Author Topic: Advice required re fork stanchions  (Read 1791 times)

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Advice required re fork stanchions
« on: May 05, 2022, 12:31:52 PM »
I have ordered a set of fork stanchions for a CB550 K3. The specs required are 35mm diameter and 570mm length (part no. 51410-404-003)
The chap I’ve ordered them from says he can no longer get the exact ones I’ve ordered but can get another Honda set which measure 35mm diameter and 576mm long. He doesn’t know the part number or what model they are from.
Does anyone know if the slightly longer ones can be used in place of the originals and whether the original internal baffles and springs will be useable in this configuration.
Any help or advice will be greatly appreciated.

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #1 on: May 05, 2022, 01:51:25 PM »
Why new stanchions Mark?

The old ones are usually ok to have hard chromed unless they are really bent.

Hard chroming is better, cheaper and of course no problems with the wrong parts being fitted.

I'm taking a pair of stanchions to Dynasurf in a week or so, already had my CB1300 ones done and a pair off my 550F2 that are being fitted to my CB500K, all of those had some pitting, rust etc but all came back perfect. The 1300s one have been on a few years now and still look as good as new, the chrome is so hard it resists chipping etc and hard chrome is self lubricating so it improves seal life and reduces striction.

Phillpotts in Luton also do hard chroming for motorcycle stanchions but are more expensive than Dynasurf and their price has recently gone up to £225 a pair from about £160 IIRC.

You can post them to be hard chromed if that's better.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Re: Advice required re fork stanchions
« Reply #2 on: May 05, 2022, 02:00:11 PM »
Hi Ken. I have a sneaky feeling that these aren’t going to polish out, lol [ Guests cannot view attachments ]

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #3 on: May 05, 2022, 02:14:12 PM »
Actually they can straighten them, so long as there is no crease in the metal they may be ok.

Check where the yokes would have clamped and see if the chrome is cracked there, if it isn't they may be salvageable.

How far from Luton are you, I know your in Sudbury area but unsure if it's a vast distance or not.

Your fork ears are in the post BTW, recorded delivery. Could be with you tomorrow, with luck.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Re: Advice required re fork stanchions
« Reply #4 on: May 05, 2022, 03:05:32 PM »
Good news about the fork ears, thank you.
Luton is a couple of hours away so would be doable (my brother lives there) but I’ve had someone look at the tubes and was advised that one may be salvageable but the really bent one is too far gone.
That mess you can see in the top left corner of the photo is the back end of the seat pan. It seems that after the initial front end impact the bike flipped and landed on the back end. The frame was bent in 3 places and was a category B write off. It was a very sorry sight. [ Guests cannot view attachments ] [ Guests cannot view attachments ]

Offline Johnny4428

  • SOHC Master
  • Posts: 2031
    • View Profile
Re: Advice required re fork stanchions
« Reply #5 on: May 05, 2022, 04:40:49 PM »
Ouch! That’s a sorry looking mess!
1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1. Running resto,
1978 Honda CB550K3.
1999 ST1100 Pan European 50th Anniversary.
1975,1980,1984,1986 Honda C90’s
1973 Honda CB750K3

Offline Bryanj

  • Grogu
  • *
  • Posts: 10694
    • View Profile
Re: Advice required re fork stanchions
« Reply #6 on: May 05, 2022, 05:40:05 PM »
Worth talking to phillpots, they will adise on straightening and re chroming of the hard sort not show and they do the top nuts as well.
The longer tubes will require spacers for the springs but all else should be ok

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #7 on: May 05, 2022, 05:42:24 PM »
Oh dear, that's bad. Not the worst I've ever seen but I've scrapped better than that if I'm honest. MUCH better.

Maybe send that pic to Phillpotts and see what they say. If they say far too bent at least you'd know.

Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #8 on: May 05, 2022, 05:58:40 PM »
Have you by any chance measured the stanchions that came off the bike, the bent ones. See what they measure first, suppliers have been known to get it wrong.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Re: Advice required re fork stanchions
« Reply #9 on: May 05, 2022, 06:22:31 PM »
Thanks for the advice again guys. I will fire off an email to Phillpots in the morning.
The bent tubes are definitely 570mm as per spec.
Did you notice the massive hole in the crank casing - that required a new bottom end but everything is looking good now. [ Guests cannot view attachments ]

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #10 on: May 05, 2022, 06:39:15 PM »
Nice polishing on the breather cover. I'd recommend changing the exhaust studs for stainless or at least new ones. They have a disturbing tendency to snap just when you don't want them to.

Another tip, the bolts next to the tappet covers on the cam cover, check and see if any threads are protruding out past the bottom of the thread hole, if there are, trim them back, if you don't they go rusty pretty quick, then when you try and remove them it strips the thread out if your unlucky. Why Honda specced a bolt too long I have no idea. You'll also find that using allen keyed bolts means the holes collect water and rust out the hole so when you try and remove the bolt it just rounds off. Even stainless ones rust, just not as badly. Either use the original JIS screws or use the later 8mm headed and flanged bolts that Honda started using around the 250N era. Those fit great and no trouble with rust.

Engines looking very nice, I'm betting the tacho drive was broken? Always seems to happen and they ain't cheap to find or easy to find second hand.

And no I didn't spot the hole in the cases, I have now.

In actual fact I think the original spec was 571mm as I have a pair in front of me. These were mine that I had hard chromed. Strange as they came out of a 550F2 not a K3.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Re: Advice required re fork stanchions
« Reply #11 on: May 05, 2022, 06:54:03 PM »
The tacho drive was actually ok except for the fact that we couldn’t get the damned cable out. Had to drill and re-tap the retaining screw.
I though the F2 tubes were longer by a good margin.

Offline Oddjob

  • SOHC Jedi
  • Posts: 4296
    • View Profile
Re: Advice required re fork stanchions
« Reply #12 on: May 05, 2022, 07:55:25 PM »
I bought a pair of 550F forks the other month. I really only wanted the sliders but had to buy the whole lot. Strangely those are much longer, 585mm. I honestly can't remember now, it was a LONG time ago, so whether the 550F2 tubes were damaged when it was written off I can't honestly say. I might have also broken a 550K3 at the same time so maybe I robbed the tubes off that instead. Bike handled just fine regardless of which bike they were off.

Maybe someone with a set of F2 tubes can confirm the length they are supposed to be. Unless they are apart it's impossible to tell though.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline 3scs

  • SOHC Member
  • Posts: 171
    • View Profile
Re: Advice required re fork stanchions
« Reply #13 on: May 05, 2022, 08:53:29 PM »
I think the K3 F2 forks are the same mine measured 570mm

Offline Bookmark1

  • Newbie
  • Posts: 38
    • View Profile
Re: Advice required re fork stanchions
« Reply #14 on: May 06, 2022, 09:39:48 AM »
That F2 tube and the internals looks the same as my K3 ones 3scs

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal