Genesis of the Jota: Part 1 - The Laverda 3CE

helicopterjim said:
It would be more stable with standard yokes.

Jim
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hi, it wasn't so much about the yokes and head angle as shit tyres at the high speed which these bike could do, I remember putting a pair of red arrows on my 3ce in 1979 because everybody was saying they were better than TT 100 s wrongful then there was the k181 wrong. Then phantoms were brilliant until they got halve way down and then they did the same as the above mentioned tyres and weaved like a bastard.
Tyre pressure was an other issue with tyres which is better understood nowadays but will course weaving.
  But having said all that, call me mad but I do enjoy the triples when they bucking and weaving as it get the blood flowing.
Regards Andy 😁
 
Piranha Brother 2 said:
Sorry PB, but the weird angles involved produce a more stable front end at high speed.
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It is actually geometry .... not physics. I would have to draw a picture to show you I guess ..... but the forks angled rearward put the center of the wheel further back from the point where the axis of the steering head meets the ground. This gives increrased trail. Increased trail give increased stability.

If you wish the issue to be confused a bit more we can start talking about the reduced wheelbase and more weight on the front wheel. We can also introduce tire choice and tire profile.

I prefer to introduce sarcasm ...... however I shall attempt to hold off on that now. I may wait until closer to Christmas when this thread hits page 72.

Jim
 
pf1 said:
Do they weave in fast corners? Putting a 4.25 on the rear instead of a 4.10 made mine weave.
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I did not like a 4:10 on the front and 4:25 on the rear of the machine in any brand. Did not feel right to me. Don't recall any weaving though.

I ran 4.25s TT 100s front and rear without any problems. I dont think they were perfect..just okay. I did find Michelin racing (M45?) 4:10s front and rear were very sticky and the bike a little easier to ride fast. That is saying something too. The 3C was/is not an easy machine to ride quickly.

Never had any weaving problems, even at Rockingham on the very fast banking. I used a 36 tooth rear sprocket on those sort of tracks.

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I was told, and accepted, that it was unwise to run a 4.25" tyre on a 2.15" rim. Pretty muchj every tyre manufacturer stated that.
When the Phantoms arrived, I ran 110/90 front and back on the original rims, without any handling issues. They were far superior, in terms of grip, particularly at high lean angles, on track.
As those who know my bike will confirm, mine has always been stable at all speeds.
My only downside with the Phantoms was the rear wear rate. I could trash a new rear 110/90 tyre, in a morning, at Donnington Park.
In '91, I fitted a 3.00 rim on the rear with a 150/70 Pirelli Match rear tyre. Went to the Factory on that one with absolutely no handling problems. Came back (760 mls./1,300kms.) in a day of serious high speed cruising. Did a bunch of Track Days and still got over 7,300 miles out of it.
When Pirellis were NLA (2008) I fitted Bridgestone BT45s, still 110/90 Front and 140/70 Rear.
I'm on my third set and have never suffered a high speed weave. i did have a little wobble on worn fronts until I learned to run higher pressures than I'd used for the TT100 and Phantoms.
 
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