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Old 06-15-2009, 10:24 PM   #16
Rucksta
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Prressure

Quote:
Originally Posted by PaulRS
Nope. (sorry )

By adding more oil, you reduce the volume of air above the oil and by doing so the trapped air will act like a spring.

Adding too much oil will eventually push that airpressure op to a level the forks will not compress anymore and feel rockhard. (like your hydraulic lock)

Paul.
Paul the air will keep on compressing until it either liquifies or blows the fork seal. The Increased air pressure on compression does as you say increase the spring rate progressivly but also increases the damping as it is harder to move the oil into a higher pressure chamber.

When I ran a stock front end on my R80G/S I used 230ml of ATF and was happy enough with the results(for a stock front end). The manual says 200ml +/_ 10%. 250 ml gave me lock up at about the same point the forks bottomed which was before the coils bound. I found 250ml stiff over medium bumps , bowling ball size rocks would cause the front to skip sideways but 250ml was very good under hard braking on road.
Increasing the level above the 250ml mark reduces the amount of travel available and risks damage to the internal fork components under max load.

Give it a go. As long as you don't exceed the parameters you can always drain the oil out if you don't like it.

P.S. oil level below 180ml caused cavitation on rebound and frothing of the oil, not good.
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Old 06-16-2009, 05:42 PM   #17
zenben
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Of the three G/S that I've owned, all had the right side damper rod assembly come apart during use.
The damper rod unscrews from the top retaining portion, so that retention of the fork slider and damping are both handled only by the left side of the fork.
This is probably a tad dangerous, but easy to both check and fix.
I've put both the current damper assemblies back together with a helping of loctite to prevent this situation in the future.

Unfortunately, even with both dampers working, fork performance is still lousy.
Heavier oil helps a little, as does increased pre-load, but the sad truth may be that these just aren't very good forks.
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Old 06-16-2009, 05:56 PM   #18
SOLO LOBO
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Quote:
Originally Posted by zenben
the sad truth may be that these just aren't very good forks.
with a fork brace, alu top triple and racetech emulators they are decent, not great, but decent.... the R100GS with a brace and an emulator are better...
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 06-16-2009, 05:59 PM   #19
StephenB
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Quote:
Originally Posted by SOLO LOBO
. the R100GS with a brace and an emulator are better...
+1 ... a lot!
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Old 06-17-2009, 03:55 AM   #20
Caddy82rats OP
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Quote:
Originally Posted by One Less Harley
Caddy-looks like you've been spraying some paint on the old girl. Looks good.
yep the old girl was nacked some time ago : after a broken valve, the best was to put out the angine to clean it



during the rebuilding process



you can see at the back ground some kind of "cooper" rings
this is part of aircraft ball bearings I use to put hot pans on the table !!! And of course a botle of french alcool

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Old 06-17-2009, 03:59 AM   #21
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Quote:
Originally Posted by SOLO LOBO
with a fork brace, alu top triple and racetech emulators they are decent, not great, but decent.... the R100GS with a brace and an emulator are better...
I've got the BMW fork brace, and a aloy upper triple clamp
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Old 06-17-2009, 09:58 AM   #22
zenben
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Quote:
aloy upper triple clamp
I have used these, and am unconvinced of any significant benefit.
A solution to a problem that didn't exist IMHO.
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Old 06-17-2009, 10:03 AM   #23
SOLO LOBO
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Quote:
Originally Posted by zenben
I have used these, and am unconvinced of any significant benefit.
A solution to a problem that didn't exist IMHO.
I don't think the change with the alloy triple is significant, but in theory it is better...

I had my R100GS forks dialed in completely and there were really plush, predictible and just worked... my G/S forks are getting really close...

Not compared to say a modern dirtbike for sure, but overall they do a fine job.
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 06-17-2009, 10:07 AM   #24
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Quote:
Originally Posted by zenben
I have used these, and am unconvinced of any significant benefit.
A solution to a problem that didn't exist IMHO.
I've seen a real diference with the fork brace, but you're true, nothing with the aloy triple clamp.
Thats a nice part, and I fond it more easy to use than the steel one to put the fork tubes in line.
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Old 06-17-2009, 02:06 PM   #25
batoutoflahonda
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I've put .85 weight straight wound Race Tech springs in. Hardly any preload. Also put the Race Tech emulator in it with maybe one turn on the spring on the emulator. It has 10wt Amsoil fork oil (Mobile 1 ATF worked well too) in and filled to about 6" from the top of the fork.

I weigh 180lbs with full gear. I was going for good road manners and bad dirt road handling, not the crazy single track stuff some ride.

With this set up it and a Wilbur's shock in the back, it handles amazingly better than it did. The "wallowing" in corners on the road are gone as far as the frame will allow. Off road, the forks feel great and I literally feel nothing through the bars on high speed compression, and at 50mph on really rocky pot holed road it tracks true and just soaks the stuff up. Including foot and a half wash outs.

It's taken me 3 months, 4 oil changes (to get the rebound I liked) and at least 4 times adding/subtracting oil to get the "packing up" or top end compression worked out. Thing is, I think a lot of folks, myself included, look for the magic bullet. You just have to get in and play with it, understand how everything interacts, and set it up for YOU and how you ride.
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Old 06-17-2009, 03:58 PM   #26
SOLO LOBO
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Quote:
Originally Posted by batoutoflahonda
filled to about 6" from the top of the fork.
Looks like the oil height may play a significant role in setting up G/S's
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 06-17-2009, 06:48 PM   #27
batoutoflahonda
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Quote:
Originally Posted by SOLO LOBO
Looks like the oil height may play a significant role in setting up G/S's
It seems to help in that rapid-popping the front up-rebound when it nears fully compressed by slowing the spring down. But then again, I turn around at bowling ball sized rocks. Softball sized is my limit. Well, on my cherished G/S any way. You know, they don't make them any more.
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Old 06-18-2009, 06:16 AM   #28
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Quote:
Originally Posted by batoutoflahonda
I've put .85 weight straight wound Race Tech springs in. Hardly any preload. Also put the Race Tech emulator in it with maybe one turn on the spring on the emulator. It has 10wt Amsoil fork oil (Mobile 1 ATF worked well too) in and filled to about 6" from the top of the fork.

I weigh 180lbs with full gear. I was going for good road manners and bad dirt road handling, not the crazy single track stuff some ride.

With this set up it and a Wilbur's shock in the back, it handles amazingly better than it did. The "wallowing" in corners on the road are gone as far as the frame will allow. Off road, the forks feel great and I literally feel nothing through the bars on high speed compression, and at 50mph on really rocky pot holed road it tracks true and just soaks the stuff up. Including foot and a half wash outs.

It's taken me 3 months, 4 oil changes (to get the rebound I liked) and at least 4 times adding/subtracting oil to get the "packing up" or top end compression worked out. Thing is, I think a lot of folks, myself included, look for the magic bullet. You just have to get in and play with it, understand how everything interacts, and set it up for YOU and how you ride.
I think that you've to put a 100 GS kit in the G/S fork ?
But here in Europe, I think this is a expensive option. I've got to check that.
Thanks for all those great informations and sharing
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Old 06-18-2009, 02:52 PM   #29
batoutoflahonda
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No. It's a R80G/S standard. It started here:

http://www.advrider.com/forums/showt...ight=race+tech

Lots to read. The meat of it starts around post 90.

Also this explains things really well:

http://www.sportrider.com/tech/146_9502_tech/index.html
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Old 06-18-2009, 03:47 PM   #30
meijer's trails
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Thumb Sweet Ride!

I just wanted to say "Sweet Ride!" Sorry I have no technical info. but that bike looks great!
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