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Air valve on G5 forks

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FlyingTiger View Drop Down
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    Posted: 10 Jan 2019 at 07:22
Gents,
My forks have an air valve on the top.  As far as I can see they are original forks with the valve added (which also retains the damper rod).  Has anyone got a similar mod and if so what pressure do you run at please?
 
Thanks
Mark Serj
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c13pep View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 09:01
The air/pneumatic suspension is a standard feature on older Guzzis (front and back) with my V50`s running at 3Kg/Cm2 which equates to 42.6 psi. It will be mentioned in the workshop manual so check out Greg Bender for your model specific pressure.
CHRIS
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johnno View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote johnno Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 11:02
Originally posted by c13pep c13pep wrote:

The air/pneumatic suspension is a standard feature on older Guzzis (front and back) with my V50`s running at 3Kg/Cm2 which equates to 42.6 psi. It will be mentioned in the workshop manual so check out Greg Bender for your model specific pressure.
CHRIS
I think you've made a mistake here unless I miss understood . On my T5 I run without any pressure but when I did I think it was no higher than 3 psi . 
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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 11:20
I thought the pressure was very low too. It's not air suspension.
Brian.

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FlyingTiger View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FlyingTiger Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 12:54
Its not mentioned in my Haynes manual, or my workshop manual or the G5 manuals on Greg bender.  A mystery......
Mark Serj
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Post Options Post Options   Thanks (0) Thanks(0)   Quote johnno Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 17:18
If it's like my T5 it's a waste of time anyway in my opinion
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c13pep View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jan 2019 at 20:54
I was quoting from my V50/3 workshop manual for OIL PNEUMATIC SHOCK ABSORBERS which says 3Kg/sqcm +/- 1
It also quotes V65 at 1Kg/sqcm
It also quotes rears at 1Kg/sqcm more than fronts
The manual mentions two types of forks the other being HYDRAULIC but these appear to be only on the V35s
My current Monza is fitted with Benelli forks but are identical to the originals and are also oil/pneumatic

CHRIS
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FlyingTiger View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FlyingTiger Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 2019 at 07:13
Not the first time I have heard that opinion on air assisted forks......have had the same view myself in the past!
Mark Serj
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TonyF Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2019 at 08:48
Hi

It sounds as if your bike has non original damper cartridges fitted. These could be from a later model bike or an after market version. The air valves may either allow for a few pounds of pressure to be added to the forks to boost the spring (I have a set of A/M dampers like this) or may be pressuring an air bag in the damper cartridge to alter the damping.

Could you post a photo of the fork top?

Tony
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2019 at 14:12
V1000 G5 did not have air suspension so off different bike ...the ones that did have air in forks it is no more than 3psi The correct Forks for a G5 are the ones with internal dampers they are like the rear shox just longer dampers 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2019 at 15:43
http://www.thisoldtractor.com/mg_manuals/workshop_manual_850-t5_it.pdf

The above link shows T5 manual with G5 supplement and shows air forks and pressures on page 217 unfortunately it`s in Italian

CHRIS
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TonyF Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2019 at 20:15
Originally posted by c13pep c13pep wrote:

http://www.thisoldtractor.com/mg_manuals/workshop_manual_850-t5_it.pdf

The above link shows T5 manual with G5 supplement and shows air forks and pressures on page 217 unfortunately it`s in Italian

CHRIS


Its actually the other way round. The manual in the link is the supplement to update the original SP1000/V1000G5 manual (published in 1979 or there abouts) for changes made in the 850 T5.

The fork dampers and the shocks shown both have internal air bags. These first came out on the Le Mans 3 and other bikes of that mid 80s era. A friend of mine bought a new LM3 and was never happy with the suspension. He went to aftermarket dampers and Koni shocks early in his ownership. Yes, he still has the bike.

These systems weren't much better than the original sealed damper cartridges fitted to the pre LM3 bikes. I'd be surprised if any of them are still in use and working effectively.

Tony
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2019 at 21:27
Originally posted by TonyF TonyF wrote:



Its actually the other way round. The manual in the link is the supplement to update the original SP1000/V1000G5 manual (published in 1979 or there abouts) for changes made in the 850 T5.

The fork dampers and the shocks shown both have internal air bags. These first came out on the Le Mans 3 and other bikes of that mid 80s era. A friend of mine bought a new LM3 and was never happy with the suspension. He went to aftermarket dampers and Koni shocks early in his ownership. Yes, he still has the bike.

These systems weren't much better than the original sealed damper cartridges fitted to the pre LM3 bikes. I'd be surprised if any of them are still in use and working effectively.



Would the above equally apply to the V50s as it would help me understand the suspension on my Monza also fitted with air valves.

CHRIS
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TonyF Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jan 2019 at 08:27
Originally posted by c13pep c13pep wrote:


Would the above equally apply to the V50s as it would help me understand the suspension on my Monza also fitted with air valves.

CHRIS


I'm not very familiar with V50s but they most likely used a similar (Paioli) system. The diagrams of the fork in the manual show the link pipe to balance the fork cartridges and an air valve on one cartridge. The shocks had the same arrangement but the link and valve are not shown in the diagrams.

Part of the problem as I recall was keeping the air pressure in the correct range as the specified pressures were small.


Tony
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jan 2019 at 08:39


I'm not very familiar with V50s but they most likely used a similar (Paioli) system. The diagrams of the fork in the manual show the link pipe to balance the fork cartridges and an air valve on one cartridge. The shocks had the same arrangement but the link and valve are not shown in the diagrams.

Part of the problem as I recall was keeping the air pressure in the correct range as the specified pressures were small.


[/QUOTE]

The stated pressures in the manual equate to 42psi which everyone here, including me, seems to think is excessive, can you recollect what you remember them as

CHRIS
you can`t have any fun in a straight line

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