My Penske shock arrived a few days ago so I thought I'h have a quick fiddle and see what's what.
A while back I picked up an engine hoist from Lidl (absolute bargain!) so used it to lift the rear, and plonked it on a bar through the swing arm bolt on axle stands. The rear wheel came out ok, and after much pulling pushing and general persuading the exhausts and 'collector' were dropped.
With that out of the way I could get the bone and shock out. So far, so good.
Wait - what's that on the floor? Looks like ... a roller bearing. Arse, loose needle rollers in the linkage bearing. Ok, time to play the old car stereo speaker magnet wrapped in a plastic bag trick. Moderate success, followed by the removal of the remaining rollers and age hardened grease got me to a clean bone and bearing. While I was there I used a bit of WD40 to clean up the inner faces of the swing arm - which came up beautifully clean.
The guy who sold me the shock which came off his 03 RSV-R, very kindly sent the long bone and smaller triangles to go with it to suit the Falco, again all good there. A few minutes in the blasting cabinet and they look great.
Then I got to thinking about the spring and the rating. The seller said the Penske.RSV shock was sprung for 16 stone rider (hence my question of a few days ago) which is about what I weigh, but if that were the case why would I need to fart around with changing the linkages and not just bung the RSV shock into the Falc?
I knew I'd have to check the spring rates, so I took both springs off their respective shocks and used this rate calculator to work out their values, and this is what surprised me a bit...
Falco: 163n/mm - 930 lb/in - 16.62 kg/mm
Penske: 132n/mm - 782 lb/in - 13.97 kg/mm
I was expecting the Falco spring to be weaker, but it in fact is stronger than the Penske/RSV. My calcs aren't too far out I think as the Penske site reckons the standard rate for the RSV is 800lb. and this Apriliaforum page suggests that the earlier RSV's should have an 800lb spring, so I'm beginning to wonder if mine is for the earlier bike rather than the '03 RSV-R the Ebay seller suggested.
Other than that the eye to eye values are similar (if the Penske unit's ride height adjuster is wound in) but the Penske has around 8mm more stroke than the Sachs unit - is this where I'd need to use the RSV bone/triangles to restore the swing-arm arc to the Falco value?
I was hoping to have had the bike reassembled with the new shocker, but I'm half tempted to do some dry (spring-less) runs with the combinations of bones and triangles to see what effect they have on swing arm travel.. in other words, does the RSV bone/triangle combination give the same swing arm arc from a longer shock stroke.. But if that's the case would I need a higher rated spring, and as my Falco spring seems to be harder than standard should I use that in the Penske?
Unless there's anyone who can tell me different?
Now there's a surprise...
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I'd suggest you have a look at this thread first. It gives a run down on what shocks fit the Falco and what linkages are required. However with you having a Penske shock, a lot of the Ohlins-related information is surplus to requirements.
https://www.ridersite.com/viewtopic.php?t=9153
One thing I would double-check is your spring rate measurements. It's generally agreed that the OE Falco spring rate (and that of the first RSV Mille's) is 800 lb/in (14.3 kg/mm). Your measurements seem excessively high.
Before going further I'd take the spring to a suspension specialist who can accurately measure the spring rate of the Penske shock. That way you have a sound base to start from, and should be able to ascertain whether to use Falco linkages or later RSV linkages. Using the correct linkages for your shock is vital.
The fact that the Penske shock has 8mm longer stroke than the OE Falco Sachs would tend to indicate that it's set up for the later RSV linkages. The later RSV shocks needed more shock travel as the linkage ratio was noticeably lower than the Falco.
But the first step has to be to accurately measure the spring rate of your Penske shock. I don't know what weight you are, but if the shock was sprung for a 16 stone rider you may well find it unpleasantly harsh.
https://www.ridersite.com/viewtopic.php?t=9153
One thing I would double-check is your spring rate measurements. It's generally agreed that the OE Falco spring rate (and that of the first RSV Mille's) is 800 lb/in (14.3 kg/mm). Your measurements seem excessively high.
Before going further I'd take the spring to a suspension specialist who can accurately measure the spring rate of the Penske shock. That way you have a sound base to start from, and should be able to ascertain whether to use Falco linkages or later RSV linkages. Using the correct linkages for your shock is vital.
The fact that the Penske shock has 8mm longer stroke than the OE Falco Sachs would tend to indicate that it's set up for the later RSV linkages. The later RSV shocks needed more shock travel as the linkage ratio was noticeably lower than the Falco.
But the first step has to be to accurately measure the spring rate of your Penske shock. I don't know what weight you are, but if the shock was sprung for a 16 stone rider you may well find it unpleasantly harsh.