Bimota Forum

[Mako]

I wanted to check the bearings, clean them and regreese...

but I can't understand how to take off the lower tree: the upper one went off easily and now I see the naked upper bearing, but I cant push away the lower one..
it seams the upper bearing is screwed onto the steering tube...

any trick?
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

[oily]

Big hammer

Lets have a picture to explain what you mean Marco
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SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[Mako]

[oily]

I see
I repeat....bigger hammer
No, the bearing is not threaded to the pivot pin.
Obviously, you need to protect the threads whilst using a big hammer.
I use a block of wood between the pivot pin and the hammer.
It transpires that the Bimota factory was afraid of grease during the SB6 era.
Which model have you got? Mk1 or Mk2? If Mk1, do NOT damage the bearings as they are unobtainable
_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[Mako]

[Evilchicken0]

There isn't anything in there to hold it once you taken the torque nut off (with a C or hook spanner). See fi you can take the top bearing out ... I guess you've tried to jiggle it a bit. The top bearing shouldn't be attached to the lower race
If not try hitting it from below on the bottom yoke to lift the top bearing then the bottom yoke should drop free (probably).

You have taken the forks out haven't you
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Don't read everything you believe

[Mako]

I tried with a 1.5kg bricklayer hammer and a piece of wood... NOTHING.
it's still tight to the pivot pin with no game.
Tried to heat with an heating gun with the intent to liquify the old grease that could has became glue between pin and bearing... NOTHING. NOT A MOVE

this is the situation:



and this the retaining clamp that has no way to be torqued properly (only by hand i guess):



do you think I have to hit harder or I'm missing something???
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

[oily]

Bigger hammer

Looks like the Mk1 headstock too.
Try not to damage the bearing as they are unobtainable and you will be trying to convert to standard taper bearings instead of the barrel shaped rollers

They are a really tight interference fit and when you finally get the bearing off (with a bigger hammer) it might be worth shaving a few thou off the stem

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[Mako]

[Evilchicken0]

Use some carb cleaner to dissolve the grease on the stem and then some penetrating oil
_________________
Don't read everything you believe

[oily]

Heat would certainly help but on the bearing not the stem.
Yes you right, they are far too tight with or without grease. I assure you it is not the grease holding it together but the interference fit

Bigger hammer
_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[Mako]

THANK YOU!!!

Done!

hit with no fear and the lower stem went down. Cleaned,




checked for scratches and regreased. Remounted heating the upper race to decrease interference.
I think I'll tighteen a little bit with a tool I used to fit the headraces in the Honda fours... a 8mm rod with flat faces to be compressed: using a proper brass spacer I would have to fit it right:









I think I'll check even the swingarm pivot as it seems in Bimota were saving on grease...
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

[oily]

The solution to all the worlds problems......

A bigger hammer

Well done, you now know why the adjustment only needs to be hand tight
_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

[Mako]