Author Topic: CB550 fork problem  (Read 4033 times)

Offline internix

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CB550 fork problem
« on: July 13, 2009, 09:09:58 PM »
Hi everyone,

I`m very pleased to have found this forum having recently bought a 1977 CB550F2 which I have begun to restore. I actually bought one brand new back in 1977, same colour as the one I`m working on and always regretted trading it in a couple of years later. One of the first things I noticed when I bought it was that the fork gaiters appeared to be "scrunched up" and the front end was sitting a bit low. Also it was very difficult to get onto the centre stand. I have begun to strip the forks out and check them over. I pumped the old oil out and measured the quantity which was low at about 200cc total from both legs. I`ve measured the spring length at 18.5 inches which I hope is ok as my haynes manual doesn`t give the length for the F2 (can someone confirm that this length is ok please?). I want to replace the oil seals but I`m having no luck getting the damper rods detached from the legs. I`ve tried undoing the hex bolt at the bottom end, with the filler cap and spring in situ as per the manual but the damper rod just spins round with the hex bolt. Does anyone have a solution for this problem please? Thanks


Nick

Offline matthewmosse

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Re: CB550 fork problem
« Reply #1 on: July 13, 2009, 10:50:32 PM »
sharpen up an old wooden broomhandle or similar stick as if it were a oversized pencil and ram the sharpend end down the fork leg (after removing the spring) and knock it firmly in, then undo the hex bolt. that's the bodgers way anyway, cann't recall the sizes of fastner inside the fork leg but I'm sure there will be other better advice along shortly. my method worked on the last few things I took appart ::)
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock

Offline internix

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Re: CB550 fork problem
« Reply #2 on: July 13, 2009, 11:12:40 PM »
I`ll give that a try tomorrow....cheers. Let`s hope "`er indoors" doesn`t miss her broom...lol

Offline internix

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Re: CB550 fork problem
« Reply #3 on: July 14, 2009, 06:21:41 PM »
Thanks matthew....the piece of wood worked perfectly. Seals now replaced.

Offline internix

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Re: CB550 fork problem
« Reply #4 on: July 23, 2009, 06:51:56 PM »
Thought I`d give an update on my original post. I replaced the fork oil seals and refilled with the correct amount of 30 weight fork oil, but I was still left with the original problem of the forks compressing too much. As I`ve been unable to ascertain the correct spring length for the cb550F I decided to experiment with spacers inside the top of the fork legs to take up some of the "static sag". After a bit of experimentation with 22mm plastic plumbing overflow pipe I have settled on a spacer length of 20mm. this makes the bike sit right but obviously I won`t be able to see how the bike handles until I`ve completed the restoration. I will update this when I have ridden it.

Offline Dave M

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Re: CB550 fork problem
« Reply #5 on: July 23, 2009, 07:55:33 PM »
20mm sounds an awful lot of sag to take out.

As you say you won't know how it handles until you ride it but may find it bottoms out easily under braking due to the springs compressing fully and becoming solid.

Perhaps it might be wise to consider replacing the springs.
Dave
Melbourne.

Offline matthewmosse

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Re: CB550 fork problem
« Reply #6 on: July 24, 2009, 02:27:14 PM »
25mm sounds fine in my expirience- depending on how you intend to ride of course- last owner tells me my 500/4 has 6 inch spacers in it's forks to make up for the weight of a sidecar and luggage - have put 100 000 miles on it with most being on bumpy Welsh roads and at a fair pace and as far as I've noticed it's not bottomed out. I'd use something a bit more substantial than plasic pipe though. Alternatively Hagons can do fork springs to order and are sure to be able to match or inprove on original speck.
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock

 

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