fork seals/oil changes

[tvnacman]

so my front shocks seem too soft From day one . I have not been in there not sure If the effort will be worth the reward if any . Have any of you guys worked the front fork shocks seals springs . Where to start how and what to expect .

John

[90GTVert]

I've always jsut added either more oil or a thicker oil to stiffen up the front end. Just make sure you use an equal amount. Some scoots you can remove the cap on the top to add oil or siphon it out without even having to remove the forks. You can get fork oil from a motorcycle shop, but most of mine just have motor oil in them.

[Upgrayedd]

you can make short pvc spacers to stiffen the preload, and stiffen the fork a bit. ive always used the thicker schedule pvc, whatever size will go snug in the fork works - same diameter as the spring. you must purchase and place a large washer in between each spring and spacer (there isnt one in the fork) it will keep the spring from grinding at the pvc spacer. the spacer itself can sit right against the fork cap.

progressive fork spring kits come with pvc for spacers, it works well. id start by adding an inch of preload, you dont want to add too much as whatever you add as a spacer will stiffen the fork, and it will also shorten the fork's total travel by its own length.

if ya take the cap off the fork and pull the spring, you can flip it face down over a coffee can and compress the fork a few times and all the fluid will come out. ive known lots of folks who used motor oil. i use valvoline atf+4. compared to fork oils, its almost identical viscosity figures to Silkolene or Showa 10W Fork Oil.

[Upgrayedd]

*edit* id start with filling them up like 90GTVert said - when forks get low on oil they'll get real spongy.

[tvnacman]

Any pictures or video's of how to .

John

[90GTVert]

That's one of the things I've yet to ptu any info up about I guess. Coulda swore I took pics at some point on one of the scooters but I've got almost 8,000 pics online and now I can't find them.

There's really not much to the way I do it. You'll probably have to remove plastics to get a clear view of the forks in most cases and make it easy to reach/pour. If you're lucky your forks will have caps at the top with a hex head protruding so you can get a wrench or socket on it. Loosen one and hold pressure down on it when you think it's about to come out. There is a spring pushing against it so you don't want it flying off. Remove both caps.

At that point you can see the spring and oil inside. You may want to measure how far the oil is from the top. You can either add oil or take it all out of there and refill so it's all one kind of oil. I've done both. Either way has worked OK for me. You'd have to siphon it or something to remove the fluid with the forks installed. When I've changed all of the fluid I removed the forks from the stem. In most cases there's a bolt squeezing the stem around the fork and you remove that to remove the fork. Easiest to have the wheel off doing that, but I'm sure it can be done with the wheel attached.

Add either all fresh oil or add to existing oil to stiffen the forks. Measure each side and try to get them even distances from the top. Reinstall the caps whatever else you need to and see how they feel. Add more if needed or take some out. Once you're satisfied, reinstall the plastics and such.

[tvnacman]

Brent , it sounds simple I will just have to dig in .

Thsnks gor the reply guys .

John

[tvnacman]

I spoke to someone that worked many years with hydraulics on heavy equipment . He suggested using a larger diameter spring with the same circumference . He suggested maybe adding a 1/2 inch spacer first .

What do you guys think ?

John

[Upgrayedd]

different folks tinker with forks in different ways. if it were me, i'd start with a fluid fillup and that 1/2 inch spacer. pvc is cheap. big washers are cheap. oil/atf is cheap. you want enough fluid in there so that when the fork tubes are fully extended and you look in, you can't see the plumbing at the bottom of the top tube. on mine, that works out to filling it to about the top of the dust seals with the fork fully compressed (spring out of fork). best to go by level of fluid vs fluid volume - some forks actually have different capacities (not common, but they are out there) if its one of those then ya want the fluid same level from top of tube, even though one will have more fluid than the other.

you could try a heavier spring. the progressive spring kits for bigger bikes are just that - heavier springs. they run about 70 dollars a pair for bigger forks, i dont even know if they make em for scooters, or where you'd source an off-label spring that was stiffer.

yeah a half inch spacer will add preload to that spring and stiffen it up, sounds like a winner to me.