doing fork spring upgrade tomorrow, what to watch for?

tomorrow im going to put new progressive fork springs in my 550 and im wondering what i should watch out for. the caps and very top of the fork tube are pretty badly rusted so i have kroil to loosen it up and i hope to remove that rust while im at it. anything else i should watch out for? im not doing a complete rebuild for now - im giong to get some fresh oil in there and see if its necessary to do a full teardown to replace the oil seals before i go down that road.

 

Make sure that you have the front end elevated enough that the caps don't become projectiles!! When you loosen the fork caps, keep your hands over them so they don't fly out and hit the pavement threaded side down. Makes it a pain to screw back into your forks. Also make sure you have the correct length PVC spacers called out by progressive. If you are on the heavy side, try a 1/4 inch longer than suggested. You also might want to replace the fork oil. Actually I would replace the fork oil if you are not the original owner, you have no idea on how old that oil is.

Sean

 

I also remember reading that in a motorcycle magazine a way back, they said they used a little bit heavier oil than called for, and it really helps fork dive during braking.... I will try to dig up the article...

 

hope that helps

heres the link: http://motorbikearchives.com/Bike-Tests ... -1981.html

 

thanks. yeah i had already planned on replacing the fork oil since i can only imagine based on the guy i bought it from that the oil (or whatever is left of it) is original and im kind of a fatso so i already planned ahead and got 20 weight oil which should react better to my big ass bouncing on the springs. i was going to cut 31.5mm spacers to begin with so maybe i should go a bit bigger than that? progressive suggested around 28.5mm so maybe ill be good with the 31.5 ill try that from the start. i already planned to have the front end up on jack stands just in case; when i replaced the fork oil on my cbr i didnt jack the front end up and i ended up pissing my girlfriend off by forcing her to lift the front end while i screwed the fork caps back on, which im sure was hilarious to watch.

 

doesn't the 550 have fork caps retained by circlips and not threaded?

 

-the fork caps on the 550 are indeed retained by ring clips not screwed in.

-pull the rubber caps off and get some Kroil in there well ahead of the job it will go much easier.

-If you still need to hammer the caps down to get them moving, BE CAREFUL. The inside of the fork has a tapered bore and you don't want to push them down any further than just necessary to remove the ring clips. Too far and they can become stuck.

-pull the drain plugs and get the old oil out FIRST, while you can still "bounce" the front end.

-if horrible nasty gooey mud comes out instead of oil, plan to change the fork oil again real soon, and expect to discover you're probably going to need seals.

-I weigh right at 200lbs, and with the Progressive springs in my 550 Seca, I use 15W. The 20W, while fine for roadracing, might prove to be a bit stiff for street riding. Try it and see, if the front feels harsh over bumps drop down to 15W.

 

Check the top pinch bolts are not over tightened. This can cause the caps from moving. Been there done that got the t shirt.

 

+1 That too. More "PO tracks..."

 

yeah the top pinch bolts were holding the caps in i figured that out. neither cap wanted to come out once the circlips were out but pushing down on the front end made one of them pop out but the other one just doesn't want to come out. the top of the cap is just about flush with the top of the tube and doesnt seem to want to go any further. it moves freely under that point but it just doesnt want to come out. ive shot a ton of kroil in there and it all seeps inbetween the cap and the fork tube but still isn't coming out. ive been pushing on the front end hoping the spring pressure will budge it out but to no avail. what else can i do to get it out? right now its soaking in kroil with an old shirt tied over it incase it decides to pop out while im not in the garage.

 

try pushing the cap down as far as you dare and see if you can find a burr on the inside of the fork tube maybe try to clean it with some scotchbrite
if it's on the side stand and the cap does pop out the bike might fall over when the forks collapse

 

its on the center stand and the front end is jacked up for the night. i stopped in just now to spray some more kroil into it and hopefully itll pop loose over night. otherwise ill shove it back down and see if i can't force it out like i did the other one. both caps are in for a hell of a cleaning once/if i get the other one out.

 

Polock hit the nail on the head. Plenty of Kroil, and push it back down (put the clip back in if necessary.) Take some Scotchbrite to the inside of the tube and get it cleaned up, see if you can find and cure any obvious bind points. Get the clip back out and then work it up and down, see if you can manage to rotate it any, it will pop eventually. I had a HECK of a time with one of mine.

 

i was considering pushing it back down but the thought of wrestling that circlip back out makes my third eye get tight. it was a nightmare getting those things out but if i comes to that tomorrow morning ill give it a shot.

 

Even after I got the inside of the tube reasonably cleaned out, I had to work the cap up and down repeatedly against the spring pressure to get it to finally break free.

It's incredibly frustrating when it appears as though there is NO REASON the blasted thing won't pop out. Wait'll you see the condition of the plug.

I've been considering getting another set of plugs, and taking them to a machinist to get drilled and tapped with about a 12mm hole, and using screws with gaskets as "upper" drain plugs. Disassembling the bloody forks every time you want to change the oil is a PIA.

 

how many cc's of oil should i put in it? the haynes says 230cc, but chacal says in his post with a spacer cut to 31.5mm that he sells it needs an extra 13cc for a total of 285cc. that a pretty big difference i don't know which to do?

 

The Haynes? Clymer maybe?

Either way, that's incorrect. The factory Maxim supplement says 272CC (9.2oz,) the 550 Seca (smaller forks) takes 230cc.

I'd go with 272cc.

 

i went with the 285 yesterday. but that 2nd cap is still not coming out. i finished the left fork and put it back together with the new spring and just can't think of what i can do to get the other one out. i even pushed the bike off the center stand and grabbed the front brake and kept throwing my whole weight forcefully forward getting the spring to compress really far and it just will not budge. would using cold or heat do anything? say get some dry ice from the store and cover the tube in canvas and put dry ice on the cap to get it to shrink a little so i can break it free? maybe im just grasping at straws now. or maybe a shot of compressed air up the drain hole at the bottom of the fork

 

i wish you didn't put the other one back together yet, but, did you hit the cap down and let the spring recoil and smack the cap up or just compress the forks and have the spring push up on the cap
the recoil is the way to go
if that does nothing you may have to get ugly with it and drill and tap it while it's still in there
i suggest a 1/4X28 tap and a 7/32 drill bit, a starter tap would be best then a plug tap The fine threads are easier to twist
the most important thing is to start the tap in the hole straight
(starter tap) If you use a crescent wrench be careful, thats a good way to bust a tap If the plug spins you might try a cordless drill with clutch settings to get it a little farther

 

what was wrong with finishing the other fork? i sanded the cap down and cleaned the tube out and it went back together extremely easily, didn't fight at all. ive compressed the forks and hit the cap with a socket extension and a mallet to get spring recoil and many many combinations of both to get the thing to come out to no avail. its just awful because its stuck right at the very top of the tube to where the cap is flush with the top of the fork. im ready to go insane because now i have to get my girlfriend to drive me to work every day as thats my daily driver.

 

The tube is dented or distorted at the very top.

Push the cap back down, and put the clip back in. Take the whole bloody assembly to a machine shop and see if they can make the top round again.

OR: Get medieval with the top 1mm or so of the inside of the tube with your Dremel and a cylindrical grinding stone.

 

Jeez stone the bloody crow's, didn't know yous lot over there were familiar with th proper use of bloody terminlogy. You know, th right thing t'do with it. It's good to see yez bloody catchin' on at last :>

 

I WIN. borrowed this really nice dewalt rotary tool from work since i dont have one, got a cylindrical grinding tip and a wire brush tip on the way home and went to town on the top of the fork. grinded away everything above the top of the cap, and used the wire brush to get between the cap and the tube. i gave the front end a couple shoves on the center stand, nothing. so i push it off the center stand and stradle the bike grab the front brake and start throwing myself at the front end and on the 3rd or 4th push POP! there was so much force behind it that the cap blasted away the shirt i tied over the top of the fork and the whole spring shot passed my face and slammed into the shut garage door about 10 feet behind me. i was so happy and the situation was so funny i couldnt help laughing out loud to myself.

but really, +100 on the kroil. when i picked the cap up off the floor it was practically immaculate. i guess there was a semi circular patch of rust on the rear facing side of the fork tube about an inch and a half down that the kroil had been slowly working on over the last couple days and finally with the other junk out of the way let go. i used the wire brush to clean up the inside of the fork tube and sanded down the cap. everything went back together very easily, i even tried popping the cap out again with no problems.

unfortunately i broke the head off the drain screw on one of the forks when i was putting it back in so the fork slowly drips oil if i put pressure on it so i need to wait a day for the gasket i made with rtv silicone to cure before i can do a good test ride. but i did take it arond the parking lot and it does feel alot better.

so i guess the moral of the story on getting stuck fork caps out is persistance and kroil