Rear shock pre-load adjuster

[old-man-andy]

I was doing a bit of fettling at the weekend and out of curiosity I thought I'd check my rear suspension settings as I'd never checked them before.

I can't turn my pre-load adjuster at all. The prongs/tabs on the plastic tool bend alarmingly and I don't want to snap them.

So, just how easy/difficult should it be to turn the adjuster?

cheers.

 

[Greggers]

You should be able to turn it without the tool ... it might just be that it its Already At full adjustment so you could try unloading it first.

 

[mark2jag]

You should be able to turn it without the tool ... it might just be that it its Already At full adjustment so you could try unloading it first.

You're not alone. I cant turn mine, either up or down it just refuses to budge.

 

[Dean]

My original one was stiff with the plasticky tool also.



(but have Ohlin instead now)

 

[v8legend]

You really shouldn't need the tool for this, I can do mine by hand.

Try it on the centre stand (suspension unloaded). It sounds to me like yours has seized up a bit. Once you've freed it off, wind it through the full range of adjustment a few times.

 

[Greggers]

Stilsons...??

Seriously though you might need to use tools to free it, but once you have keep it lubed and it is adjustable by hand..

G

 

[old-man-andy]

You should be able to turn it without the tool ... it might just be that it its Already At full adjustment so you could try unloading it first.

Without another bike as a reference, I have no idea whether it is fully wound-in, fully wound-out or 'stuck' somewhere in between

You really shouldn't need the tool for this, I can do mine by hand.

Try it on the centre stand (suspension unloaded). It sounds to me like yours has seized up a bit. Once you've freed it off, wind it through the full range of adjustment a few times.

I've tried it; on the centre stand, on the side stand, with me sitting on the bike - no movement either way

Stilsons...??

Seriously though you might need to use tools to free it, but once you have keep it lubed and it is adjustable by hand..G

I tried to remove the screw holding the plastic adjuster 'head' (for want of a better word) to see if I could get a spanner etc on a bit of solid metal, but, guess what, the screw wouldn't budge either

I think Stilsons or some other grippy thing must be the way to go - what could possibly go wrong.............

(Answers on the back of a postcard)

Cheers

Andy

 

[Uncle Rob]

got any round bar such as 2 phillips screw drivers,stick them in the holes and then a longer lever between the bars and you will have all the leverage you need,ps mines free

 

[old-man-andy]

Result!!

All sorted - Stilsons did the trick - turns out the adjuster was 'stuck' at the minimum pre-load postion.

 

[Greggers]

Wow - that would have been bouncy!

Wind it up a bit - in fact a lot!! I've got mine almost at max preload and it make a huge difference to the bike's responsiveness and agility!

Greg

 

[v8legend]

Wow - that would have been bouncy!
Greg

Are you talking pre-load or damping? Surely pre-load relates to static sag, and damping is what stops it being bouncy?

 

[Greggers]

Yes ... and no .... The adjuster that needs the tool is spring preload, so by pre-tensioning the spring you're taking out some of the 'softness' out of it ... strictly speaking the spring-rate remains constant but winding up the pre-load alters the point at which the spring starts to react - more like a ride-height adjuster.

The damping is controlled by the little screw adjusted down on the bottom of the shock unit and that controls the speed at which the spring can be compressed - high compression damping makes it harder to compress the spring quickly, softer comp damping lets the spring react more quickly.

So - no preload lets the spring compress with less effort so the suspension will compress more readily and travel through a longer arc hence the greater 'bounce'. Adding more compression damping slows the spring's reaction rate which can also make it feel harsh.

I made an error in setting mine by having the pre-load too high and having too much comp damping - the net effect of that was that as I was hitting bumps in the road the rear wheel ended up skipping, and in wet conditions was giving me wheelspin if I was on the gas. Softening the comp damping allowed the rear wheel to react more quickly to the bumps and kept the tyre in contact with the road surface - ride quality improved and no more wheelspin.

 

[ricfrench]

I adjusted my preload the other day (f650gs) does the shock also need adjusting to firm it up a little?
Is there any relation between the two or is just a case of spend some time getting it all dialled in through trial and error?
Just for reference the spring preload is just a couple of turns off maximum and as yet I've no idea where the damping is set, should the also be near its highest setting?

 

[Dave Ett]

Wow - that would have been bouncy!

Wind it up a bit - in fact a lot!! I've got mine almost at max preload and it make a huge difference to the bike's responsiveness and agility!

Greg

Depends how fat you are!

Mine is on minimum for just me, and goes up for carrying a pillion. Maybe cuz I have the shorter spring on it, it's stiffer... can't remember. Either way, don't just wind it up for the sake of it, set your static sag up properly if you want it to handle its best!

 

[Greggers]

Whilst not strictly speaking a fat tosser, I am less svelte than average lol..

My preference is for stiffness rather than a saggy wallower - although when I sat on a F650GS a couple of weeks ago I was pleasantly surprised by how 'compliant' the set-up was, indeed it was almost plush!

YMMV as usual

G

 

[old-man-andy]

My understanding of it is that the pre-load acts as a ride-height adjuster - by pre-compressing the spring (adding pre-load) you increase the distance between top and bottom shock mounting points. As the wheel is (hopefully!) in contact with the ground this raises the seat height (although it looked like there was only about 10mm difference between max and min pre-load).

So, say, if fat-bifta rider causes 10mm static-sag, he/she needs to set static-sag to match. If f-b rider & equally f-b pillion* sit on bike, the bike will sag more, hence the pre-load needs winding on towards max.

The compression damping adjuster (at the bottom of the shock) alters the speed of damping. Keep it softer if you're a svelte, genteel, easy-going rider, and keep it harder (pfnar, pfnar (sorry, couldn't resist ) if you are f-b rider and/or you take a f-b pillion*, or you like riding hard.

Personally, being under 11st, I find that min pre-load and 1/2 turn off max compression suits my riding - so it looks like my bike was perfectly set up for me and I didn't even know it



f-b pillion* - this could also refer to some of the 'larger' pannier/top-box combos that some seem to prefer

Andy