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GS500F Modifications

Discussion in 'Modifications and Projects' started by Miraz, Jul 18, 2010.

  1. This GS500 was not initially my preferred choice for my first bike, but I just couldn't bring myself to pay $10k for something new and shiny fresh out of a showroom.

    I found this 2004 GS500 for sale about 500m up the road in good condition, one owner, 28,000km so I snapped it up.


    I've put another 10,000km on the clock over the last 3 months, I've learnt a lot and had a great time, but there are a few things that I'd like to change if I'm going to keep this bike for another 12 months until I come off the restricted license.

    - The suspension is too soft for my weight, which has led to some scares on the road as the forks bottom out under even moderate braking. I suspect that the damping offered by the original front forks and rear shock is not helping much either.

    - The brakes could be better - the front disc is slightly warped, the original brake hoses have not been replaced and balloon visibly under pressure. Whilst it is possible to overwhelm the suspension under braking, there is very little feel or feedback.

    - A number of other bits of maintenance are falling due - there are tight spots on the chain, both sprockets are pretty worn, and the tyres that were new when I bought it are both suffering - the rear has squared off and the front has scalloped.

    I'm not intending to throw a lot of money at the bike, the idea is to learn a little about bike maintenance and take the opportunity to see if I can address the suspension and braking problems along the way.

    So I thought I'd start a thread to keep track of what I've done, and share the learnings along the way...
  2. I thought I'd start at the back, as I'm still figuring out what to do about the front end.

    I managed to find a rear shock from a 2008 R6 on ebay for US$45 with the lower linkage and dog bones still attached. This shock seems to be an easy swap for the original unit - the only mounting challenge is that the mounting holes in the lower clevis are marginally larger - however as the roller bearings in the linkage are the same size, it is possible to re-use the bearing sleeve and mounting bolt to get it to fit. The R6 has a slightly higher spring rate, but a much better adjustable nitrogen charged damper.


    After removing and cleaning all the parts of the suspension linkage, it slotted into place pretty easily. Looks like it belongs there.

  3. Next on the list is the rear tyre...

    As the solution for the front end will probably involve replacing the forks, and that is likely to also mean a replacement of the front wheel....I've decided to change the rear wheel at the same time.

    Another round with ebay nets me a rear wheel from a 2000 GSXF 750, this is also used on the SV650 from the same period. This will allow me to move up a couple of tyre sizes, the original tyre is a 130/70 Bridgestone BT45, whereas the new wheel should accomodate a 160/60 tyre.

    This wheel uses the same wheel bearings, cush drive and spacers as the standard GS500 wheel, so the rear axle and most of the original hardware remains unchanged making for a very easy swap.

    The only other changes are a new rear brake disc $80 from a wrecker in Silverwater and a brake torque arm, also from a 2000 GSXF 750. The original unit does not provide enough clearance for the bigger tyre, I could muck around with bending it - but another round with US ebay finds me the right part for US$10.

    I had hoped to change the chain and sprockets at the same time, but ended up with a 49 tooth rear sprocket instead of the 39 tooth needed!

    New Brake Torque arm in place, not much clearance - but it does fit!

    Rear Wheel in place shod with a Metzeler Z6 170/60
  4. Looks good. Hows the ride? Did it remove the spongieness?

    Get new sprockets ASAP if they are worn, and throw a new chain on if it is abnormally tight. No use waiting until your sprockets turn into pulleys. :p
  5. I've also started pondering on upgrades for the bike and have researched a little bit on the subject. Now that I'm becoming a bit more confident on the bike I feel I am starting to brake a bit harder and I, like you, have found the bike shuddering under (what I would call) moderately hard (about 80% of locking it up) braking.

    This shuddering makes me think it is the front suspension bottoming out under load given that I have only put around 3,000kms on the bike. I found the following a good read (and if you have the money/time) and worthy of a try to stiffen the ride. It has step by step instructions including pics about halfway down;


    Another good read, seeing as you'd expressing concerns over ballooning brake lines and a warped disk.... and it's local ;)


    ps. Ok wow you are doing multiple posts before I can construct mine! Keep it up!

  6. Looks good Geoff, let me know when you want to meet up for a ride again.


  7. Bike looks good man, nice photo where exactly was that taken?
  8. Looks to me to be along the water of Kirribilli?
  9. Wrong side of the harbour - it's actually over on one of the Wharfs off Hickson Road.

    Sam - Thanks, I'd seen those posts already - my baseline solution was to rebuild the front forks using stiffer springs and cartridge emulators - then replace the aging brake components. I'm fast reaching the conclusion that the cost difference for an entire replacement front end is not that high, with potentially better results.

    iEdd - I bought the chain and sprockets, and would have fitted them yesterday if they had been the right size. I swapped them for the right components this morning, so I might swap them on during the week.

    Swapping the sprockets over today gave me an excuse for a test ride from Mona Vale to Auburn and back via Bobbin Head and West Head. I started out very gingerly with the fresh tyre, and a little nervous about clearance between chain and the wider tyre. I stopped several times during the first few km to check that nothing was rubbing....all seems good.

    Once I'd gained a bit of confidence that the rear end of the back wasn't about to fall apart, and the tyre had been scrubbed a little I was able to push it a little harder and start to get a feel for the improvement made.

    As expected the rear end now feels a *lot* more planted, the rear end doesn't compress so readily under acceleration and no longer feels skittish when tracking over mid corner bumps.
    There are a couple of corners coming up from Akuna Bay towards West Head that used to result in the center stand crashing into the tarmac (spectacular showers of sparks at night!) that now not only felt much better controlled, but had clearance to spare. Simon L will attest to this as the scraping noises were apparently audible over the sound of his beast when he was following me!

    The ride quality is also significantly better as though the minor ripples in the road surface have been ironed out. It feels much happier on the power pulling out of a corner than it did before....difficult thing to describe really.

    So I'm pretty happy so far - only about 3 hours of spannering involved and significant improvement in handling already.

    I'm leaning towards a post 2004 GSXR front end swap, which will give me a decent set of upside down cartridge forks and radial brakes if I can find one for the right sort of money.
  10. Hey Geoff, Steve F here, looking good :)

  11. Thanks Steve, we should organise a run....I'd love to have a look at what you've done to that CX.

    Another foray on ebay last night has secured most of the front end components;-

    For US$450 I was able to get the complete front end from a K5 GSX-R 750 - 50mm USD forks, upper and lower triple, radial brake calipers, master cylinder, levers, clip ons, wheel, brake discs, new brake lines - hopefully that should be delivered early next week.

    A further $75 has secured a front fender from another ebay seller in Queensland.

    So the two big outstanding questions are now:-

    1. Instruments - the new front end has no provision for the existing cable driven speedo, and the new upper triple has no mounting tabs for the existing instrument cluster and warning lights.....so I'm going to need to figure something else out.

    2. Bars - I want to preserve the upright riding position, so I'm going to need to come up with something to replace the clip-on bars that are coming with the new front end.
  12. 1. it shouldn't be hard to find a non-critical point ot drill and tap a bracket onto the top tripple clamp.

    2. look up streetfighters. the gsxr will definitely have some aftermarket bits that allow you to bolt on bars. Won't be cheap however. Alternatives you can get riser style clip-ons. Also not cheap.
  13. Mounting the instruments shouldn't be that tricky - I suspect that the lack of cable drive from the front axle will mean that the speedo will need to be replaced with an electronic unit.
  14. I run an acewell speedo, imported it from the US and cost about $140, mine doesn't have a fuel gauge though and those versions are a little more expensive but works really well and has a lot more functionality than my 30 year old stocker did :)

  15. I was just looking at the Acewell units, the other option seems to be Trailtech, but I think I prefer the look of the Acewell unit
  16. I run an Acewell for a while on a streetfighter. Hard to see the grey on blue readout in half light and/or rain. Also I never go the tacho to work properly, though this was a little bit of laziness on my part. I can't remember what I paid, but it was the one with the fuel gauge and I remember having a sore arse afterwords.
  17. How did you hook the tacho up?
    - did you just wrap the lead around a HT lead, or take proper feed from the coil?
  18. Tried both. In the end I concluded it needed the resister. From memory I tried one. That didn't work, but I never went back and mucked around with different resistors. BTW it was a gsxr1100, so the problems may well translate to the gs500.
  19. You do need the screen at the right angle to see it well, In saying that I've had no problem with seeing mine. And yep, dont buy locally, they are at least twice the price of getting it from the US, www.electrosport.com

    Hmmm, looks like electrosport dont stock speedos anymore, cant find them on the website.

  20. Next round of parts has started to arrive, if all goes well then I'll start to tackle the front end next week. I've modified the triple clamp already by pressing in a GS500 stem and making up some steering stops for the lower clamp.

    GSXR-750 forks, axle, brakes and modified triple.

    New front wheel to match the rear fitted a few weeks ago