Topic: 1971 CB500 fork disassembly question

[Goofaroo]

I'm about 30 minutes into my new project bike and already stumped. I pulled the right side fork leg, removed the cap from the lock nut on the damper rod, removed the bolt from the bottom of the housing, and removed the seal. The stanchion tube is removed as well. The question is: How do I get the damper rod and spring out of the housing? Am I just not pulling hard enough or am I missing something? I looked at the service manual and it doesn't really explain what my problem is.

[Jordan]

by bolt on the bottom are you referring to the drain bolt or the allen head 6mm on the underside of the very bottom? if they are all out the innards should slide right out, if not then something is jammed or rusted up inside.

[Kevin400F]

I think they're probably just lightly stuck in the bottom case (housing).   Try threading a longer 8mm bolt into the damper from below and give it a few taps with a mallet.  That should break the damper free from the case.

Kevin

[Goofaroo]

Thanks for the input. With a few taps it came right out. While I've got the advice of those in the know; Can I assume that the damper unit is not serviceable? Just clean it and reinstall? It seems to operate freely and properly.
Also, on another note, before I took these off the bike, if I compressed the front end and then pulled up during rebound, they would top out with a clunk. Can I assume this is primarily due to the lack of decent oil? These forks had very little oil and I would guess they have never been apart. I looked at the parts diagram and didn't see any kind of rubber bushing to prevent the clunk as it tops out so can I assume this is normal?

[TIM TINGEY, age 55]

With the forks re-assembled use 10 wt. Bel Ray fork fluid or another motorcycle only brand. Athough ATF was recommended in the S/M,10 wt will compliment the forks dampening abilitys. It will help with the fork topping noise but the level is responsible for cushining the fork when it tops out. Add 5.6 ounces or 165cc's. to each leg. If you install a set of Progressive brand springs(if their still availabe) then run 15wt. oil.

[Goofaroo]

Hi Tim,

You might just be able to save me a lot of guesswork if you don't mind me picking your brain. I am planning to have a set of straight wound springs made for my weight and for fairly aggressive street riding. I was assuming I would start with 15wt oil but you are suggesting 10wt with the stock springs. Can I assume you are suggesting 15wt with progressive wound springs to compensate for the travel that is wasted almost immediately by the progressive springs?  As far as I can tell these forks just have a hair over 4 inches of travel so I'd like to have some quality results from every inch.
I can get the springs set up so I will be happy with them but not knowing what to expect from the factory dampers it is all just trial and error for me to find out what works. I am open to any suggestions you have as a starting point. I know that these forks aren't the holy grail of sport suspension but I think I can get them to perform pretty well with a little effort. I've never had any luck with running emulators or any of that fancy crap. I just need a good spring, some proper oil, and everything in good working condition.

Thanks,
Andrew

[BoCoJohn]

I just took my forks apart yesterday (73' cb500). I cleaned and put new seals in them.  I put 5.4oz of 10w-30 just like the original service manual says.  I normally tend to do what the manufacturer says unless there is a good reason not to.  The bike feels great!

[bryanj]

On a 71 if you undo the threaded rod from the top nut the whole lot should slide off the steel stanchion without undoing anything else.

If it dont perhaps it has the 72 onwards stanchions which have a collar in the bottom to stop the damper going downwards, in which case they dont need the threaded rod.

Whilst some parts look like the same they dont mix-n-match properly

[TIM TINGEY, age 55]

HEY GUFAROO, SORRY I HAVEN'T GOTTEN BACK TO YA, I HAVEN'T CHECKED MY POSTS  SINCE NOV' 010. THE REASON I RECOMMENDED 15WT IS DUE TO THE PROGRESSIVE SPRINGS HEAVIER WEIGHT/SPRING WIND RATING. IT WAS ORIGINALLY MEANT FOR RACING OR BIKES WITH A TOURING FAIRING TO COUNTER ACT THE ADDED WEIGTH UP FRONT. PROGRESSIVES INFO SHEET IN THE BOX RECOMMENDED 15WT. I HAVE TO TELL AY I HAVEN'T USED 550 FORKS SINCE 1976. SINCE THEN I SWITCHED TO THE 500'S EARLIER CARTRIDGE TYPE. THEY ARE FAR SUPERIOR IN DAMPENING CONTROL AND RIDE QUALITY AND BETTER FOR ROAD RACING WHICH IS SOMETHING I DID ALOT OF FROM 72 TO 91. ADD IN THE SUNDAY MORNING RIDES AND AROUND 30 TO 40,000 MILES A YEAR FROM 74 TO 85. I STILL OWN THE BIKE AND RIDE IT ABOUT 3,000 A YEAR. MY FORK ALSO USES THE "NUMBER ONE FACTORY FORK KIT" DAMPENER ROD WITH DAMPENING ADJUSTABILITY. THIS IS UNOBTAINIEM SINCE 78. YOUR 500 FORKS ARE EXCELLENT FORKS, EVEN IF STOCK SPRINGS ARE USED, YOU CAN PRELOAD THEM TO REGAIN THE RIDE HEIGHT. CONTACT ME AT timmanyatingey@yahoo.com. REGARDS, TIM