setting up forks

[plumbob]

Did the standard fork upgrade last week and have spent most of this week playing with rebound and pre load. They feel O.K. but my sag readings are nothing like those recommended by Roger at the end of Carls post. His target figure is 28mm. the best I can achieve is 16mm. with the pre load wound fully out. Always thought suspension was a bit of a dark art , and this has confirmed it. Dave

[VTRDark]

You wont be able to reply as you have yet to reach 50 posts but I have sent you a PM so check your inbox

[Roger Ditchfield]

There is a problem here. Please telephone me on 07970915259 anytime and I will try and resolve this issue.

[AMCQ46]

Did you fit new springs? If so it sounds like you need to shorten the spacers to compensate the new spring length

[plumbob]

Thanks everyone , yes I did fit new springs. They were 8.5 n K- tech springs, which are the standard length, so I didn't alter the spacer length. Everything else I did as in Carls post. Carl has P.M d me a bit of additional info which I will look at tomorrow. Been out on th the bike this afternoon and it feels really good Dave.

[fabiostar]

i have two storms. one with good condition pretty standardish forks and one with the Rogered front end.....they are miles apart ....night and day comes to mind

[plumbob]

i have two storms. one with good condition pretty standardish forks and one with the Rogered front end.....they are miles apart ....night and day comes to mind

They are definitely better than they were, just a bit confused by the sag measurement.

[fabiostar]

i have two storms. one with good condition pretty standardish forks and one with the Rogered front end.....they are miles apart ....night and day comes to mind

They are definitely better than they were, just a bit confused by the sag measurement.

my bike with the non rogered forks have the adjusters backed right out and i have about 10mm sag so im kinda in the same boat.

[plumbob]

Can anybody confirm that the figures I am trying to achieve are static sag. I am getting close with rider sag. And as the springs fitted were rider weight related , it makes more sense to me to measure rider sag. Sorry to appear thick but I have never dabbled in the dark art before.

[popkat]

How much do you weigh and what weight springs have you put in ?

Were the new springs the same length as the old ones ?

static sag between 25-30mm, I usually go for 27mm for road but if you can get that range on your preload adjuster you can alter it easy.

If you can't get the sag you want you would need to cut the spacer on top of the spring down.


If you set your rider sag but the static sag is not enough you lack some feel at the front.

Also the stock firestorm has lots of static sag, too much and really soft springs, for firmer springs and correct sag you will need to pull your forks through the yokes to lower the front end as it will be sitting too high. These bikes have a rear bias anyway you don't want to make it like a chopper, you could try 5mm but if your shock is stock you go to 10mm. even then the bike will sit slightly higher at the front but will ride well.


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[popkat]

Just seen your post above, I see you have .85 K-tech springs, I also have these in my Firestorm, they dropped in with the stock spacer and I have 27mm static sag with adjustment on the preload adjuster available either way.

Strangely I put .90 K-tech springs in my VFR with a Firestorm front end and I've had to cut 6mm off the spacer. Maybe K tech changed spring manufacturer and the latest ones are longer ? I never measured as thought they would be the same as my others.


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[Cadbury64]

If you have the adjusters backed right out then the spacers may be too long for the new springs. The stock springs need a lot of preload to get them sort of working so the spacers are fairly long.

For most road use you should have the springs compressed about 10-15mm when the fork is fully extended. To work out the spacer length, drop the springs and washers into the extended fork and measure down from the top of the fork leg to the top of the washer. Now grab your fork cap, set the preload to midway and measure from the edge of the cap where it will contact the fork tube to the underside of the cupped washer that will bear on top of the spacer, with the locknut in its normal position. Now subtract one measure from the other and that is the spacer length with no preload, add 10mm to that and that will be your spacer length.

You also need to make sure you get the caps screwed onto the damper rod to the correct position so the rebound adjuster needle works properly. Screw the adjuster needle into the cap until the top of the screw is level with the top of the cap. Now wind the cap/needle into the damper rod until the needle just bottoms out gently. Now wind the locknut up to meet the cap, back the needle out a turn and tighten the locknut/cap.

[plumbob]

Thanks everyone, even with my little knowledge I was coming to the conclusion that I may have to trim the spacers down. Although the bike feels a lot better than it did before , my concern was that it might become a safety issue if I had done something wrong .Interesting that Fabiostar has a similar problem with one of his bikes. Going to look at it this morning . Will report back. Dave

[plumbob]

If you have the adjusters backed right out then the spacers may be too long for the new springs. The stock springs need a lot of preload to get them sort of working so the spacers are fairly long.

For most road use you should have the springs compressed about 10-15mm when the fork is fully extended. To work out the spacer length, drop the springs and washers into the extended fork and measure down from the top of the fork leg to the top of the washer. Now grab your fork cap, set the preload to midway and measure from the edge of the cap where it will contact the fork tube to the underside of the cupped washer that will bear on top of the spacer, with the locknut in its normal position. Now subtract one measure from the other and that is the spacer length with no preload, add 10mm to that and that will be your spacer length.

You also need to make sure you get the caps screwed onto the damper rod to the correct position so the rebound adjuster needle works properly. Screw the adjuster needle into the cap until the top of the screw is level with the top of the cap. Now wind the cap/needle into the damper rod until the needle just bottoms out gently. Now wind the locknut up to meet the cap, back the needle out a turn and tighten the locknut/cap.

This seems to be getting worse I think it's time to admit I'm out of my depth here. When the forks are fully extended , the caps sit about 15mm above the fork tube , which in my mind equates to 15mm compression when there tightened in. The measurement down from the top of fork leg to top of washer measures 31mm. The measurement from the fork cap to the underside of the washer is 58mmwhen left to settle on its own or 69mm when pulled up.( Which is the right one I don't know) but either one will give me a spacer length of either 37mm or 48mm , which is less than half of the original spacer length, then surely I wouldn't have any spring compression when the forks are fully extended. At least I getting my posts up towards 50 , then I'll be able to advertise the bike for sale on hear.

[plumbob]

Sorry just remeasured the fork cap above the tube fully extended and it's 22mm. Shall I just cut 7mm off the spacers to give me 15mm compression ? AAaAAAaaaaaaaAAAaaaAAaaaaaAaaargh. Pubs open in an hour.