Kezza's DR650 RMZ fork upgrade

Discussion in 'Thumpers' started by kezzajohnson, Feb 26, 2016.

  1. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    A great buy came up on a local facebook page that I couldn't resist. I have already upgraded my suspension with Eibach 0.47 springs and Cogents DDC's on the front, plus a 7.5kg/mm spring and Gold Valve on the rear shock and I have the suspension working much better than the stock flexible and soft stock suspension, something is still missing from the DR... more ground clearance and ridgitity. Now, the DR is no Motocrosser but there is often some harsh terrain I can cover where even the upgraded stock suspension's limits are quickly realised. I have always had it in my mind that if a set of inverted forks came up at the right price, I would grab them and put them on the DR.

    It started out as this. A 2006 RMZ frame, front end, rear shock and swingarm and complete set of wheels including bearings, seals, axles, front and rear calipers, master cylinders including the brake lines and the CDI.

    When I got it home, I stripped it down and promptly listed on ebay what I didn't want.

    [​IMG]
    #1
    Benduro likes this.
  2. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    I found and downloaded a free PDF Manual online for the 2004 KDX250F which is actually the same bike as the 2006 RMZ250 that was joinly manufactured by Kawasaki and Suzuki. The manual has theses exact forks thus made working on them and gathering specs so much easier.

    The forks were striped down for an inspection and everything looked pretty good - The inner (lower) tube chrome surface undamaged, no pitting or scratches. They still had oil in them, albiet a bit dirty and the seals weren't leaking but the bushes were worn beyond their serviceable life. The springs measured exactly as per the standard free length in the manual (460mm), so they haven't sagged at all. I could feel a bit (very very fractional) of lateral (side to side) play between the lower and upper tubes but it was very had to measure and is probably normal. The outer tube bores looked in good order apart from a section near the top where it looked like the spring has been vibrating/rattling against the outer tube. The area swept by the inner tube/bushes looked perfect so a new set of Bushes, seals and wiper seals were ordered from my local Suzuki dealer. I decided against rebuilding the valve cartridge at this stage mostly due to the fact I didn't have the right tools to stop it rotating while undoing the bottom cap, so I have left them as is at this stage and will just flush the tubes with a bit of fork oil before rebuilding with new oil. I am just going to see how it rides before I lash out on new springs and revalving.
    These are 48mm KYB forks also common to the Kawasaki KX250F, and are reported to have 0.44kg/mm springs which may be a bit light on for the DR considering I have 0.47kg/mm springs in the stock forks. Not sure about valving but the rebound damping is adjustable so I guess the springs, fluid and valving will define the compression damping.

    Offset is identical to the DR.

    [​IMG]

    They are 40mm longer (axle centre to top of tube) than the DR stockers.

    [​IMG]

    Tubes seperated to replace seals and bushes

    [​IMG]

    Worn guide bushes -Lower- New one on the left, worn one on the right

    [​IMG]

    Worn Guide bushes - Upper - New one on the left, worn one on the right

    [​IMG]

    Glad Wrap over end of the inner tube to assist putting new seals on without cutting them on the very sharp bush recess at the top of the tube. A bit of grease on the inside of the seal also helps it slide over. There is a tool called a fork bullet for this purpose if you really want one.

    [​IMG]

    After fitting the seals and bushes the forks were reassembled and with the spring removed and upper fork tube fully compressed, approx (gradually) 560 mls of 5 weight suspension fluid was added. With some pumps of the the piston rod assembly and outer tube to bleed the fluid into the bottom chamber, whilst keeping the fluid topped up to the top of the inner tube, sufficient extra fluid was added to bring the level up to 100ml from the top of the upper tube. Specs say between 70 and 120 mm so I have gone a happy medium to start with until I have sorted springs and valving.

    I needed two x 1 litre bottles of this @ $20.00 per litre and may yet go to a heavier fluid.

    [​IMG]
    #2
    Benduro likes this.
  3. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Talk about the Chicken or the Egg... I am reinvigorating these forks with new seals and bushings before I even know they will fit, but initial measurements and some guess work led me to be believe that they could. I had a boss once that taught me to "bite off more than you can chew and chew like hell until you can swallow"
    I decided to apply that here. I had committed to the purchase and I was going to cement that commitment by spending money on the forks first and then I would have no choice but to make them fit. The forks were obviously going to raise the front of the bike and I would have to find a way of raising the rear to suit, but that can come later.

    First Problem:

    Not unexpected as I had read Snowy's account of fitting the same forks to his DR650. The problem being the RMZ stem is about 10 mm longer and the upper bearing ID is smaller than the DR meaning the DRs upper outer bearing can't be used. That's OK, cause you could use the RMZ's outer in the DR's inner but I am not sure about contact area between the two. Secondly, the bearing surface on the RMZ is about 10mm higher than where it is on the DR which would mean using the RMZ outer on the DR inner on the RMZ stem would only just have the upper bearings ID contacting the stems bearing surface. Most of it would be over the taper of the stem and not making contact. Snowy's solution was to use a set of 07 RMZ triples (47mm) which have a shorter stem but he also had to bore the clamps of each triple (upper and Lower) out a mm to accept the 06 RMZ's (48mm) outer tube. He also said something about lacking height adjustment due to the clamping area on the '06 RMZ uppers, but I am not too sure I understand what he was getting at there. This is not really a big deal but I didn't have a set of '07 triples laying around like he did and nor did I want to purchase any. I got to thinking, why can't I use the DR's stem and have it pressed into the RMZs lower triple. It is the right length, would utilise the stock DR inner and outer bearings and the triples are the same thickness at the stem insert areas. After asking here on ADV and some research, I didn't really get any definitive answers as to why or why not it could be done. From all accounts and my measuring using digital verniers, the lower bearing surface is the same as the DRs. The underside stem flange (under the triple clamp), measured the same at 30mm, so one would assume that the pressed in portion of the stem would be the same. Everything else matched up and really now it came down to equipment. I was going to bite the bullet, so if no one else has pressed a DR650 stem into a '06 RMZ lower triple before, I was going to be the first. Jo Marino, an aquaintance, fellow DR650 owner,the owner of Ural dealership and a light engineering shop called Old School Engineering here in Cairns offered his services (for a smal fee) to press the two stems for me.

    I took them in to his shop and he got to work. RMZ stem pressed out, DR stem pressed out, DR stem pressed in. About 15 minutes later the job was done -easy peasy... Well how did it stack up?

    On inspection, after pressing the DR stem into the RMZ clamp ( and we didn't really measure anything as they looked the same) the lower flange portion of the stem was sitting proud of the underside of the triple. I asked Joe to give it another go, which he did but it would not budge any further without bending or breaking something. It was in as far as it would go.

    [​IMG]

    Trying to figure out what was going, I dropped the RMZ stem into the DR's triple and it fell straight in - all the way - no pressing, just by hand. It turns out that although the lower bearing inside diameters are identical, the pressed portion of the RMZ stem is about 0.5mm smaller in diameter than the DR's -yes 0.5mm - that's all it takes and had me asking, why do manufacturers do this shit ?

    The DR stem has obviously pressed in OK (having 0.5mm larger diameter at the pressed area than the RMZ), so it is in and it's in solid and it will just mean I will have to space the mudguard a bit rather having a flush fit. The circlip (metal oring) had only just gone in (due to slight taper at the base of triple) and then stopped it pressing in any further.

    I am happy that it is in and is not going anywhere soon, but my main concern now was stem length above the triple, the threads for the bearing preload castle nut under the top triple being in the right spot and there being enough threaded stem above the top triple for the clamping nut. This was all in the middle of my normal working day, but I just couldn't work with this on my mind. I ducked home quickly in between jobs and carried out a test fit... Fucking perfect !! Couldn't be better - I am wrapped.

    Below: DR stem pressed into RMZ clamp and the removed RMZ stem. you can see the difference in the lengths, bearings surfaces and threads.

    [​IMG]

    Below: Thread above upper bearing for the preload castle nut ... Heaps.

    [​IMG]

    Below: Bearing preload castle nut on but not tightened yet

    [​IMG]

    Below: Upper triple clamp on. Will have to use a thick washer to space to the nut.

    [​IMG]

    Below: Top nut on with a couple of washers under it - beaudifull !!

    [​IMG]

    [​IMG]
    #3
  4. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Now my next challenge is the axle wheel combo. The RMZ axle is 20mm with one end stepped up to 25mm and will only work in the RMZ wheel. I would prefer to use the wider DR stock rim. Unfortunatley the Dr's axle is a tad too short and would also need two bushes/top hats made up of different O/D for each side and one would need a thread in it. The nut end of the DR's axle will also disappear into the cavity of the fork leg axle hole and be difficult to do up/undo. Seeing as I bought the RMZ bit and have disassembled them, I found the swingarm axle is 17mm and just the right length and it has a self locking nut (same type as DR rear axle nut). I am only going to need a plain bushing made up for each side - 1 of 20mm O/D x 17mm I/D and 1 of 25mm O/D x 17mm I/D that of length that spaces the fork leg axle hole. I haven't trial fitted yet but I am assuming the DRs stock spacer and the speedo drive eliminator on the other side are going to space the wheel in the right spot but will get to that.

    Below:

    Left - DR axle, Middle - RMZ axle, Right - RMZ swingarm axle.

    [​IMG]

    Seeing as I am going to use the DR wheel, I am going to want some brakes and a caliper adapter will be necessary to run the Caliper from The RMZ fork to the larger 290mm DR disc.
    In view of this, I decided to go the whole hog and purchased Torpedo 7's DR650/RMZ oversized disc/caliper adapter combo to go with my DR wheel on these forks.

    [​IMG]

    That's all for the moment but stay tuned as the build comes together.
    #4
    fanatic291 and 97707 like this.
  5. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    7,960
    Location:
    Snowy Mountains Oz
    Looking good :thumb
    #5
  6. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Ok, so in view of the fact that this is very much a 'fly by the seat of the pant's' build, I have test fitted one of the fork legs to see exactly where the clamping areas are on the RMZ upper fork legs in relation to the RMZ triple clamps with the now shorter DR650 stem pressed in. Here is how it looks.

    Below: I am able to lower the forks in the triple all the way such that the upper tube is level with the top of the clamp and the cap just above it (as it would be with the DR) and still have the lower triple within it's clamping area also on the upper fork tube. This would give me the full 40 mm of extra length available at the axle over the stock forks of the DR650. I really have no idea exactly how this translates in to actual ride height difference, seeing as the forks are raked and not vertical, but some rough calculations tell me about 28mm increase in ride height at the front given the DR's 28.50 degree steering head rake.
    Don't ask me to regurgitate how I calculated that, but lets say it took a few beers and here's how:
    (and if you are a mathematician or geometry expert -please step in)
    Lets just say @ 90 degrees (vertical) the forks would increase the height by 40mm but the forks are not vertical but raked/angled) by the DR's standard head-stem rake of (I think) 28.50 degrees.
    That is 31.7 percent (close enough to 32 percent) of the 90 degrees. 32 percent of 40 mm = 12.8.mm. Take that away from the 40 mm and you get 27.2 mm. Close enough to 28 mm in extra height. Now, I am no mathematician or engineer, but that's my theory and I am sticking to it !!

    All of this is going to help me determine how I will raise the rear of the bike to match the front so as to not affect the rake or trail a great deal over what I have already. From there, it is going to be seat of pants -no more fancy smancy calculations - just trial and error.

    Below: Fork upper tube level with top of triple clamp

    [​IMG]

    Below: With the top of the tube level as above, the lower triple is fully on its lower clamping area (upper extremity of it) and you can see the available clamping area below it should I wish to raise the forks in the triples to lower the height (shiny part of the fork tube).

    [​IMG]

    If I did want to drop the forks to alter the height, I have the 25mm available to me to keep the upper triple within its clamping area of the upper tube and this would put the forks at 15mm longer than the stockers at the axles

    [​IMG]

    That will still keep the lower triple within the clamping area (see below)

    [​IMG]



    So, with regards to ride height and keeping the bike level and steering handling optimum, I have two choices.

    a: Lower the forks to level with the top of the top triple (28mm approx at the front in height) plus raising links in the rear that have coming from Germany. (reported to give 35mm height in the rear - provided they clear the linkages)

    The above is my preferred result, as it will give me the ground clearance and height I am after.

    b. Raise the forks till they are 25mm above the upper triple which will give only about 12.5mm ( given the rake and calculated as per above) and which is about the half an inch that an 18 inch rear wheel will give me to raise the rear a bit to match the front.

    I prefer to go the raising link option, as it will give me the height I am after but if there ends up being clearance issues with the linkages, I may drop that and run with an 18 inch rear wheel (which will also give me larger tyre choice) instead and raise the forks in the triples by 25mm.

    All else looks good. the RMZ steering stops are perfect and clear the oil cooler and I wouldn't expect any issues with my Acerbis 20litre fuel tank either

    [​IMG]

    [​IMG]

    [​IMG]

    By the way, if it all looks a bit dirty and marked, This is only a trial fit and measure. I will be pulling it all back down and cleaning/blinging it all to make it look like brand new. Not that it really matters ... Go bike - not a show bike.

    Options options...

    Stay tuned.
    #6
  7. sh4kes

    sh4kes Been here awhile

    Joined:
    Oct 17, 2012
    Oddometer:
    454
    Good work kez.

    I was going to ask how it all fitted with the Acerbis tank ;p I used '92 RM250 USD Showa's (cartridge forks) they *look* identical - they're not though as the triples on mine drastically fouled my Safari tank when turning. (Although the plus side was the stem was the right length and the RM250 bearings directly fitted the headstock of the DR, as well as the front axle being the right size, and fork spacing being bang on for the DR650.)

    Does the T7 brake adaptor bolt straight up to your new forks? I ordered the larger rotor but no adaptor (as none exist to fit my forks). I'll make my own adaptor later (when the engine is sorted), but would be very keen for some close up photos of the adaptor before and after install to get a handle on what sort of shape I need to machine.
    #7
  8. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Supposedly the disc setup will match. The adapter is for Kawasaki, Suzuki and Yamaha fork legs which all carry the same calipers and mounts. It is the size that will bring the caliper out to a 320mm disc, which in this case has the DR650 bolt pattern.
    #8
  9. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    7,960
    Location:
    Snowy Mountains Oz
    Your math does need a little tweek,
    length x cos(28.5) = result
    40 x 0.8788 = 35.152

    5 mm less than the 40 mm extra fork length is the answer, or 35 mm more height.
    #9
  10. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Throw that in me face... haha. Cheers for that. End of the day I will measure my heights after fit up and compare to the measurements at the same points that I have taken with my stock (upgraded) setup, which was good for what it was. Will get to even up through a combination of raising forks in triple and lifting the rear. Sag etc will need some work with springs/preloads both ends but I will get the ride heights sorted first.
    #10
  11. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    To answer your question sh4kes. Yes, with the 20 litre Acerbis tank, there is about 10mm clearance from the tank at full lock left and right - no worries.

    Probably doesn't look it in the photo, but it's there.

    [​IMG]

    [​IMG]

    Mock up with front wheel in place. Still have to instal larger 320mm rotor and caliper adapter so I can measure up bushings/spacers for the axle. With the wheel centred (rim to fork leg either side), the stock DR brake side spacer looks right but the left speedo drive eliminator is not quite long enough but a longer bushing/spacer for that side will work I think. I will however, do more precise measurements once the brakes are fitted to the wheel and fork leg.

    [​IMG]

    [​IMG]

    [​IMG]

    Looks like the RMZ swingarm axle is just the perfect length.

    And the stock DR bar clamps and risers fit into the RMZ triples rubber mounts nicely, however, I have some warp9 1 1/8 risers and fat bars coming for this build.

    [​IMG]
    #11
  12. Carl Childers

    Carl Childers Ghost in the Machine

    Joined:
    Dec 27, 2012
    Oddometer:
    3,342
    Location:
    Northern New Mexico
    It all looks great Kezza!

    Interestingly on mine I put it together with the stock RM wheel and rotor using the DR caliper, after reading the about the need for a bigger disc I planned on getting a bigger one with the adapter but in the interim have been surprised how well the bike stops with the smaller disc! Now I'm in no hurry to get one although I probably will to see what the difference is but for now it is stopping every bit as good as it did with the stock front end.
    #12
  13. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Cheers. Did you know we have a Town called Childers in South East Queensland Australia ? It's a Sugar Cane Growing area and a lovely little place.

    Anyhow...I love a powerful front brake and the 320mm disc with the stainless steel braided line I have already should be great. I am more worried about brake fade than anything which is why I went for the larger disc plus it looks horny. I could have gotten a 320mm disc for the RMZ front wheel that I have but I prefer to have the wider DR rim.
    #13
    Carl Childers likes this.
  14. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    7,960
    Location:
    Snowy Mountains Oz
    [​IMG]

    [​IMG]

    On my WP conversion this is how I set my axle up, bushing on the RHS end of the axle. This clamps against the speedo drive, or eliminator. I also tack welded a washer to the stock spacer on the disc side which gave me the disc alignment needed. The LHS bush is inside the fork. Note both are split, the LHS one not aligned yet with the split in the fork leg clamp. The bushes can be pinned with a roll pin if necessary.


    [​IMG]

    [​IMG]

    The RM conversion I did is very similar, except that the bush in the LHS leg has a top hat spacer for disc alignment. This one used a DR swingarm pivot bolt that had some more thread cut onto it, later shortened. I also used a set screw into the underside of the fork to lock the LHS bushing. Its visible in the above pic if you look closely.



    [​IMG]

    Here's the RM axle, with bushing roll pinned to it.

    Its normal to have the nut clamping the wheel to the LHS/disc side fork leg. I note that others have done it the other way though, and it appears you may be heading that way from the pic above.

    Not trying to steal the thread, just float some thoughts :D
    #14
  15. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Nah, that's great Steve. Gives me a much clearer idea of what to do. My axle in the photo was just put in there without too much thought about its orientation but I will be sure to swap it around so nut clamps against the caliper side. Not too sure how this can make a difference but if you say so, that's good enough for me. I like the idea of roll pin on one end- is that bush still split? Tacking the other into the fork is good too. Will save having wayward bushes during wheel removals.
    Thanks again. Kezza
    #15
  16. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    7,960
    Location:
    Snowy Mountains Oz
    All my bushes are split, means that there is no resistance when clamping them up. When making the bushes, then splitting them, sometimes the ID will shrink, it did in the case of my WP axle such that it didn't need pinning as its a nice tight interference fit. Residual stresses in the extruded bar no doubt.

    Because the forks can move a bit left to right, clamping to the brake side always ensures disc alignment.

    Shouldn't be an issue, but not unknown for spikey/sticky suspension to be a result of forks not parallel.

    Always leave the RHS clamp undone until bike is off the stand and undergone a few bounces to feel if its right. That's often enough to get them parallel, but sometimes some encouragment is needed, a tap with a soft hammer underneath the fork leg, or just pulling the leg one way or the other.
    #16
  17. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Good one. Ok so tonight I swapped the Torpedo7 disc on to the DR wheel and installed the caliper adapter so that I could start looking at spacers.

    Previous unused order of OEM disc bolts came in handy at last. 5 Of them plus the magnetic bolt for the vapor speedo pick-up. A bit of extra blue loctite on each one and 23 nm of torque to each one.

    [​IMG]

    [​IMG]

    The caliper adapter went well and fits up nicely to the DR caliper. This is just a trial fit as I have a rebuild kit for the caliper that I am going to do before the final fit up.

    [​IMG]

    [​IMG]

    [​IMG]

    I used the DR's caliper bolts and found out the hard way that are a tad longer than the RMZ ones - you can see them protruding in the photo below and ended up scratching my nice new disc. Have swapped them now.

    [​IMG]

    With the wheel fitted using the 17mm swingarm axle, my speedo eliminator as the axle bush on the non disc side and a plastic bush I made up on the disc side, you can see the gap between the fork and the stock spacer. This is with the disc centred in the caliper and I found the swingram axle nut washer was just the right thickness to take this gap up. I will follow Bergdonks lead and tack weld the washer to the spacer and then have a proper bush made up for that side fork.

    [​IMG]

    Below you can see the disc centred.

    [​IMG]

    With the disc centred, if you look closely and you will notice the wheel looks off centre and that is because it is.

    [​IMG]

    Being naturally gung ho by nature and often believing everything I read, when deciding to use the DR wheel, I had not considered the differences (apart from their width) before now. After a close comparison, the offsets of the two wheels are different. The DR has same size spoke both sides where-as the RMZ has longer spokes on the right hand side, shorter on the disc side. On top of that, the distance from the hub disc mounting surface in to the bearing is different (less than the DR) by about the same amount as the washer will make up for with the spacer on the axle. The DR and the RMZ spacers on that side are exactly the same length and the two hubs are exactly the same width. That's cool, the different bearing to hub offset is made up by the washer on the end of the spacer on that side but the rim/hub offset is a different. What it means is the DR's rim is actually 6mm closer to the right (non disc side) fork leg than the other side. Right side there is 16.5 mm to the fork leg and the Left side 22.5.

    End of the day, I dunno whether I should ditch the DR wheel and get a larger disc for the RMZ wheel and be done with it, or try and tweak the spokes on the DR rim to shift it by 3mm the other way. That will mean more work but less dough.

    By the way, the desert tyre you see on the front there has about 4500kms on it. Bloody good tyre that one...

    Ahhh... another sleepless night.
    #17
  18. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    7,960
    Location:
    Snowy Mountains Oz
    Take the tyre off and tweak the spokes, it'll pull across fine. The 50/50 ATF/Thinnners mix is great to loosen the threads too. You can attach a pointer to a fork leg and it'll work as a jig once the bushes and axle are sorted. A magnetic base and a dial gauge is good if you have it.
    #18
    kezzajohnson likes this.
  19. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Figured it will be easier with the tyre off and will measure the offset first and tweak it 3mm on my truing stand and dial guage. Place in forks and check - tweak again if necessary.

    These arrived today from Germany...but that's another thing :scratch

    [​IMG]
    #19
  20. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    3,270
    Location:
    Cairns - Queensland Australia
    Ok, so after fitting the disc and caliper and measuring up everything with ad-hoc bushes in the forks, it looked like the axle washer was going to be the addition spacer between the stock DR axle bush and the fork. The other side , the speedo, eliminator bush didn't need anything and in fact was about 1.5mm too long according to my calculations, but being an outside diameter of 25mm would still fit inside the fork axle space and I would just allow for that with the bush on that side. I decided rather than use the axle washer on the disc side though I would have a top hat style spacer made up to take up that gap. I messaged my mate Jo Marino -Old School Engineering with what I wanted but he didn't really understand and asked me to provide a diagram with the measurements. During my working day, I whipped up some drawings, with measurements, in my work car and dropped them off to Jo. Although a bit rough he then understood what I wanted.

    EDIT: After getting the bushes made up, it appears this arrangement is not going to work, mainly because is the one fix (nut) end of the swingarm axle which really needs to be able to pull into the right fork end once bouncing the forks and settling the legs. The other issue I had was on the assumption that the O/D of the RMZ swingarm axle is 17mm, the I/D of both the bushes was made the same when in fact they should have been a little bit less, say 1/2 mm or so, so that they would be a night tight interferance fit with the axle. As it stands, they feel snug but I can feel a bit of play between them and the axle. What this meant was they wouldn't clamp up on the axle when tightening the axle clamp. The axle clamps on the forks only open about a mm when undone and with the bushes in place, that mm was is not enough to clamp the bushes against the axle. Each time I fitted and measured the disc centreing, I was getting a different result, only by mm's one way or the other but enough to have to rethink the whole setup and dimensions of the bushes. Also considering that I am going to have to adjust the DRs rim offset by some 3mm or so, when I really don't want to change too much with the stock fixtures - I have already done the head stem but that is easy enough to reverse if I ever want to go back to stock. As I don't have a milling machine (yet), I have to outsource this so in the meantime, I am going to get a larger disc for the RMZ wheel and run with that -Seeing as I have the complete RMZ wheel including bearings, seal axle it is going to make for a much simpler swap at this stage and I can live with the slightly (1/4 inch) narrower rim. When I buy and lathe/milling machine (little way down the track), I will revisit it and have a play in my own time on my own gear rather than have to shim the bushes.

    FURTHER EDIT: See further posts as I have worked out the issue with spacing and bushings and am going back to the DR wheel. I couldn't find an oversized disc for the RMZ wheel either and didn't like the idea of 4 puny little disc mounts on the hub.


    Seeing as I really have no idea what the fork springs are that came with these forks, I am going to put these in 0.48 kg/mm based on advice and gut feeling. My eibachs in the stock DR forks are 0.48 and pretty right for what I do.

    [​IMG]

    And a bit of farkling too. Opening out the cockpit a little with some fatbars and Warp 9 risers.

    [​IMG]

    DRZ400SM headlight brackets are on backorder through Suzuki (couldn't find any second hand ones anywhere) and may well hold the project up.
    #20