Gen 1 w/zx6 shock, 05 GSXR forks, notes & question

Hello All,

Some results and a geometry question:

Put an 05 ZX6 Showa shock in and have run some laps. The shock measures 333mm (4 mm shorter than stock shock). The spring rate matched the rate of the Ohlins that I could not afford. Very happy with it. Feels great. No more trampoline effect. Wheel hop gone too. I wiegh 210 lbs without gear. For now I need no better than this. The GSXR shock I tried was no f'n good.

Lowered the front by sliding the tubes up about 20mm. Turned my best lap time by two seconds. Maybe coincidence - too soon to tell, but with the legs back in the stock position I have not matched that time. That was with stock dogbones.

Now I put in shorter dogbones with legs in stock position and ran real well, but the lap times were not my best (I thought they were as I ran those laps).

Getting ready to put on an 04/05 GSXR 600/750 Showa front-end complete. The legs have been Race-Tek valved and sprung for me. They also have the extenders fitted, so that gives them another 10mm length. They now measure (very roughly) about 25mm shorter than my stock SV legs. The SV legs measured (again-very roughly) center of axel to top of leg, approximately 756mm not counting the cap.

The question, as I prepare, is: Does anybody have favorite "golden" numbers for the geometry? I wonder if I need to put the stock dogbones back in, or just try it with the increased angle that will result from the shorter forks. Got a Scotts damper on, BTW.

A fellow from SVraceshop helps by telling me they have had luck with 415mm between center of swingarm pivot to ground with no rider. That still leaves the question of bias. Also they suggest a 120/70 to get back another 10mm height.

Any experimentation time that is saved is a great thing because it all has to get tested on the track, so I'd like to minimize the noodleing. Not gettin' any younger ya know.

Thanx,
Denis

[northwind]

Is it SVRS that are doing the work? They're internationally renowned thieves and liars, they were caught out selling "revalved" GSXR shocks with terrible bodges and outright unsafe defects a while back... They didn't even attempt to deny it, just wrote off the entire SV Rider reading market as a dead loss, since they were so obviously caught bang to rights- the fraud was found by about 4 different independants (as well as a couple of non-independants like Twin Works and Traxxion) and they could only come up with dismal excuses. It's worth posting in SV Rider about this if you want to learn more, quite a few guys there got burned and some of the people involved in outing them are still on there too. I would personally like to punch each and every one of them in the teeth, though.

The numbes for the front forks there sound a tad off, most of the GSXR forks sit around 25mm shorter at standard length, without the lengthening kit. I don't know that particular model though, I have a set of those in teh mail but not yet fitted.

Personally, I like the high tail, low front approach, but not everyone does- it makes it very quick turning, but also makes it almost too easy to turn- midcorner it's very easy to change direction, which is nice if you're about to crash but it makes it less easy to hold a line. With more conservative geometry it's slower to turn but much more settled. I have the Ohlins stretched out and the forks (GSXR750 K3) at standard length, and I like it a lot.

Good to hear results on the showa 636 shock, it seems like a great option but so few people have tried it.

Hi Northwind, was hopeing you would see my post and reply - but did not expect that news. They sounded professional and on the level on the phone. Everything they sent looks good.

They sent the original valves and shim stacks in the race-tech box with papers. I had no reason to doubt. Now what? Do you think I need to take it apart and check it out? I'm no fork man. Hell.

BTW: I know my numbers are off - I used a tape measure and was not careful.

Thanks for the input NW. Let's see what else comes back on this.

[21QUEST]

I'm no expert but I'm running same forks(standard but playing around with different oil viscosity) on mine.

If they have been extended then forks shouldn't measure 25mm less than standard SV forks . Standard GSXR forks measure roughly 20mm/25mm shorter than the SV.

352mm(+15mm) shock length has been said to the magic number for a good swinging arm angle...all arguable as the say

Personally, for waht it appears most of your riding is, I'll say 25mm to 30mm extra ride height(compared to standard) measured at tail using shorter dog bones. You'll have to work out the dog bones to give that figure. I'm assumming 5mm longer shock is roughly 10mm at tail.

Run rider sag a bit more than you'd normally IMHO. I'd run no less than 35mm and could probably run a bit more(possibly up to 40mm). Depends on how the forks have been lengthened/worked on

Base numbers as that's all they can be as we all prefer different setups.....For an example I couldn't ride Northwinds bike and he'll probably think my bike steers like a barge lol

*If forks have been extended run them them flush with just the fork cap bit protruding.
*sag between 35mm/40mm
*120/70
*Ride height measure at tail between 25mm/30mm(roughly 10mmm of that is account for shorter shock)
*Rear sag 25mm-30mm

PS if you liked the bike on the standard forks dropped 20mm with the standard 120/60 size(correct) then no reason why you can't run the forks flush(as above) if they have indeed been lengthened.
The GSXR 600/750 yoke offset are pretty close to the SVs as it goes. So with a 10mm extension and stronger(read better rated springs), it's very likey be very close to what you liked.

To be honest though I'll say go with a 120/70 all said. For street riding which all of my riding is done I do prefer the more neutral feel of the 120/60 myself especially at slower pace.......oops that'll be my pace then lol

Yep, double check your figure again. Hope you found some useful stuff in amongst all that..... hehe. Others may have view though



Ben

ps:
My set up is as below.....no track riding here mind
*120/70 front
*Forks set 10mm shorter than standard or extended 10mm depending on how you look at it
*38mmm rider sag on
*Silkolene Pro RSF 7.5W(will be trying silkolene Pro RSF 5Wwhen I get the chance)....tried Putoline HPX 5W and Silkolene Pro RSF 10W so far in last few weeks and feel I'm getting nearer to what I'd like.....oil wise.
*Standard shock but a Penske will be replacing that soon to give an extra 5mm(possibly 7mm/10mm at a push) longer shock length

I prefer the stability....and argubly better feel a lazy(lazier?) set up gives me.

Great 21Q! This is exactly the kind of info I am needing. Thanks so much for these responses.

I think I will probably go towards the fast turn-in side of things to begin with.

From what is being said here, it looks like the legs have not been extended. Can't trust them now. I had better take apart the forks and check them out for myself. Just watched the Race-Tech video. The job is not a big problem, but there's alott of ways to screw it up.

Better yet - may bring them over to European Cycle Services in Middletown, NY. I trust Steve and Jay. They have the seal drivers and other tools that I don't. They also have Race tech experience. Every once in a while I guess it's OK to defer to another mechanic's ability. This may be one of those times. It's a safety issue now, and another side-trip.

Thanks again for help.

[21QUEST]

Originally Posted by JuicyGuzzi

Great 21Q! This is exactly the kind of info I am needing. Thanks so much for these responses.

I think I will probably go towards the fast turn-in side of things to begin with.

From what is being said here, it looks like the legs have not been extended. Can't trust them now. I had better take apart the forks and check them out for myself. Just watched the Race-Tech video. The job is not a big problem, but there's alott of ways to screw it up.

Better yet - may bring them over to European Cycle Services in Middletown, NY. I trust Steve and Jay. They have the seal drivers and other tools that I don't. They also have Race tech experience. Every once in a while I guess it's OK to defer to another mechanic's ability. This may be one of those times. It's a safety issue now, and another side-trip.

Thanks again for help.

Re highlighted, sounds a good idea. Atleast gives you piece of mind and you know exactly what's what then

If you do take them to Steve and Jay, make a note of what make of fork oil and the viscosity they use plus the base air gap. As you know, there can be a big difference between say an oil labled 5W of two different brands. Also don't forget to note down the base air gap.

Re fast turn in, even in that case I don't think you'll go much wrong with 120/70 and starting of with forks flush (once we are sure they are extended) or 5mm showing and the shorter dog bones you have. Do you know roughly how much they raise the tail?

Perhaps if dog bones are cheap enough, you can aget a couple of so of differing lengths.

Good link this. Got a few others but have to sort them out properly. I can't say I fully understand all this suspenson lark but very much interested in it and do try out stuff myself.......
http://www.sigmaperformance.com/suspensionarticle.html

Good luck with the forks, setup and enjoy the ride. the forks are quite nice even as standard.


Ben

That was a good read Ben.

My present dogbones are to raise the rear 1 inch.

OK, I will sort this out, find out if the SVraceshop did what they said they did and did a clean job or not, and report back to this thread in a couple a few weeks. I'll include the numbers for our database.

Thanx, ride hard, stay safe.
Denis

[northwind]

Sorry to be the bearer of bad news I'd get them checked over or pop 'em open and have a look. Clayton at SVRS is entirely capable of excellent work when he wants to, that's the frustrating thing, so hopefully it'll all be as promised. Sounds like it's maybe not, though. If it was me, I'd have a wee eye on the prospect of legal action there and record everything, in that light it'd maybe make sense to have them checked professionally too.
I hope it all works out though, don't want to be too negative as even at their worst they were still knocking out some good jobs.

OK, I called the SVRS shop (now called Omaha Ducati) and spoke frankly with the mechanic who worked on my legs. His name is Kelly. He did acknowledge that there was a problem with a GSXR shock revalve in the past and that there was trouble. We went over everything that he did to my forks. I asked why the gold valve kit had a different number than the one reccommended by Race Tech. He said that this kit (FMGV S2046) is a special kit that many folks don't know about and it includes the 10mm extenders. This kit is the one to use for 04/05 600/750 GSXR legs on an SV. You will see it listed on the Race Tech site as the kit for the 00 to 03 GSX-R 750. He also took the liberty of adding the digressive shim kit (helps for road race applications), and says he did put in the extenders. He explained to me about the pre bottom-out pump mechanism that exist on these forks and the change that has been made for more length. He says he used the correct Loctite and proper torque settings, and was careful to place the cup washer on properly (as that is an easy way to mess up). I am satisfied that he was honest with me and he seems competant. I think I can go ahead with these legs as they are now. Will know more later...

However, Northwind, just for grins, would like to know the length of those legs you got coming, if you wouldn't mind.

Thanx,
Denis

[northwind]

Hum. FMGV S2046 is for 96-03 forks... But then 04-05 are very similiar forks, so it's perfectly reasonable that the kit would work properly, and the extra length would generally be a plus. So it could be that it's ideal for the job. If he's telling you it was designed specifically for the SV, that's a wee fib But I don't think it's any real reason for concern.

"A GSXR shock revalve" is also a wee white lie, there were quite a few different cases with an assortment of defects, but you can't fault them for that really, can't expect them to fall on their own swords.

So this is all quite encouraging. Allegedly my forks will arrive this week, though the UK postal service was on strike for the last few days so it'll be delayed, I'll check it out once I have them just to give a second eyeball on top of Ben's. It'd also make sense to speak to Robw, he actually knows about this stuff whereas I'm just bluffing

I have to say that if it was me, I'd still get them checked over though. But I'm pretty biased to be fair.