GSPD 100 wobble ( again )

Captain Black

Captain Black

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I mentioned this last year pre my TT 16 trip. Bike is great solo with no load or pillion.

When I left the campsite in peel last year all be it loaded up but not what I'd call excessive load, especially as I was riding solo . The fecking thing was unridable and the bars were shaking like hell at set off speed. So I had to rearrange the load as best I could to push everything forward as much as possible , bare in mind though I was on the single seat set up and pillion seat rack.

I filled the tank and things improved a lot , but that front end still felt vague like it was hovering above the road.

Fast forward to yesterday I've decided to try and improve things so drained fork oil ( 300 ml from left fork ) bit more from the right but not measured yet. I'm going to buy some 15/20 wt and try the millichamp cocktail ( worked well on my lads basic last year after fork seal replacement ) . Would the fact that only 300 ml of unknown wt oil came from the left leg drain plug have a big effect on handling, I've only left bike on main stand draining over night with top fill bolts removed, I can't work the forks as I'm in a confined space and its peeing down outside I'm assuming it matters not and I'll only be left with a tiny bit of oil right below the drain holes ? I'd assume if SHB or WB were faulty the handing would be poor ( front end wobble ) at all times ? So process of elimination , new rear shock factory shock last year , try the heavier millichamp mix, then I'll replace the Sahara tyres if that doesn't work .

Failing that just ride solo with no pillion or load...:blast
 
Often, as it is so gradual, you never notice how your suspension is deteriorating. A refresh of oil etc can make all the difference.

You did reset preload on the back , and adjust the damping ?

Poor backend makes the front overlight.

Sent from my GT-N7105 using Tapatalk
 
Millichamp brew works fork me on my GS & GSPDs. You could pour a bit of kerosene through the forks to flush out any residual shit. Set the sag when it's all back together.
 
fayeslane said:
Millichamp brew works fork me on my GS & GSPDs. You could pour a bit of kerosene through the forks to flush out any residual shit. Set the sag when it's all back together.
Click to expand...

I'll squirt some brake cleaner down before refill.

Not sure how to set the sag ( that's the drop of the suspension off the ground on main stand isn't it ? ) I'll do the fork oil change and go from there..:augie
 
Don't think much of the article.

It gives sag figures around half of what works on the road, confuses the fact that in an ideal world when you have the suspension as you want it it will be 1/3 of the way into its travel, with a requirement to set sag at 1/3 of travel which is not the same thing, and has it round the wrong way when he talks about the effect of raising the front and lowering the back.

And as the only way to set sag to its optimum position is by a test ride his palaver about fork friction is just bulldust, you just ride it and adjust the preload until it works best and it matters not a jot why you need that amount of preload.

But his silly sag figures might explain why the Racetech spring calculator nominations are 25/35% higher than Ohlins recommendations.

Setting the suspension extremely stiff like Racetech suggest is the easy way to get almost acceptable suspension if you only ride on smooth roads, as if the suspension doesnt move spring and damping rates match perfectly.
Setting it soft and well damped is considerably harder, and requires better equipment, but once you experience the Ohlins magic carpet as you glide along the roughest of tracks you wont be satisfied with just good enough ever again.

I also like around 60 mm front sag on my GS, but with the stock 450lb spring in the Ohlins I have 50/55 mm at the back, and it works well for me.
I use the best Synth suspension fluid, which makes a noticeable difference to the fork action, something Racetech never seem to mention either.
 
Done the millichamp cocktail , just a drain and refill no flushing or faffing , seals are good I did the gator rub 5 second test. I've put 410cc in the left ( sat on bike ) that only had 300 cc in it, and 440cc in the right, 32 psi front 36 psi rear. I'll do a high speed test tmrw around the lanes after my MOT. Hope it works ok, the real test will be when I next load it up.

Surely if it handles ok solo there can't be anything wrong ? Just set up ? I may run it in somewhere for a proper set up if this doesn't work . I think it needs another riders opinion maybe when loaded up. :blast
 
A smidgen more preload on the steering head bearings will probably solve the problem but you could also put 40psi in the rear tyre and up the preload on the rear shock when loaded up.
 
ChasF said:
A smidgen more preload on the steering head bearings will probably solve the problem but you could also put 40psi in the rear tyre and up the preload on the rear shock when loaded up.
Click to expand...

I tend to go 32/36 solo , 34/38 loaded on everything ... :D
 
Check for rear wheel play and play at the swingarm pivots. Mine started to track grooves in the road, I put it down to the old tyres I'm on but then discovered rear wheel play which was in fact the swingarm, now tightened up and no more tracking.
 
So MOT'd today , millichamp cocktail makes the front feel much firmer, I like it. Tyres at 32/36 psi and after 100 mile test ride its a dream to ride ( solo no luggage ), feisty lanes , low high speed, motorway high / higher speed hands off , sweeping left / right bends at motorway speeds hands off , brilliant runs true and no wobbles at the bars !! I'm going to check my suspension at weekend do some measurements as per the above chart, ( thanks red boots ).

Got a few questions as I've been to my mates garage ( cars but knows his stuff ) he reckons my back end off stand no rider looks low, but the free travel when you lift the rear isn't very much. Can I wind the spring down to lift the rear ? Does it matter if I've no free play lift pulling up on the suspension minus rider/ luggage ? As once I'm sat on it it will compress and allow some free lift or will I be hitting the end of the suspension travel ? My mate thinks the rear needs to come up and or the forks dropping in the yokes , only about half inch available on forks or they'll hit the bars . They are set currently at their full length, ie no fork showing above the top yoke but flush with it. I've softened my rebound as well. Maybe when I'd do the measurement as per red boots chart ( two man job ) that will give a clearer picture ? Does it matter where I measure to from the centre of the rear hub to a point on the bike ? If I'm measuring tat the same as red boots I'll ( GSPD ?? ) I'll get a better picture.

Jeepus its great solo , just want to achieve the same for pillion / luggage as well if its possible. I'd like to see another PD to see how high it sits at the back ... :D
 
I think they all look low at the back end but you could check that your rear shock is the correct length. I seem to remember there was some variation between various aftermarket shocks.

My bike, although not a PD, has a Technoflex shock and handles the same solo and with a pillion/luggage but the shock is set up for two up with luggage so it does ride a little better when loaded
 
ChasF said:
I think they all look low at the back end but you could check that your rear shock is the correct length. I seem to remember there was some variation between various aftermarket shocks.

My bike, although not a PD, has a Technoflex shock and handles the same solo and with a pillion/luggage but the shock is set up for two up with luggage so it does ride a little better when loaded
Click to expand...

Mine is a " shock factory " shock. I spoke with the guy who makes them and he assured me they were correct for the bike. I think it was Rob who put me onto them, as I recall he has one fitted to one of his bikes, can't remember if its his PD or not. Think I need to get a peek at another PD and swap some set up figures to see if I can achieve the best balance. Thing is I do camping trips in the summer so its important that I get it handing properly. God now what it would of been like at the TT last year two up, it was bad enough just with luggage. :blast

Maybe get a pro specialist to set it up. I'll give it a go first myself though ... :beerjug:
 
Captain Black said:
Does it matter where I measure to from the centre of the rear hub to a point on the bike ? If I'm measuring tat the same as red boots I'll ( GSPD ?? ) I'll get a better picture.
Click to expand...

Nope. As long as its the same 2 points for all 3 measurements.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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