Topic: WTF - 550F triple tree won't fit on 400F ???

[Speedy]

I've read many a post where guys bolt up a 550F front end on a 400F, like this:

http://forums.sohc4.net/index.php?topic=103463.0

I bought a 77 (or 78, the model w/o the fork boots) 550F front end but the steering stop on the 400F frame hits the bump in the lower tree so it won't go in far enough the engage the tapered bearings!  Are the older 550F lower trees different?  The tapered bearing kits are the same so it must be, but I can't find any on ebay right now.  My other option is a 750F tree but the stems on those are longer.  I am desperate to get this back on the road so any help appreciated.   

[Powderman]

Pics?

[Speedy]

The bearing is in there trust me.

[chewbacca5000]

The bearing is in there trust me.

Looks like you need a spacer under the tapered bearing to give you the necessary clearance.  Can you post a pic not so close up? 

[Speedy]

If I put a spacer under the bearing the stem would not be long enough.  As it is right now I cant screw on the top spanner nut that's why I'm holding it in place. The problem is the bump in the bottom tree of the 550F, it's not on the 400F and the stems are the same length.  I have to assume it not on older 550Fs if no one has had this problem before?

[Speedy]

400F next to 550F, you can see the bump that hits the frame steering stop tab.

[chewbacca5000]

400F next to 550F, you can see the bump that hits the frame steering stop tab.

Me thinks your right the F is Fing you.  Could alway grind the bump off.  Wear safety glasses as those grinders like to launch aluminum into your eyes.  I have 750 k model no bump. Sorry I can be more help.

Check out this thread.  1st post 2nd page.  Said used tripple from 75 550.  77 / 78 things change up quite a bit on some of the Hondas.

http://forums.sohc4.net/index.php/topic,103463.25.html

[Powderman]

Post a pic of the underside of the hump, is it solid or or a cast recess? Can it be ground down as mentioned?

[Speedy]

Cast recess. If I ground it to fit there would be a hole...

[chewbacca5000]

Cast recess. If I ground it to fit there would be a hole...

So you can't grind it or space it?  Guess you will have to replace it or go back to stock.

[Powderman]

Looks like your tree is from 77 or newer. You need the 76 or earlier. They seem to be very popular. You can get yours from CMSNL for $50lbs. You can't get the one you need from them for $441lbs.

[Speedy]

Well doesn't that just take the cake. I also have a CB400K tree that won't work too (no mount for ignition key) plus it also has the same bump.  Oh, did anyone know that CB550 guages are larger in diameter than a 400F?  Looks like I'm going to have a blowout sale of various CB parts when all is said and done! I just hope I can get this thing on the road before the snow flies again.