Spring rates - showa front, blue spring, white spring?

[mmchutchon]

Hi all,

I'm nearly there with a major fork repair and service. Been a monstrous ball ache but should be sorted in a week or so. Just put a white spring Mille shock on too.

So, next step is sag. I've got tons of conflicting advice a % sag, mm sag, with/without rider, then I've got 10 mm ride height adjust available on the white spring mille shock. Then I've got conflicting advice about how to set up a bike for the road and correct spring rate vs. pre-load issues.

Bottom line is I'm going to figure it out myself. To that end, does anyone know what the spring rates are for the Showa forks, old blue spring and Mille white spring? I've heard the fork springs are 1.05 kg/mm, is that correct?

Thanks,

Mark

[mangocrazy]

Hi Mark,

Yes, showa front fork spring rates are 1.05 kg/mm. Way too high for anyone except the most dedicated pie-muncher...

Rear (blue spring Sachs) shock has a spring rate of 14.3 kg/mm or 800 lbs/in.

White spring (Mille) shock has a spring rate of 14.5 kg/mm or 820 lb/ins.

Shock info comes from here:

http://www.apriliaforum.com/forums/show ... p?t=162440

Not sure what you weigh, but most people wind up with a linear fork spring rate between 0.85 kg/mm and 0.95 kg/mm. I went for a progressive rate Hyperpro spring.

Graham

[Aladinsaneuk]

re setting it up

no disrespect BUT

if you are not certain, go to a suspension specialist - its worth the cash

[mangocrazy]

I understand what you're saying Pete, and if I need any internal work (re-valving etc.) doing, then it's off to a specialist (although this coming winter I'm planning to have a fiddle with that, as well). But if someone wants to experiment with different spring rates and is mechanically competent, then I see no reason why they shouldn't have a go themselves.

Suspension is often regarded as a 'black art', but it's like anything - it can be learned. And these days there is so much information on the Googlewebs that it's never been easier to find out how to do stuff.

And to completely confuse yourself...

[mmchutchon]

Brilliant, thanks folks. Just what I was after.

I shall be consulting the Ohlins set-up guide and going from there once I have my forks back together. Previous owner had gorilla'd the rebound adjuster on the forks and sheared the rod that moves the piston. Replacement fork internals from some bent ebay forks will do the trick I hope.

I've had the fork oil and seals done by Steve at Peak Performance. The white spring mille fork will be setup as best I can and ridden until winter when it shall be given to Steve or Gareth@Reactive for fettling.

I have an MEng and PhD in mechanical engineering so I'm going to do what I can with: -

• Bathroom scales
  Tape measure
  C-spanner
  Flat bladed screw driver
  Cable tie on the fork stanchion
  Test riding

Will let you know how I get on!

[Samray]

There are modders and then there are fettlers .......