopped from 188 mph in 3/10ths of a mile all OEM A1 stuff.
Switched to nissin calipers and was able to REPEAT the performance SEVERAL times back to back, no ther change besides the calipers and pads, not sure what pads are in em, not that great....don't brake much better but they don't DRAG like the shitty 6 piston tokicos after several high speed shutdowns. Braked firmly and backed off a split second, repeated procedure since I felt sorry for the brakes and didn't want to warp anything....not near locking up but firmly using all the brakes. rubber lines allow you in a way to apply more w/out locking up....depends on what you're looking for.
In the mile going 200 mph 1 rotor has been fine for me shutting down in 1/2 a mile single rotor but it took some concentration.
In the mile going 220 with dual rotors up front on the zx14 ... braking was very minimal....they stop better than the early 12s for SURE....just dabbed the lever front and back a little...stopping was no drama whatsoever with 9/10ths mile shutdown.
I would look into OEM rotors or something THICK. Do you Airbrake with your body much? Practice at lower speeds of course. Can't go wrong with anything Brembo but OEM is pretty good. galfer is too thin/light IMO for this kinda stuff.
A.
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Gemini Motorcycles
Topping out everything from Ninja 250s to nitrous ZX-14s.
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Bigbore4
Zone Head
Posts: 806
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posted August 30, 2011 08:16 PM
PFM ductile iron discs are the best you'll ever see. Their calipers also, but you can use others. The thing with the PFM calipers is they have almost zero drag, which lets them cool down between applications.
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Shane661
Needs a life
Posts: 11494
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posted August 31, 2011 04:14 AM
 Edited By: Shane661 on 31 Aug 2011 12:15
Ken if you want 14 brakes there are a couple of options, including swapping the front ends over (that is what I am doing). At 250 lbs your braking needs will likely be significantly different than those of a 125 lb rider.
I think the big thing to consider is the shutdown length. With a mile shutdown you shouldn't need a tremendous amount of braking....but obvously the shorter the distance the more you will need. For someone your size/speed you probably want to stick with dual rotors for the heat-shedding capability. At 220 lbs suited and over 210 mph I have used a single rotor application on the 14, but I had a mile to shut down and the bike was 80 lbs lighter than stock.
The guy I normally deal with on brakes/suspension is Rick at Cogent Dynamics. He is stateside, but if you email him he may have some suggestions.
http://www,motocd.com
Anyway, lot's of good suggestions in this thread. Good luck with whatever you choose! 
Shane
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Ken 12r
Novice Class
Posts: 86
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posted August 31, 2011 12:12 PM
Edited By: Ken 12r on 31 Aug 2011 20:14
Thanks for the imput guys,I have three rolling ZX12s The B model road bike has Nissin 6 pots and Galfer wave discs which work fine for road use but the wavy discs eat pads.
The big bore soon to have a wiff of gas has Brembo race 4 pots running Brembo discs and a Brembo radial master cylinder,this is by far the best set up and can stop from 200mph plus easily,trouble is that the discs are no longer produced and as I bought the complete set up used from a friend the discs are getting a little thin.
The Turbo has Harrison Billet 6 pots which will stop me as I have had them on a ZX 11 where they had no problems but I think the problem is with the stock discs not mating up properly with the pads because I used them previously with the Galfer wave discs on the road bike.I did run them a little together but pehaps it was not enough.
I will probably try for PFM discs but for the remainder of this year or two possibly three meetings I have been given some Lucas discs to try that came highly recommended from the guy who built my big bore bike.
They are a wavy style but much thicker than the Galfer and have a good smooth surface.
The next top speed meeting on September 13th has the option of one mile or one point 4 miles so I can just run the mile and have point eight of a mile to stop in so no problems.
I still think I will stop in 4 tenths of a mile if I get the set up better but I am back on the diet anyway
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www.uklandspeedracingassociation.co.uk
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