Forks sticking?

Lardedah · Derestricted Danger Joined: 09 Oct 2013 Karma :

I recently fitted new front end (handlebars, tripple trees, forks, wheel)to my keeway speed 125. I did a 30 mile journey up the A50 and have noticed that they compress down a little bit with each bump until they are all the way down (and ride is rock hard) and they just don't want to come back up and need to yank the bars up to bring them back to proper position. :S I put 140 ml of fork oil into each after reading about it on the old web. Hoped someone might be able to suggest any other issues I may have overlooked or just been purely ignorant of. Confused

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Fisty · Super Spammer Joined: 11 Apr 2007 Karma :

Are there springs in the forks?
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Lardedah · Derestricted Danger Joined: 09 Oct 2013 Karma :

"Quietly and consistently taking the piss."

yep !
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Raffles · World Chat Champion Joined: 14 Apr 2009 Karma :

Did you remember to re-install the caps at the top of the fork stanchions?
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Fisty · Super Spammer Joined: 11 Apr 2007 Karma :

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

put the bike on the centre stand, grab the fork bottoms and pull the forks front to back. check if there is any movement. your fork bushes may be fucked.
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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Does sound like it is acting as though there are not springs in there, or missing spacers Laughing

.

However check that the forks are straight (assuming 2nd hand, might have come from a crashed bike) and are not twisted in the yokes.

All the best

Keith
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Teflon-Mike · tl;dr Joined: 01 Jun 2010 Karma :

What grade fork oil did you use?
Did you flush them?

It 'sounds' like gross over-damping; that would happen to lesser degree with too heavy a fork oil, or the damper plunger / orifice ' fouled.

If the forks were left dry of oil, and or not properly cleaned could have gone rusty inside?

Have you stripped them?

Otherwise, as suggested, the fork bushes could be buggered, and or the stanchions not straight... you can get such effect from a fork that doesn't 'look' bent, as in the classic kink you get from a front end smash, but are slightly banana'd along their entire length.
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kestrel · Nearly there... Joined: 04 Sep 2006 Karma :

Lardedah · Derestricted Danger Joined: 09 Oct 2013 Karma :

So, I've taken them off springs and spacers both present and correct and in pretty good condition. I fitted the new forks to the bike the same way the old ones came off, literally just cycled through steps backwards.

And have just noticed there's a slight bend in the top half. Warped way near the top but assume could be other related damage further down.

:edit:
Had to replace old forks (worked fine) because previous owner had done a proper bodge job and knackered the threads on top nut and fork where they bite, don't suppose anyone know somewhere/someone around staffordshire/cheshire who could rethread them to save me buying another set??

Also, new forks were from 2012 model (mines a 59 plate). And the 'bottom half' were slightly longer and the chrome top half was shorter to compensate. Yokes were identical (but much shinier)
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