Fournales Air Shocks

Does anyone have experience with these shocks on the VFR? Opinions?

Never heard of them.

Without a spring, if/when the seal ever goes and you lose all your air, the bike would drop and you'd be dragging your tail all the way home. (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/sad.gif)



Linkage:

http://www.fournales.fr/site_ang/page_moto...nsion_moto.html

khep, Apr 7 2007, 10:09 PMDoes anyone have experience with these shocks on the VFR? Opinions?

NOPE never heard of them , but thanks for posting up about them. Looks interesting...Air Ride Suspension. (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/491.gif)

Popular shock with the "scooter" crowd and stunters......can adjust ride heights, weight changes real well and the ride stays consistant. Only rode them on a 600 Silver Wing scooter (friend that lived here and moved to Colorado) and a 650 Burgman scooter (still here in Tullahoma). Impressive shocks (IMO) on the large "Maxi-scooters". Air Force buddy (in Germany) has one on his Hornet (European 599). All I can contribute.....they do ride/ handle great on the scooters I've ridden........... (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/fing02.gif)

Fournales Air shocks were used by some custom bike makers of the 80s. (Mostly French)
I think a lot of them found their way on the rear ends of Custom V-Maxes. Look at most books from the 80's on custom bikes, and you will most likely see at least one example sporting these air shocks.
Air has been regarded as the perfect progressive type spring, but for some reason it is not perfect, or we'd be all riding on air charged shocks. Must be a problem with cavitation of damping fluids or leaks. I think Fournales has been pretty much filed way by most as suspension systems from the past by bike designers. I haven't seen the brand on any new custom bikes in a long time. And as Skuuter mentions, now maybe condentrate mostly on scooter applications.

Beck
95 VFR

Tony Foale in 'Motorcycle Handling & Chassis Design - the art and science' discusses gas suspension struts and includes a cutaway picture of the Fournales shock. He says the problem comes when you want to adjust the ride (assuming you had a good starting position but now increase bike load or want to run on better/worse roads). It sounds simple - just subtract air for softer spring but all that does is reduce ride height as exactly the same air pressure is required to support the same weight. In the other case (increased load) add air which will lift the rear of the bike under the increased load but now the spring will be stiffer - oftentimes too stiff (remember that air springs are highly progressive & we have now moved along the curve).
Foales made many 'specials' & used these shocks on some of them.
He writes "In my experience, most of the complaints levelled at the after-market gas shocks are due to the rider's expectations of the adjustability benifits being raised excessively by the manufacturer's advertising hype. Once a suitable unit is matched to a particular application, then the ability to perfectly compensate for load differences by changing the pressure is a valuable benifit, although, unless the unit also has adjustable damping, that cannot be optimum throughout the full range of load conditions. Do not expect to match any gas shock to your bike by changing the pressure, it doesn't work like that.'

I certainly had thought that a gas shock would be the universal panecea for adjustable shocks.

I have three of these things sitting in my garage or basement
They are way lighter than coil over shocks - umm, that's it with the benefits
That said, when they were fresh and I did not adjust the pressure they were pretty amazing on my BMW K12RS, but I would spend the money on proven shocks, i.e. Penske, Elka, Ohlins

YMMV

Ummm.. I REALLY liked the air valves the suspension on my VF500 had - it was so easy to adjust the suspension when carrying a pillion. I liked the compression damper too; made it easy to do stoppies - just set the dial to "0". (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/squid.gif)

Last I heard, Fournalles had a "two-stage" adjustment thingy--one setting for sport and the other for touring, I suppose. I was seriously considering buying one at one point for one of my bikes when I heard that, but was told the extra parts required for the adjustability option meant it would no longer fit that bike. This was maybe three years ago? I assume the company is still ticking over somewhere in SW France.

A friend of mine also had a good experience with them doing an emergency fitment on his Goldwing; nice people, apparently.

Ciao,

GIXXERSTEPH, Jun 7 2007, 02:25 PMI have three of these things sitting in my garage or basement
They are way lighter than coil over shocks - umm, that's it with the benefits
That said, when they were fresh and I did not adjust the pressure they were pretty amazing on my BMW K12RS, but I would spend the money on proven shocks, i.e. Penske, Elka, Ohlins

YMMV

What bikes do they fit?

Hobie1dog, Jun 8 2007, 08:48 AM

GIXXERSTEPH, Jun 7 2007, 02:25 PMI have three of these things sitting in my garage or basement
They are way lighter than coil over shocks - umm, that's it with the benefits
That said, when they were fresh and I did not adjust the pressure they were pretty amazing on my BMW K12RS, but I would spend the money on proven shocks, i.e. Penske, Elka, Ohlins

YMMV

What bikes do they fit?

Sorry Hobie - don't check in here too often
If I recall correctly I have one rear BMW R1100GS shock, and a front and rear for a BMW K1200RS and the nigh pressure bicycle pump too

GIXXERSTEPH, Jun 12 2007, 01:55 PM

Hobie1dog, Jun 8 2007, 08:48 AM

GIXXERSTEPH, Jun 7 2007, 02:25 PMI have three of these things sitting in my garage or basement
They are way lighter than coil over shocks - umm, that's it with the benefits
That said, when they were fresh and I did not adjust the pressure they were pretty amazing on my BMW K12RS, but I would spend the money on proven shocks, i.e. Penske, Elka, Ohlins

YMMV

What bikes do they fit?

Sorry Hobie - don't check in here too often
If I recall correctly I have one rear BMW R1100GS shock, and a front and rear for a BMW K1200RS and the nigh pressure bicycle pump too

I was hoping you were going to tell me you had one for a viffer.

Hobie1dog, Jun 14 2007, 11:08 AM

GIXXERSTEPH, Jun 12 2007, 01:55 PM

Hobie1dog, Jun 8 2007, 08:48 AM

GIXXERSTEPH, Jun 7 2007, 02:25 PMI have three of these things sitting in my garage or basement
They are way lighter than coil over shocks - umm, that's it with the benefits
That said, when they were fresh and I did not adjust the pressure they were pretty amazing on my BMW K12RS, but I would spend the money on proven shocks, i.e. Penske, Elka, Ohlins

YMMV

What bikes do they fit?

Sorry Hobie - don't check in here too often
If I recall correctly I have one rear BMW R1100GS shock, and a front and rear for a BMW K1200RS and the nigh pressure bicycle pump too

I was hoping you were going to tell me you had one for a viffer.

Trust me Hobie - if I had one that was for a Viffer I would have already tried it, though that said, one never knows - a project to check on......

anyone have a picture of a 90-93 Viffer shock to see if it's even worth checking out?

This is a pic of my FL-FP Ohlins:
(IMG:http://www.vsource.org/VFR-RVF_files/Images/RC-36Ohlins.jpg)

Ciao,

JZH, Jun 16 2007, 06:17 AMThis is a pic of my FL-FP Ohlins:
(IMG:http://www.vsource.org/VFR-RVF_files/Images/RC-36Ohlins.jpg)

Ciao,

NICE eye candy
OK -I'll have to dig out the shocks I have and take some measurements and then check the Haynes.....

That's like this Fox Racing Shock that is on Ebay now. But the guy lists all the measurements for it but doesn't know what it goes on.

http://cgi.ebay.com/ebaymotors/FOX-SHOCK-G...1QQcmdZViewItem

Looks good.

VFR P shock is 345mm long, has eye top mount and clevis bottom, R-V shock is 324mm long has eye top and bottom.

The Fox shock listed in the Ebay auction SAYS its 335mm long, with eye top and clevis bottom, neither fish nor fowl. That having been said, I want it, because I have a use for it. My 97 frame, with a 93 swingarm. it would add 10mm to the shock length, OK by me. IS EVERYONE LISTENING, so I don't have to fight anyone here for it.

Larry
VFRrider

vfrrider, Jun 16 2007, 08:36 PMThe Fox shock listed in the Ebay auction SAYS its 335mm long, with eye top and clevis bottom, neither fish nor fowl. That having been said, I want it, because I have a use for it. My 97 frame, with a 93 swingarm. it would add 10mm to the shock length, OK by me. IS EVERYONE LISTENING, so I don't have to fight anyone here for it.

Larry: You should see that there are two listed back to back on Ebay.....I assume that they are both by the same seller, I didn't click on the other one to see if it was different.

Just when I think I find just what I need at a decent price, someone rains on my parade.

You're probably right.

JZH, Want to make a deal on that Ohlins? Oops, won't work for me. (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/pissed.gif)

Larry
VFRrider

vfrrider, Jun 17 2007, 01:52 AMJZH, Want to make a deal on that Ohlins? Oops, won't work for me. (IMG:http://www.vfrdiscussion.com/forum/style_emoticons/default/pissed.gif)

No, it won't, cuz it's on my bike! Surely a good Ohlins shop could make you exactly the shock you needed? Penske certainly would (they made one for my NC30), and my ST1300's is essentially a custom jobbie. All it takes is money! Good luck.

Ciao,