Recommendation for fork upgrade - 2nd gen SV650s | GTAMotorcycle.com

Recommendation for fork upgrade - 2nd gen SV650s

voyageur

voyageur

Well-known member
Site Supporter
So I'm planning on refreshing my forks which are currently stock. I replaced the rear shocks with 04 gsxr ones, courtesy @matt365

I'm planning on getting springs, seals, and oil from Sonic Spring as they have decent reviews on SVrider. Wondering if anyone has experience using them?

Initially, I was planning on racetech but these seem to be cheaper, and decent... and I'm on a budget. The expectation is to have some predictability and better response while touring.

Also, any recommendations on oil wt? I'm planning on 7.5 or 10wt since I'll be using a heavier spring than the stock. Any suggestions?

TIA
 
Oil weight has to do with flow through valving.

Stiffer springs don't mean heavier fork oil.

Whatever the manufacturer of the fork internals suggests is what you use.

If you're not doing valving, then you can slow down the fork by adding thicker oil, if needed.

See what svrider suggests



Sent from my SM-G960W using Tapatalk
 
Or if you really want to go all in, a friend has an '07 gsxr front end that he was going to put on a track-only sv650. He'd sell it if you're interested.

Likely $1000 though... not exactly budget.

Sent from my SM-G960W using Tapatalk
 
Thanks Matt! Suzuki uses 10 wt for sv650 from what I saw in the service manual (Showa SS8). I was comparing viscosity and centiStokes yesterday with Belray 15 wt. I think I'll use the table to find something that's closer to what is already there. Few folks on SVrider recommend Belray 15wt but not sure if they have got their emu kits going or not.

And yeah, don't think I can spare $1000. This probably is my last purchase for the season or that's what I'm telling my wife...
 
I would install racetech emulator valves rather than changing the oil weight. choose your spring based on your weight, bike, and riding style - racetech helps you make choices via their website. choice your bike at the racetech "prodiuct search" and explore options.

subscribed
 
Last edited:
boyoboy said:
I would install racetech emulator valves rather than changing the oil weight.
Click to expand...
With metering rod suspension, the rebound is dictated by the oil viscosity. More viscous oil= more rebound damping. You can "tune" rebound by messing with oil viscosity.
Compression is dictated by the hole size in the metering rod... but because (most of the time) oil is being forced through the hole with more pressure than the springs provides... viscosity has little affect on compression.
... and you can get an aftermarket cartridge setup for not a lot more than Racetech emulators.
... but since we're talking about a SV: slap some cartridge GSXR forks on there and be done with it.
 
Anyone with previous experience buying stuff from Sonic springs?

I went with their sv650 spring for my weight and fork seals. 8 days later no update. Their website is a bit tricky with no phone numbers, but just a contact form. I have sent a reminder, and a couple of emails previously but no response so far.

I understand the owner is a member of the svrider forum. Worst case, I'll probably create an account and see if I can reach out.
 
I know nothing of that supplier. What spring rate are the springs (If they can't answer that, don't buy. If it's "progressive" / variable-rate / dual-rate, don't buy.) The spring rate should be established by what you weigh and what you're going to be doing with the bike. If those questions weren't asked of you in order to establish what spring rate should be selected, don't buy.
 
Update:

Getting the springs was a hassle too, had to involve PayPal as I wasn't getting responses from sonic springs. Sonic springs didn't have 0.85 kg/mm springs in stock. The rep confirmed that a 0.9 kg/mm spring rate would work fine for a 175 lbs rider (without gear), and I thought how much difference can a 0.5 kg/mm make. I had Frekeyguy put it together. Turned out to be unbearably stiff, it was as if I were riding on wheels without tires. Frekeyguy also confirmed that he didn't add much preload either. I'm planning on removing 1/3rd of the preload to see if it makes any difference, I don't think it would.

I used the Belray 15wt oil, stock was 10 wt I believe. And, left the airgap at 105-110 mm.

I got back to the Sonic springs rep, this was the response I got:
For sure the BelRay 15w and 110mm air gap are both incorrect. You should be running 10w with a gap of 130mm. Both of these will make a big difference in how the forks feel.

Something to keep in mind: if your complaint is when the bike is moving that is the damping, not the springs. Problems with spring rate generally are bottoming (too low) or not using enough travel (too high). In extreme cases the springs can cause other issues but being 0.05 or even 0.10 off is not extreme.

Take a look at your fluid and air gap to see what kind of improvement that makes and please let me know what you find.
Click to expand...

Probably follow their lead and see if I can get this sorted.
 
You must log in or register to reply here.

Back
Top Bottom