The current VFR800 has the same Tokico front brakes, complete with crap pistons, however I took this up with Powerhouse and they make replacement Pistons in stainless steel @ £19 each or £150 for all 12 They also do seal kits at great prices, very helpful people and will go out of their way to help, they also do a rebuild service if you don't feel up to it I've rebuilt mine with their kit and the brakes are transformed, real solid bite to them So before you go swapping your brakes over try these and throw those rusty old Tokico pistons in the bin
my hrc just passed its MOT with flying colours so as a well done present I bought some SS pistons https://www.ebay.co.uk/itm/Honda-CBR1000-RR8-RR9-front-brake-caliper-stainless-piston-set-2008-2009/182045557057?ssPageName=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649
Managed to fit them with new seals over the Christmas period. Got to say my instant reaction was not too good as I could not get a decent solid lever, took it out for a test run and needed to reprime the lever to get any good braking force. Seriously disappointed I took them off again for inspection. I concluded that it was not air in the system but the seals gripping and pulling the pistons back causing massive travel. Though the stock pistons corrode they seem to be chromed to a mirror finish, the SS pistons though very fine still have machining marks. Got to the pistons with a little abrasive polish and reinstalled using silicon lube rather than red grease (which I used first time). Also rotated the pistons until they moved freely. The difference is quite marked absolutely rock solid lever all the time and very little binding. 120 quids worth, only time will tell. Definite improvement on the lever travel. The stock pistons seem to bind a little causing alot of wear on pads and discs so hopefully in the long a cost saving here too
Hi Jon, Glad you posted that as I have put the Same stainless pistons in mine and found the lever travel massive even bled the master 3 or 4 times. What brand of silicone lube and polish did you use please mate as I’m going to have to have mine apart again. Cheers
Hey Raphael, Started very gently with 1200 grit wet and dry, followed by 421 compound then autosol both applied with a buffer on a dremel. It took ages!! The lube was WD silicon spray(probably in hindsight should have used gel), liberally applied to the piston and seals. Inserted the piston half way sprayed again then when fully in using a piston clamp rotated the piston until little resistance was felt. Repeated on all 8 pistons. The whole caliper was then wiped down to ensure there was no residual lube before reinstalling with pads. My bleed process is probably an over kill but it works for me: Put 1 reservoir full or fluid through each nipple, (M/c, n/s , f/s, M/c) repeat 3-4 times. Then left the lever under pressure with zip tie, tapped the feck out the lines and calipers with a rubber mallet and left overnight. Next morning quick bleed through each nipple then solid lever. Hope this helps! edited post to 1200 grit, thought my paper grade went up to 3000!
EDIT to original post DO NOT USE silicon Spray on the seals. The initial lubrication is excellent but it will eventually expand/swell the seals causing a lot of drag in the pistons - stick to red grease!! Left is a 32mm seal soaked in silicon for only 20min!!. Right is a brand new 32mm seal. Apologies for the duff advice
The manual states to use silicon, it must be the solvent used in the silicon spray that fecks up the seals. In any case, polished up the pistons again using a dedicated buffer machine using three grades of polishing wax, they are now a mirror finish! The RCS 19 is set on 20mm ratio for small lever movement and with next no drag on the seals a solid bite is almost instant, now that's what I'm talking about
Hi I am new to this thread and have had binding brakes from when I got it at 700 miles, what do you gain going to ss pistons. I have taken mine out and serviced them this has improved a lot but not a patch on my sons R6.
SS pistons are only really going to resolve binding/excessive travel if the OEM alu ones are corroded. The chrome coating on the OEMS gets pitted and soon just flakes off causing excessive friction with the seals. As yours is only 700miles I doubt corrosion is your problem. The seals on the tokicos can be quite tight resulting in drag. The dust seal especially can gunk up quite quickly. When I service mine the pistons are very free and cause little drag. If I take them off It only takes a 10-15 PSI of air pressure to activate the pistons and very little finger pressure to retract them.
