Harsh Cer Forks.

I just shocked myself, I started this thread almost 2 years ago and its had 10,921 views. That's stunning. Now, who in that bunch has put a cable tie in a set of 38mm Marzocchi forks and found out that travel they use.
 
Yep , guilty Vince ! On Jota with 10w oil - 280ml and new boingee things. Round 110mm of travel after Broadee Bonanza and some spirited riding with the Wrecker :D
 
Both my SF2s with emulators. The race bike bottoms out (sort of not surprising) and I have run up more preload on the main fork springs, emulators at standard (can?t remember, 2 turns preload?) and it is great, much more stable than it was before fitting emulators. The roadbike was fairly harsh, and wouldn?t use more than a bit over an inch of travel. I swapped to the light emulator springs, just the same. I have now backed off the emulator preload to zero preload, and now have 100mm travel with normal riding. I could probably run half a turn preload but it is so much better I?ll leave it for a bit. I haven?t gone drilling extra holes or anything.
 
Bit more testing to do but It seems I will be getting lighter fork springs, its got 0.95 springs now with bearly any preload and I am still only using 80mm of travel. Those springs work fine in the cer forks on my 3C. Take one spring out and the frontend move through 130mm of travel easily so nothing is binding. Weird.So with 35mm of sag and 80mm of travel its only got 50mm of effective travel on our crappy roads.
 
That was a dumb thing to say, I thought the Pantah would be 200kg approx. I have done the Race Tech spring test on their site and that supplies the bike weight and you add your weight and riding style and both the Laverda and Pantah came up with 0.95 springs. I didnt ask but that's also what Terry Hays supplied so I just expected they would be correct.Not so sure now. With one spring out the fork moves through 130mm easily, everybody including the Race Tech bloke in the US was expecting damping changes to fix it and they have made it much more compliant but still there is the missing 50mm of travel.
 
That's a $180 test, but that's where it's heading. I just emailed Matt at Race Tech to ask how much softer.
 
Here is Matts reply, so its flip a coin as to 0.8 or 0.85.That's quite a percentage difference to 0.95 that its got now.
I want all the travel I can get but I don't want it bottoming and needing huge amounts of preload either.


It appears you do have .95kg springs. Pretty firm for a vintage bike due to chassis geometry , fork friction, etc. It has been my experience more often than not vintage riders will prefer softer setup than that of comparable late model motorcycle.

I personally never install anything higher than .90kg in a bike for this type. However opionions vary, ask any 3 suspension guys & will get 3 different solutions. I cannot speak to road conditions in the land down under. As for USA riders I would install .80 or .85g rate for street riders, .90kg for vintage road race & setup at 15-25mm spring preload as needed to achieve desired sag & ride quality. If Gold Valve setup Blue #40 GVE Springs @ 2-3 Turns. Oil Level 130-150mm using 15wt as needed to use full fork travel & avoid undue bottoming.
 
Vince, Racetech mention the standard as being 8.4 or something, but recommend 0.95 for canyon, what ever that is and 1.45 for the track. I went through this with my Jota and settled on 1.0 based on 100kg. At the time I weighed a lot more than 100kg and it was still a bit harsh so I'm never telling the truth ever again ....

On my bevel, that I'll have going again when my kids leave home, one side only was sticking at full compression. No amount of reaming with a piece of dowel and wet and dry could make them any looser and even Dave Kellett had a crack with a tool he invented for the job. So I wonder if a lot of Marzos and Ceriani forks stick because it's not pretty what's down inside the slider? When you throw in the tiny tolerances between the stanchion and the slider and that's supposedly taken up by the fork oil you feel like pulling your hair out. 

Sooo ticking off the 2 year long list one more time. Are the tubes dead straight and is the air gap a consideration?

I did come across a reference to some non Maxton drop in cartridges for these forks but in the end nothing will make then any better until you reduce stiction.   
 
Hi Chris, the fork lowers were Hard Anodised and its got a set of SKF oil seals and dust scrappers so that's as far as I can go reducing sticktion. I just ordered a set of 0.8 springs, the US Race Teck vintage bloke said he has never recommended 0.9 and above for vintage bikes, so we will soon see how that goes. Looking past the limited travel it appears the damping is a lot more compliant after recent changes. There never going to be as good as modern stuff but hopefully there heading to a better place.
 
Hey Vince, I?m using 0.85 in my Mirage and Darmah. The guys here reckon the forks feel good and I reckon to be using about 100mm travel on an average ride out on SA roads: I don?t see why you need to have full use of the travel all the time as it?s always good to have a bit extra in reserve for that extra special bump or pot hole.. :o :o
 
AndyW said:
Hey Vince, I?m using 0.85 in my Mirage and Darmah. The guys here reckon the forks feel good and I reckon to be using about 100mm travel on an average ride out on SA roads: I don?t see why you need to have full use of the travel all the time as it?s always good to have a bit extra in reserve for that extra special bump or pot hole.. :o :o
Click to expand...

I?ll be buggered why you blokes spend so much effort in trying to set up antiquated forks, to ride like something out of the 2000?s.

This afternoon I adjusted my forks preload, dampening and rebound in 5 minutes.

Ok, they are not original, but really, if you want modern suspension, get it. Not only suspension, but my bike has 310mm disc and four spots, and instead of wobbly 38mm forks, I have 46mm jobbies.

Okay, it?s not for everyone, but frankly, you are pushing shit up hill.

So once you get the front end sorted, your up to looking at the back end, once you get that sorted you?ll be bracing your frame, and then ........

If I jumped of my ZX7R, and onto, let?s say, a stock 1980 Jota, and tried to ride it in the same manner, I?d end up hugging a tree, but not in a nice way.

If you want to keep it anywhere near original, settle for what you have, and enjoy it for what it is. Redax aren?t blitzing the competition with 280mm brakes and 38mm Marzochi forks, why, because they have a far better alternative.

Vince, the rant is not pointed at you, but the fact that you?re post has hit 10,000+ looks, proves that there are a lot of people looking for better suspension than as 1970?s modern and superb quality ..... in it?s time.



 
Agree with Chris, why try and change a 70's bike into something equivalent to a modern bike? Cannot be done, well not without a huge amount of cash. If it hasn't got the power and handling you want, by an additional modern bike, it might work out cheaper.
 
I?ve got 0.90 in both of mine. I only weigh 67kg. With the emulators backed off in the street bike it now uses 100mm travel on normal riding.
This post is for people who want their original bikes updated to as good as they can get within the prettywell original framework.
Anyone could come on here and criticize all the work people do with engines and tuning and make the same comment "why don?t you just buy a modern bike". It is what we do.
 
I have known this bike, Pantah for at least 20 years and I used to say to the earlier owner that he should attempt to soften those horribly hard forks. Its been mine for about 10 years and a while back I decided to put my money where my mouth is. I expected to take it to a pro and spend about $400 and Bobs your uncle. It seems it wasn't that easy. I am pretty sure that pro isn't too interested in older bikes. Chris, I take your point, but finding a better set of forks from another bike integrating the wheel and brakes is about 10 years late, time to do, cost wise for me and availability. So I went the easy route or so I thought. Tippie I am twice your weight so why your springs work and mine don't is a head sctratcher, except if your Laverda twins are 25kg heavier than my Pantah.
 
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