New fork springs, 1/4" shorter

seevtsaab · May 11, 2011, 06:39:17 PM

I've received some S4 fork springs from Nick (thank you) to replace the progressive rate
stockers in some 06 S2R1K Showa's I'm reworking to replace the Marzocchi's in my 620.

Should I plan to shim the replacements, or can the 1/4" be accounted for via preload?
The Showa's are adjustable.

Thanks.

Bill in OKC · May 11, 2011, 10:38:51 PM

I would try shimming with a few washers (~1/4" worth) and then see how it goes. I'd guess you would have a better chance of not needing to take it apart again and you have to start somewhere.

EEL · May 12, 2011, 06:36:09 AM

You sure its a 1/4" I didnt this on my m1000 forks and it was more like a 1/2"

corey · May 12, 2011, 08:21:49 AM

You sure the springs dont just "appear" shorter because they are likely stiffer and non-linear?
Typically, a softer spring would appear "longer" than a stiffer one for the same application, right?

EEL · May 14, 2011, 12:02:23 PM

I actually made a new preload spacer instead of shimming with washers. but my distance was a good half inch. BTW I got s4 springs from speeddog too.. you can go to home depot and buy brass drain pipe (1 1/4" 20 gauge) and make your own. Its the same OD as the spacer in your fork.

seevtsaab · May 18, 2011, 08:41:05 AM

EEL thanks - for the tip. I'll look for some of that pipe or resort to washers (actually closer to 3/8" diff).
Been away, and now I'm having issues getting these installed, what with riding and all.

Cory not quite sure what you're getting at - the stiffer single rate S4 spring is 3/8" shorter than the softer, progressive rate stocker. Ideally I'd have these installed so that minimum preload compresses the spring the same amount the springs I removed would be compressed with same preload.

Speeddog · May 18, 2011, 09:29:17 AM

The S4 springs are significantly stiffer than the initial rate of the dual-rate OEM springs you guys had.

Thus, they don't need as much preload to support the same weight at the same sag.

corey · May 19, 2011, 04:23:26 AM

Quote from: Speeddog on May 18, 2011, 09:29:17 AM
The S4 springs are significantly stiffer than the initial rate of the dual-rate OEM springs you guys had.

Thus, they don't need as much preload to support the same weight at the same sag.

this is what i was getting at.

seevtsaab · May 19, 2011, 09:57:15 AM

Think I got it, I just got the first one reassembled last night.
No spacer, so the spring is about 3/8" shorter than the original.

My 'grunt meter' measured a similar grunt factor when compressing the spring, to get to the jamb nut,
as when I dissasembled. Give or take a few squirts of fork oil on ym shirt, doh!

So, despite the shorter spring, there is still 'some' preload built in with preload adjustment backed off.

News:

New fork springs, 1/4" shorter