3CL steering head bearings. I'm not that bright, I don't understand....

While everything I've built for a large number of years now has used tapers top and bottom - principally cos they've got cheaper - using a ballrace top has got me out of a couple of situations where I could not source the correct size top taper...

If you're really paranoid about a top bearing accepting loadings in the vertical plane - use an angular contact ballrace.
 
Assuming the factory guys weren't mad, there must be a reason they changed from roller bearing on the top to tapered bearing on the RGS 1000 SFC at least. Not sure about the RGS, but the RGS SFC definitely had two tapered bearings. So...

Also, there is a company specialised in headstock modifications in Germany called Schwarz http://www.emilschwarz.de/dev/index.php?id=304

They offer a special tapered top-bearing system that eliminates the free-play in the components while also reducing the resistance, which is said to improve handling dramatically.

So - there seems at least to be a point in using tapered bearings on the top, too...  ;)
 
Cosi said:
It quite simple why the dog weaves its most likely bent, but mr ghwallace is not a subsciber :-*
Click to expand...

Cosi, interesting thing is that, on the dog, I pumped the tyres up and put Tammy on the back. We've done over a thousand klm and not once has it shown a weave....
 
ghwallice said:
Cosi, interesting thing is that, on the dog, I pumped the tyres up and put Tammy on the back. We've done over a thousand klm and not once has it shown a weave....
Click to expand...


Swing arm bushes/bearings all good and true? Rear tyre not too squared off?
 
Laverdalothar said:
Assuming the factory guys weren't mad, there must be a reason they changed from roller bearing on the top to tapered bearing on the RGS 1000 SFC at least. Not sure about the RGS, but the RGS SFC definitely had two tapered bearings. So...
Click to expand...

Let' analyse what they did, just for fun, and see if we can get into their heads as to why they made the change.. Can anyone put up a sketch of the laverda taper+taper design? (A croosection of all the component parts would be fab). No need for accuraacy, just what is used and what goes where.
 
Andy, first up we are talking about 2 different 3CL's. Cosi is referring to Sully the Dog, and I am referring to Luther.

The Dog is an ex race bike, and as Cosi has stated may have a bent frame. At the moment I am not going to spend $600 to prove/disprove that. Within the last 5000klm the Dog has all new frame bearings, reworked Konis, reworked Ceriani's with emulators. I put new tyres, front and rear (Pirelli) before my trip to Eastern Creek. Marginal change, but no fix. I've played with oil weights (technically kinisthetic viscosity) spring weights, preloads, fork seals ect ect to point of boredom/frustration.

Not also to mention the time checking the tubes for straight on a surface plate with dial guage, and the tubes for parallel when fitted.

The last 1000klm I ran 38/42 with Tammy on the back, and not once was there an issue. WTF!!!

The bike I am on the forum about is Luther, which I am cleaning up at the moment. I've gone for the ball in the top, cleaned up the Ceriani's, put the original rear Ceriani's off the Dog on the back( there was no change with the Dog when I went to the Koni's), and...fitted the tyres off the Dog that I replaced before my trip to Eastern Creek. I'll be interested to see how it rides.

Regards, Greg
 
Any Laverda I have owned that was prone to weaving at speed was always calmed down by adding a passenger.
More mass to damp out weave/vibrations?
Better centre of mass?
No idea, I just know it helps.

I also discovered that a lot of 'front end' weaves are caused by the back end, whether swing arm pivot, tyre profile/pressure/balance, shocks or whatever.
Too tight steering head bearings can lead to a sort of rolling weave at speed, usually above 80mph.
 
taking a pillion will always change the steering head angle for the betterment of less or no weave.
CLEM
 
I found with my Series 2 Jota the addition of a Cico fairing steadied the ship - I put that down to more weight on the front end rather than aerodynamic advantage...do miss my Jota which alas remains in a million pieces...

Nick :-)
 
ghwallice said:
...reworked Konis, ...
Regards, Greg
Click to expand...

Greg, have you checked the rebound-setting on the Konis? Weaving most likely comes from the rear as Grant correctly stated. there is a littel rubber cap at the top of the Konis. If you lift it with your finger, you will see a small dial with numbers 1-4. Put it to 3 and check again... if the waiving is gone but the back hurts, put it to two. if it still waives, put it to 4.

If these Konis don't have that dial, you need to take the spring out, compress the sucker completely and then turn the top until you notice a "click". Try which way there are more clicks. Factory setting is position 1 (low rebound), so it might be they are simply not set to the right rebound damping...

All 7610-xxxx should have a dial. See the pic below, the left one has the rubber removed, the right one still has it in place. If you look closely, you might spot the dial...

7610-1298.jpg


for more information, refer to the ikon homepage hosting even the old pics from Koni obviously...:

http://www.ikonsuspension.com/fitting-and-adjustment.html

cheers


Lothar
 
Or just watch this, starts talking about wobble and weave at around 4 minute mark. My bike never ever wobbled or weaved despite the frame and swingarm being totally out of whack, even when the rear wheel was so buckled it alarmed people riding behind me it never went out of line.

 
Laverdalothar said:
Greg, have you checked the rebound-setting on the Konis?
Click to expand...

Yes, they have the 4 position knob thing. The interesting thing about the Koni, now Ikon, is that that there is no separation between the rebound circuit and the compression circuit. You dial up the knob and it opens up both circuits. They need to be set up wit a valve of some sort to separate the circuits.

The other thing about Konis is that the shims and washers are only set up for low speed compression. I spent some time looking at restacking to see if I could get a high speed compression circuit, but ran out of time. It should be easily possible with Koni's. But again, no real point until the rebound and compression circuits are separated.

Also, as previously stated, the Dog had the original rear Ceriani's with original 40 year old oil, and when I fitted up the Koni's it made no difference.

Hope all the above makes sense. I have had some beers after working all day on the western side of a house in 36C heat.

Regards, Greg
 
I have seen 2 references to Race Tech Gold valves being used in Konis and I expect Icons over the years from blokes who know their beans, spoke to the local Race tech bloke and he does not do twin shocks and the Race tech site says nothing about Gold Valves for twin shocks. Anyone know anything about this? Blab there are options but none under at least a Grand.
 
When Keith told me the ?reconditioned? Marzocchis on my Mirage were little more than cosmetic items and unfit for the road I cut to the chase: bought a set of Wilbers and never looked back... 
 
not sure if the bike in question gets ridden in classic racing where non-classic suspension might cause issues?!?

If not, YSS are a good way to go. I have them on my Jota and can't feel any difference to the comparable Wilbers, which cost at least 50% more...
 
Have YSS shocks on my RGS, took a while to dial them in but now work a treat. They were $800 AUS.
 
You must log in or register to reply here.
Back
Top