M900 suspension question

[Speeddog]

AFAIK, koko64 is in Australia.

[junior varsity]

Ah, that makes a difference here by a lot then.

[koko64]

Yes I'm in Australia.

Items like suspension and FCR's are double the price here. Buying them direct from the US is definitely worthwhile. The Euro is so strong if I was going for a new shock I would get a Penske instead of an Ohlins.

The shock will be receiving a new Racetech gold valve ($200-00), remote Kayaba canister and hose($60-00) with compression damping adjustment and set up/tuned for $100-00 to $140-00. So that's $360-00 to $400-00 all up with ongoing tuning support. This guy machine finishes the canister to make it all shiny.

The suspension guy had two main points regarding overcoming the inherent design flaws of the Sachs/Boge shock.

1. Replacing the piston (with a gold valve or other equivalent) and not just re-shimming the stock one, because the standard piston valve is so bad.
2. Providing a greater gas volume with the remote gas canister to prevent oil cavitation, and controlling compression with valving at the canister. There is too little gas volume and pretty useless compression valve control of the shock.

It's getting done next week.

[slowkitty]

While we are on Ohlins, anyone used them?  Seems cheapest by far.

http://stores.ebay.com/Chicago-Performance-1_OHLINS-Suspension_W0QQ_fsubZ277075013QQ_sidZ821817633QQ_trksidZp4634Q2ec0Q2em322

Cheers

[al@sktc]

i heard that an 888 shock will fit. loads cheaper if you can find one.

[koko64]

Got the shock overhauled today.

Total cost including all parts was $360-00. New piston/valve, shimmed with remote cannister and compression damping also re-shimmed.

I'm testing it over the next few days and can drop by the shop for shim stack adjustment when needed for no extra cost.

The bike is composed and turns in with good feel. I can feel the rear tyre now and there is no pitching. I didn't realise how badly the rear was affecting the front during turn in untill now.



Will test .9 and/or .85 springs when I settle on the shock settings. Will test oil heights also.

[Speeddog]

Glad to hear you've got it mostly sorted! 

[koko64]

Thanks SD.

The bikes looking pretty trick with the remote resi.

Just spending the next couple of days working on damping and preload settings. Using my favorite roads and looking for the bumps I have in my mental map rather than avoiding them!

Believe it or not I am also testing some different shock springs (again). I've had the shock in and out three times since yesterday afternoon.The suspension guy fortunately used to work on 851 and 888 Corsa suspension for the Aus Superbike Championship. He had to go back and remember what he did back then! He gave me some advice about experimenting with spring rates and compression damping. Interesting..

In the end, if you want it set up 'just so', you have to fiddle around the base settings to get the ideal for how you ride. It's fun when you are starting in the ballpark, but hell when chasing your tail when you're not.

I'm on holidays at home (vacation) having a ball being a test rider for Team Me!.

Next test regime will be lighter fork springs from our "spring bank" with a little more oil height.

[Speeddog]

Are you still using the Eibach 9.5/550 spring?

[koko64]

Are you still using the Eibach 9.5/550 spring?

I removed it on advice and went back to a lighter spring. "It can't hurt to try", I thought. I fitted an 8kg Eibach last night and used 20mm preload at the suggestion of the suspension guy.

I thought the spring would be too soft as 20mm is about the max I could get with the preload adjustment. He said he ran softer springs with particular compression damping rates due to the linkage set up.  He described the linkage as 'strange' compared to other bikes.

It worked!

Could the progressive link be aggressive enough to require me to run a softer spring (with more preload) to allow for the 'ramping up' effect of the linkage in the later part of the stroke? I really don't know.

The 9.5 was way too hard in the last half of the stroke compared to this set up which surprised me (I'm 180-190/80-85).
I had tested an 8.5 and it was way too soft from our 'spring bank'. It was an Eibach with the number rubbed off.. Yep, when checked it was really a 7.5 . Contaminated methodology! No wonder my arse was draggin'.

This brings to mind Brad Blacks comment about a guy who tried a lighter spring set up from a certain suspension specialist. I'll ask Brad if it's the same guy. Maybe it's just a particular approach.

I also backed off the internal preload 5mm on the 0.95 fork springs. It was an improvement but 0.85-0.9's will be kinder to me.

More "test riding" today.

[Speeddog]

Hmmm.

I've not tested the early style suspension linkage for progression.

Not to be an arse, but have you checked that 8 kg Eibach to verify the rate?

[koko64]

 
It's an Eibach 450lber. It was calculated at a bit over 8KG by the suspension guy.

Does that sound correct to you? 

I got static sag 10mm, rider sag 30-35mm with 20mm preload (spring down from 180mm free length to 160mm).

It's been the best combination so far.

Are you aware of a paradigm difference among suspension specialists, i.e. light spring heavy/compression damping Vs heavier spring/light compression damping?

[Speeddog]

Yeah, a 450 lb/in spring is 8.05 kg/mm.

I've not done any rear suspension tuning on the old-style Monster, so I'm going by data I've collected second hand. 
I'm surprised you can get static/rider sag of 10/30 with 20mm preload on the spring.

I suspect that the hoop-style suspension linkage isn't very progressive.

The most important thing is that it's working the way you like it, or at least it's the best of what you've tried.

As far as suspension tuner 'philosophy' goes...

One of the folks here, stopintime, has an S2R800, and he got his suspension worked over.
His suspension tuner set him up with a *really* stiff spring, far stiffer than I would have.
But he's in Norway, and I'm in California.
I don't know how rough his roads are.
He likes the way it performs.

IMO, most race-oriented tuners are going to set a bike up pretty stiff.
Works good on a track, as they're quite a bit smoother than the street.

[stopintime]

................


One of the folks here, stopintime, has an S2R800, and he got his suspension worked over.
His suspension tuner set him up with a *really* stiff spring, far stiffer than I would have.
But he's in Norway, and I'm in California.
I don't know how rough his roads are.
He likes the way it performs.

..................

My spring is 150N (=857lbs/inch?) It's a very long spring - there are very few threads left to back out the preload. My understanding is that a longer spring will allow a more consistent action throughout it's travel. Don't know how much it's preloaded, but sag is 12mm and 36mm.

No compression adjuster on my WP 4014, but it was built for me with the "correct" valves. Rebound set at 5 clicks - played with 3 and 7 at the track - went back to 5.

Road conditions varies, but the bike is predictable and very stable. It's set up more towards track performance, not comfort. When I have a passenger it's still very stable, but obviously a softer ride.

[Speeddog]

Just to help clarify things a bit:

Stopintime is about 210-220 lbs.
S2R800 is the new style linkage, which seem to need a spring about 1.0 kg/mm stiffer than the old style linkage.
I would have set him up with an 11.6 kg/mm (650 lb/in).
His spring is about a 15.4 kg/mm.