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Project Yamaha SRX 250 3WP

Discussion in 'Your 250cc Projects' started by Andych, Oct 9, 2016.

  1. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Around A$90 via eBay Global shipping. The forks are now in Australia and cleared Customs... apparently.
    That $$ figure includes all Customs charges etc but it was still overall less than half what people here wanted for the same item.
     
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  2. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Another update... Forks were delivered this morning :dance2:
    Shipped on the 13th March in UK so eBay Global Shipping program seems to work really well from the UK at least.
    And it was still half the price of any similar item here.
    I will throw some pics up later but initial look at them and I am pretty happy. they will need seals and a paint job but that was always going to happen. Caliper mount is 40mm but uses smaller bolts so I will need to look into that but shouldnt be a big issue.
    I have also secured a front wheel that I believe is complete with the disc and a tyre (I wont need thathe tyre). The seller is going to drop it off for me in Sydney in a week or so and I will pick it up (hopefully) when I go up to see my new grandchild (due sometime around Easter).
    I need to check but it appears that only one of the forks has a spring in it and both do the damping??? Plenty of time to sort that out... :cool:
    Screenshot 2023-03-29 at 11.13.33 am.png
     
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  3. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Finally got around to taking a pic of the forks.
    I will confirm all the measurements in your online spreadsheet or just give you the measurements I have for now.
    I will get the disc offset once I get the wheel.

    Forks.jpg
     
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  4. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    I have just been working out some front end geometry if I use the Aprillia front end.
    Trail ends up at 3.88" where standard SRX is 3.66". That is assuming the rake angle will be the same.
    I will only be able to measure that once it is all together... Could be years based on my current pace :headbang:
     
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  5. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Raise the rear a smidge if possible and lower the forks a tiny bit if possible, even a change in front tyre profile can effectuate a change in front end geometry, so although an increase of ~5.5mm in trail will slow steering, you can make minor adjustments to correct for it.

    Is there a ~5mm difference in the triple clamp offset?
     
  6. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    No, it is fork length... that is the theoretical calculations based on having the same rake angle... but that will potentially change slightly once it is all together. My best guess is it will end up pretty close to the original SRX.
     
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  7. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    So, the wheel was delivered to my daughters place in Sydney at 4.30am this morning. I will pick it up sometime soon (when she has the baby I guess). The bonus is the disc comes with it... all for $150 which is a bargain.
    Even the stem bearings seem to easy to sort. I just need to pull the front end off the SRX to measure up the stem length and distance between the bearings to see if I need to have a new stem machined. It would probably make sense to do it that way, then I ccan use the same bearings from the SRX.
    Both bikes weigh pretty much the same but I suspect the spring and damper rates on the Aprillia forks may be slightly better than the SRX although the RS125 is really for jockey like GP wannabe's :)
    At least different springs etc are available for these forks.
     
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  8. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    After spending the last couple of weeks either with the dreaded Man-Flu or working on the Range Rover to get it updated to how I want I managed to get something done on the SRX today... albeit as a result of doing some Range Raover stuff :)

    I have a set of 6 Pot Brembo Big Ar$e calipers to go on it with 380mm front discs (it weighs 2.8 tonne, needs all the brake it can get) and finally got around to cleeaning them up, wire brushing, painting etc.
    On went the Brembo stickers and then for the clear coat... can you believe that it is impossible to get hold of the VHT high temp caliper clear coat... I did manage to get the last can of Red caliper paint though.
    So I bit the bullet and decided to use my last can of 2K clear...
    Rather than wast 2/3 of a can I looked at what else I could finish and I had nothing else ready to paint... unless I clear coated the underneath of the SRX tank... it has 2 coats of colour which is sufficient for the underneath.
    Wow the DNA Spilt Blood candy really jumps with some good clear on it.
    IMG_7190.jpeg

    IMG_7188.jpeg

    IMG_7189.jpeg

    IMG_7191.jpeg
     
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  9. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    I am super impressed with the 2K clear that I used... It wasnt cheap though... I originally bought it from DNA Paints and I think right now they are $66 a can... but wow, those pictures dont do the finish any justice at all. I gave the tank one last heavy coat to finish the can and then left it to dry.. If I can achieve the same finish on the rest of my painting I will be happy.
    We had to make a quick round trip to Sydney on Friday to go and see my new Grandson so I managed to also pick up my Aprillia wheel at the same time.
    I am very happy with that purchase... rim, tyre that will go to the tip, disc and 1 of the 2 wheel spacers for $150 was a bargain.
    It all fits together too, all I need to buy is 1 wheel spacer and I am waiting on another factory handlebar...
    Then I can put it all to one side until I get the rest of the SRX completed.. yes famous last words...
    I think I will get a new stem machined up for the Aprillia front end with the correct SRX250 stem bearings and spacing but suiting the Aprillia top triple clamp. That will need for me to pull the front end of the bike to measure it all up so it will be a little while before I get to that.

    IMG_7198.jpeg

    IMG_7199.jpeg

    IMG_7200.jpeg
     
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  10. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Well... it has been too long between posts so I figured a bit of an update would be in order...
    First.. the SL125 has gone to a new home in Griffith so that has freed up (or will) some time and space for the SRX to get some love.
    Battery is on maintenance charge so that is all sorted. I have tested all electrical circuits other than the starter circuit.. once that is all operational I can top up the oil and crank her over to make sure oil goes where it should and the sparks are a happening thing.
    Paint has been purchased but yet to decide exactly what will get the Cherry Black Candy.. maybe the rear fairing or a large stripe down the middle of the tank.. I mean it isnt really paying homage to any Yamaha paint scheme anyway.
    Lastly it appears I might be onto a bit of a winner with the Aprillia USD forks... I had my cheap SRX lower yoke delivered today and I have been doing some measuring... it appears that the only part of the yoke stem that needs attention is for the bottom bearing. I believe the SRX is a 48mm od x 25mm id x 13 Top bearing and 48 x 30 x 13 bottom bearing where the Aprillia is 47x25x15 top and 52x25x16.5 bottom.
    The distance between bearing lands is identical 174mm lower seat to top of the bearing land for top bearing.
    Based on that I can either try to find a 48 x 25 x 16 bearing for the bottom and use the standard SRX item for the top or... have a sleeve made up and shrunk onto the Aprillia stem to take the lower bearing dimension to 30mm and use standard SRX bearings.
    From what I can see... the top yoke mounts down onto the retaining nut and then another large allen head bolt retains it to the shaft...
    I will want to mock it all up to ensure it fits etc and then I can start re-furbing the USD etc.
    The priority will be to get her registered or Blue slipped for Club Rego first... then worry about sorting the final fit of the USD.
    I will post some pics over the weekend if I get the chance to take some...
    I still have some organising to do in the shed though so that is the priority right now.
     
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  11. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    A little bit more investigation tonight...I will need to have a stepped shrink on sleeve made up for the Aprillia stem.
    The distance between the bottom bearing face (with seal) to the top of the upper bearing land (where the treads start) is 168mm. The same dimension on the Aprillia is 174mm so I would end up with a 40mm OD lower step to the 30.49mm (cheap verniers) bottom bearing land which will allow me to then use the standard SRX250 FZR250 headstock bearings with the correct spacing. Overall a realtively simple conversion. The only real sticking point will be that the sleeve will have a 2.52 mm wall thickness which could be problematic getting a good shrink fit over the existing stem.
    Hmm I might need to look at how the bottom yoke comes off the stem, that might make the process a bit easier. Still plenty to figure out on this "simple" conversion lol
     
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  12. 2valve

    2valve Well-Known Member

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    Hi Mate
    Good to hear operation Big bore SRX is being worked on , looking forward to seeing update picture's.
    Especially of the front end mod , i'd love to improve the suspension on my bike also.
     
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  13. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Have a look on aliexpress or what's available in thicker (higher) lower bearings with 25mm I.D. 48mm O.D. - otherwise a 3mm spacer washer below the stock FZR250 upper bearing in the lower position could work and another 3mm washer spacer above the top bearing should get you there - correct?
     
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  14. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    To have a stepped spacer made up isnt a big deal... my mate across the road has a contact at the local TAFE so I will prbably go down that road...I will get it drawn up and then there will be some documentation... hopefully.
    That way I can have the bottom step the same size as the SRX to ensure it suits the lower seal as well.
     
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  15. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    AAH - that makes it easy then - I got one made for mine, it was all wrong, too high and too tight - used nearly 0.1mm interference fit on a 30mm bore, when I went to remove it all to 'repair' it, the bearing inner race just cracked from being pressed on so tight - colour me unimpressed
     
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  16. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Wow... that would have been a tight fit. As I have the SRX stem for comparison I will have them match up as close as possible to that, maybe a fraction of a smidge (technical terms of course) under. I can always loctite the inner race to be sure.
    I will look at keeping the Aprillia stem in the freezer for a day before and then warm the bearing inner up with a heat gun (every little bit helps). I dont have a press anymore so the more subtle I can be the better for setting the sleeve onto the shaft and the bearing inner on the fitted sleeve :)
     
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  17. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    A fraction of a smidge is all it needs IMO - subtle is the go.

    One trick I spotted on youtube is wrap bearings in a wet paper towel or small rag and then hit cook until it's steaming - let it heat soak for a bit then try and fit - should be very close to 100 degrees - works for sealed greased bearings especially well as it doesn't risk burning anything by overheating
     
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