Eliminating Linked Brakes 6th gen

Discussion in 'Mechanics Garage' started by CaptGarvin, May 11, 2018.

  1. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    To simplify, say we have a certain pressure on a line connected to two pistons side by side like in a caliper pushing on a brake pad. One piston has a larger diameter than other thus the extra surface the pressure has to work on provides more force,(Pascals Law?) but moves less than the smaller piston due to larger volume of fluid needed to move the same distance. My question I think is with this in mind, for example the rear caliper of my vfr with 3 pistons, the outer 2 are larger diameter than middle, will the force applied to pad be even from the 3 pistons if all linked to one line, which from my un-educated, burned-up brain thinks it is not. Not going forward till figured out. If it is the case then, I plan on just blocking off center left front and rear caliper piston for the trial, and go front there. Thanks for input, is this more clear
     
    Last edited: May 15, 2018
  2. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    As I said before, this is coming from an uneducated, burn up brain(was intelligent at one time, but in my lifetime I’ve killed a lot of brain cells, they just turned out to be the ones I needed), the different sized piston configurations I’ve seen are in a two piston caliper designed to give the bottom (smaller diameter) piston a leading contact of the pad to the rotor. Purpose of this is gone with those brain cells I mentioned, but with the smaller piston in the middle I have no idea on what the force behind the pad is as more pressure is applied, but guess the middle is acting on it first.
     
  3. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    Thanks by the way on the video comment, some of the shots the drone was mounted on back of my vfr to take advantage of the gimbaled camera(spur of the moment idea) 1st trip my set up transferred too much vibration to drone and by 3rd had right amount of cushion, weighted balance arm, more cushion, and by this trip my corner speed had improved, but on corner exit as I applied power to get out of the way of my following volunteers the v4 made the video have some shutter, right at the moment I wanted camera to catch them at the max lean on apex, so had to cut out. This summer will have a rig to catch it all, I hope. Thanks again
     
  4. OZ VFR

    OZ VFR Insider

    Country:
    Australia
    Joined:
    Feb 25, 2013
    Messages:
    1,036
    Likes Received:
    260
    Trophy Points:
    128
    Location:
    Old Toongabbie, Australia
    Map
    As I stated earlier, my rear caliper has been working with the three pistons for over 30,000km, and the pads are wearing evenly.
    Feel and stopping power is spot on, enough to be usable without being too strong and cause unintended lock up.
     
  5. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    Hopefully sounds like though the middle piston moves further on same press, yet the increase of pressure brings the outer pistons to join forces with the middle, should do same on front. I’m going to give it a try, have braket to hold secondary master cylinder, but will do the fluid thing you did before capping it off. Thanks, this hydraulic setup is puzzling
     
  6. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    Do you remember what size and thread the bolt you used to plug secondary master cylinder, and did you first try not using the extra pistons front/rear by plugging those also, and then go to using all, and if so how different was the results? Thanks by the way, captg
     
  7. OZ VFR

    OZ VFR Insider

    Country:
    Australia
    Joined:
    Feb 25, 2013
    Messages:
    1,036
    Likes Received:
    260
    Trophy Points:
    128
    Location:
    Old Toongabbie, Australia
    Map
    The bolts are M10 x 1.25.
    I got some stainless full thread short ones and cut them down so they wouldn't go too far onto the calipers.
    The rear I went to the internally drilled three pistons straight away as I already had the new master.
    The front I just used the two pistons until I gathered everything I needed for the lower fork/calipers swap.
    I use EBC HH pads, and I had already swapped to two braided lines when I did it and they worked fine.
     
  8. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    I made a mistake, and this answers my question about a different diameter piston between outer 2 pistons, it must equalize because the caliper with the different sizes is the right! The left and rear are same size pistons, the length is different for the middle on both, clearly shown on service manual. So now I’m gonna tie the left front pistons together at the caliper(how is yet figured out, as well as the rear caliper) and the rear so only one braided line runs to the split at the front fender and there one line to each caliper and same on rear. Sorry for confusion didn’t study manual enough before I spoke. Anyway this gives me the confidence this is going to improve the performance and control. Thanks for your input, I don’t think I would have gone down this far the path without your feedback, should be done in two weeks, waiting on chain slider. vvertigo
     
  9. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    Going for it, have removed all linked lines and will first try all six pistons on front and two outer on rear( until I find where to drill or get another short braided line to bridge the two banjo,inputs like I did on the front) have to pull the swing arm just to get new chain slider on, waiting on that part to test, let you know
     
  10. mello dude

    mello dude Member

    Country:
    United States
    Joined:
    Jan 3, 2006
    Messages:
    3,359
    Likes Received:
    49
    Trophy Points:
    78
    Location:
    Southwest Ohio
    Map
    Curious as to, why wouldnt you just swap to F4I lowers on your 6th gen upper fork tube? Then there are several caliper choices that are direct bolt on very simply. You would save 5 pounds of unsprung weight on your front end. Plenty of guys have gone that way..
     
  11. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    I found a Galfer Braided lines set for the vfr at half price, had bike since new And hadn’t thought about replacing lines until recently friends bmw blew a rubber brake line coming to a stoplight, near crash result got me looking. Then looking on forum saw where some had delinked, such as you and others, and wanted to try just by-pass the pv’s first in case I wanted to swap back, but have sorta committed to it now and if it like I think it’s gonna work out, then consider the forks. Are F4I lowers same length? Another concern I have now is with 35k miles is what shape are my front forks in, especially the fluid level and condition. Have never had any fluid seepage, but not experienced enough to know when forks are not performing as should. While I have calipers off thought about pulling forks, pull spring out and pump fluid out so don’t have to try draining from bottom, if fluid is dirty and/or low, then consider rebuilding per service manual(or consider replacing lowers if can find at good price) But want to test delinked brakes first and can’t till chain slider arrives(June28th, ordered from wrong place), replaced pipes, re-tensioned CCT’s, new ebc pads and rotors, rewired headlights with led bulbs, repaired cruise control, new seat, and I’m tired and ready to ride so may put off fork check until test rides. But appreciate so much the feedback from you guys, wouldn’t even be at this stage without this forum. And if you have time, what effects does unsprung weight have on a bike?
     
  12. Terry Smith

    Terry Smith Member

    Country:
    New Zealand
    Joined:
    Nov 18, 2013
    Messages:
    1,822
    Likes Received:
    198
    Trophy Points:
    78
    Location:
    Auckland, New Zealand
    Map
    The length of F4i lowers should not matter as the extended length of the fork is dictated by the bottom edge of the top-out springs on the cartridge catching the lower end of the upper fork tube. I'm making the (reasonable) assumption that the distance between the axle and the inside base of the leg where the cartridge fits will be the same across the different parts. If you are using the 6G uppers and cartridge outer, that should give exactly the same topped-out length as a stock VFR.
     
  13. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    I just tested with all 6 pistons connected on front, used 5” braided line for now to link main line to center piston, stock master cylinder, two finger brake lever and I really like the feel, I eased into emergency braking and the stock master cylinder is doing the job. However, the rear brake I only had single line going to the outer pistons on the rear master cylinder with middle piston blocked off, stopping power reminds me of Fred Flintstone method of stopping, totally inadequate. Since I rarely need the rear brake, will try next to link all three pistons, and if no better will look for either different master cylinder or two piston caliper if there’s one that fits, or both. Has anyone replaced either of the two? And are there any mods needed to get them to fit. Wonder how just using the center piston on rear will brake, might as well try when linking all three just so I’ll know. And by the way, what surprised me is the right front is only caliper that has a different diameter piston in the center, left front and rear are all same diameter, but middle ones are different length, sorta answers my original question. More to come soon.
     
  14. mello dude

    mello dude Member

    Country:
    United States
    Joined:
    Jan 3, 2006
    Messages:
    3,359
    Likes Received:
    49
    Trophy Points:
    78
    Location:
    Southwest Ohio
    Map
    Plenty of guys in the VFR community have done the delink work, and for the rear, if you want to use all 3 pistons on the caliper, you need a 14mm master cylinder.
    - RC51, F4i, VTR, most Honda sport bikes have 14mm - Honda uses the same castings for the rear master cylinder and machines different sizes. I purchased a new RC51 M/C to do mine. - Then you have a choice of adding a small loop bridge between the outside pistons and a single line to the master, (I just used a stock line) or using 2 lines - one on the center piston and the other on the outside pistons - like stock to the M/C. Some guys like the drill the hole between pistons, that works too. You still need the 14mm m/c
    - This setup has been proven to work well among the delink guys who have done this....(oh, forgot I posted photos on page 1. )

    Then.. Please dont take offense, but I am somewhat conserned for your safety, on plumbing the front calipers as a separate setup. Its specifically designed to work in a linked environment... experimentation is not the best way to the solution. Kinda playing with fire.... - If I had to do it, I wouldnt start without getting the calculator out.

    Still the best and proven way for a 6th gen for delink - assuming you are going to keep the 43mm dia fork, is to convert to using F4i lowers, then use any Honda sport bike calipers available with the matching front M/C (RC51, 954, F4i, etc.) These calipers are a direct bolt in, just like Honda intended.

    If you didnt want to do the work, you could send the forks to Jamie Daugherty and have him do a fork rebuild and add the new lowers. (Ebay or new). Jamie could do some upgrade work too...

    General note - this delink stuff has been banged on and beat to death on the VFR forums... and above is the groups consensus.(without jumping at alternate forks).I am probly guilty of fanning the flame on it (possibly starting it) -- been hanging out here and over the other side waaaaay too long.. :Behindsofa:
     
    Last edited: Jun 24, 2018
  15. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    DFE44F2E-A4F3-49B0-8C72-967CB008830B.jpeg
    No offense taken, if I was smart I’d be worried about my safety too! And you’re right, I didn’t even consider delink until looking at some older post on the subject, but I know this is what I wanted. And I understand exactly why the naysayers comments. I’ve ridden this bike for 15+ years and the brakes have been flawless, but want more rider input. Tried to research hydraulic properties using different diameter or same diameter but shorter pistons, and the front has both of those. Still testing front performance, mostly in a high school parking lot. Took me a long time to lear to make a u turn on a two lane road, now without the rear brake automatically helping in this turn the front brake wants to snap the front sorta speak, like learning to walk again(exaggerating). Following your advice, Looking for 14mm rear brake master cylinder, need them rear brakes. But so far thrilled with the front, mostly one finger and two in traffic with plenty of bite, may consider lowers swap out later, have feedback from Jamie on options. Pic shows jumper from short hose included in kit to link the left front caliper, due to angels of banjo fittings seems under stress, can’t trust long term, will find better fit or where to drill to link 3 pistons. Thanks for feedback, will follow up after rear master cylinder swap, will bridge pistons with loop line like yours.
     
  16. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    I just looked at F4i rear master cylinder sets on eBay and it only has a one piston caliper, will this improve brake feel over my stock(14mm vs 17mm) m/c?
     
  17. mello dude

    mello dude Member

    Country:
    United States
    Joined:
    Jan 3, 2006
    Messages:
    3,359
    Likes Received:
    49
    Trophy Points:
    78
    Location:
    Southwest Ohio
    Map
    Yes, ANY Honda 14mm master cylinder will do the job. You may have to shorten the push rod once you install. I had to do that for the RC51 m/c I purchased new outright.
    (Assuming you are using all 3 pistons.) Do it...
     
  18. Terry Smith

    Terry Smith Member

    Country:
    New Zealand
    Joined:
    Nov 18, 2013
    Messages:
    1,822
    Likes Received:
    198
    Trophy Points:
    78
    Location:
    Auckland, New Zealand
    Map
    I second Mello in this. I used a 600F4i master, from memory I needed to cut the pushrod down a bit, and drill out the mounting lugs as they are threaded on the 600, easy jobs. I used the double banjo bolt that comes out of the linked brakes, and joined the two standard rear hoses at the new master, leaving the other end/caliper completely stock. That second rear hose will mate up like it was meant to join at the master. Works like a charm.
    upload_2018-6-28_16-58-42.png upload_2018-6-28_16-58-42.png
     
  19. OZ VFR

    OZ VFR Insider

    Country:
    Australia
    Joined:
    Feb 25, 2013
    Messages:
    1,036
    Likes Received:
    260
    Trophy Points:
    128
    Location:
    Old Toongabbie, Australia
    Map
    Yes, and if you find a CBR250RR rear master, you don't have to cut the rod.
     
  20. vVertigo

    vVertigo New Member

    Country:
    United States
    Joined:
    May 11, 2018
    Messages:
    32
    Likes Received:
    1
    Trophy Points:
    8
    Thanks guys, had already ordered a F4i rear m/c before seeing this about cbr250rr. I assume push rod that may need cutting is the threaded portion that attaches to pedal??(or internal m/c rod?) will figure out when arrives. I drove yesterday trying to see how much pressure on the rear pedal to get decent braking which was a lot, but then noticed a new sound and looked back and was leaving tire streak marks(never before on a vfr800) and with it locked was surprised how poorly it was slowing the bike down, straight line of course. Getting m/c Monday and will try as plumbed now using only two outer pistons but if F4i m/c will push all 3 pistons like you guys say will either drill or order a pair of custom short braided line like mello dudes, need a different one for the front anyway. Pulling the new clutch line thru frame I’ve done something to mess up my cruise control, my favorite mod on the bike done soon after I got it. Now got to pull tank(need more coat hangers), thanks again guys
     
Related Topics

Share This Page