Hyperpro spring kit

[Guest DelBoy]

Hi Guys,

 

 

I decided, this weekend, to fit the basic Hyperpro springs & oil, as I have fitted this to other bikes in the past and found that the front was significantly improved.

 

I do have a question for anyone that has fitted the same kit to an NC.

 

The manual states that the spring should be fitted with the progressive part at the TOP. However,  when I removed the old ones the progressive part was at the BOTTOM.

 

So I fitted the Hyperpro spring the same as the original.

 

I then Emailed Hyperpro regarding this and they say that the spring should be fitted with the Progressive part at the TOP.

 

 

So, before I go and change this I was wondering if anyone else has had the same situation etc.

 

Cheers 

 

P.S. I have looked at the Honda parts fiche and it also shows the OEM spring (Showa) with the progressive part at the BOTTOM...

[Tex 36,816]

Ohlins fit the close coils at the top..

 

 

I guess it’s one for the boffins to argue over - does the wheel come up to meet the bike or the bike go down to meet the wheel?  

 

More seriously, do what Hyperpro says - they make them..

[SteveThackery 3,090]

I might be wrong, but I don't think it could possibly make a difference.  I say this because it seems common sense, but mostly because at uni we did numerous calculations involving progressive springs (and progressive links), and nowhere in the mathematics is any account taken of the spring orientation. 

 

Anyone have a different view that they could explain?

 

 

Edited May 27, 2019 by SteveThackery

[rjp996 1,091]

I'm with Steve here, can't see how it would make a difference 

[Slowboy 20,344]

Likewise, I agree with Steve, don't see how it can have an effect.

[fred_jb 10,264]

I agree too.  I would think that the coils with a lower spring rate will compress more than the others and presumably eventually become coil bound before the others do, regardless of their position, be it top, bottom, or even middle!

[Guest DelBoy]

I do agree with you all that it should not make a difference, however Hyperpro state that they recommend fitting the fork springs with the progressive part at the top so that less spring area is in the oil. So I have done so.

 

 

Anyway, the front feels a lot better now.  

[SteveThackery 3,090]

4 hours ago, DelBoy said:

I do agree with you all that it should not make a difference, however Hyperpro state that they recommend fitting the fork springs with the progressive part at the top so that less spring area is in the oil. So I have done so.

 

Ah yes, I can see that.  If there's more spring volume in the oil, it will raise the oil level beyond what it's supposed to be.  

 

Presumably they could have specified the spring either way up, but they would then have to specify two oil volumes, one for each case.  Obviously choosing just one spring orientation and one oil volume makes much more sense.

 

Cheers, DelBoy - learned summat today!   

[Tel 4,711]

I had Hyperpro springs fitted to my FJR1300 at The FJ Owners Club workshop a few years ago and they fitted them with the wider-wound springs at the top [although Ernie there said he wasn't sure which was correct] but I think it is wrong.

To my mind the softer spring should be at the bottom to absorb ripples and small bumps before compressing the tighter/harder springs. I also think I've heard before that you should keep the unsprung weight lowest!

  

[makman 975]

I used FJ Club for my FJ1200 servicing. Aces work by Doc. Always ran like a dream after his ministrations.

 

I only changed oil for lighter weight oil for the forks. I'll think about springs if I keep the bike for longer.