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Forks - Improvement / Replacement Advice Please

Discussion in 'Supersport (1974-2007)' started by p murphy, Aug 7, 2019.

  1. The 2002 750 ie sport (dark) has been trundling around in a satisfactory manner and I want to improve the forks.

    The rolling restoration included a refresh of the existing items ( and rear shock) but the forks are unadjustable ( Marzocchi's ?) and crude by any modern standard. Note, I think the existing forks are NOT the originals as the bike came to me with dual front disks - however, they do seem to be off another ducati model of the same vintage.

    My options are ;

    1. Refresh again with lighter oil and see how much improvement that is

    2. Replace with suitable, adjustable forks from another bike - this is where some guidance would be appreciated. Which ducati forks fit straight on ( with the correct leg diameters for the yokes) and have the correctly spaced brake caliper fittings? Have you done this swap and how much improvement was there ? I believe spacers to sort out any difference in fork leg diameters - v - yokes are available but from where ?

    3. Buy some very expensive alternatives from new - the bike value does not warrant this in my view and I would rather throw that money at a better rear shock in due time.

    Patrick
     
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  2. The top yoke diameter should be 50mm and the lower yoke 54mm.
    I've got several pairs of forks that pontentially would work, ST3, 749, Monster etc.
     
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  3. Monster and SS forks are similar, but the spring rates are different. Monster are lighter.

    Adjustable Showa forks are a little longer than non-adjustable, though shouldn’t cause too much trouble with clip ons.

    Have you spoken to a specialist such as Maxton to find out what they can offer as there’s still a lot of dissatisfaction with the Showa adjustables.
     
  4. In my carby I have Maxton internals in the original Showa forks, and a Maxton shock, handles awesome. In my ie, it's the standard forks, which are fully Adjustable. Maxton not cheap but best mod I made
     
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  5. Thanks for helpful response.

    Will measure and report on diameters asap - forks off bike at present and with suspension people near me but we have failed to source correct replacement springs and so I am now considering wholesale change as, even with better springs, the current forks would be non-adjustable.

    Maxton will sort no doubt but cost will probably be uneconomic ? .. mind you, no-one buys a Ducati for reasons of economy !!
     
  6. I went for option one, which worked fine for me, as I’m no Marquez
     
  7. Absolutely uneconomical, however its a keeper for me and worth the big improvement in handling. It's up to you how far you go. The standard forks are good according to Maxton. Hence the reason I replaced the internals. Phone them, very helpful
     
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  8. An Emulator kit from K-Tech/Maxton/ Wilbers will be a cost effective upgrade that won't break the bank.
    Are your front springs Linear or progressive?
     
  9. believe the forks from a 900 ie are a direct swap and adjustable considering it myself
     
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  10. I did a complete front end swap on my carb 900 ss. After looking at the Suzuki cartridge swap for the SS adjustable Showas (some details on the internet and Performance Bikes, just needs one hole enlarged from 10mm to 12mm in the forks to fit apparently), I ended just buying a complete GSXR 600/750 K6 front end and it was a simple fit.

    Best of all it was a significant improvement not just in suspension function and feel, but with the benefits of lighter wheels and great radial brakes. Bit of a win!

    This front end will actually be for sale in a month as I am duplicating my 848 front end on the SS to make track days easier. So let me know if you, or anyone is interested.

    Here's a photo of the forks in action at Brands :)

    upload_2019-8-8_13-57-21.png
     
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  11. Andrew

    Noted

    May be interested as the front brakes are also a little ancient

    Can you confirm stanchion diameters at bottom and top yoke fittings ( I don't know if Carby yokes are same as my 750 ie sport yokes), likely price and where you are.

    Patrick
     
  12. Hi Patrick,

    It is a complete front end with triples and clip ons included, so it is more a case of making sure the steerer tube length and internal diameter are the same as the carb frame.

    Depending on where you are if you bring the bike over we could do the install in an hour or so of you decided to go for it. Not thought of a price yet but will work it out over the next few days.

    And yes, you'd love the modern brakes!!
     
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  13. Noted

    will advise steering tube length and internal diameter later this evening -
    the tube is on my workbench at present.

    I am based in sunny Plymouth where it has just started to rain !

    Patrick
     
  14. I'm stuck in Holland with a 2 hour delay back home to a village near Brighton...... I'd prefer being home in the rain :)
     
  15. Measurements

    Steering tube length 175mm

    Internal diameter approx 52.36mm - hard to measure as either end has the bearing collars inserted - this is more or less the correct reading.

    The current steering stem is 25.79mm in diameter and 215mm long

    Let me know what you think. Some other considerations for me are aesthetic ie "loss" of the (recently) re-sprayed front wheel to match the rear ( see my "rolling restoration" posts) / mismatched wheels.

    Of course the pluses would be decent forks and brakes in one go ...
     
  16. Update

    Thanks for replies everyone - will go for re-assembly with 4 weight oil
    to see how much difference that makes. Gets me back on the road.

    Find out if Suzuki front end from Andrew will fit and consider purchase - I looked through parts nos for Carby 900 steering stem (3422071A) which is the same as my 750sport ie steering stem part no SO, conclude steering tubes are probably same dimension on both models and a swap may not be too much trauma. Caveat is I don't know if Carby 900 part was changed during its manufacturing run/ which year version you are running, Andrew ?
     
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  17. I've checked the bearings I used as that seems the easiest way to asses the fit across models, and the bearing OD (and ID of the head stock) is 52mm. Bearings are Taper Roller Bearing 30x52x16mm

    So, does this fit the IE model? I'll check the length later today when i get to the shed!

    BTW mine is a 1992 model.
     
  18. It’ll be interesting to see what difference the lighter oil makes for you.
    I combined 5 and 2 1/2 to get something like 3 1/2 and it certainly took the harshness out of the forks.
    More dive when braking of course but I didn’t mind that too much.
     
  19. What air gap did you leave on top of the oil as that affects dive too?
     
  20. When doing the ones on our old track 600 monsters, which were not allowed to be adjustable, we would go 7.5 wt, correct weight linear springs, and IIRC 150mm air gap as a starter. Seemed to work pretty well for cheap cost :)
     
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