Laverda tricks: easy installation and removal of the (needle)bearings

Thomas aus LAU

Thomas aus LAU

Hero member
Location
near Nürnberg/Germany where the best hops grows
The installation and removal of the steering head bearings and the needle bearings in the swingarm are often dificult.

In addition, the bearing is stressed if the bearing seat is not exactly round and the bearing may be not installed at an exact right angle.

Solution steering head bearing:
Grind the bearing in a lathe or simply with a belt sander on the outside with a minimal surface.
Now the bearing has minimal play and you can e.g. simply glue in with Loctite 638.
The bearing is therefore optimally relaxed and can no longer getting out of round.

The dismantling is easy if you add some heat (hair dryer, hot air dryer, ...).

Don?t forget to install the washer under the steering head bearing. With it dismateling is easyer.


Solution needle bearing swing arm:
Grind the bearing seat slightly larger with a small cylindrical grinder.
Now the bearing has minimal play and you can e.g. simply glue in with Loctite 638.
The bearing is therefore optimally relaxed and can no longer getting out of round.

The dismantling is easy if you add some heat (hair dryer, hot air dryer, ...).

Best Thomas aus LAU

 
Steering bearings have never been a problem.
Whack them out using a suitable drift and I then use the old bearing cage to knock the new frozen bearings in.
There's also the bead of weld technique to get them out.

Swing arm bearings. I needed to glue the ones in my SF2 last time I did them, they were a bit loose but I have the feeling that it's the last step before something radical has to be done like oversize bronze bushes. I had a difficult time getting the old ones out of my 3C currently in restoration resorting to the Dremel. I'm having a tough time getting the new ones in. I hope that they won't need changing again in my lifetime.
I currently have a 15 year life expectancy, but in what state?

Paul
 
Hello Paul,

i often have seen that the bearing seats on the steering heads are not round.
It is possible that Laverda did not rub out the bearing seats after welding.

As a result, there is too little play in some places and too much play in other places.
Material removal during installation and removal is the result and uneven loading of the bearing.

With the method above described you have a technically clean solution.

For the swing arm mounting I wrote the tip, because some report that they tried to expand the silentblock with heat and/or enormous force.
But you don't have to look like a coal miner at work doing this job  ;-)

Understand my tip as an experience report and not as a requirement.

Best Thomas aus LAU

 
Yes, I have heard about ovalized steering head bearings but never come across them. I'm only an amateur so have done those bearings on maybe 6 or 7 bikes.

However, I find your method for the swingarm bearings really drastic.
Enlarging the bearing housing is changing a maintenance operation into a repair operation. Not a good idea.

I've just finished getting mine in. Swingarm back in the frame tomorrow.

Paul
 
I found an oval steering head when changing the bearings on a 3C. It was the upper bearing housing that was oval. I forget the actual ovality measurement, but judicious application of a lump hammer and re-measuring between hits soon had it perfectly round. Well, as near to perfect as I could measure with a digital vernier caliper. The bearing went in nicely and steering wasn't notchy like it had been before.

Before any other pedants mention it: Yes, I know that "digital" + "vernier" is a contradiction.
 
In practice, many frame steering heads are oval to a certain degree.  Very few manufacturers gave them the attention they would deserve from an engineering point of view. 

At least in the case of Laverdas, it hardly makes itself felt.  Normally, it's the upper bearing that is affected most, but, if a ball bearing is fitted as the factory specified, it comes close to perfect once the lump hammer has done its work  :D.  Imho, going to the trouble to ensure the bearings are perfect is complete bollocks when dealing with 40-year-old clapped-out telescopic forks on the same bike.  Newly installed bearings will be shot within a decade, perfectly circular or not.  Same applies for swingarm needle bearings.  Just a fact of life...

piet
 
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