120 Jota handling

Scrumpy I saw that thread and the one from the bloke in WA looking for his old 120 Jota,for a supposedly interim unloved model they spark some interst
 
Especially since there are many SFC/RGS's with the too short Koni dampers at the rear end. It makes them slower in handling terms. They lack 16mm. Pref. more like a raise like 26mm in total suits it better.

Cheers,
Jacques.
 
that's a lesson I had to learn, too, but it is even worse: 18mm.... the swing-arm mounting-bracket was tailored on there fore a 370mm AG Strada ORO. Fitting a 362mm Koni makes a difference...

And - not to forget: the fork also needs to be put through by roughly 4,5 - 5cm to make it work. Since I have the 370mm Wilbers on the SFC, the handling is so unbelievable improved over the Konis, really love the handling now. But could even be a bit higher on the rear; am thinking about exchanging the Wilbers with length-adjustable YSS in 370 (plus 9mm). We'll see...
 
Laverdalothar said:
that's a lesson I had to learn, too, but it is even worse: 18mm.... the swing-arm mounting-bracket was tailored on there fore a 370mm AG Strada ORO. Fitting a 362mm Koni makes a difference...

And - not to forget: the fork also needs to be put through by roughly 4,5 - 5cm to make it work. Since I have the 370mm Wilbers on the SFC, the handling is so unbelievable improved over the Konis, really love the handling now. But could even be a bit higher on the rear; am thinking about exchanging the Wilbers with length-adjustable YSS in 370 (plus 9mm). We'll see...
Click to expand...

That is what i am talking abuot , just bought Wibers and instal it a progresive ( wich was wrong , Linear are corect )spring for fork also from Wlibers .
It work bether than original , but front high and back low as original from factory  .
Dont change Wilbers , send it to factory they schould make them longer plus extra lenght adjstment ( extra 3-4cm cca ) then you can lover front end with linear spring inside ( from CBR 600 91-93 ) .

It fels much beter to drive , the man who did this on my bike works in Wlibers repairshop , if I remember corect name is Strohmann .
 
The front end will get some way better upgrade soon... And for the price Wilbers takes to make them length adjustable plus change maybe other settings, I can buy new YSS, believe me...
 
Hello Gents

What are the physical (not internal) differences with 180 Jotas using Ceriani and Mazz forks . Is shortening the mazz  forks recommended for road use .
Many Thanks
Merry Christmas
Tetley  
 
I pushed the Marzocchi fork roughly 2 cm through and have 370mm shocks on the rear. Handling is close to a VFR 750 with the BT012SS and the GSX-R rims... On the race-track, I would need less weight (me...  :-[ ) and/or stiffer springs, as I am touching ground (see my Avatar - Alternator of the 180?ND is touching the tarmac).

HTH
 
Tetley

The Cerianis are 795mm, shorter than the Marzocchis, I don't know exactly how much, a couple of cm anyway (maybe somebody here has a more accurate figure?). But they have very slightly thicker walls on the stanchions and are arguably a little stiffer because of this.
And the Cerianis on triples have a little more offset on the top yoke than the bottom. The steering stem has a nominal 28o rake(with bottom frame tube horizontal), but the effective rake is 26o 30'. This does give a little more straight line stability at the expense of increasing turning effort on the handlebars. Not that the Marzocchi-equipped front ends are any easier to turn, but my limited experience (my Ceriani Jota vs an RGS, with a wonky shock, so be judicious) has been that the Marzocchi front end does feel a little bit less precisely located.

Ken
 
Isn't it so, that linear springs are used on track bikes, and progressive is better for varying tarmac on a b-road?

Cheers,
Jacques.
 
redfox said:
Isn't it so, that linear springs are used on track bikes, and progressive is better for varying tarmac on a b-road?

Cheers,
Jacques.
Click to expand...

Exactly I instaled progresive it was ok for the road , but once on track it was not ok . Now i have linear wich is good for the road and track , bit hard when the road is not in perfect condition .
 
I shouldn?t get involved in this because I only have twins, but...
The weirdo triple angled clamps on the 38mm Ceriani Laverdas are in my experience unique. I have never heard of similar on any other bike. A rake of 26deg will steer quicker at the expense of stability than 28deg. Whether this is relevant to an "artificially " steepened rake is debatable. On my SF2 bikes one has "Jota" parallel Marzo clamps and the other original Cerianis. The Marzo clamped bike steers absolutely neutral and the other has a tendency to stand up in corners, something that I ride around and barely even notice any more. This is something I have felt on every Lav with those clamps that I?ve test ridden after a service. I cannot compare them directly now as the Marzo bike is now only raced.
Does anyone know of any racing bike with a rubber mounted engine? Laverda used those silentbloc mounts on the 120 in what to me looks like an otherwise pretty normal triple frame. A rigid mounted engine must help the stiffness of any frame. It doesn?t come as a surprise that they are more sensitive to setup and correct fitting/tightness of the mounts etc. The RGS frame was designed from the ground up with rubber mounting incorporated and despite cracking around the headstem they seem to be ok. 
"Handling" as a subject is as subjective as this hilarious shitfight SFC vs RGS "debate". There are just too many variables involved when you start talking handling. The greatest variable is the rider.
In Oz in the ?80s a Suz GSX1100E (16" front wheel faired monster) owner advertised widely in the press to push a case against Suz Aus for selling a bike that handled so badly. "If you value your life..." his ad began. In the washup Suz invited him and his group to Oran Park which they had hired for the occasion. They had a bike set up to factory spec and it handled like a dream for all of the group there. The mechanics checked all of the private bikes and they had been "adjusted" out of all sense. Wrong fork oil weight and amount, steeringhead bearings, mismatched tyres and wrong pressures etc etc.  A short course in basic bike setup and their bikes were transformed.
There was a guy from NSW raced a 120 Jota at Bathurst in ?83. It seemed to handle great until he retired with engine probs.
 
Tippie, I think some of the last air cooled Kawa Z1000s had some sort of rubber mounts in some of the engine mounting points, not all of them, think it was the rear only.

I am enjoying myself in the RGS vs crappy SFC thread too.  :D  :D  :D
 
Is it recommended to reduce the length of mazz forks on a 180 Jota to help handling for road use . Does this reduce ground clearance

Many Thanks
Tetley

 
Hi Tetley,

I have not shortened the forks, I have just pulled them through the jokes so they are 2 cm roughly above the top joke. That, together with longer shoks and some other modifications, made the bikes handling very nice. Ground-clearance is more an issue on the race-track, although I must say I have also touched the ground with the Alternator cover of my ND 180 Jota once on the road. Scary thing, but nothing that makes you drop the bike if you stay cool (I just did because I did not recognize what happened, just saw the scratched cover afterwards...). So - if you lower the front and raise the rear, the ground-clearance should be almost the same overall, just the stearing-head angle in relation to the road changes, which gives better handling and a bit less straight running.

HTH
 
Laverdalothar said:
Hi Tetley,

I have not shortened the forks, I have just pulled them through the jokes so they are 2 cm roughly above the top joke. That, together with longer shoks and some other modifications, made the bikes handling very nice. Ground-clearance is more an issue on the race-track, although I must say I have also touched the ground with the Alternator cover of my ND 180 Jota once on the road. Scary thing, but nothing that makes you drop the bike if you stay cool (I just did because I did not recognize what happened, just saw the scratched cover afterwards...). So - if you lower the front and raise the rear, the ground-clearance should be almost the same overall, just the stearing-head angle in relation to the road changes, which gives better handling and a bit less straight running.

HTH
Click to expand...

everithing corect , in my case . Nathing changed in straight running , stering damper is mor show off then neded .
 
My understanding of the non-parallel Ceriani fork yokes, is that it increases the trail - the rake, derived from the steering stem angle, is not affected.   

I've replaced the non-parallel Ceriani yokes on my 3C with a set of SFC 750 parallel yokes, and the result is a bit more stability in corners. 

The Marzo yokes are parallel, and their offset is noticeably less than that of the the Ceriani offset, resulting in more trail. 

Tom
 
Tippie said:
The weirdo triple angled clamps on the 38mm Ceriani Laverdas are in my experience unique. I have never heard of similar on any other bike. A rake of 26deg will steer quicker at the expense of stability than 28deg. Whether this is relevant to an "artificially " steepened rake is debatable.
Click to expand...

Tippie,

Rake isn't altered by the "wierdo" yokes.  Headstem stays as it is, so rake remains...... only trail is increased by the steeper stanchions to enhance straight-line stability.  Could also have been arranged with yokes with less off-set, but that compromises steering lock.  OK for  a race bike, a serious no-no for a street machine, see Ducati Bevel-SS!!

Guess the early triples were a bit lively and the factory chose to quieten things down before too many pimple faces shat themselves....  Triple racers preferred the "straight" SFC yokes to get the beast to turn quicker.  Drum brake twins are also a bit agiler than the later disc braked models, same reasons.

Know of no other bike to use this "technology" either.... still think it's quite clever, though!

piet
 
Lothar,
am I being dense here? The forks on my jota cannot be pulled higher in the yokes because the bars are in the way.With the bars as they are, they cannot be raised at all.
Nick7
 
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