Evidence against USD forks

[skidMark]

Its not like a go for a once a week sunday afternoon ride.

They get cleaned as and when the bike gets washed - usually fortnightly.

Unless ive been riding in rain and mud, then a hose down is always good.

I have a rag wrapped around the stanchon and cable tied so it doesnt fall down. Seems to be keeping some of the oil away.

Nah man you have to get down there by hand loop a rag around them and move like your buffing it up...gotta get al lthe way around the back, doesnt mean ya wont blow a seal. Just means not as easily.

Either way though, if they were WWU (wrong way up...yer damn straight!) forks, a blown seal is a blown seal.

[Disco Dan]

Does it REALLY matter.... *sigh*

Seems to me unless your racing in motoGP then it does not matter too much...

[skidMark]

Does it REALLY matter.... *sigh*

Seems to me unless your racing in motoGP then it does not matter too much...

Your forks bent disco.

[Mikkel]

so it will be like VFR and RVF and RVF is a VFR with USD's, thus CBR becomes RBC.

Hmmm, I'm not entirely sure if that is indeed the entire truth of that...

[skidMark]

Hmmm, I'm not entirely sure if that is indeed the entire truth of that...

Well RVF has Carbs with flat sided carb sliders (not flat carbs)

And USD's....

So nya nya

[ManDownUnder]

Yawn.

Lots of wanking between people that can't ride well enough to appreciate or benefit from the differences...

USD, RWU, WMD, JPY, NZD, GBP and TLA (just to throw a few other relevant acronyms in there...)

[skidMark]

Yawn.

Lots of wanking between people that can't ride well enough to appreciate or benefit from the differences...

Speak for yaself.

I'm the fecking man.

[ManDownUnder]

Speak for yaself.

I'm the fecking man.

And I'm a fecking license holder.... your point is?

[Mikkel]

Anyone actually give a fork?

[steveb64]

Well my fluid had gone brown, and my first reaction was to order new fluid, pads etc.

Bugger. Oh well - at least you have half the bits you need! It's better to replace yer pads if they've been oil soaked - and new brake fluid NEVER hurts!

You going to fix your forks yourself? ...if you are, then get a Haynes (www.haynes.co.uk) manual - I had one when I stripped the USD's apart on my Ducati - brilliant manual, and even gave a template/instructions on how to build a couple of 'special' tools to get the forks apart!

[FROSTY:Me]

What USD forks did you use & what parts did you trick them up with Tony?

Ok Its a sad tale really.
First it was a factory set of GSXR750 forks/tripples from srad or a the model right after.-Anyhoo the forks were straight and undamaged inside n out.
I fitted them to the SV With not too much trouble I must say.
NO experience with setting up USD forks I took the bike out for a ride at PUkie.
By the fact that the usd forks are 20mm shorter than SV ones right away the bike turned quicker and other than bottoming out the internals worked so much better than the factory forks I thought --shit hot -right track here.
Then I gave the bike to Brownie at colemans.He got in a set of springs that were 30mm longer than the ones in it as well as being 1.1
No internal valving was done just fresh oil
Another ride at pukie and it felt bloody good everywhere except at the hairpin where the front end sledged terrebly.
I refered to various people with more experience than me who by twiddling knobs n stuff improved it a bit --but still that scarey --oMG THE FRONTS BOTTOMING OUT AND POGOING
That "setup" was still good enough to get 1.07 at pukie--grinding boots and kneescrapers and having a jolly good ol time-but still scarey at the hairpin Then the "big guns" came to town. Ther bikes had the back end about 50mm higher than mine and they diddnt have clearance issues.-and for sure they were braking 50-100m after I dared to.
So I had my rear shock modified to raise the back end -which then emphasised just how shit the front end was.
Dougal rode the bike and said something to the effect of--"this is friggin scarey"
So over the phone advice from Shaun Harris and the static sag was measured -hmm--wot sag??
The preload spacers were shortened by 16mm and the whole plot bolted back together
Hmm--should be better right--WRONG
Darn thing was a pig to get to turn and when it did it diddnt want to stay on a line.
MY BIG mistake right then was not asking for help- RT sat there -laughing at the pink pig and the terrible setup. It had
Shaun just shook his head -waqiting for this stuborn prick to ask for help
Meanwhile I got in a blue funk and blamed the whole issue on ME and my riding --has to be my riding --the bikes gotta be right.
Shaun did some work on it that made a Huge improvement once you are riding the bike FAST -But I was by now so miserable I was riding well--fucking slow --barely cracking 1.09 at pukie
Then I had a decent er--well "incident"
As things stand now the front end is in the hands of a KB mechanic called OZZIE -good bloke --spannerd for some unknow called sherrifs -carl or craig or summat like that.
He's rebuilt the shocks again. First of all to make sure they aint bent this time for me and my bike. Hes modified the shim stacks,changed the springs,rebuilt the spacers and done some other techie stuff thats over my head.
Test of the pud as they say is in the eating --so thanks to the guys at Kiwi Rider Im gonna be doing some laps of Taupo on the beast mid april -theyre creatting a class just for me--super slow

[westie]

I believe BTF forks should be employed.

Really if you weren't trying to do wheelies all the time MORCS then the forks would probably be ok.

On another note, if you wait long enough then the fork oil drains out and eventually its all gone.(must get around to replacing my fork seals, but they're RWU forks so whats the point!)

[n0regret5]

I'm pretty sure the Britten bike had Cavantalier type setup (sorry can't spell it)

cantilever?
heres a shock..the cantilever is the same as a girder is the same as a hossack is the same as a duolever..ok the duolever is the odd one out cos its still running a set of forks..
why not go for the ultimate in handling options? though apparently it reduces your 'feel' for the road;

[steveb64]

Ok Its a sad tale really.
First it was a factory set of GSXR750 forks/tripples from srad or a the model right after.-Anyhoo the forks were straight and undamaged inside n out.
I fitted them to the SV With not too much trouble I must say.
NO experience with setting up USD forks I took the bike out for a ride at PUkie.
By the fact that the usd forks are 20mm shorter than SV ones right away the bike turned quicker and other than bottoming out the internals worked so much better than the factory forks I thought --shit hot -right track here.
Then I gave the bike to Brownie at colemans.He got in a set of springs that were 30mm longer than the ones in it as well as being 1.1
No internal valving was done just fresh oil
Another ride at pukie and it felt bloody good everywhere except at the hairpin where the front end sledged terrebly.
I refered to various people with more experience than me who by twiddling knobs n stuff improved it a bit --but still that scarey --oMG THE FRONTS BOTTOMING OUT AND POGOING
That "setup" was still good enough to get 1.07 at pukie--grinding boots and kneescrapers and having a jolly good ol time-but still scarey at the hairpin Then the "big guns" came to town. Ther bikes had the back end about 50mm higher than mine and they diddnt have clearance issues.-and for sure they were braking 50-100m after I dared to.
So I had my rear shock modified to raise the back end -which then emphasised just how shit the front end was.

That's an interesting one! My 5c worth - change the oil again to something with a bit more viscosity (to give more damping for both compression and rebound), increase the amount of oil in the forks (from standard) - which progressively increases the spring rate - particularly at (or approaching) full travel.

Umm - you did check that you were getting full travel by putting a small cable tie around the fork leg, and measuring where it was being pushed to?

I was going to say "and reduce either the rear ride height, or the rear preload - so the back of the bike sits a bit lower, which will help counter the lower front ride height." - then spotted the last bit of your post... ...was that 50mm extra height when they were sitting on the bike, or off it? I suspect that your clearance problems stem more from the front end being shorter (20mm is a LOT), than the back not being high enough... ...and making the back taller, when the front is already too short will usually make poor handling even worse.

I admit to being kind of surprised that you needed to change the springs at all - I would have though that both bikes (yours and the donor) would be a fairly similar weight? Was that to try and increase the front ride height? Maybe go back to original springs, just with a bit more oil?
Or bite the bullet, and use the 750 forks as a trade-in on a longer set...

One other heads up - years back, I converted my old GSX11 from 19" front 17" rear to 18" front and back, with the end result being that it steered a hell of a lot quicker. However, it did some really weird things to the countersteering - like I'd countersteer to start the initial lean/turn in, but as the corner tightened up, the countersteering would disappear (go neutral), and then as the corner got even tighter, I'd end up positive (turning the bars IN) steering through the corners! Was a really odd feeling, but it worked! - Trials done on the Rimutakas!
I blamed it on the steeper steering head angles, due to the wheel size changes. I also ended up stretching the front out (max preload, more oil, AND air) to maximise my ground clearance... Used to scare the crap out of some of the Vic club riders, when they saw it flapping and bucking it's way over the hill - just stood up on the pegs a bit, and rode it like a MXer!

Hey! You added more! Oh well... sounds like you're in good hands...

Following is from an Ohlins manual: (For MX forks - but basic theory still applies)


Oil level adjustment
As the air trapped between the oil and the top nut acts as an air-spring, a change in oil level will effect the damping forces. Not in the early stage of fork travel, but a great deal in the later stage.
The air-spring gives the Öhlins USD fork a progressive spring rate, preventing it from bottoming out hard.
By using different combinations of springs and oil levels/air-springs you can alter the characteristic of the fork and tailor it to suit different tracks and conditions.
CAUTION!
The oil level must be the same in both front fork legs.
When the oil level is raised: The air-spring in the later half of travel is strong, and thus the front fork hard.
When the oil level is lowered: The air-spring in the later half of travel is soft, and thus the front fork soft.
CAUTION!
Adjust the oil level with the fork leg fully compressed and no pre-load washer or spring installed.
NOTE!
See Mounting Instructions for recommended oil level.
The oil level is measured from the top of the outer leg, with the top nut off.
Changes in oil level should be made in small steps. We recommend a change of 5 mm at a time and not outside the range of 80-130 mm.

[FROSTY:Me]

Short version.I fucked up and now a suspension expert has the forks set to a reasonable baseline for me to start from.
I really want to give the final chapter to this sorry tale but untill I can ride the beast again I cant