Fork seals (38mm Marzocchis): 2 x 7mm or 1 x 10mm?
- Thread starter Ventodue
- Start date
mcnicol
Hero member
- Location
- Safety Harbor, Florida, USA
Cyriel
Yes, the 7mm seals are easy to get. You only really need 1 on each side, use one of your old seals (with the sealing lip removed) as a cheap but perfectly adequate spacer, and you'll reduce stiction (and improve fork action) quite a lot. You can have that seal last forever if you put gaiters on the forks, but they do look a bit daggy. Fluorescent woven nylon ones from dirt bikes would do the same job and certainly make your bike easier to pick out in a lineup of identical Laverdas outside the pub
.
And, try to get seals made for motorcycle forks. Many industrial seals are for sealing high pressures on a shaft with limited movement, so they "squeeze" the seal a lot harder than you need. Quite a few newer bikes do use the same sized seals as our old bangers, they're not too hard to find. I think I got Gold Wing ones last time (iirc).
Ken
Yes, the 7mm seals are easy to get. You only really need 1 on each side, use one of your old seals (with the sealing lip removed) as a cheap but perfectly adequate spacer, and you'll reduce stiction (and improve fork action) quite a lot. You can have that seal last forever if you put gaiters on the forks, but they do look a bit daggy. Fluorescent woven nylon ones from dirt bikes would do the same job and certainly make your bike easier to pick out in a lineup of identical Laverdas outside the pub
.And, try to get seals made for motorcycle forks. Many industrial seals are for sealing high pressures on a shaft with limited movement, so they "squeeze" the seal a lot harder than you need. Quite a few newer bikes do use the same sized seals as our old bangers, they're not too hard to find. I think I got Gold Wing ones last time (iirc).
Ken
Hi
I prepare the change of my fork tubes of my Jota. Wear, impact and leaking seals ... (this subject on the fork seals is timely !...).
Before dismounting, I wish your advices
I have a Jota of 1981 with Marzocchi 38 mm diameter
I read on Laverdamania that the tubes are 630 mm long, and the springs are 465 mm
Forks :
tube length Oil quantity Viscosity Spring length
Ceriani: 35 mm (750>74, early triples) 595mm 170cc 25 to 35 485 mm
Ceriani: 38 mm (750<74, 1000) 595mm 200 cc (usine)
380 cc (recommand?) 5 to 10 505 mm
Marzocchi: 38mm (1000>80) 630mm 300cc 5 to 10 465 mm
Marzocchi: 38mm (1000 RGS, RGA, Corsa) 660mm 300cc
Can you confirm
Any advice for disassembly and reassembly and where to find tubes is welcome
Regards
Xavier
I prepare the change of my fork tubes of my Jota. Wear, impact and leaking seals ... (this subject on the fork seals is timely !...).
Before dismounting, I wish your advices
I have a Jota of 1981 with Marzocchi 38 mm diameter
I read on Laverdamania that the tubes are 630 mm long, and the springs are 465 mm
Forks :
tube length Oil quantity Viscosity Spring length
Ceriani: 35 mm (750>74, early triples) 595mm 170cc 25 to 35 485 mm
Ceriani: 38 mm (750<74, 1000) 595mm 200 cc (usine)
380 cc (recommand?) 5 to 10 505 mm
Marzocchi: 38mm (1000>80) 630mm 300cc 5 to 10 465 mm
Marzocchi: 38mm (1000 RGS, RGA, Corsa) 660mm 300cc
Can you confirm
Any advice for disassembly and reassembly and where to find tubes is welcome
Regards
Xavier
mcnicol
Hero member
- Location
- Safety Harbor, Florida, USA
Xavier
For dismantling, Marzocchis are easy. Take the wheel and mudguard off, leave the forks in the yokes until you take the fork caps out, drain the oil, and remove the M6 Allen bolt in the bottom of each slider (it helps to use an air gun sometimes). Then the sliders come off, the damper rods are held in place by circlips. That's about it.
And where to find tubes, Wolfgang Haerter had new ones a while ago, Andy Wagner, maybe Slaters or Keith Nairn, OCT. Tarozzi makes them (some people have said they don't fit well, though) also Forking by Frank in Illinois http://www.frankmain.qpg.com/ are very highly recommended and cheaper than Tarozzi. Why do you need new tubes? If yours are worn or rusty you should get them hard chromed and ground to size.
Ken
For dismantling, Marzocchis are easy. Take the wheel and mudguard off, leave the forks in the yokes until you take the fork caps out, drain the oil, and remove the M6 Allen bolt in the bottom of each slider (it helps to use an air gun sometimes). Then the sliders come off, the damper rods are held in place by circlips. That's about it.
And where to find tubes, Wolfgang Haerter had new ones a while ago, Andy Wagner, maybe Slaters or Keith Nairn, OCT. Tarozzi makes them (some people have said they don't fit well, though) also Forking by Frank in Illinois http://www.frankmain.qpg.com/ are very highly recommended and cheaper than Tarozzi. Why do you need new tubes? If yours are worn or rusty you should get them hard chromed and ground to size.
Ken
mcnicol
Hero member
- Location
- Safety Harbor, Florida, USA
CraigVentodue said:Not from the bike shops round here, they're not, Kenmcnicol said:
Try Aprilia part # 1057071, Ducati part # 079537367, Moto Guzzi also sells them but I couldn't get a number. You're right, 38x50x7mm fork seals were hard to find, but 38x50x8mm are common in dirt bikes, I think they're what I used. There's enough slop in the circlip groove to allow the clip to seat positively even with 1mm thicker seal stack (if you use an old seal as a spacer), but frankly the seals fit so tightly you could probably get by with just 1 seal (8 or 10mm) inserted to just below the circlip groove.
I had a 650 Yamaha once that didn't even have a circlip groove. But the seals did blow out of the sliders on extremely rough roads.
Ken
mcnicol said:
Thanks Ken
I looked at Tarozzi, but the lenghts are different then the preconization of Laverdamania
The only I've found on Tarozzi website in 630 mm is for the 1000 SFC of 1990
LAVERDA 1000 SFC (Mod. Marzocchi) 1990 - 630 mm
Do you think that it's not a problem with a shorter tube for the geometry of the bike ?
Xavier
mcnicol said:
Hi
I looked at to hard chromed the tubes. But it's very expensive here in France
I've found some sellers like Bihr Racing who sell tubes for 1000 Laverda 1975 at a reasonable price. But the tubes are 595 mm length ...
http://www.bihr.eu/productdetails.aspx?sku=770424&cat=BDM&typ=Bihr&st=Vehicle&v=26314&vt=2&vtm=34&vcy=1000&vy=1975&vn=1000+JOTA
Hence also my previous question on the effect of shorter tubes on the balance of the bike
Regards
Xavier
mcnicol
Hero member
- Location
- Safety Harbor, Florida, USA
Xavier
A lot of people have commented here that dropping the forks by up to 30mm and making the rear shocks longer really helps the handling of these old bikes. Remember, if you drop the front of the bike 30mm you may start to have ground clearance problems, and if you buy the shorter tubes you will not be able to raise the front back up if you decide you want to.
Try the dealers I mentioned, plus maybe Gijs van Dijk and Guiseppe Andrighetto. Do try an email to Forking by Frank, even with freight and customs I think you'll find their price is competitive (especially with the devalued US dollar
) and their quality is very high.
Ken
A lot of people have commented here that dropping the forks by up to 30mm and making the rear shocks longer really helps the handling of these old bikes. Remember, if you drop the front of the bike 30mm you may start to have ground clearance problems, and if you buy the shorter tubes you will not be able to raise the front back up if you decide you want to.
Try the dealers I mentioned, plus maybe Gijs van Dijk and Guiseppe Andrighetto. Do try an email to Forking by Frank, even with freight and customs I think you'll find their price is competitive (especially with the devalued US dollar
) and their quality is very high.Ken
Cosi
Hero member
- Location
- Kingscliff
Xav
Wolfie has them, Darty just bought some for the 1200, 630mm, correct size and much cheaper than anyone else
We pulled them apart yesterday and there is scoring on the bottom of the dampning rods, from our deductions was from the circlip being a little proud in the yoke, nothing a little filing on the clip wont fix
anyone else have this problem?
Wolfie has them, Darty just bought some for the 1200, 630mm, correct size and much cheaper than anyone else
We pulled them apart yesterday and there is scoring on the bottom of the dampning rods, from our deductions was from the circlip being a little proud in the yoke, nothing a little filing on the clip wont fix
anyone else have this problem?
D
Davo
Guest
Ventodue said:mcnicol said:
Not from the bike shops round here, they're not, Ken
Ciao
Craig
Any number of online ducati dealers stock them and will post worldwide.
e.g. http://shop.bevelheaven.com/detail.aspx?ID=221
mcnicol said:Xavier
A lot of people have commented here that dropping the forks by up to 30mm and making the rear shocks longer really helps the handling of these old bikes. Remember, if you drop the front of the bike 30mm you may start to have ground clearance problems, and if you buy the shorter tubes you will not be able to raise the front back up if you decide you want to.
Try the dealers I mentioned, plus maybe Gijs van Dijk and Guiseppe Andrighetto. Do try an email to Forking by Frank, even with freight and customs I think you'll find their price is competitive (especially with the devalued US dollar
Ken
Cosi said:
OK, I see ...
I had a doubt but you confirm of what I thought about changing the lengthes of tubes.
The lip seals of my fork flees. As long as to change them, and seen the state of my tubes I intend to put back all this for new
Have a good day
Xavier
Laverdalothar
Hero member
- Location
- Germany
OCT should have them, too, at reasonable prices. www.octeam.de. They also have the according seals to go with.
If you want something real good, www.hh-racetech.de do a complete change of your forks to a cartridge system with preload, rebound and compression damping, all adjustable from the top. Forks work WAY better... That combined with some nice shocks from YSS, and your bike turns quicker than ever with way more control and feedback. Comes at a price though... (Fork upgrade is about 700? plus shipping, Shocks are about 450? roughly). But an investment that really pays off if you have the money on hand (as it always should be with a hobby...
If you want something real good, www.hh-racetech.de do a complete change of your forks to a cartridge system with preload, rebound and compression damping, all adjustable from the top. Forks work WAY better... That combined with some nice shocks from YSS, and your bike turns quicker than ever with way more control and feedback. Comes at a price though... (Fork upgrade is about 700? plus shipping, Shocks are about 450? roughly). But an investment that really pays off if you have the money on hand (as it always should be with a hobby...
Davo said:
mcnicol said:
Ta guys. Yeh, cheers Davo - I did know Steve Allen had 'em. However, Curious of Glasgow is now sending me some, so we've managed to 'Keep Things in the (Laverda) Family'
...P.s I've now found an Ariete part ref for 38x50x7 fork seals: it's ARI. 029. And seeing as it's most likely Ariete who made them in the first place ...
Ciao
Craig
Laverdalothar said:OCT should have them, too, at reasonable prices. www.octeam.de. They also have the according seals to go with.
If you want something real good, www.hh-racetech.de do a complete change of your forks to a cartridge system with preload, rebound and compression damping, all adjustable from the top. Forks work WAY better... That combined with some nice shocks from YSS, and your bike turns quicker than ever with way more control and feedback. Comes at a price though... (Fork upgrade is about 700? plus shipping, Shocks are about 450? roughly). But an investment that really pays off if you have the money on hand (as it always should be with a hobby...
Hi Lothar
Your advice are wise. My hobbys are full, but my hands are dry
I am more in the choice to keep my motorcycle in the technical integrity of its vintage wine (year ?)
My Marzocchi are superb, and the original fork is perfect for my driving
The transformations which I bring to my motorcycle are more to enhance the reliability and his usage easy to quotidient (DMC2, intelligent side stand and some light modifications).
I am not a relentless of the strictly "origin", but overall my bike is close to his presentation of those years.
And I like driving with her old-fashioned perfumes
Bonne journ?e ? toi
Xavier