GSXR1100 (1991/1992) Fork upgrade

[Dan Filetti]

Is there anything wrong with mounting a shock upside down?  Compression and rebound are still compression and rebound.

Does the nitrogen leak out when upside down?  :-)

It IS upside down.  Who cares?  There's a bladder between the oil and the nitrogen.
It would have been near on impossible to modify the stock lower mount and keep it upright.

+2 I wondered the same thing...

Dan

[RichBaker]

Back in the old days I had a two stroke and decided that with a grinder and a ruler I should port it, great ran better, more porting, great power band about 200 RPM wide !, ported some more and you know that damn thing can run backwards...... Its just in my nature....
George

Had a friend with a Husky that would run backwards if you didn't kick it hard enough, thanks to a home porting job..... We used to have contests to see who could ride it the farthest, backwards.  Great fun!!

[movenon]

Back in the old days I had a two stroke and decided that with a grinder and a ruler I should port it, great ran better, more porting, great power band about 200 RPM wide !, ported some more and you know that damn thing can run backwards...... Its just in my nature....
George

Had a friend with a Husky that would run backwards if you didn't kick it hard enough, thanks to a home porting job..... We used to have contests to see who could ride it the farthest, backwards.  Great fun!!

Yes and it would sound a little different when it happened. It was kinda fun to play with but ultimately it was off to the Yamaha dealer for a new barrel ..... Back when bikes were easy to work on. High tech was a reed valve.....
George

[FJNovaScotia]

Back to the Honda F4 shock upside down discussion....

Arnie,   how long have you been riding with your current setup?   As I understand it you are the one that first modified the F4 shock to fit a post 89 FJ.

Hey if the front forks work best upside down....why not the rear shock!   

[Mike Ramos]

Good afternoon,

Well, at the risk of this looking like another discussion about oil...

As they pertain to FJ's SPECIFICALLY the upside down forks are not better, however they may be comparable to the Fork Valves (& the Fork Brace to tie it all together). That being said, based on how the vaunted usd's have performed on other non-FJ motorcycles that I have come across, any advantage was inconsequential.

And back to FJ's, the main problem was the front wheel "pushing" when cornering (regardless of speed). Also front tire "cupping" was a problem & premature wear as well. The Fork Valves, at least in may individual case, eliminated the negative aspects of tire wear while allowing for enhanced cornering. Just to keep the focus [not to mention the peace] this has been my individual & most enjoyable experience....

Now, Mr. Conlon please do not execute , I mean excommunicate me & Flynt, remember, it is not nice to shoot a midget (especially a pudgy one)... 

Gentlemen, keep smiling & ride safe,

Midget Ramos.

[FJmonkey]

Now, Mr. Conlon please do not execute , I mean excommunicate me & Flynt, remember, it is not nice to shoot a midget (especially a pudgy one)... 
Midget Ramos.

Mike, if you would just grow a grey beard, we could bestow the the honor of "FJ Gnome" to you.

[Arnie]

FJNovaScotia asked, "Arnie,   how long have you been riding with your current setup?   As I understand it you are the one that first modified the F4 shock to fit a post 89 FJ."

I answered this last night, but it isn't here.  ?? I wonder if I was so tired I never actually posted. ??

Anyhow, 20-January-2009 and 20,000 kms ago is when I fitted the F4i shock.  I chose the F4i shock because the spring rate was about right, it had lots of adjustabliity, and it was cheap.  If I was unable to get it to work, I'd have just tossed it.  To fit it to my '91 B FJ, I had to have a clevis on one end, and the top eye was much easier to cut and weld a clevis bracket to then the bottom (almost impossible since some of the damping adjustment is there).  Gas filled shocks have a bladder separating the Nitrogen and the oil, so orientation doesn't matter.  There is nothing magic about "upside down" suspension IMO.

Upside down forks are a bit different, in that as well as being cartridge type forks (as opposed to damper rod forks), the legs that are now in the triple clamps are much larger in diameter.  This makes the whole front end stiffer.  I question whether this can be felt on the street.
BTW  my other bike has upside down forks.

Lets see if this time it makes the list :-)

Arnie

[Pat Conlon]

Ho Hum, nothing new from Mike here...same old same old....However, I do wonder specifically what FJ Mike has ridden that has USD forks...?

He would not be speaking hypothetically would he...? Naaa...He must be speaking from experience... (I added my signature line just for you Mike)

Note to others: I really do enjoy Mike and Mike's company at the rallies. He is a good guy...just a wee bit misguided.... Cheers!

[oldktmdude]

   Performance of RPM valves against USD forks put aside, I know which setup looks the best.    Pete.   

[Pat Conlon]

   Performance of RPM valves against USD forks put aside, I know which setup looks the best.    Pete.   

Yep, the USD's gets the chicks......

[yamaha fj rider]

The shock does not know or care which way it its mounted, works the same either way.

Kurt

[movenon]

The shock does not know or care which way it its mounted, works the same either way.

Kurt

So I got a drink and went out in the cold dark garage and ask my shock "if it minded being upside down" ? After a pause and another drink it answered    "nope".....
Then I asked it if USD forks really do get the chicks ? Again after a long pause it said "YEP , but when you get them you won't have any money left to spend on them"........ I said "OH" and went back inside the warm house.     
George

[giantkiller]

I have always understood the main reason  for USD forks. Besides being stiffer. Was to drastically reduse unsprung weight. Witch would allow any suspension, cartridge or rod. To get and keep the wheel/tire back to the pavement quicker/easier. Improving traction. I know with my limited skill set that I would never feel the difference. But I need any advantage in traction I can get. Just might be the difference. That I didn't know. Kept me from feeling the pavement against my person (again)

And they get the chicks

All that being said If I didn't have the Mod Problem. I would have already installed Randy's valves in my original forks. I've (even though I have USDs on my86 and adding them to my 87)already spent over $1000 @ rpm and have a list for the future that will probably be in the thousands before I can stop... Help Me..

[FJNovaScotia]

Nothing better than an FJ debate...other than more pictures of FJ stuff:

Here are "side by side" pics of the 88 and newer FJ rear shock and the F4:








You can see the bolt on the top left that will have to be turned down to fit both the FJ Chassis and the F4 shock.

[FJmonkey]

A match made in heaven.... Unless you have the RPM shock.... Randy!!!! Where the hell are you with your shock?