updating GSXR forks in my 2003 SV 650 track bike.

dtrides

Well-known member
I have 2005 GSXR 750 forks on my 2003 SV650 track/race bike and looking at upgrading due to being out of further adjustment in valving.

I have input from my suspension tuner I can just have the shim stack changed to accomplish what is needed but am wondering if there would be further improvement with a full valve kit ?
I had the forks rebuilt at the beginning of last year and have a Ohlins two way shock on the rear.
New cartridges aren't in the budget this year unless some one wants to sponsor me. :p
Thanks!
DT
 

usedtobefast

Well-known member
If you have a good/great suspension tuner that knows what they are doing, a revalve of stock components should take care of it.

There are several 20mm piston kits for Showa forks (Racetech, Ohlins, K-Tech, Mupo, Penske) ... where you get the compression and rebound pistons and valving stacks. These are in the $180 - $350 price range for the kit.

So one theory is, these engineers (Ohlins, Racetech, etc) designed their piston and valving stack to work in this fork ... and they did a better job than Suzuki/Showa ... so by just installing the kit you have better valving/suspension than stock.

So I think a kit is better than stock, and better than a novice tweaking stock shims.

But there is nothing really wrong with the stock compression & rebound piston/valves in the Showa fork. So if you have an experienced tuner they should be able to set the stock ones up as well or better than the stock kits.
 

stangmx13

not Stan
IMO

if working with a great tuner that has prev experience with racers on your class of bike at approximately your pace at your tracks:
1. re-valved piston kit (best)
2. re-valved OEM piston
3. out of the box piston kit
4. OEM valving (worst)

if working with a tuner that has little experience with racing and your bike:
1. out of the box piston kit
2. re-valved piston kit
3. re-valved OEM piston
4. OEM valving
 

Holeshot

Super Moderator
Staff member
Very important part, Duncan, will be having the tuner be track-side or available by phone when getting the feel to where you like it. Oil level and settings and a revalve can make a bike go pretty darn good, but without good setup, things may work well below optimum.

Front end feel is paramount, as you know.
 

dtrides

Well-known member
Thanks for all the replies.
One issue is the track side person wont be the installer person, but will relay the shim stack to the installer.
This all came about when I did a track day at Sears Point and demo'ed the new R1. The front end felt soooo much better entering the corners I had Jim from Catalyst take a look at my forks( he was the provider at this event). He made some adjustments and relayed that I probably need firmer springs and a re-valve as I was out of adjustment.
The bike felt much better (still not as good as stock R1) and I promised my self that I would do something in the off season.
I had planned to do GP cartridges after talking with Jake Z. but my budget went away when I decided to examine the pavement up close at a track day.
At the track I normally work with Dave M.
DT
 
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TWF

training hard
Guys winning that class are using stock valves with different shim stack.
 

dtrides

Well-known member
Guys winning that class are using stock valves with different shim stack.
Yeah, but they probably have one of your motors as well...:rofl
Ok, I will start with a shuffle of the shim stack!....and save my pennies for more motor.:teeth
DT
 
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