lorenzo Posted July 30, 2014 Report Share Posted July 30, 2014 So, I've got this GSXR600 that's had some money thrown at it during its time as a race bike, with a proper (did the TT, came 2nd at the manx type proper) rider on board. However, after having a tootle around donington the other day, I found it really odd going into bends on anything other than an open throttle. Basically, round the fast stuff, I was fine, Hollywood, Craner, Coppice all felt great, the Melbourne Hairpin & Goddards both felt, even at only very gentle amounts of lean, like the bike was going to low side from under me, it was like riding on shit tarmac in the wet. As soon as it started to go over it'd be really twitchy. The suspension guy had a look, backed a fair few things off as most was on max, and although it improved, it still wasn't great. As I went back to him later in the day, he was swamped with loads of guys wanting tweaks being done, at one point he was turning people away as there was a queue of 5 or 6 people waiting, so it's no wonder he didn't spend hours fine tuning my bike. He had the time to take me cash, of course.... So, I've taken a few measurements, still on the same settings as when I finished at Dono, the forks are fitted with WP cartridges in there, which I beleive are closed, hence revalving could be an issue for a pleb like me: 7 clicks of preload from its minimum, 22 clicks of rebound from min, 24 comp from min, oddly the left fork can do 38 clicks, the right just 30 of rebound. Is this a knackered adjuster or do these forks come with hi & lo in a leg each? The static sag, from a full stroke of 120mm, dropped the bike 22mm to 98mm. With the preload wound off fully this sag only increases by another 3mm to 25mm. After Dono I still have another 19mm of fork travel left unused. So, given that info, I think my front end is too firmly sprung, I've got .95 springs in there at the moment according to the receipt I've been given. I've had a mooch on youtube and there's a guy on there showing how to change the springs in a closed cartridge WP fork, but it's on a motocross bike, so they're not exactly the same as my forks. Is it just a case of swapping them, as per the video, or is there more to it, as mine aren't the motorcross ones, but GSXR forks with WP carts? Link to comment Share on other sites More sharing options...
lorenzo Posted July 30, 2014 Author Report Share Posted July 30, 2014 Here's the video which details the ins & outs, but I wonder how similar these forks are to mine? Link to comment Share on other sites More sharing options...
chrisexup Posted July 30, 2014 Report Share Posted July 30, 2014 i'm no expert, but 0.95 isn't an outlandishly heavy spring you can check race tech's recommendation for your bike and weight http://racetech.com/ProductSearch/2/Suzuki/GSX-R600/2006-09 Link to comment Share on other sites More sharing options...
lorenzo Posted July 30, 2014 Author Report Share Posted July 30, 2014 That's what I thought, but the lack of use of the full length of the fork probably says otherwise, as does the fairly small sag amount, plus it does feel very firm, even with the damping wound right off. Of course, the receipt I have could be for old springs and I have 1.20's in there or something! I'm not unduly concerned about the damping as the range of adjustment on that is really quite wide, I'm sure I could get it to suit the spring without doing anything internally. Link to comment Share on other sites More sharing options...
couchcommando Posted July 30, 2014 Report Share Posted July 30, 2014 Have you measured front sag and rider sag, those figures will tell you if the preload can be set right, .95 prob isn't far off for you Personally I'd set sag front and rear and damping on the soft side, have you access to a standard bike to feel what normal damping is like, set yours similar Link to comment Share on other sites More sharing options...
Gobert Posted July 30, 2014 Report Share Posted July 30, 2014 If you can only get 25mm static sag with minimum preload then something doesn't seem right.......... Link to comment Share on other sites More sharing options...
couchcommando Posted July 31, 2014 Report Share Posted July 31, 2014 25mm static sag sounds ok for track use, what is the rider sag if it's 35-40mm then the spring is right for you Link to comment Share on other sites More sharing options...
vfr4 Posted July 31, 2014 Report Share Posted July 31, 2014 http://www.bikersoracle.com/vfr/forum/showthread.php?t=115923&highlight=ibbott+code This (pdf in second post) demistifies suspension and breaks it all down into simple steps - I've found it very useful Link to comment Share on other sites More sharing options...
Gobert Posted July 31, 2014 Report Share Posted July 31, 2014 25mm static sag sounds ok for track use, what is the rider sag if it's 35-40mm then the spring is right for you I agree but usually you have more than that at minimum preload? Link to comment Share on other sites More sharing options...
willbloke Posted July 31, 2014 Report Share Posted July 31, 2014 http://www.bikersoracle.com/vfr/forum/showthread.php?t=115923&highlight=ibbott+code This (pdf in second post) demistifies suspension and breaks it all down into simple steps - I've found it very useful Looks like you need to be a member to see it ? Link to comment Share on other sites More sharing options...
lorenzo Posted July 31, 2014 Author Report Share Posted July 31, 2014 Looks like you need to be a member to see it ? Yep, that's a bummer, but if you were to link to the PDF directly, would that be allowed? Link to comment Share on other sites More sharing options...
couchcommando Posted July 31, 2014 Report Share Posted July 31, 2014 I agree but usually you have more than that at minimum preload?Maybe but if both figures are right it's not a worry, Lorenzo have you measured static and rider sag ? Link to comment Share on other sites More sharing options...
vfr4 Posted July 31, 2014 Report Share Posted July 31, 2014 http://compostriders.com/charles/suspension%20articles/Suspension_Education_Program.pdf this appears to be a retyped and poorly formatted copy of what i posted above. If anyone wants a copy of the original just let me know. Cheers, Al Link to comment Share on other sites More sharing options...
TLRS Posted July 31, 2014 Report Share Posted July 31, 2014 How's the shock setup? Link to comment Share on other sites More sharing options...
lorenzo Posted July 31, 2014 Author Report Share Posted July 31, 2014 With the 7 clicks of preload and me on the back it drops to 88mm, 32mm of sag. With the preload on minimum this grows to 36mm sag, the same 4mm difference as before. Basically, I drop it by another 10mm. Incidentally, that set-up guide, it's awesome. I'm finding it really frustrating that the bike's not road registered yet as I'd love to be able to have a play with some of these things and get an idea of what's going on a bit more. A track day is a fucking expensive way of finding out about suspension settings (but fun getting there too i suppose!). Link to comment Share on other sites More sharing options...
dansp1 Posted July 31, 2014 Report Share Posted July 31, 2014 How's the shock setup? This, how is the rebound on the rear? too much and it will keep the weight off the front and make the bike feel nervous Link to comment Share on other sites More sharing options...
lorenzo Posted July 31, 2014 Author Report Share Posted July 31, 2014 To be honest, I've not played much with the rear, bluntly, it's fucking hard trying to take measurements ferreting about in the garage on my own! My gut instinct tells me that the whole bike is hard, front and rear, and that'd make sense really, the previous owner wouldn't have had it rock solid at one end and not the other, he'd have done them as a pair. With regards the damping, the range on both ends is so wide that I'd have thought that the damping is within the scope of the adjustment as it is at the moment, but the springs are certainly fairly firm and there's not a huge way around that, as far as I can see, which brings me back to the first question: These closed cartridge forks, is it possible to change the spring like in any other fork? Link to comment Share on other sites More sharing options...
couchcommando Posted July 31, 2014 Report Share Posted July 31, 2014 So was the sag set correctly or have you changed it now you've had the guides ? Link to comment Share on other sites More sharing options...
lorenzo Posted July 31, 2014 Author Report Share Posted July 31, 2014 I can't set it correctly, even with the preload at minimum it's still at the softer end of 'race' or the firmer end of 'road'. According to the Andy Ibbot guide I'm after 30-40mm static and 35-50mm rider at the front, I have 25 & 36mm with the preload at its minimum. As i said, I'm struggling to do rider sag on the rear, but static is ideally 15-25mm rear in that guide and I have 8mm. My figures pretty much put it in the middle of the race sag figures in that guide, which would probably be fine if I was a racer! I know I can change the rear spring without too much difficulty (I may speak to a suspension specialist to see if they can tell me how much softer I want to go from here), but my big worry is over the front and if they require a specialist to sort the gas charge in them with just changing the spring. Link to comment Share on other sites More sharing options...
Mark/Foggy Posted July 31, 2014 Report Share Posted July 31, 2014 As it goes I was starting to think that the rear spring was much softer in comparison to the font, but it seems that the balance should about right. Where's the rear rebound clicker set in it's range? 'Nother thing, now you've got some data, does the geometry seem right. Front ride height you've been through, how's that unladen rear ride height compared to the data you've just got. Also, nobodies fucked about with the bell crank and dog bones have they, it has been known. I have seen a bike reassembled with the crank the wrong way round, which had an alarming effect on what the bike was doing. Looked quite normal on the bench. Link to comment Share on other sites More sharing options...
blow_away Posted August 1, 2014 Report Share Posted August 1, 2014 You're going to need another pair of hands to get the static sags measured accurately. Don't forget to wear your riding kit when you do it as it can add a significant amount to your weight, and sit in the crouch when you do it. You can't really do any good setup work until you have got the sag right. I'd disagree about the track day being an expensive way to get a setup - on the road you don't get the same repeatability as the track. Getting a cheap track day is way cheaper than taxing, insuring and MOTing your track bike, unless you are going to do it Joey Dunlop style :-) Link to comment Share on other sites More sharing options...
Gobert Posted August 1, 2014 Report Share Posted August 1, 2014 I can't set it correctly, even with the preload at minimum it's still at the softer end of 'race' or the firmer end of 'road'. According to the Andy Ibbot guide I'm after 30-40mm static and 35-50mm rider at the front, I have 25 & 36mm with the preload at its minimum. As i said, I'm struggling to do rider sag on the rear, but static is ideally 15-25mm rear in that guide and I have 8mm. My figures pretty much put it in the middle of the race sag figures in that guide, which would probably be fine if I was a racer! I know I can change the rear spring without too much difficulty (I may speak to a suspension specialist to see if they can tell me how much softer I want to go from here), but my big worry is over the front and if they require a specialist to sort the gas charge in them with just changing the spring. 30-40mm of front sag is a lot on a track bike. Link to comment Share on other sites More sharing options...
lorenzo Posted August 1, 2014 Author Report Share Posted August 1, 2014 As my van implosion has skinted me out, I'll be doing cadwell with just minimum preload and see how that feels. If it improves things then I know that I'm on the right path. I'll also keep my eye on the cable tie on the fork leg, see if I start using more of the travel. Link to comment Share on other sites More sharing options...
lorenzo Posted August 5, 2014 Author Report Share Posted August 5, 2014 So, I did a little experiment this morning, I whacked the front preload and the damping up to maximum on the little NC as my test mule, then went on my normal route, riding normally, all stuff I'm used to. Although it wasn't identical, the effect was very similar, a bit nervous going into corners on a neutral or closed throttle, but quite good when accelerating harder through the corner. Tonights experiment on the way home will be to back one of the values off, probably the preload, but keep the other where it is, and see what difference that makes. Obviously, this isn't a perfect replication of the issues I had with it, it's a different bike with different spring rates, geometry etc, but it's interesting to see how things respond and how i respond too. I've never really thought about the fact that rider A might prefer one set of settings for the very same bike that rider B doesn't get on with, but it's interesting to find these things out about myself. If it turns out that I like firm damping but softer springs, i know what I need to do. Of course, I still need to find out about how I take these closed cartridge forks apart, which'll be my next step. Link to comment Share on other sites More sharing options...
lorenzo Posted August 5, 2014 Author Report Share Posted August 5, 2014 More testing on the nc: preload back to where it started, but damping still on maximum. The bike felt better but odd, the front didn't have the same about to wash out feeling but it still felt a little vague and remote. At least I'm learning what difference various things make and can hopefully translate this into changes on the gsxr. Link to comment Share on other sites More sharing options...
lorenzo Posted October 13, 2014 Author Report Share Posted October 13, 2014 So, get some 9KG springs Kais said, yours are 9.5KG. It'll make it all much softer they said. I managed to find a bit of a bargain at Ten Kate, a set of 9KG WP springs, delivered for £33! Bargain, snapped them up, and dropped them off at Kais, along with the forks. They turned them round double quick, about an hour, so I just had some lunch and zipped off home to fit them. Exactly the same, to the millimetre. Arse. Maybe I didn't have 9.5's on to start with then... Link to comment Share on other sites More sharing options...
stupid luke Posted October 13, 2014 Report Share Posted October 13, 2014 So, get some 9KG springs Kais said, yours are 9.5KG. It'll make it all much softer they said. I managed to find a bit of a bargain at Ten Kate, a set of 9KG WP springs, delivered for £33! Bargain, snapped them up, and dropped them off at Kais, along with the forks. They turned them round double quick, about an hour, so I just had some lunch and zipped off home to fit them. Exactly the same, to the millimetre. Arse. Maybe I didn't have 9.5's on to start with then... If all else fails sell the 9.5's on ebay and you should get more back than you just paid for the 9's.I put 9.5's in the Fazer and cheapest was K Tech (90 quid ish). Wouldnt it just be cheapest to ride a bit faster and brake a bit harder and later though Link to comment Share on other sites More sharing options...
lorenzo Posted October 13, 2014 Author Report Share Posted October 13, 2014 If all else fails sell the 9.5's on ebay and you should get more back than you just paid for the 9's.I put 9.5's in the Fazer and cheapest was K Tech (90 quid ish). Wouldnt it just be cheapest to ride a bit faster and brake a bit harder and later though That's the thing, i don't have 9.5's, I've got 2 sets of 9's... The other annoying thing is that I can't just get hold of these springs from anywhere, they're a diameter that're specific to WP cartridges, which is the real pain in the arse. Link to comment Share on other sites More sharing options...
couchcommando Posted October 13, 2014 Report Share Posted October 13, 2014 As you're not the smallest fella surely 9's can't be too stiff, I always have 9.5 or 10's and we're a similar size. I may go a bit quicker but no suspension man ever asks your speed just your weight, maybe they should I dunno ? Link to comment Share on other sites More sharing options...
lorenzo Posted October 13, 2014 Author Report Share Posted October 13, 2014 I have a feeling that it's possible that the difference is because of the length of the springs; I'm far from a suspension expert (you may have guessed this already), but previous suspension dealings I've had usually had much longer springs, these are obly 280mm long. I've a feeling that this shortness is what makes them so firm; if they were longer the bike would sit down on the springs a bit more. Link to comment Share on other sites More sharing options...
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