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progressive lr springs and fork spacers
Posted: Mon May 23, 2005 7:52 pm
by Blake Sobiloff
This past weekend I got around to installing the Progressive LR fork
springs I bought from Robert Wayne (thanks, Robert!). I had saved
several emails from the list regarding the appropriate size and
material for the new spacers I'd need, but of course I didn't print
them out before I headed down to the garage. (My garage is 30 miles
south of me, so "heading down to the garage" is a bit more involved for
me than for most!) Once I got to the garage I went to a nearby
Internet connection and tried some searches, but wasn't able to find
the outer diameter information I wanted.
So, for the record, my stock fork spacers measured 1 1/8" in outer
diameter (or approximately 28.5 mm) and 5.518" (140 mm) long.
I put my fork back together and rode to the local hardware store and
bought some 3/4" ID series 80 PVC to cut into 2" long spacers, per
Progressive's recommendations. I rode back to my garage and while
cutting the PVC freehand with a hacksaw I realized it's kinda hard to
make the cuts perfectly! (Ah, for a house and a big, big garage with
room for all the nice tools!) I did a better job with the second one,
but the first has one side about 1/8" higher than the other.
I drained the original muck residing in the forks. I have a 1999 with
about 9,000 miles on the original fluid, and that stuff came out grey
and stinky! Glad to replace it with some 15W Silkolene semi-synth. Of
course, the first drain screw was rusty and I expected a big battle
ending in a stripped screw. I also predicted that I'd drop the screw
and it'd fall into my oil catch pan which has a small drain in the
middle and a spout on the side, meaning if the screw fell in I'd have
to pour all the old oil out through a strainer to get it back. So, I
put the plug in the drain and began working on the screw. Luckily, the
screw came out quite easily!
The other side's screw was clean, so I figured it'd be an easy out.
Not! It took a lot of persuasion to get the screw out without
completely stripping it, and of course I dropped it into the oil pan I
over-confidently failed to plug the drain on. Argh!
Now I had to wait for my girlfriend to come by so that I could borrow
her car, run to Safeway and buy a mesh strainer, then stop at AutoZone
and recycle my used oil and filter it for the screw, then run to the
hardware store and find a replacement. (M4 X .7 pitch, BTW.)
Filling the forks and installing the springs and spacers was
straightforward. I did hear the clicking that others have noticed with
the Progressive springs when you compress the forks. However, I only
hear it from the left side, with is the side with the slightly
lop-sided spacer. I wonder if perfectly even spacers would prevent the
clicking? Makes sense intellectually. I might try cutting a better
spacer the next time I dump the fork fluid and see if it makes a
difference.
Anyway, I highly recommend the Motion Pro fork oil level gauge (thanks,
Fred!)--it made getting the correct level a piece of cake.
As for the ride quality with the new springs, it's better but still not
where I want it. Front end dive under braking is significantly
reduced, but the poor high-speed sharp bump damping still exists. I
need to get a set of RaceTech gold valve emulators in the forks to take
care of that problem.
--
Blake Sobiloff
San Mateo, CA (USA)
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 8:34 pm
by JRC
> I rode back to my garage and while > cutting the PVC freehand with a
hacksaw I realized it's kinda hard to make the cuts perfectly! (Ah,
for a house and a big, big garage with room for all the nice tools!)
I did a better job with the second one, but the first has one side
about 1/8" higher than the other.
PVC pipe sands well. Use 140 grit on a flat surface, and move the
pipe, not the sandpaper.
I changed the preload on my stock springs 2 weeks ago and used 3/4
inch schedule 40.
>I wonder if perfectly even spacers would prevent the
> clicking? Makes sense intellectually. I might try cutting a better
> spacer the next time I dump the fork fluid and see if it makes a
> difference.
See my above comments on sanding.
> Front end dive under braking is significantly
> reduced, but the poor high-speed sharp bump damping still exists. I
> need to get a set of RaceTech gold valve emulators in the forks to
take care of that problem.
When you say poor high speed damping, is it too much or too little?
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 8:46 pm
by wannabsmooth1
Snip>>>>>>>
Glad to replace it with some 15W Silkolene semi-synth.
SNIP>>>>>>>>
Front end dive under braking is significantly
> reduced, but the poor high-speed sharp bump damping still exists. I
> need to get a set of RaceTech gold valve emulators in the forks to take
> care of that problem.
> --
> Blake Sobiloff
> San Mateo, CA (USA)
Blake,
IIRC, Silkolene is rated a little differently than some of the other
fork oils - just going by memeory, what I read on the FJR list
(Wilbers recommended 7.5 for the FJR). Very important = how many mm's
below the top did you set? A common settin seems to be 170 mm below
top of tube, with the springs out, forks compressed. Note:YMMV, this
is not the "official" book value.......Depending on your weight, 2.5"
preload may be better......
All the best,
Mike
Eagle Mfg & Eng since 1990
San Diego, Ca
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 9:13 pm
by Blake Sobiloff
On May 23, 2005, at 6:34 PM, JRC wrote:
> PVC pipe sands well. Use 140 grit on a flat surface, and move the
> pipe, not the sandpaper.
Thanks for the tip!
> When you say poor high speed damping, is it too much or too little?
The front is too stiff when it hits a sharp bump quickly. This is
because the fork fluid can't flow quickly enough through the orifices
in the rods, so the front acts almost solid in this situation. The
gold valve emulators are designed to greatly increase the flow during
extreme pressure, allowing the forks to quickly compress and absorb the
sharp bump.
It really is an amazing difference. My favorite test is to ride over
the reflectors that are embedded in the lane markings on the highway
here in CA. They're probably 1" high. With gold valve emulators you
hear the forks thunking and working, but you barely feel it. Without
the emulators you get a sharp jolt over each and every reflector and
quickly tire of it.
--
Blake Sobiloff
San Mateo, CA (USA)
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 9:35 pm
by Ed Chait
> I wonder if perfectly even spacers would prevent the
> clicking? Makes sense intellectually. I might try cutting a better
> spacer the next time I dump the fork fluid and see if it makes a
> difference.
There are a couple of tricks that help to cut them straight if you're just
using a hacksaw.
You can use a couple of hose clamps close together as guides to keep the cut
straight.
You can also just put a sheet of sandpaper on something flat, like a mirror
or piece of glass, and sand them down even.
A small miter box also makes these jobs real easy. You can buy one pretty
cheap or just make one out of scrap wood.
ed
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 9:51 pm
by wannabsmooth1
--- In
DSN_KLR650@yahoogroups.com, Blake Sobiloff wrote:
> On May 23, 2005, at 6:34 PM, JRC wrote:
> > PVC pipe sands well. Use 140 grit on a flat surface, and move the
> > pipe, not the sandpaper.
>
> Thanks for the tip!
>
> > When you say poor high speed damping, is it too much or too little?
>
> The front is too stiff when it hits a sharp bump quickly. This is
> because the fork fluid can't flow quickly enough through the orifices
> in the rods, so the front acts almost solid in this situation. The
> gold valve emulators are designed to greatly increase the flow during
> extreme pressure, allowing the forks to quickly compress and absorb the
> sharp bump.
>
> It really is an amazing difference. My favorite test is to ride over
> the reflectors that are embedded in the lane markings on the highway
> here in CA. They're probably 1" high. With gold valve emulators you
> hear the forks thunking and working, but you barely feel it. Without
> the emulators you get a sharp jolt over each and every reflector and
> quickly tire of it.
> --
> Blake Sobiloff
> San Mateo, CA (USA)
If it's too harsh, you might want to try 10 weight. Most of the time 7
1/2 for the dirt, and 10 wt for the street works pretty good. 15 is
pretty heavy.
all the best,
Mike
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 9:54 pm
by JRC
> > When you say poor high speed damping, is it too much or too little?
> The front is too stiff ...
Before you spend more money, maybe you should try a lower weight fork
oil. The 1 inch reflectors you speak of are low amplitude, but high
frequency bumps. Lower viscosity oil work bettr.
progressive lr springs and fork spacers
Posted: Mon May 23, 2005 11:32 pm
by Eric L. Green
On Mon, 23 May 2005, Blake Sobiloff wrote:
> Progressive's recommendations. I rode back to my garage and while
> cutting the PVC freehand with a hacksaw I realized it's kinda hard to
> make the cuts perfectly! (Ah, for a house and a big, big garage with
A little $5 miter box from WallyWorld solves that problem just fine.
> Filling the forks and installing the springs and spacers was
> straightforward. I did hear the clicking that others have noticed with
> the Progressive springs when you compress the forks. However, I only
> hear it from the left side, with is the side with the slightly
> lop-sided spacer. I wonder if perfectly even spacers would prevent the
> clicking? Makes sense intellectually. I might try cutting a better
Nah, mine click, and my spacers are perfectly even. I got my springs from
Happy Trails so they came with spacers the correct length and quite even
thank you.
-E
progressive lr springs and fork spacers
Posted: Tue May 24, 2005 5:55 am
by dooden
--- In
DSN_KLR650@yahoogroups.com, Blake Sobiloff wrote:
> Progressive's recommendations. I rode back to my garage and while
> cutting the PVC freehand with a hacksaw I realized it's kinda hard to
> make the cuts perfectly! (Ah, for a house and a big, big garage
Next time in Wally World/Menards/Local hardware store do yourself a
favor and buy a pipe cutter, just a cheapy is fine for plastic pipe,
stick it on the pipe snug and turn till your 2" l PVC pipe has a nice
even clear cut.
(Looks like a "C" clamp with a rollers on the end and a small knife
like wheel on the moving jaw)
http://www.ridgid.com/Tools/Pipe-Cutters/ > Anyway, I highly recommend the Motion Pro fork oil level gauge (thanks,
Is that a Long zip tie on a stick ?
> Blake Sobiloff
> San Mateo, CA (USA)
Dooden
A15 Green Ape
progressive lr springs and fork spacers
Posted: Tue May 24, 2005 9:13 am
by Blake Sobiloff
On May 23, 2005, at 6:46 PM, wannabsmooth1 wrote:
> IIRC, Silkolene is rated a little differently than some of the other
> fork oils - just going by memeory, what I read on the FJR list
> (Wilbers recommended 7.5 for the FJR).
Hmmm, I hadn't heard that! Do you mean that their 15-weight is not
really a 15-weight, but some other viscosity?
> Very important = how many mm's
> below the top did you set? A common settin seems to be 170 mm below
> top of tube, with the springs out, forks compressed. Note:YMMV, this
> is not the "official" book value.......Depending on your weight, 2.5"
> preload may be better......
I set it to the book value (180 mm?--don't have the book with me). I
weigh 175, but you should probably add another 25 pounds for clothing,
riding gear, my Givi top box, and the laptop I usually carry.
The instructions that came with the Progressive springs said that the
fork oil level affects only the final 1/3 of the compression range; if
the oil isn't high enough you'll frequently bottom out the front forks.
I need to put some zip ties on the forks and verify how much the front
suspension is collapsing, but it hasn't felt like its been bottoming
out.
I must confess I haven't measured the front sag with the new springs
and spacers. In fact, I don't even recall seeing a recommendation in
the manuals. What's the rule of thumb for a dualsport bike? A little
Googling turned up a recommendation from Race Tech via Dirt Rider
Magazine of 22-25% static sag in the front.
--
Blake Sobiloff
San Mateo, CA (USA)