Rear Suspension Problem (I Think)

[thunderbolt]

I think your referring to one that goes through the base of the swingarm. I would remove the lower shock bolt which may give you a little more movement to either wiggle the bolt out or use a drift and hammer to knock it out. Bit there's a good chance it mat be seized in there in which case you need some heat. Blowtorch time me thinks!
(:-})

I have removed all the bolts from the rear plate except for the one that attaches to the lower shock. But the rear plate arrangement will not come away from the swing arm. There are no other bolts to come out. See pictures. Is there something else holding this rear plate in place on the swing arm? Does the long spacer/bush thingy go through the swing arm to hold this rear plate in place or does it only sit in the rear plate arrangement. The microfiche drawings are not clear.

Thanks

[darkember]

I think your referring to one that goes through the base of the swingarm. I would remove the lower shock bolt which may give you a little more movement to either wiggle the bolt out or use a drift and hammer to knock it out. Bit there's a good chance it mat be seized in there in which case you need some heat. Blowtorch time me thinks!
(:-})

I have removed all the bolts from the rear plate except for the one that attaches to the lower shock. But the rear plate arrangement will not come away from the swing arm. There are no other bolts to come out. See pictures. Is there something else holding this rear plate in place on the swing arm? Does the long spacer/bush thingy go through the swing arm to hold this rear plate in place or does it only sit in the rear plate arrangement. The microfiche drawings are not clear.

Thanks

It should just drop away. Loosen the bolt on the bottom of the shock & give it a firm tap with a hammer.

[thunderbolt]

Some more pictures of what I am doing for those interested.





Do those two front plates that bolt to the engine crankcase need to be removed?

[thunderbolt]

I know its a pain, but I take the swing arm off to check and replace any dead seals when checking the suspension linkages. Do you have the rear wheel removed?

For your reference when you put the Allen bolt back in the plate that fixes to the swing arm put some grease or copper-slip in the head as I had a problem removing mine because of corrosion as it is a tight fit, the same with the bolt through to t-bar rod.

Thanks Bazz,

I do not have the rear wheel off at the moment. My Allen bolts came away easily enough with some light tapping with a drift and lump hammer.

[Wicky]

Get the rear wheel out and free some weight that is probably interfering with what you are trying to achieve. Then if you can get the swing arm out with the linkage to work on.

[darkember]

Get the rear wheel out and free some weight that is probably interfering with what you are trying to achieve. Then if you can get the swing arm out with the linkage to work on.

Bull, just ram a lump of wood under the real wheel, that will raise the linkage up slightly making it easy to remove. No need to remove the swingarm or the rear wheel

[thunderbolt]

Well I got the rear swingarm plate out by levering it with a large screwdriver. So nice clear space in there now.



The shock came out without too much trouble, a bit of wiggling to and fro.



I think I've found the cause of the noise/creaking. As seen in the picture below there is very little clearance between the top of the shock and the top bracket that holds it to the frame.



And when the shock is rotated even slightly in the bracket the two parts come together and no more rotation is possible. And you can see where someone has previously removed metal from the top of the shock to try and create sufficient clearance. See picture below.



On a slightly different issue, can someone explain to me how this type of shock works, it appears to have various adjustments on it. At the bottom of the shock there is a large round adjustment knob that turns left or right as required. It has about 30 different positions, it clicks from one position to another. What does this control/alter if moved?

Also what are the two large nuts on the bottom of the shock for?



Looking at the top of the shock there seems to be a hydraulic adjustment knob that mounts to the frame. See pic below. What does this control? What are the two Allen screws for that are on there as well please?



I also now have the swingarm and rear wheel off the bike. All the needle bearings look to be in good condition and are well greased.





I will clean out old grease as best I can and regrease with moly and reassemble everything after I have removed more metal from the top of the shock tp prevent future creaking.

[VTRDark]

That's not good the way that rubs on the top bracket. Is that a Penske shock and is it one designed specifically for the Firestorm. I think I would be tempted to have another bracket made or change it in case it's damaged. Better than grinding bits off the shock

OK I shall do my best to explain the various controls but there are others on here that could explain suspension settings and setup a lot better than me.

At the bottom of the shock there is a large round adjustment that turns left or right as required. It has about 30 diferent position, it clicks from one position to another. What does this control/alter if moved?

That's your rebound adjustment which controls how the suspension springs back up from being compressed. You want to set this for fastest possible return but under control as to not bounce you around.

Also whar are the two large nuts on the bottom of the shock for?

That would be your ride height adjustment. The same as inserting a shock spacer accept this is already built in to the shock. Personally I would leave that alone and if you want to increase the ride height use a spacer between the top shock mount and frame. Reason being is if you adjusted the ride height from the bottom of the shock then it exposes a thread which could be a weak point. As it stands those two nuts add a bit rigidity to the bottom of the shock.

Looking at the top of the shock there seems to be a hydraulic adjustment knob that mounts to the frame. See pic below. What does this control?

That's your compression damper control remote, so the opposite of the rebound and affects how the spring compresses. You adjusts this to set your sag or just for comfort depending on the type of road surface and condition your riding on. For example if you was to carry more load (pillion/luggage) you would want to tighten up the compression so it's stiffer.

What are the two Allen screws for that are on there as well please?

~Dont mess with these. They are either for servicing the shock/re-gas or for repositioning the line from the compression damper control knob. Sometime an allen bolt will be there as part of the design for cheaper shocks that don't consist of a separate compression damper control remote. So part of the manufacturing and blanked off.

Here's a good site with that explains suspension set up
http://www.gostar-racing.com/informatio ... set-up.htm

(:-})

[AMCQ46]

I think it is an emulsion type shock and the lower thumb wheel will change both compression and rebound.

The 2 nuts ate the bottom are to increase the length for ride height adjustment, and I agree with Carl that it is easier to put 1mm washers in

The remote body mounted to the top spring mount is a hydraulic preload adjuster not a damping reservoir

[VTRDark]

I stand corrected. I said there are others more knowledgeable than me I'd take AMQ's word over mine. I've not even owned a shock with extremal controls. I did try

(:-})

[lloydie]

If it had compression dampening res it would fit there

[thunderbolt]

Hi Carl,

Thanks for the easy to understand explanations of the shock operation. I liked your idea of a new top shock bracket to provide the clearance required rather than grinding more material off the top of the shock mounting point.

The shock is a SACHS shock absorber, it could be it is not for my Firestorm. I don't know. There is not much info on the web about Sachs shocks for motorcycles. They do them for cars as well. It seemed to work well on the bike when riding it for the 500 odd kms that I have done on it so far.

Thanks also for the link you posted.

[thunderbolt]

The remote body mounted to the top spring mount is a hydraulic preload adjuster not a damping reservoir

Can you explain to me the difference in hydraulic preload and damping reservoir?

How does hydraulic preload work?

Thanks

[thunderbolt]

A couple more questions if I may?

Do they make different size top shock mounts to provide the clearance I need (the one that bolts to the frame behind the fuel tank)?



What is the best way to remove the old grease from the roller/needle bearings in the swingarm and the lower links that join to the swingarm?



Thanks

[Wicky]

Looks like the shock wasn't originally made for fitting to the firestorm - the spacing washers are a giveaway if I'm not mistaken. Did you take the rear wheel out?

With a new new shock mount you might want to try getting slightly thicker spacing washers (measuring precisely) or get an engineering shop to knock you up some spacers so when torqued up won't cause the shock mounting sidearms to distort.

What's the length from centre of mounting eyes? (considering 345-347mm is ideal range)