Need some new fork springs in Aust

[Chop1961]

Hi all, the beauty about this site once again. I didnt want to annoy you with my issues, i would normally just do research and read and read but here we go. I have just relocated to Darwin for a 6 mth gig up here working so what i normally do is fly where ever my job is and then get bike transported to the same spot, do a bit a bit of site seeing while working there, buying all the goodies for the bike while making good coin then when we get de-mobbed take the long way home.. the longest way possible 😎 2-3 weeks on the road sometimes, stayin at pubs, meeting the locals, camping out etc. List goes on.. But something i really enjoy, to me what riding is mainly about, getting out there and living it. Anyway.. loaded bike up with gear (ill try and upload pic before i took bike into Cairns for transport too show load) well, i took off from home giving it a stick full and then at about 130klms it started these mad tank slaps/front end head shakes that put the wind up me, ive been riding for 50 yrs so it wasnt me, it just went ballistic, enough to make me sit on the speed limit into Cairns which is 130 klms away. Some may say a good thing 🤔 i dont but anyway. So me thoughts are to start out with sone Progessive fork spring (or something similar) and a fork oil change but me drama is that i have looke high and low and cant find anyone in Australia here who sell them for the GSX? Cant find nothing at all so any ifeas would be appreciated, thanks,

[Chop1961]

Just a mention, the bike has always felt a little twichie in the front, you can sit on 160 or what ever and it fills stable but a silght difference in the road will make it buck more then normal, with most bikes you can take ure hands off the handlebars at speed and control the steering with your body weight where with the GSX you can do the same but you dont have as much confidence with it so you are always on guard, its not like that is the way we ride but after miles and miles in the saddle we like too strech back every now and then so there something there that needs amending. Now ive only just got the bike so i dont know the history but what i do know is that ol mate who i bought bike off has done a wonderful job of keeping that bike well looked after in cosmetics, its like new. But it has about 37,000klms on it and im guessing its a fork issue. Like i mentioned i have had bikes all of my life and thought i knew quiet a bit but after finding this forum (my first) i have relized there is so much more that i can learn, thanks again.

[KiwiCol]

Gidday Chop, the fork oil change is a simple job & would be well worth doing. I doubt the tank slapping is to do with the fork springs myself. I've had it happen to me on one of mine as well, could of been about the 180k mark and slapped all the way back down to around the speed limit, could of, nothing official mind - I'd be looking at your stem bearings. They are often bypassed in routine maintenance for greasing & checking the load.


I'd do the fork oil change - 5w - 10w (there go the can of worms escaping) & check the bearings for free play, grease & wear.


Another thing that also contributes to tank slapping is a big load of luggage on the rear combined with highish speeds - among other things too. That wee fairing can also contribute to them as well if it's not fitted perfectly symetrical, with the wind pushing on the bars at high speed it can generate unequal force on either side, this combined with your load on the back, slight cross wind & high(ish) speed can all be contributing factors to a tank slapper requiring undies to be changed asap!!


Basically, unless the bike does it every time you hit 140 or so, I'm plumping for it being caused by a cumulative of factors at the time. 

Have a google & read up on tank slappers on ST1300, the UK police had those bikes & even had a name for the phenomenon, which escapes me at the moment, it was to do with the additional luggage & weight at the rear on the police bikes, a few coppers were killed because of it too.

[Chop1961]

Thanks for reply mate. I understand what you are saying for sure. With the panniers loaded it rode fine, it was as soon as i put that army bag on bag it went ballistic which i took off as it was flying up with me, i weighted it at airport and it was 17 kg. Now, i should be able to load them panniers up and throw a girl on the back and ride off into the sunset you would think eh. I have ordered a bigger windscreen which i will fit up here, i will also change fork oil and check steering head bearing like you have recommended. I do remember being told time and time again when when we had dirt bikes as well that they never ever put enough grease in headstock and swing arm bearing from factory which is why they they should be fittes which grease nipples.. which is another story, anyway thanks mate. I will upload the windscreen ive got coming for it knowing it may start a debarkle about bein a naked bike etc 😎 i swear by them now for doin big miles. I think it will suit it.

[seth]

The front of my bikes tend to go a bit lose with less feel especially ant higher speeds when the rear tyre is getting worn .
The bike spends most of its time loaded with luggage.

Not sure if this helps but it's something else to think about

[Mister Fishfinger]

I'm with KiwiCol, I reckon it's a combination of things - extra weight on the back, a large screen and also those big hand guards. The front of the bike is like a sail now, so it wants to flap in the wind.

I would start by taking bits off the bike, one at a time, then repeat the same ride conditions where it was previously slapping. You'll soon find the culprit.

Fork oil is always worth changing if it's old (mine was like soup), but it's unlikely to be the cause of this.

By the way, I love your work/holiday setup, good idea 

[Edit: just noticed they aren't hand guards, now that I zoomed in on the picture]

[ARH]

I know this might be a daft question... but have you checked the back tyre and suspension?  Looking at that loading I reckon if the rear end is not set up correctly you would run into the issues you describe.  I also noticed you have a brace on the front forks.. is that aligned correctly?
I have my doubts if its really front fork related.... but stand to be corrected 

[Hooli]

Lower steering bearing is where I'd start (it's often rusty when the top one is perfect) after checking for uneven front tyre wear.

[Cykik]

Only time I had proper head shake was very hard acceleration over whitelines.
A "challenge" had been made & accepted!!

[Hooli]

The only time I get headshake is when something is broken or worn, I'll continue to avoid it cheers.

Oh I've just thought of another one, it's unlikely as it's a low mileage bike but with the front off the floor pull the bottom of the forms around & see if there is any clunking from the fork legs. That's wear in the fork bushings & makes the front end feel loose & wobbly.

[Sweaty]

I think it is just a simple case of a fully loaded bike & high speed. When you look at how much weight is behind the rear axle on the bike. Well that is going to lighten the front significantly & is a lot different to having a pillion sitting on the bike with her weight over or in front of the axle.
Now the bike is also not streamlined, with panniers and bits sticking out every wear, so the wind buffeting is going to effect the handling.
My advise is, find the speed limit you can reach safely with it fully loaded & don't go over that 

[grog]

Sweaty, totally what you said.

[RickC]

I changed my fork springs out @3 years ago, 08 model, the fork oil came out black and I swore that I would regularly change it but I didn't, I did a fork seal
the other day and changed the seal and oil and the bike is sitting up nicely again - it was surprising how black and watery the fork oil was after 3 years.

I put linear springs in mine from Racetech in the USA but there springs are for k3's so I had to get a spacer made to use them, about 30mm or so difference between earlier and later model springs.

[Chop1961]

Thanks for suggestions and sorry about slow reply (phones not allowed on job) when i think back the front tyre is due for replacement with more wear on the right hand side which maybe due to the chamber of the road so i will do as suggested and replace the tyre, fork oil and get front wheel in the air and check for play. The bike rode fine with loaded panniers but had a change when i fitted that17kg army bag which makes me think it may be a rear shockie thing, are they wound up equal or do they need to be wound up to make them a bit stiffer? I will read up on how to stiffen them up. Thanks again 😎

[grog]

Chop, change that front tyre. Its your major problem in my view. Pirelli Angel is my choice but others like different. Check and adjust those head bearings. Check suspension settings, front & rear, make same either side. Make sure rear wheel is aligned properly. those are the basics.fork oil also a must to change. After all that done, can then change springs, adjustments etc. Basics first. A tank slapper on mine, on ebay next day. my most feared. mid 70s, kawa 900 did it to me, never rode it over 100kph after. tank slapper was at 140. that was because they were a flawed design. 14 isnt, just needs setting up. IMO