Re-valve GSXR forks, YC-Voodoo!!

[DavieSV]

What can I say... WOW!

Earlier this year I replaced my forks that were fitted with Racetech 0.90 springs, racetech emulators and 20wt oil with a set of GSXR 750 K7 forks.

I did like the standard forks with the emulators in, but I had set them up over 3 years to suit me fine. Hard braking and fast tip in were just where I wanted it. rebound was nice and slow to keep the front wheel on the floor when letting off the brakes into corners. They were good but lacked a bit on little high speed bumps. They were a bit choppy on rough surfaces.

I selected the k7 forks for their physical dimensions, (18mm longer than the previous years I think) to try and keep the attitude of the bike near to where I wanted it. I have a RSVR adjustable length shock on the rear and have increased the length of that, so I didn't want the nose to be too low.

I knew the springs were going to be hard, but I went with it to see if it would be OK with the 518lb/in spring on the back.

The forks went on nice and easy and I have retained the SV front wheel.
The first impressions were that they were a bit smoother that the SV front end that they had replaced, They were OK but no drastic improvement on the emulators. The compression didn't seem too bad but the rebound was still a bit lacking I thought. The brakes are fantasic though.

As time has gone on and I have covered more miles, I had come to the conclusion that I had to change the springs. Over bumpy road surfaces, it was just too hard. A quick blast round Wales trying to keep up with my mates K5 Gixxer would physically tire me out. Then coming back across A50, the expansion strips in the concrete surface would rattle my teeth and blur my vision.

I bought some Racetech 0.90 springs and approached Yorkie-Chris to ask his advice.

YC has completely revalved my forks for the way I ride.
I got the forks back on Saturday with the 0.90 springs in them and fitted new tyres.

I set the Sag to 25mm/35mm front and 10mm/25mm rear and wound all adjusters out by 1 1/2 full turns. Checked tyre pressures and then went for a quick ride.

I did a little loop (8 corners in total) WOW what a difference . It was like the council had been around at night and resurfaced all the roads. I carn't explain the difference between any setting on any of the fork setups I have had on my SV before. I was completely amazed.
Tire grip and braking were excellent, I didn't notice any rebound when coming off the brakes and everything was just so smooth.

I then had to go and pick Matilda up from Grandma's, so I couldn't do much tweeking.

That evening though I managed to get out for an hour and went down the A6 to Matlock with my little screw driver in my pocket.
As the tyre's started to scrub in and the braking/accelerating increased I have settled on both compression and rebound adjusters 1 turn out.
Time to go back home.
On the way back through the sweeping bends of the A6 It felt like I was counter steering quite a bit through the bends.
Holding the bars with just my right hand, I was pulling the bar through left handers and pushing through rights. Fork angle too steep I thought.

The next morning (Fathers day) my Wife asked me what I would like to do for the day...
Ta Daa then, and into the garage I went, to get my bike.
Before I set off, I lowered the forks through the top yoke by about 5mm. I was hoping that this was enough to stop the counter steering, if not I would have to shorten the shock length.
Off I set. not raining but very damp and still not scrubed my tyre in.
I set off towards Matlock again, this time down the A615.
The front end was amazing! neutral steering through the bends, floated over all the bumps and more than enough grip even on the damp roads.
All my concentraition had gone to the rear shock.
I stopped in Matlock and wound the rebound off the shock by 6 clicks, then headed over the A5012 to Buxton and the Cat & Fiddle. the bike was just getting better and better. At the Cat I wound the compression off the shock by 1/2 turn and headed towards Macc where I wound it back in again.
The roads started to dry a bit as I headed towards Leek and then back over the A53. Thoughts of trying to read the suspension and tweek a bit more, had now gone out of my head as the grin slowely spread across my face.
The rest of the morning was just play

YC - I carn't thank you enough for the revalve. It has turned my bike into a completly different beast again

I thought the forks off a sports bike would be fantastic, but then again they have to valve them to fit all sorts of riders.
If you want your forks to perform a lot better, consider a revalve and talk to YC.

I for one, love what he has done to my bike.

[dyzio]

Glad you're happy, one question though:

Originally Posted by DavieSV

Before I set off, I lowered the forks through the top yoke by about 5mm. I was hoping that this was enough to stop the counter steering, if not I would have to shorten the shock length.

You said you've lowered the front, wouldn't shortening the shock have the opposite effect - as in lower the back end?

Or is it that a shorter shock gives more ride height through the linkages? - if that makes any sense.

[DavieSV]

Originally Posted by dyzio

Glad you're happy, one question though:



You said you've lowered the front, wouldn't shortening the shock have the opposite effect - as in lower the back end?

Or is it that a shorter shock gives more ride height through the linkages? - if that makes any sense.

lowered the forks through the yoke / raised the yoke on the forks = front end higher.

Shortening shock would lower back = same effect

[dyzio]

Originally Posted by DavieSV

raised the yoke on the forks

A, thought you've lowered the yoke, ta!

[andrewsmith]

Cracking write up Davie

There mustn't be any virgins left in West Yorkshire now

[Bibio]

nice write up there Davie. and i totally agree that the SV is a completely different bike once sorted properly. think i'll chin YC at the GM as i feel the fast comp is a bit harsh on mine and the rebound is well out of scale even with this its night and day comaired to standard pogo sticks.

[CodeJACK]

Cool write up, thanks.

Do you think the new tyres had anything to do with the improved handling?

How did you manage to retain the SV 650 wheel in the GSXR front end?

[DavieSV]

Originally Posted by CodeJACK

Do you think the new tyres had anything to do with the improved handling?

I was scrubbing the tyres in at the time, so not really exploring the corner grip or handling at full lean.
But yes, the tyres have made a difference & I've gone for the 70 profile front.
I don't think the tyres would have contributed to the ride quality though.

Originally Posted by CodeJACK

How did you manage to retain the SV 650 wheel in the GSXR front end?

See here!

[yorkie_chris]

Great stuff! Glad you're enjoying them.

[CodeJACK]

Originally Posted by DavieSV

I was scrubbing the tyres in at the time, so not really exploring the corner grip or handling at full lean.
But yes, the tyres have made a difference & I've gone for the 70 profile front.
I don't think the tyres would have contributed to the ride quality though.


See here!

Wow, I missed those threads. Very well done modding there. Enjoy