Modern Vespa

Having two new tyres fitted this morning and when finished the mechanic pointed out something to me....
With the Scoot stationary and upright you gently steer the handle bars through their full turning arc. Right in the middle you can feel like a knotch or minor 'clunk'.

The mechanic says the steering head bearings have had it. It is common apparently, shows me another GT stripped down and there are top and bottom bearings just like the head-set on a bycicle.
He says these bearings are prone to damage and rust as they come from the factory with very little grease.

It is a bit of a major, two and a half hours labour in the shop, though he did say I could manage it at home. The whole front guard, callipers and everything has to come off to withdraw the forks up through the front structural member.

Comments or similar experiences?

I had to change these on my old Typhoon. If you've done it on a push bike it's pretty much the same except you have to remove more kit!

crazy that those would need replaced so quickly, but it's bound to happen.

yeah, it's a piece of work to knock it all down. if you've got the tools and the know how, it's really not all difficult of a proceedure. just lots of little things to pay attention to and a bunch of work.

best,
-greasy

Boulty, how many miles do you have on your scooter?

I see where Val is going with this. Her headstock bearings were toast, yet she managed to muscle her scooter anyway.

Every motorcycle manufacturer specifies periodically checking the headstock for wear or damage at regular intervals. They take a beating.

Ummh, they were reinstalled up-side down after I had the front fender replaced. I've been told that the steering on my scoot is still kinda wonky, but since it's my first scooter, I have nothing to compare it to. Just asking.

18000km. I have owned it since 8000 and it is in mint cond. Not ridden hard or anything....but then there are the ten sets of judder bars (speed humps) that I cross twice a day at my Uni????

What's the thougts on steering head bearing maintenence? Is it worth tearing all that down to grease them from time to time or should you just wait for signs that they are wearing out and then replace them. I'm thinking with all the work it would take to get to them (and I'm thinking they probably have to be taken out to properly re-pack them with grease) that it's not worth the effort. Why don't they just use sealed bearings that don't ever need greasing? Or am I correct on all of this? Thoughts? Has anyone else had their steering head bearings worked on or adjusted/greased? So far I haven't and mine still feels smooth and fine (I think).

Yes, my 7000 mile ET4 commuter's steering has that same, notchy feeling right in the center. I only noticed it when I took the wheel off to replace the disc rotor. I found the bearing replacement pictorial for a GT and GTS.

Anyone here have a pictorial how to replace the bearing(s) on an LX or ET? I'm not too fond of my local Vespa Dealer.

Any mechanics out there drill and install grease fittings?

It's not so much the grease, it's the torque-down on the bearings that kills them. Some water-cooled models have particular problems when the radiator is in front of the headstock. This is the theory:

The notchiness nearly always appears in late winter early spring, and there may be a reason. With the radiator in front of the headstock (or steering tubes on an MP3) the outside gets warmed up many degrees above ambient - the inside is at ambient or below if there is moisture in the air. There is a very small differential expansion due to temperature here - this will increase the effective torque-down on the bearings as there may be a 0.05mm difference in length between inner and outer tube depending on the temperatures reached, especially on a long fast ride in the cold. That's equivalent to about a 20 degree turn on the lock-ring, assuming a 1mm thread. The fitting requires a certain torque to be applied (to drive grease out of the way) then a 90 degree back-off before the lock-nut is done up. The temperature differential effect can make that 90 degrees into only 70, and there is now a much larger torque on the rollers and ring. Do 200 miles at 70+ mph and the surfaces will be compromised. Repeat this a few times and you need new head-bearings.

Note that the problem is very rarely seen in warmer climes, Piaggio in Italy were perplexed by the repeated number of UK machines that had this problem, particularly in February/March by high-mileage riders.

The trick is to obey the re-fit instructions, but to back-off by an extra 15 degrees or even more, as long as no free play is detected. Then the bearings last the rest of the life of the bike. The bearings aren't bad in the first place, they just need to be looser than factory-fitted.

My Fuoco ones are being re-fitted after only 7,500 miles at the moment.

Under warranty mind.

Are there any bottom bearings as well?

yes. these rarely go out. larger ball and larger surface.

best,
-greasy

there's really not a provision for this. the bearings (both top and bottom) sit in their respective races, which happen to be shallow with minimal contact area and even less area for a possible grease fitting due to body work and location.

best,
-greasy

Jimc, for my dealers info. Ta