Just took the GS for a ride after installing a set of 0.85 sonicsprings, its like a whole new bike, feels very stable in corners and under braking. 

So for anyone thinking about it, or even not thinking about it, an upgrade on the stock fork springs is a worthwhile investment.

I found the people at sonicsprings to be very helpful, i wasn't sure what stiffness to get. Told them the bike, my weight and they type of riding, they said the .85s were the go and they were right.
To top it off, the springs were a good price and arrived in a reasonable time.

So basically, just recommending sonicsprings to anyone looking at upgrading their fork springs

-Mart3y

just ordered mine too and cant wait!!. bit of a novice but did it come with instruction, spacers and info about oil level? (i heard its a lower level than stock because the springs are thicker)?
What weight fork oil did you use???
Cheers
Clancy

Quote from: Mart3y on March 07, 2011, 03:51:09 AM
Just took the GS for a ride after installing a set of 0.85 sonicsprings, its like a whole new bike, feels very stable in corners and under braking. 

So for anyone thinking about it, or even not thinking about it, an upgrade on the stock fork springs is a worthwhile investment.

I found the people at sonicsprings to be very helpful, i wasn't sure what stiffness to get. Told them the bike, my weight and they type of riding, they said the .85s were the go and they were right.
To top it off, the springs were a good price and arrived in a reasonable time.

So basically, just recommending sonicsprings to anyone looking at upgrading their fork springs

-Mart3y

I got sonic spring too and it's very good!  Way better bike than before.

I'm planning a GSX-R front end conversion for my race bike. Watch the for sale section... My production legal race front end will probably be going up for sale later this month.

.85 Racetech springs
Racetech emulators
15 weight fork oil
Buddha brace
Woodcraft clip-ons
Stainless steel brake lines
SV-650 brake calliper
EBC Extreme Pro racing pads

Quote from: burning1 on March 07, 2011, 11:18:37 AM
I'm planning a GSX-R front end conversion for my race bike. Watch the for sale section... My production legal race front end will probably be going up for sale later this month.

.85 Racetech springs
Racetech emulators
15 weight fork oil
Buddha brace
Woodcraft clip-ons
Stainless steel brake lines
SV-650 brake calliper
EBC Extreme Pro racing pads

Anfd how much are you thinking for all that?

Retail on the parts is:
$100 for the springs
$170 for the emulators
$60 for the brake line
$30 for the brace
$150 for the clip-ons
$100 for the pads
$120 for the tire
------------------
$730 new + tax


Going rate for the factory parts is
$200 for the OEM fork tubes
$50 for the OEM wheel
$40 for the SV650 caliper
$75 for the triple
$0 OEM master cylinder (needs to be replaced)
whatever for Odds and ends (fender, axle, etc)
-------------------
$365

Front tire is pretty fresh, with 80% of its life remaining.
Brake pads are about halfway through their life. Still running amazingly strong - see my review in the racer's corner.


So... I'd probably ask $500 for the fork tubes & brace with internals, $95 for the clips, $75 for the brake parts (caliper, pads and cable) and going rate for the rest of the OEM parts. Or, I'd take $650 for the lot (complete front end including tire, just slide the tubes into your triple.) I'd be more than happy to re-spring the forks, for the cost of the spring and oil (~$100, must use Racetech springs, since the spacers are already cut for them.) I'd be happy to replace the master cylinder, and bleed the system so that the brake parts are a bolt on (buyer pays for a new M/C.) I can throw in the OEM throttle, and right instrument pod.

Buyer pays shipping, of course.

All parts are bolt on. Clip-ons are already drilled for OEM parts. Front end should be production legal for most classes - the SV650 calliper is an OEM update part for newer GS500E/F models. The only part that probably isn't prod legal is the brace. I'd be happy to throw in a prod legal brace.

Springs are .85, installed oil is 15 weight. I weigh about 180, and the springs are a little soft for the pace I run at the track. On the street, they should be suitable for a heavier rider... Say, 190-220 lbs.

Whoever purchased could put their stock parts up for sale, and probably get $200+ for it.

I'd prefer to keep the emulators with the fork tubes, since the tubes have to be modified to fit the emulators and cannot be reverted to stock. Installing the emulators in the factory tubes will require a complete disassembly and modification. Getting that work done alone will probably cost $100 alone. Again, the stock parts could be sold to recoup a good bit of the cost.

Parts probably won't be up for sale for another month or so, while I complete my GSX-R front end and test it on the track.

Combined with a Katana Shock and good rubber, it's amazing how fast you can go on a stock GS. At local trackdays, I run faster times than the majority of C and B groupers on 600s using this suspension.

Quote from: Clancy on March 07, 2011, 05:09:19 AM
just ordered mine too and cant wait!!. bit of a novice but did it come with instruction, spacers and info about oil level? (i heard its a lower level than stock because the springs are thicker)?
What weight fork oil did you use???
Cheers
Clancy

it came with generalised instructions, but i used the service manual i have, found it to be better because it has torque specs, pictures and explanations on how to do some of it.

i had to bodgey up some tools to that i could get the damper rod out, get one of the metal anti friction rings in and also get the fork seal back in place.

i also put 1/2" preload onto the springs and used fork oil #15 which is ISO 46 if i remember correctly (someone correct me if im wrong).

As for the oil level, when the fork is fully compressed with no spring in it, i filled it to 99mm below the top (pumped it up and down a few times to distribute the oil), then extended the fork, put the spring, spacer and everything in and put it back on the bike.

Quote from: burning1 on March 07, 2011, 11:18:37 AM
I'm planning a GSX-R front end conversion for my race bike. Watch the for sale section... My production legal race front end will probably be going up for sale later this month.

.85 Racetech springs
Racetech emulators
15 weight fork oil
Buddha brace
Woodcraft clip-ons
Stainless steel brake lines
SV-650 brake calliper
EBC Extreme Pro racing pads

It may be a stupid question, but what do emulators do?

They emulate real suspensions/dampers... 

Quote from: tb0lt on March 08, 2011, 01:26:49 AM
They emulate real suspensions/dampers... 

Well there we go, i've learnt something today, hasn't been completely wasted lol

In an ideal world, your suspension would be very plush over hard objects like potholes and speed-bumps. It would be very firm under braking. It would recovery quickly from bumps, but never over-shoot and pogo. It would make sure to always apply even pressure to the tire, keeping it in firm contact with the ground; never overloading it, and never underloading it.

Traditional forks, like the ones on our GS500 use a ported damper rod design to achieve some of those goals, with a check valve to separate compression and rebound damping. Suspension fluid flows through a hole in the damper rod. The restriction of the hole controls how much resistance the damper applies against compressive forces, and how quickly the spring is permitted to extend upon rebound.

The problem with a ported damper rod, is that when fluid flows through a restrictive hole, the resistance to movement increases exponentially with the speed of the fluid flow. The result is that the suspension gives very little resistance to slow movements such as breaking, and way too much resistance to fast motions, such as hitting a pothole. It's a highly progressive form of damping, and it's exactly the opposite of what is ideal. We want digressive damping.

Modern forks achieve this by using huge ports, and installing a valve over the ports. The valve is actually a series of washers, that form a very finely tuned leaf spring. They restrict fluid from moving when the fluid moves slow, but really open up a lot when the fluid moves fast, giving much more ideal suspension action.

Emulators emulate this behavior. They are designed to be dropped into traditional forks, like ours. They use a pre-loaded spring and a valve to provide a firm suspension under braking. The valve opens up when we hit a hard bump, significantly softening up the suspension. The result is a better ride, better traction, and better tire wear. Their performance is somewhat similar to a cartage fork.

With emulators, rebound is still handled by the stock rebound ports, which is actually okay, since rebound is in response to how far the spring compresses, not by what kind of a bump you hit, or how hard you are on the brakes. We can tune the rebound by installing thicker oil.

With the emulators, high speed compression is adjustable by installing a firmer spring on the emulator, or by increasing the pre-load on the spring. Low speed compression can be adjusted by adding extra bypass ports to the emulator. So not only do they make the suspension behave better, but they make it so that you can tune compression separately from rebound (without modifying the forks.) Again, they add some adjustability to the forks, but you will have to disassemble the forks to adjust them. The good news is that the adjustment can be made on the bike.

In order to install the emulators, the forks must be disassembled, and the compression ports have to be drilled out so that they don't provide any restriction to fluid flow, allowing the emulators to do their job. The modification takes a little installation time, and is not trivial to reverse.

Ah, thanks for that explanation burning1 

I finished the GSX-R front end conversion. The emulators and everything else are up in the for-sale section.

http://gstwins.com/gsboard/index.php?topic=55702.0
http://gstwins.com/gsboard/index.php?topic=55699.0
http://gstwins.com/gsboard/index.php?topic=55697.0