Questions on Sonic Springs ?

[naturally wired]

Hi Guys,
Going to replace front springs in 2 weeks on my 04 st1300
from the look of things I see on the forum the sonics are the
way to go I weight abot 250 and ride hard at times.not alot of gear
but hard in the corners and fast on the straights.
I went to the Sonic sight and the calc gave me 1.2 so it looks like
ST1300 - 1.20kg/mm Sonic Springs are correct?
need to know tube length to cut to and what fluid would be best to use?

Thank you all for your help/answers ahead of time!

Sincerly Naturally Wired :^D

 

[ksievers]

IMO the thing to do is call him... when I had my V-Strom 650 I called him (I live about 30 miles from him) and had a bunch of questions.. he was incredible. He wound up doing the install for me, on his time, at his garage, and refused payment (other than for the parts). I can't presume he'd do that for everyone with a question, but he was amazingly generous and knowledgeable. Fascinating to talk to.. and of course it's a great product.

 

[SteveST1300]

I went with HyperPro and they did all the calculations for me.

 

[wjbertrand]

The instructions that come with the springs will tell you to fill the oil to about 130mm from the top of the fork tube, leg collapsed and spring out. To cut my spacers, I laid the OEM spring, spacer and washers together and then cut the Sonic spacer to match the overall length of the OEM stack (unloaded of course). This ended up giving me about 3/4" of preload and 1/5" of sag. I weigh about 225 and also ride pretty hard at times.

 

[TomD]

The instructions that come with the springs will tell you to fill the oil to about 130mm from the top of the fork tube, leg collapsed and spring out. To cut my spacers, I laid the OEM spring, spacer and washers together and then cut the Sonic spacer to match the overall length of the OEM stack (unloaded of course). This ended up giving me about 3/4" of preload and 1/5" of sag. I weigh about 225 and also ride pretty hard at times.

This is exactly what I did and at 250, I'd say they are right on. The ride is a bit firmer. It did feel a bit harsh until I got use to them. The handling and front end feel is very much improved. Take your pick smooth or sporty. You will grow to like sporty!

Tom

 

[stoc445]

Regarding the spacers, I did exactly as Jeff described. In addition, I used Amsoil Medium Suspension fluid and installed a fork brace. Made a huge difference. As a side note, don't over look the rear shock. I'm running a Penske and the combination is a real crowd pleaser!

 

[wjbertrand]

don't over look the rear shock. I'm running a Penske and the combination is a real crowd pleaser!

As an option, you can avoid the expense of the Penske and still get a good improvement having Race Tech re-valve your OEM shock and fit a stiffer spring. It's not going to be as effective as the Penske, but at less than 1/2 the price, worth consideration. I'm running a Race Tech re-valved OEM rear shock with a 1200lb/in spring. That spring is on the edge of being too stiff running one up lightly loaded but helps hugely running two-up or fully loaded.

 

[Highrider]

I recall the three ST's that I installed Sonic 1.2 springs ended up with a 4.25" spacer.

 

[stoc445]

I'm packing a few more pounds, I have a 1400 spring on the Penske and it seems to be good. Definitely stands taller than stock.