RaceTech - Ceriani

I was pretty happy with my suspension heading to Tassie, except I hadn't accounted for the luggage load. And I found out I couldn't get at the shocks with the soft saddlebags fitted and pulling them was a bit complicated. I just had a look and the bump stop on the Icons is fully up so they have bottomed during the trip. Maybe they need upping a touch of preload, I think damping 3 will be needed as well on the Icons. It did become harsh towards the end of the week including the forks. They used 100mm of travel, will check the fork sag as well. Better wash the bloody thing soon as well
 
Tippie said:
Good points there Carlo. Regarding the basics I went through the wringer with my VFR800. It had needed new tyres before a high speed trip from Norway to the med, and the Scandinavian testers raved about the new Metzelers so I fitted them. The bike developed instability and nervousness which I put down to the rigours of that ride. After coming home I bit by bit as each thing didn't fix it replaced the headset bearings, swapped the original cartridge valves to Racetech gold ones (Toddy got the originals form me iirc), even bought a Maxton rear damper. The worst bit was that the front felt like it wanted to tuck in any corner unless I pushed hard on the inside handlebar unless I was hard (really hard) on the throttle, which doesn't work on public roads in traffic. I then replaced the tyres for the next trip with Dunlop Roadsmart which had just come out. Before I was out of my driveway I knew the bike was fixed, hard to believe but true, bike has been a gem ever since especially with all the stuff I did to compensate for tyres which didn't suit the bike (or me). Two other mates "fixed" their bikes the same way on my advice after describing similar symptoms, and both said that within 5 metres they knew a bike they had started to not like riding was fixed. I remember reading somewhere that Metz and Pirelli use a different construction technique for sidewalls to Dunlop and Bridgestone. There are many variables in "handling".

Ye fark didn?t even include tyres I junked they electronic suspension on an HP4 and bought Ohlins to solve what turned out to be 3psi.


 
It's done - I have ordered the RaceTech emulators with springs and adapters. Matt from RaceTech is really competent and had good advice for initial setups.

thanks for your advice. I'll probably get back to you with the bits 'n pieces in my hands... the emulators, I mean  :D

cheers,
Alex
 
Matt is an excellent resource. I worked with him to set up my RGS with RaceTech emulators. The change in performance is incredible. I also installed their shocks, equally excellent.
Richard
 
Sorry fellas, I need to drag this thread up again...

Right - I have decided to get a RaceTech kit. Installation is really simple. Setup seems to be something else, though. I had some pretty detailed instructions from Matt with regards to "popular initial settings on a 38mm Ceriani front fork"...

Popular Setup for 38mm forks on Laverda is:
? Black/Blue #40 GVE Springs @ 3-4 Turns with 4 Bleed Valve Plate (under colored spring, see attached picture)
? 15wt Fork Oil @ 130-150mm Level (spring, tube compressed/bottomed: Top of Oil > Top of Fork Tube distance
? 15-25mm Fork Spring Preload (Cut spacer flush with top of fork tube sets preload 15-20mm range, perfect to start with)
Gold Valve Fork Tuning Guide: https://racetech.com/page/title/Emulator%20Tuning%20Guide, Kit Instructions attached


I have followed the instructions closely but the bike has become really unstable at the front, now. Used 3 1/2 turns on the emulator, 15W oil viscosiy and an air gap of 140mm. The bike now tends to drop into corners like a stone, even going straight line requires one hand at the handle bars now as it always tends to go leftor right on the slightest impulse.  :(

Yeah, yeah, I hear you... shouldn't have touched it in the first place... blablabla ;)

So far I have checked the following:
- steering head bearings: tried both: towards the loose end and tightend up. When tighter it feels better in slow corners but introduced high speed wobble. So then tried going with less torque on the adjuster nut. Back to square 1, unstable overall handling.
- Checked if front wheel is running true - all good here
- wheel bearings are fine
- using same tire as before

How much SAG are you setting it up to? Found contadicting numbers -  Racetech mentions a typical range of 2-40mm. Laverdamania states no more than 15% of total travel. That would take me to around 18mm only. Reading other sources they suggest around 30% of total travel. So, how is it now??

Any suggestions are welcome, apart from "revert back to original"... :D I'm kind of stubborn and want to get this done now...

Cheers!
Alex
 
I like around 30mm sag, or 1/3 of travel. Preload includes the thickness of the fork nut threaded section. This sounds really odd, what spring rate is in it. How much do you weigh? How much travel is being used, cable tie on the fork shows this and sag. What tyre and pressure, I had a ride on an RGS with warn front tyre, scolopped, and it had a violent wobble at exactly 80kph, fine at 60 and 100kph, you could feel this strongly and with your hands off it was INTENSE. I heard a new tyre fixed it. How is the rear, swingarm no play?
 
Maxtons ideal is zero sag for the bike without rider. Most go for a small amount. With rider sitting on, 30% is generally ballpark.
This should not make your bike refuse to track true. Headstem bearings should be just snug, neither tight or loose, they should not work as a steering damper. On my street SF with Ceriani I have the weakest emulator spring at one turn preload, 10wt oil and it is ok. With the recommended emulator preload it had so much comp damping I had 1" fork travel only, so I backed off to zero preload and got travel back, then adjusted a bit in. My race SF emulators have not needed any playing around with, the soft springs with std recommended preload but 7.5 wt oil, needed more main spring preload for its racetrack environment.
It seems that emulator setup is very individual between bikes. Keep in mind that sag and main spring weight (mine are 0.95 iirc) must be set up first before playing with damping. And that emulators only affect compression damping (your old comp damping holes are drilled out and ineffective), and the state of your rebound damping valves (clearances etc) will dictate oil weight.
 
Allright, when saying that I have changed the headstem bearing nut torque, I just wanted to see an effect on the handling, really. In the end I have returned to the "just snug" setup. I know that abusing the bearing preload as a steering damper is a really bad idea. The swinging arm bearings and rear wheel bearings are all good. Can't feel any play whatsover. Double checked free movement and make up torque of the swinging arm.

I have got the 0.90kg springs. I weigh, all geared up, around 85 kg. Matt from RaceTech told me that this spring would be just fine for "spirited" riding. ;-) No idea what he meant.

I have used 20mm preload, so the spring + spacer are flush with the top of the fork before installing the cap. The thread is 20 mm to the screw shoulder. The tyre is still the same, a pretty new T30Evo. Up to the conversion the tyre was a massive improvement to the BT45, at least for my taste. No more saw teeth and better stability when breaking. I have run it with 2.5-2.6 bars. It is super sensitive to air pressure though.

Generally, I think Tippie is totally right, when saying that the SAG needs to be sorted first before playing with the dampening. I wonder if I should reduce prelaod. That would also allow me to get more SAG. Vince mentioned around a 1/3 of total travel (30mm). I am at 20mm, right now. The feel for the front wheel is hard to describe. I'll try anyway. It feels like there is comparibly little weight on the front allowing the front wheel to move easier than it should. Not a nice feeling at all when turning into a bend.

So, would it make sense to reduce the preload and, by doing so, lowering the front end? Should put more weight on front wheel, right?

Cheers,
Alex
 
I have the same tyre, use anywhere from 34psi to 37psi. I weight a fair bit more at 125kg and am at 2 turns of preload on blue spring, 130mm oil height with 15wt fully compressed forks emulators and springs out. Other than emulator spring preload I have very similar setting and mine mostly goes well. I am changing to 20 wt as it still kicks a bit of square-edged bumps and I want the damping slower.
I like the tyre as well. Try a few changes one at a time. I would try lower tyre pressure as well, 34psi. What I don't get is how it's changed to the detriment, how much travel are you using. Find a badly bumpy road and do some hard braking with a cable tie on the fork. You should use approx 100mm of travel doing this. That will give you an indication of how the spring is working. BTW 1/2 a turn of preload on the emulator spring has a noticeable effect on stiffening the compression damping.
 
Why would you lower the front to 34  Vince, you know and have been told by many people that that is not enough for a big heavy pos like a triple, 37 38 in the front 40 41 in the rear...
 
I don't know why but in those tyres its works well, definitely don't take my word for it. Easy test. I used 37 for the previous tyres BT016 and the BT 023, 022 and BT021.
 
Alex M said:
I have used 20mm preload, so the spring + spacer are flush with the top of the fork before installing the cap. The thread is 20 mm to the screw shoulder.
Assuming all is correct w/ assembly & yoke setup I think the spacers are too short-
 
Hello guys,

I know that I am pulling up an old topic here but I thought it would be worthwhile sharing my findings on the dodgy steering after the RaceTech conversion.

I'll cut it short. There was nothing wrong with the conversion kit, settings of the RaceTech valves, the wheels or tires. I have mentioend back then that the bike doesn't want to go straight anymore but I couldn't feel any step in the steering bearing either. So, I have stripped down the entire front end to get a better idea on the steering head condition. I have checked the steering bearings again with just the yokes and the steering stop plate attached. At that stage I've noticed that the force needed to move the yokes varies with its position, like it was rubbing against something. It turned out that it was the steering stop plate that was rubbing against the back of the bottom yoke. 

After grinding down the curved plate which sits on the steering stop plate I had enough clearance for a totally free moving yokes. That was all. (banghead)

Until now I don't really understand the purpose of that plate.  (any1)

For those that are unfamiliar with the steering stop plate for the Ceriani forks I have added a picture ofthat bastard.



 

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Mine doesn't actually stop the steering, it needs approx 5mm build-up of weld on the gadget pictured so it does hit and act as a steering stop. Good catch to fix your issue. It's a worry when in your case you found an issue when similar suspension setting work on other bikes. BTW what settings are you at on the Emulators?
 
Hi Alex,

The big hole in the steering stop plate has no function, other than to stop the steering stop plate itself turning around its fixing point. The plate should not really touch the underside of the bottom yoke at all. The steering stop plate should sit a bit lower than the bottom of the yoke and only engage with the steering stem about half way alone the protruding length. The fixing of the steering lock plate (the slotted end) may have spacers/washers under it to achieve this.

HTH Paul
 
Never liked that steering stop system; drop the bike even at a standstill and if the wheel/bars are forced into it, it can warp, then the probs that Alex experienced begin. Much better to control it with a solid stop at the front of the steering head tube that the stop on the lower clamp contacts at full lock.
 
Or as on the series 2 3CL with that horrible pigs nose fairing, let the brake and clutch levers serve as steering stops as I found out 3 days after having bought mine new in 1981 whilst trying to do a U turn.

Paul
 
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