1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

Mr Riggs Hydraulic Clutch Conversion

Discussion in 'The Garage' started by Bewarethemoon, Jul 30, 2020.

  1. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Just an observation Daniel... make of it what you will.
    The rotational forces on the piston are almost nonexistent. There's a ball bearing on each end of the pushrod... the inside one being continuously lubricated. A skinny rubber band could offset those forces. The pressure line will be more than capable of keeping the whole affair in place. You could delete the grub screws and your machinist could save the time to drill the recesses. That's not much saved I know, but it'll help
  2. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    I have a billet clutch basket on it’s way that with a little machining will allow for use of 8 full thickness steel plates and the 8 fibre plates from an early R1.
  3. ShaggyMech

    ShaggyMech Socal Mechanic.

    That's great to hear about the basket. I took measurements from a friend of mines basket and had that eureka moment that the R1 and the XS use the same plates. I am looking into either a slipper clutch or using a drag racing lockup type to hold the power down on the EFI high compression beast. I am hoping to use a slipper clutch personally so i can drag going into a corner as hard as I can without the rear end skipping. I also found that an RD250 rear drum is the same as the TX750, but uses a cush drive to soften the blow of the two stroke power at 9000 rpm. I am very tempted to lace up a rim and give that a try with some poly bushing hopefully giving the rear end just enough give to really hammer the throttle without fear of spitting a chain out. Slipper clutch and a cush drive would be like riding a cloud in and out of the corners hard. If i had the $ i would find myself a TZ rear spooked hub since it is disc and has rubber bushings pressed into the sprocket positions. When i built my road racing RD350 I hunted for one for a long time but they are almost as rare as an OW72 head for these XS. I have actually found one on eBay today but at 700$ that is just out of my price range yet again.
    Bewarethemoon likes this.
  4. ShaggyMech

    ShaggyMech Socal Mechanic.

    Honestly you have motivated me to start one. I will gather all my photos and information i have scattered throughout my computer, various notebooks, drawings, and start one today. Going to be one really long thread just with all the information that i collected over the last year. Mostly thanks to Griz and twin and toomanyxs1b, I believe i spent around 8 months literally reading every scrap of information and thread i could find before i started mentally planning all this out. Then I finally got my hands on 1 XS and started collecting every XS in the surrounding area i could feasibly afford.
    TwoManyXS1Bs and Bewarethemoon like this.
  5. ShaggyMech

    ShaggyMech Socal Mechanic.

    When i designed and built the hydraulic clutch adapter for the RD350, I was using R5 sidecovers and used the diamond shaped area where there is a cover over the throw out screw. 2 6mm bolts held the cover in place and those same two screws just held from the inside- out kept the entire mechanism and the aluminum slug i machined to bolt a ducati penegali slave cylinder to in place without an issue. so reasonably speaking, the slave only has to be held center but the entire cover is going to be retaining it when its under pressure. The slave because of how hydraulics work will keep the rod in place. It won't retract all the way back because that isn't how master cylinders work. They only displace fluid to push it, not suck the fluid back. the system would have to be in a total vacuum for that to be possible.
    Bewarethemoon likes this.
  6. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    I’ll be looking forward to reading the details of your engine build @ShaggyMech

    I’m building a CNC ported XS1 head 750 with bronze valve guides, and oversize valves, Beehive springs, 3.5 pattern cam from Smedspeed. Rephased 256 crank. High Ratio Primary gears from Ivan Hooey. Upgraded gearbox with 3rd & 5th gears from an XS750.

    Be intrigued to learn of all the little nuances you apply in your approach, particularly interested in the undercutting of gears.

  7. ShaggyMech

    ShaggyMech Socal Mechanic.

    Look into RD350 or TZ transmission gear undercutting. The dogs and seats are beveled in a way that allow them to drop in faster but hold tighter than a traditional square cut. Very prevalent on road racing transmissions where you shift at nearly redline.
    Bewarethemoon likes this.
  8. ShaggyMech

    ShaggyMech Socal Mechanic.

    Might want to be careful about going to large on the valves, the ports are technically to large to begin with so using to large a valve actually hampers your ability to make torque. You'll lose a lot of pumping power until over 6 if you go even 2mm larger. The intake can benefit, But the exhaust valve is best left stock or just a hair over such as .5 mm. The best engines are built to utilize the power band that you will spend the most time at. Going to large and you shift the power into redline and past. That is typically why 2-1 exhaust are actually a poor choice for an XS. unless you give the pipe adequate room to prevent reversion and the collector and step the header from 1 5/8 to say 1 3/4 then a smoothed and dynamic collector at perhaps 2 then 2.5 a 2-1 setup pushes max power to around 8500. I can keep motors right against redline but pushing 7500-8000 frequently will create some incredible crankcase pressures even with a heiden designed PCV valve. Also clutch life and ring life is drastically reduced and that is if you can manage to keep the intake valves from nearly melting. XSJohn (RIP) had oil sprayers he plumbed into his intake valve covers just to satisfy his tappet adjusters thirst for oil. Hence my pursuit for a roller rocker and perhaps even a more refined oiling system for the rockerbox area. I am going to see if ford roller rockers for i believe it is the Cleveland motors that the rocker is oiled through the rocker body. If so i will try to either adapt or "borrow" the same concept for the xs but include a sprayer at either base, cam and valve base. so even if i stay with an adjustable elephant foot or devise some form of roller bearing there should be adequate oil to push the motor to redline and hold for as long as the motor doesn't literally come apart. the biggest thing afterwards is to have everything weighted the same and dynamically balanced. Think land speed racer type engine. Max horsepower Maximum duration. That way i may not hit 165 but I can keep the heat on the modern day supersport in the corners. They may take me in the straights, but if i can keep the motor at max rpm pretty much 90% of the time they won't get away from me.
    Bewarethemoon likes this.
  9. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    These are the valves I’m using... http://www.smedspeed.co.uk/valve.html

    I must say I’m enjoying reading your posts @ShaggyMech

    I can eat all of this up, this talk of engine development.

    I’ll have a read about undercutting gears tonight and see if it’s something my machinist can feasibly undertake.

    I’m planning on having all moving internal parts deburred and super finished.
    ShaggyMech likes this.
  10. Are the 750 3rd and 5th gears different ratios? and do they slip right in? Quick reply; I don’t want to hijack!
    Bewarethemoon likes this.
  11. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    RC4MAN likes this.
  12. ShaggyMech

    ShaggyMech Socal Mechanic.

    Thank you Bewarethemoon. I have been doing research for pretty close to a decade on just vintage Yamaha's. I grew up in sunny southern california near the ontario speedway where the King Kenny Roberts once rode. I have been a Yamaha junkie since my first bike. a 1975 DT250 that i assembled from literally boxes. When you get the gears undercut they will need to be heat treated again then annealed. Afterwards you should actually have the gears cryo-treated to stabilize the grain structure. The best transmissions i've used were all done that way then finely polished to nearly a shine. Any tooling marks, burrs, or uneven edges will lead to notchy and uneven shifts at 7000+ rpm shifts under load. The RD350 I built was a literal fire breather at nearly 70 HP, and stripped back everything on the frame and chassis. i think it barely weighed in at 200 Lbs. In the canyons i would literally walk past 1000cc bikes like they were standing still.
    stinky78 and Bewarethemoon like this.
  13. ShaggyMech

    ShaggyMech Socal Mechanic.

    Bewarethemoon likes this.
  14. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

  15. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    The stock XS650 3rd, 4th, and 5th gears are undercut. 1st and 2nd are not, to facilitate entering neutral...
  16. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    I dropped the prototype Slave Cylinder off with my friend, Rick Forte of Smedspeed tonight.

    It’s going into this on Friday, it’s his son Kye’s race bike...


    It’ll initially be run up through a couple gears in the yard before being tested here on Saturday https://www.plymouth-speedway.com/

    I don’t think we could ask for better testing parameters could we?

    I’ve also spoken to a machine shop and had a quote for a ‘small’ production run of 25. I’m really happy to tell everyone that I can honour my initial estimate of cost and offer these for $150 a unit inclusive of all components I’ve mentioned previously.

    I hope everyone’s as excited as I am!

    Last edited: Apr 15, 2021
  17. SomervilleXS650

    SomervilleXS650 XS650 Addict XS650.com Supporter

    Well done Daniel! Very excited, keep us posted on the outcome of the testing.
    Paul Sutton likes this.
  18. ShaggyMech

    ShaggyMech Socal Mechanic.

    I did not know that. I have not closely inspected a XS transmission yet. Usually i focus on the exterior of the engine first. Fueling, Air, Clutch, and of course making it stop as fast as possible before I open up the guts and start tweaking them.

    FANTASTIC! I am very excited to have this. I have a ducati slave but personally i think the externally mounted units are.... particularly ugly considering they look very modern. I have a way i like to have things look, almost sleeper like, but the performance is as new as i can make it and by far that is the cleanest assembly i have seen yet.
  19. Bewarethemoon

    Bewarethemoon XS650 Junkie XS650.com Supporter Top Contributor

    Placed my largest order to date with my metal guy today...


    Enough of the good stuff for 25 assemblies, it’s being sent straight to the machine shop and should be there by Tuesday.

    Jim and SomervilleXS650 like this.
  20. SomervilleXS650

    SomervilleXS650 XS650 Addict XS650.com Supporter

    Love the hustle on this, cheers Daniel!!
    Bewarethemoon and Jim like this.

Share This Page