Forks bottoming out?

I had a local shop replace my fork seals (with Honda OEM seals) and the fork oil with stock 10w oil. Now when I hit a major pothole or bump I hear a loud clunk like the front is bottoming out? It is quite disconcerting. Other than that the scoot rides great and smooth.

Any ideas? I can and will take back to the shop but wondered if this might be something simple?

Thanks.

Since you were more or less happy with the original set up... The only thing that’s was physically changed is the fork seals. They're not going to cause the problem. The other thing is the fork fluid. It is possible that the shop didn’t refill oil fork to the correct level, or used the wrong weight oil.

My 2¢: Change to a heavier weight oil. Say, 15 or 20 wt.

Take it back. Could be a lot of things loose brake caliper, axle, pinch bolts etc. If it feels like to bottoming out then oil level is wrong.  I'd also go with a 15W helps a lot with rebound speed much to soft on SW.

I talked to the shop and they are going to replace the Honda 10w oil with 15w and check everything so I should be good. I looked on Youtube and decided I don't have the tools or patience to do this job myself

Update: Got my scoot back with the new 15w fork oil! not sure if that was the only problem but it is riding great now. The shop did not charge me for this redo so perhaps they found something else that was their issue? Nevertheless it is fixed and I call that good customer service!

I've been using ATF in my forks and find it's too light ( cause I also have that clunk). I'll go with Tim's recommendation and change to 15 weight fork oil. I don't find changing fork oil or seals that difficult to do on my own. The hardest part is to get the cap back on .

Try some Torco RFF 15w oil. Not cheap at $20 a liter but it's the best I've used so far. One enough for both forks. Flows a both high and lower temps.

I used PJ-1 Gold Series 15w in mine. Not cheap but seems to work fine.

I did mine several months ago, replaced oem fixed spacers with fairly stiff spring twice the length of spacers, in essence it ocuppies the same space when fully compressed, but gives overall longer spring/action, placed flat washers in between,etc. I just picked up a suitable spring at Ace hardware store, miscellaneous hardware bins, no real P/N ?/. Not a fan off adding spacers to forks. 
Used 15wt. and increased oil level by 4mm. The white PVC coupler was modified to fit seals and 2.5 free weight was use to drive them in, worked perfect, old trick of mine. 
 It was no fun getting those fork caps back on with all those moving parts, but well worth the effort,
forks are way better now   

It has been a while but when I did G.Wing forks I used a brace, a modified socket extension with a socket and to fit the hex fork caps a stack of 3 nuts on a short bolt. The getting back on part can be a tad tricky but what I did was take the fork cap and put it on the tube with no spring, remove the cap by hand and mark it where it comes loose, then mark the spot on the tube to match, now go counterclockwise just a tad when you reinstall then crank it on. I had a 2nd person spot me to make sure I was lined up with the fork tube. Once started it was EZ on from there.

zrx212 wrote:

I did mine several months ago, replaced oem fixed spacers with fairly stiff spring twice the length of spacers... (Snip)

Any idea of the measurements of those Ace Hdw springs (i.e. OD and free length)... and how much spring movement is left when those secondary springs are the same length as the OEM fixed spacers? 

Seems to me that if the secondary springs were totally collapsed when the fork caps are back in place that those springs would act as nothing more than longer fixed spacers —i.e. more preload. 

Oh, and hey, what are those two wheel-looking things in the back next to the pinch bolts?

All spring then, Hyperpro spring is they same no spacer required. Adding another spring instead of spacer is a good idea as long as it doesn't compress less than spacer distance would. How fast does it rebound that's one thing I'm not happy about SW fork. Why did you feel the need to change oil level?
4MM not that much once that cap is on air inside is another spring from compression but you know that.

CJ, I just carried the spacer and washer to match a spring by dia./size, just picked one that  would fit and I felt it was sttong enough,etc. Basically a non scientific guess based on my years of wrenching on bikes 


 I used a Ace Hwd 4.5 inch spring(shadow board #69) FYI oem spacer aprox 2.5 inch, IMO the new longer spring will never compress to spacer size, is adding more overall tension, it acts in unision/as one with larger spring, like Mech 1 twa said "All spring then", as I pushed the spring in to fork I could see the smaller spring compress some, but not collapse. 


 In all honesty was not easy to do this, had to hold fork in a padded vice, etc., so I could use all my 3 hands to install cap, things flew all over garage a few times and foul language may have been used, definetely wear eye protection or face shield(better).

 Using more oil makes fork less prone to bottoming out, reduces the volume/space of air to be compressed, replaced by oil that does not compress, mostly affects last part of stroke, the OP's issue may have been too little oil ?? need to do do little changes on this, it can be very sensitive.

 CJ those round things are front reflectors, my SW has is mostly reflector free now. 

In all honesty was not easy to do this, had to hold fork in a padded vice, etc., so I could use all my 3 hands to install cap, things flew all over garage a few times and foul language may have been used, definetely wear eye protection or face shield(better).

Pretty much a vice needed to get the caps back on with Hyperpro  springs doing it solo. Damm fine threads.

A good wrench has 3 hands I have 2 lefts,  stick 1 in pocket 1 hanging out no one knows.  I just wish I could type faster.

This starting to sound like a "it worked before I fixed it" thread.

steve_h80 wrote:

This starting to sound like a "it worked before I fixed it" thread.

 IMO the oem fork did work, it just did so marginally/poorly, spring too soft, minimal damping, "My DIY Fixes" vastly improved both areas, more compliant/less jarring over bumps, etc., more stable on a fast and twisty roads and bike sits sligthly higher.

 This is somewhat a seat of pants evaluation of what I did, but my long years as a Motorcycle mechanic says I'm on the right path. At a minimun changing fluid to 15-20wt fork oil is good.

The OD of the spring and the spring rate would be useful if anyone has this , I would like to try and improve the front end of the swing as mine bottoms out on a manhole cover let alone a pot hole!

Thks