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Winter project: upgrading time! (R6 forks and more...)

Discussion in 'The Garage' started by Bjorn, Dec 28, 2019.

  1. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter

    Yep, measured off the bike.
    gggGary likes this.
  2. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    The yzf600r had the clip-ons on top of the top triple, so why so much longer.
    Bewarethemoon likes this.
  3. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter

    That’s where I intend on mounting mine, that’s where they’re mounted on factory R6’s. They’re also fixed in situ via what I believe is a shallow M4 bolt.
    Last edited: Jan 20, 2020
    gggGary likes this.
  4. Bjorn

    Bjorn XS650 Addict

    This is why i want to compensate for the shorter R6 forks as much as possible with the new top yoke.

    Here is the current status :D Its in there somewhere ;)
    Today i started making the fixure for the actual machining of the yoke:
    gggGary and 350GUY like this.
  5. 350GUY

    350GUY XS650 Enthusiast

    Top notch work! I'll be following your amazing build!
    gggGary likes this.
  6. Bjorn

    Bjorn XS650 Addict

    Maybe fun to do an update. I've spend quite a few hours on the bike the last few weeks. Im always amazed by how many hours go into thinking about stuff. Spring is coming and I would like to ride the bike asap.

    The build of the top yoke went pretty good, until i decided to quit my job. I managed to get half a part out but its not usable in this shape. The good news is that I will start my new job pretty soon. They got lots of machines, so hopefully they will let me make some of the parts there:)

    starting the the Block of 5083

    kroon 1.jpg

    All the tooling I needed
    kroon 2.jpg

    First starting to see the shape
    kroon 4.jpg

    This is where I ended. Only one side is done with rough milling. Nothing is to size yet... I did manage to bore the holes all the way true. Hopefully I can ''pick it up'' from there when I get a change to finish it.
    kroon 6.jpg
    Paul Sutton, Signal and gggGary like this.
  7. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Wow, cool!
    For sure hope you are able to complete this.
    Paul Sutton likes this.
  8. Bjorn

    Bjorn XS650 Addict

    Since I dont have a mill at home I used the original top yoke to keep working on the front wheel situation including the brakes. I decided to use some 42CrMo4 steel for the front axle. They use this stuff for axles more often so i guess it will suit the job fine. I plan on keeping the original speedo and tacho on the bike. This means I will have to fit the speedo pick up on the front wheel. It does make everything more complicated.... talking about bearings, speedo ID, clearance etc. I settled for a stepped design to allow the speedo to be fitted. I bored it out from 17 to 18mm. I didnt go for 20 because there would be no material left to take the clamping forces.

    Again, quiting my job meant I no longer had access to a ''sturdy'' lathe. I did mange to rough it out and finish it on my own lathe. Was quite the hot supper for the small Emco :laugh2:
    More problems when I wanted to cut the M18x1,5 thread on the emco but couldn't because I was missing change gears for that pitch. After sourcing and making new parts for the lathe to do it.....I broke a casting that holds the change gears. So i ended up getting a thread die to do the job.

    front axle design.JPG

    When you got the rigidity and horsepower, this 42CrMo4 chips quite nicely. On the small Emco however ....
    front axle start.jpg
    front axle start 2.jpg

    front axle finish.jpg

    Here is the new axle on top, the original hollow R6 axle in the middle and the solid XS axle in the bottom
    front axle vs.jpg

    Had to use the die by hand, no way the lathe has power enough.
    front axle draad.jpg
    But I got er done ! front axle done.jpg
    front axle speedo.jpg
  9. Bjorn

    Bjorn XS650 Addict

    Got some new bearings with and ID of 20mm. Made a new spacer to fit in between, made from aluminium...because weight savings haha. Not 100% sure this can take the loads, the original one is made of steel. But I guess they value engineered it because its DOM tube with a piece of sheet metal.
    front spacer.jpg

    The new axle is in and it fits! Made some spacers to get the wheel in the centre of the forks. I plan modifying the axle a bit (might even make a new one). Make it hollow and machine a Hex to drive it. But first: onto the brakes!
    fork update 1.jpg
    fork update 2.jpg

    This is where i'm at now, I need to decide what set-up i want: 1 disk, 2 disks, what callipers, spacers for the disk brakes, spacers for the callipers, clearance......some many things to consider....:umm:

    few things im keeping in mind:
    - prices of parts, if i got it, might as well use it to save some money
    - weight of the parts, do i really need 2 disks?
    - machining parts? I like to make everything but dont have access to a mill right now...

    option 1:
    • Blue dot callipers (got 2)
    • R6 master cylinder (got it)
    • brake disk(s)? Got a 320mm brembo but the blue dots require a 300mm disk. I believe a FZR 600 disk will work. However going down in disk diameter, the callipers get scary close to the spokes.
    • More stopping power
    • More unsprung weight.
    Option 2:
    • Reuse my old set-up
    • 1 Brembo 320 disk i already got
    • Brembo gold calliper
    • Got a MS for this.
    • Make a new disk spacer
    • make a mounting plate for the calliper. This is the hard one.
    • lightweight solution, adequate stopping force.
    You guys got any ideas?
  10. 350GUY

    350GUY XS650 Enthusiast

    Sir: Option #2 with Venhil brake lines.
    gggGary likes this.
  11. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Did you look into changing to bearings with a larger ID?
    Oops cross post LOL
    how close to the lower tube is the rotor?
    I came up against the same problem with my quick look, caliper-spoke interference.
    Out in the shed the SV650 forks with the Tokico calipers, plenty of room.
    that's a stock XS650 79 special II front wheel.
    Problem was the rotors are 5 bolt, I welded the holes shut and redrilled them 6 bolt!
    Also SV650 fork length is on the short side....
    tracke front end detail.jpg
    Last edited: Feb 29, 2020
    Paul Sutton likes this.
  12. Bjorn

    Bjorn XS650 Addict

    When i mount the blue dot calipers, cant fit a piece of paper between the spokes and caliper bodies haha. So its tight! I could maybe machine some of the calliper mounting lugs to give me a bit of clearance. Although I like the ''clean'' option of not having to fit additional calliper mounting plates, i dont like the clearance to be <2mm.

    The brembo disk that is on in the picture is still around 10mm away from the lower leg. machining a thicker spacer for the disk to give more clearance for the calliper is an easy option. especially with the 320 disk, giving me plenty of clearance.

    usually i like to go with the lower weight option, just hard to say how it compares to the added braking force of 2x blue dots.
    Paul Sutton, gggGary and arcticXS like this.
  13. Bjorn

    Bjorn XS650 Addict

    @LEGEND_10 how much clearance does this give you between the spokes and callipers?
    gggGary likes this.
  14. arcticXS

    arcticXS XS650 Guru Top Contributor

    When it comes to low weight, your Brembo disc is actually pretty heavy, 18-1900 g IIRC. The gold colored center (hub) is actually steel on those discs!
    I replaced a disc just like that on my 1995 Ducati M600 with an ISR disc. Saved around 400 g just there (close to 1 lb)
    Maybe a single 300 mm disc with a blue spot caliper is enough for an XS? I mean -76 and older had a single 298 mm disc and the older (better?) 2 piston caliper. Surely the blue spot caliper is superior to that old caliper, not to mention lighter. With a correctly sized master cylinder for a single blue spot, you may have all the brake you need.
    Or you could order a custom made 320 mm disc from ISR, like I did. 5 mm thick, 23 mm offset. So no need for a spacer and longer bolts. I used a later Brembo caliper from a Ducati, the type with 65 mm mounting bolt spacing, and a home made caliper adapter. With a 13 mm Brembo MC, this is more than enough brake for any street XS.
    Paul Sutton, Bjorn and gggGary like this.
  15. Bjorn

    Bjorn XS650 Addict

    I remember you mentioning that the brembo disk is quite heavy.

    Although making a disk spacer is not a problem, a custom disk sounds interesting! But also expensive. Before I request a quotation from IRS, do you remember what something like that costs?

    I'm leaning towards one disk and calliper. One thing that's annoying is that it is hard to find a master cylinder that works. I have one I used on the old set-up, However the feeling isn't world-class. Probably has to do with MC bore and stroke. That's one advantage of running both blue dots, Yamaha already designed the perfect MC for it.
    gggGary likes this.
  16. arcticXS

    arcticXS XS650 Guru Top Contributor

    Not cheap, ends up around 300 Euro plus sales tax, for a 320 mm floating disc with 23 mm offset
    (which is what I have. Your offset requirements may be different)
    Ducati discs have 10 mm offset,. That is from outside friction surface to mounting surface. ISR have a custom disc form on their website.
  17. arcticXS

    arcticXS XS650 Guru Top Contributor

    Not cheap, ends up around 300 Euro plus sales tax, for a 320 mm floating disc with 23 mm offset
    (which is what I have. Your offset requirements may be different)
    Ducati discs have 10 mm offset,. That is from outside friction surface to mounting surface. ISR have a custom disc form on their website.
    gggGary likes this.
  18. Bjorn

    Bjorn XS650 Addict

    Yeah I found the form, great to have this as a back up plan. But it's quite a lot of money...

    I found a pair of used FZR 600 brake disks. They are 300mm with the right bolt pattern and ID. I plan on going for just one blue dot calliper. Mill down the mounting lugs, back side and maybe some of the fork lugs to get enough clearance. Saves me from making a calliper plate. And it looks cleaner. I'll get two disks so I can always add the second calliper just to see what it brings.

    Downside of the plan is that I need a mill to continue....

    Maybe I will sell my old brembo set-up as a plug and play option for another XS enthousiast. Would anyone be interested?
    O well, enough other stuff to do hehe
    gggGary likes this.
  19. Bjorn

    Bjorn XS650 Addict

    Worked on the crank breather for a bit. I used to have a small filter directly mounted at the top of the engine. always covered the top of the carbs in a thin layer of oil. Last year I got a reed valve, but still got a little bit of oil mist coming out of the filter. Now I came up with this (overkill) solution

    05-0679 (Small).jpg
    The reed value I purchased, it sits at the top of the engine.

    from the reed value, the hose will to to a oil catch can design contraption to filter out the remaining oil.
    breather 1.jpg Found some 1mm stainless. Chose this over steel because i dont have to paint it...

    breather 2.jpg
    welding was quite tricky because stainless distorts a lot and it was quite thin.

    breather 3.jpg
    the gasses will pass though the SS wool, filtering out the oil mist (in theory at least...)

    breather 8.jpg Gas will enter on top, and exit on the side (shown on top here). I ordered a small filter that will be mounted there. The catch tank has a sloped design so the oil will move towards the elbow. I tested it with water, no leaks :D

    breather 4.jpg breather 6.jpg
    turned a nipple for the hose to run downwards.

    breather 9.jpg
    And here it sits next to the RHS footrest.

    Im planning on running a hose down from the tank with some sort of cap so i can drain it quickly and easily. Now fingers crossed this whole idea will work hehe

    Attached Files:

    arcticXS, gggGary and GLJ like this.
  20. Bjorn

    Bjorn XS650 Addict

    Found some TDM 850 brake discs! They appear to be in decent condition with plenty of life left in them.
    brakes 1.jpg

    Made some spacers from some material I had left:
    brakes 2.jpg
    brakes 3.jpg

    brakes 4.jpg
    brakes 5.jpg

    After trying the wheel on the bike...............I found out that I cannot run 2 discs AND the original speedo drive :( Thats a real bummer. The reason is the disc on the speedo side comes out to much due to the spacer. There is not enough room left between the disk and fork leg.

    This because I want to run the original blue dot R6 callipers. They in turn need a 300mm disc, resulting in very close tolerances between spokes and calliper. Using a bigger disk with calliper-spacers might work but that's not the route im taking.

    So I I have two options:
    1. Run 1 disk, with the original speedo drive
    2. Run 2 disks and go for a aftermarket speedo.
    My plan is to do some testing with 2 discs VS. 1. After that I can decide if the second disk is worth it performance wise. If not I can go for one and use the original speedo. If it is worth it, I will look into another speedo.

    Next step, milling down the brake calliper mounting lugs in order to win some clearance.
    arcticXS and gggGary like this.

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