Calculating what fork spring rate I need

[dern]

I have standard fork springs in my 2005 636 zx6r and on track the cable tie is pushed down to the bottom of the fork. The bottom of the tie is a couple of mm from the casting. So I'm either at or very near the end of the travel and comparing with @Tricky's bike, his ends up 10-15mm from the stanchion.

I've tried adjusting preload and it's made tiny differences but nothing dramatic to bring it up that much. The choice of springs from hyperpro is 9, 9.5 and 10N/mm where 9 is the standard. How do I know whether to go for a 9.5 or a 10? Is there some theory or calculator that tell me?

Thanks.

[Demannu]

https://racetech.com/VehicleSearch

[Le_Fromage_Grande]

Lose weight to suit the fork springs

[Mussels]

Is it near or at the end? Near would mean you have the perfect spring already.

[Taff]

I rang k-tech for advice a few months ago and they were very helpful in advising on spring rate and oil level

[Skub]

If you can't get both static and loaded sag within the recommended settings for your weight, then spring rate will need changed.

[dern]

If you can't get both static and loaded sag within the recommended settings for your weight, then spring rate will need changed.

Ok, I'll go through that process over the winter.

It doesn't feel like it's bottoming out but given that adjusting the preload had made little or no difference to the travel seems to suggest that it might be... I think.

[dern]

https://racetech.com/VehicleSearch

That suggests I need 10s front and back.

Brooks suspension have this sheet... https://www.brooksuspension.co.uk/media ... e_2021.pdf
...which suggests the fronts are 8.3 by default and I need 9s and the rear is 9.5 and I need 10.5 based on a weight of 95Kg.

I'll get the tape measure out.

[weeksy]

YOu don't need different springs...

You need Ohlins forks !!!!

[Demannu]

I have tired standard fork springs in my 2005 636 zx6r

Ftfy

[Couchy]

Whatever you do get linear springs, the hyperpros are progressive aren’t they ?

[Tricky]

https://racetech.com/VehicleSearch

That suggests I need 10s front and back.

Brooks suspension have this sheet... https://www.brooksuspension.co.uk/media ... e_2021.pdf
...which suggests the fronts are 8.3 by default and I need 9s and the rear is 9.5 and I need 10.5 based on a weight of 95Kg.

I'll get the tape measure out.

I've got 9.0s in mine- I got this with the bike along with the receipts etc

[wull]

Did you bother adjusting compression?

[singlesman]

As above, also do you know what oil level and weight you have in there?
I wouldn’t be in a rush to stick stiffer springs in if not.