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General Category => General Discussion => Topic started by: Joshtjeerdsma on October 13, 2016, 11:28:38 AM

Title: 850t forks sticking
Post by: Joshtjeerdsma on October 13, 2016, 11:28:38 AM
  Thanks to all your help, I have my budget rat rod 850t running great and have been enjoying riding it. The one issue that is bothering me is that the forks want to stick a bit after being compressed and ride very rigid. During the mild refurbish, I disassembled the forks and put new seals in. When I disassembled the forks, there was rusty water in them. I cleaned up the internals and added new fork seals and clean ATF. The fork stanchions seemed to be in very good shape. I know the previous owner had a minor front end collision and replaced the stanchions and triples. I would like to know if there is anything to try before dropping a lot of cash on upgraded internals. I assume if the springs or dampers were shot, the forks would work like crap but shouldn't stick. Any thoughts? Thanks, Josh
Title: Re: 850t forks sticking
Post by: Antietam Classic Cycle on October 13, 2016, 12:17:20 PM
Are you sure the fork tubes aren't bent? Don't assume the previous owner replaced them.

Also, how is fork alignment? The forks need to be perfectly parallel, the front axle and center straight section of the handlebars aligned. Sometimes you can "eyeball" this if no fairing, cables, etc. are in the way.

Loosen the axle pinch bolts at the bottom of the sliders and bounce the front end through it's travel. Then tighten the pinch bolts. It could just be binding due to the sliders being tweaked inwards a bit. 
Title: Re: 850t forks sticking
Post by: radguzzi on October 13, 2016, 12:20:58 PM
Josh,
Sounds s if you may have the fork legs (stanchions) out of square for lack of a better term for it.

While on the center stand, loosen the stanchion pinch bolts, top and bottom, and just snug them back, lightly loosen the bottom leg pinch bolts at the axle.

With the front wheel chocked so that it will not roll ahead, say up against a wall or chuck of wood, Push the forks down several times letting them rebound until it becomes smooth in motion.  Repeat this when off the stand using the front brake to hold the motorcycle in place...

When you are satisfied that the movement is free, tighten all pinch bolts and go for a blast.   :bike-037:

Report back with the results.

Best,
Rob
Title: Re: 850t forks sticking
Post by: Joshtjeerdsma on October 13, 2016, 12:31:08 PM
I will give that a try. The alignment could very well be off. I wasn't sure of the orientation of the brass washers for the front axle, so I just arranged them to where the brake caliper didn't rub. I didn't even think how the axle would affect the fork alignment. Thanks
Title: Re: 850t forks sticking
Post by: Testarossa on October 13, 2016, 12:53:49 PM
Did you replace the front wheel bearings? If you drifted one of the bearings in too far, the process of centering the rotor in the caliper might pull the bottom ends of the sliders inward.
Title: Re: 850t forks sticking
Post by: Antietam Classic Cycle on October 13, 2016, 01:20:01 PM
I will give that a try. The alignment could very well be off. I wasn't sure of the orientation of the brass washers for the front axle, so I just arranged them to where the brake caliper didn't rub. I didn't even think how the axle would affect the fork alignment. Thanks

I'm not sure what you mean by this. There are no washers, brass or otherwise, on the axle except the one of the right side under the nut. There are steel shim washers used to center the caliper on the disc, but those are the only washers.
Title: Re: 850t forks sticking
Post by: Joshtjeerdsma on October 13, 2016, 02:40:08 PM
That could be my problem also. I had 2 different thickness brass washers and a sleeve about an inch long. I forgot to document how everything went together on the axle and I couldn't find anything in my manual. If my memory serves me, It seemed like I needed those washers to take up slack between the forks. Maybe the forks are supposed to tighten together to take up that slack and that is my problem. I did not put new wheel bearings in as the originals seemed ok.
Title: Re: 850t forks sticking
Post by: Antietam Classic Cycle on October 13, 2016, 03:17:46 PM
That could be my problem also. I had 2 different thickness brass washers and a sleeve about an inch long. I forgot to document how everything went together on the axle and I couldn't find anything in my manual. If my memory serves me, It seemed like I needed those washers to take up slack between the forks. Maybe the forks are supposed to tighten together to take up that slack and that is my problem. I did not put new wheel bearings in as the originals seemed ok.

You do not want the forks to "tighten together", that would definitely cause binding. The spacer on the right positively locates the right fork leg once the axle nut is tightened. The left fork leg "floats" on the axle until the pinch bolt is tightened. 

The spacer is supposed to be there, but not the washers. Here are two photos from a V7 Sport that's on the lift right now, that will show how it goes together. The only difference is the 'Sport has dual discs and a slightly narrower front end.

Right side: spacer with the bearing w/snap ring slightly in from flush in the carrier.

(http://thumb.ibb.co/cipftv/V7_Sport_done_003.jpg) (http://ibb.co/cipftv)


Left side: axle butts up against the bearing which is flush with the carrier.

(http://thumb.ibb.co/by3UmF/V7_Sport_done_004.jpg) (http://ibb.co/by3UmF)
 
Title: Re: 850t forks sticking
Post by: pete roper on October 13, 2016, 03:46:07 PM
It could also be buggered dampers pumping up if the damper holes are filled with bits of seal rubber as they invariably will be if it still has the original sebac dampers installed. This would also explain why it gets worse with work.

Pete
Title: Re: 850t forks sticking
Post by: guzzimatic on October 14, 2016, 10:50:08 AM
Pete is dead on! A friend had a 850T bobber that the fork went rigid on,new dampeners cured it!
Title: Re: 850t forks sticking
Post by: Joshtjeerdsma on October 14, 2016, 03:14:43 PM
I loosened the pinch bolts and cycled the forks. The forks don't seem to stick anymore, so I think it worked. The performance still sucks, but I know that is from the worn out springs and dampers. When the fork settled in its preferred alignment, one stanchion is about 1-2mm higher than the other in the top yoke. Would this have any negative affect? Thanks again for helping get the bike sorted.
Title: Re: 850t forks sticking
Post by: jvb on October 14, 2016, 07:39:58 PM
Maaaaate. I'm feeling for ya!

A slight difference in height would not be a concern if everything else was hunky-dory.

In your case I would be stripping down the front end, overhauling the forks and triple tree , reassemble them using a workshop manual and make sure everything that is supposed to be there is there and there are no extra bits that should not be there.

Also I'd check the all the components are straight including the lowers, fork stem, front axle and upper and lower triple tree.

A thorough inspection and overhaul would in order for peace of mind.

My 2 cents worth