How much spring/fork travel for a standard NC23?

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idl1975
Settled in member
Posts: 2
Joined: Fri May 22, 2009 11:35 am

How much spring/fork travel for a standard NC23?

Post by idl1975 » Tue Jun 16, 2009 11:54 am

I'm having some stiffer fork (compression, not rebound/helper) springs made up for my NC23 (RR-K) track bike.

Has anyone done this (i.e. not bought off-the-shelf ones) who can advise on the proper spring dimensions and rate? I haven't pulled the forks apart yet and was hoping to avoid doing so until I have the springs to swap in. Yes, I realise the best way is to measure the ones in there and will do so if necc., but I have lots of bikes and a s****box to work on and not a lot of free time.

I was going to go for c. 0.84 kg/mm as the rate. Don't want them too hard, just better than what's in there. I've just had it out for a test run at Mallory just to figure out how it handles, and it's getting well into the bottom 1/3 of travel (though not bottoming) without even properly "smokin' the anchs". This is really the only issue I have with the front end, and static sag isn't too far off. Does this rate sound about right?

Haynes lists 308mm as the free length (correct?) for the RR-K. I've found 34.7mm listed as the internal diameter of the springs.

One thing I'm definitely not clear on is how much spring travel I need to specify. Is that the same as fork travel, i.e. the stanchion position at full extension to the bottom yoke, and does anyone have that measurement?

Thanks in advance for any guidance...

stimpy
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Posts: 369
Joined: Fri May 02, 2008 11:05 am

Re: How much spring/fork travel for a standard NC23?

Post by stimpy » Sun Jun 21, 2009 1:46 pm

im using.85 racetech springs in my racebike
120mm from memory(fork travel)
you should have a chat with graeme france,for the finer points.
i ordered my springs thru him years ago after telling him my weight
havnt touched the front end since.
stimpy

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